6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set KEY-SERVER pool.sks-keyservers.net
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.info
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018 Gábor Boskovits@*
62 Copyright @copyright{} 2018 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
66 Permission is granted to copy, distribute and/or modify this document
67 under the terms of the GNU Free Documentation License, Version 1.3 or
68 any later version published by the Free Software Foundation; with no
69 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
70 copy of the license is included in the section entitled ``GNU Free
71 Documentation License''.
74 @dircategory System administration
76 * Guix: (guix). Manage installed software and system configuration.
77 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
78 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
79 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
80 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
83 @dircategory Software development
85 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
86 * guix build: (guix)Invoking guix build. Building packages.
87 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
91 @title GNU Guix Reference Manual
92 @subtitle Using the GNU Guix Functional Package Manager
93 @author The GNU Guix Developers
96 @vskip 0pt plus 1filll
97 Edition @value{EDITION} @*
105 @c *********************************************************************
109 This document describes GNU Guix version @value{VERSION}, a functional
110 package management tool written for the GNU system.
112 @c TRANSLATORS: You can replace the following paragraph with information on
113 @c how to join your own translation team and how to report issues with the
115 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
116 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
117 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}), and
118 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}). If you
119 would like to translate it in your native language, consider joining the
120 @uref{https://translationproject.org/domain/guix-manual.html, Translation
124 * Introduction:: What is Guix about?
125 * Installation:: Installing Guix.
126 * System Installation:: Installing the whole operating system.
127 * Package Management:: Package installation, upgrade, etc.
128 * Development:: Guix-aided software development.
129 * Programming Interface:: Using Guix in Scheme.
130 * Utilities:: Package management commands.
131 * System Configuration:: Configuring the operating system.
132 * Documentation:: Browsing software user manuals.
133 * Installing Debugging Files:: Feeding the debugger.
134 * Security Updates:: Deploying security fixes quickly.
135 * Bootstrapping:: GNU/Linux built from scratch.
136 * Porting:: Targeting another platform or kernel.
137 * Contributing:: Your help needed!
139 * Acknowledgments:: Thanks!
140 * GNU Free Documentation License:: The license of this manual.
141 * Concept Index:: Concepts.
142 * Programming Index:: Data types, functions, and variables.
145 --- The Detailed Node Listing ---
149 * Managing Software the Guix Way:: What's special.
150 * GNU Distribution:: The packages and tools.
154 * Binary Installation:: Getting Guix running in no time!
155 * Requirements:: Software needed to build and run Guix.
156 * Running the Test Suite:: Testing Guix.
157 * Setting Up the Daemon:: Preparing the build daemon's environment.
158 * Invoking guix-daemon:: Running the build daemon.
159 * Application Setup:: Application-specific setup.
161 Setting Up the Daemon
163 * Build Environment Setup:: Preparing the isolated build environment.
164 * Daemon Offload Setup:: Offloading builds to remote machines.
165 * SELinux Support:: Using an SELinux policy for the daemon.
169 * Limitations:: What you can expect.
170 * Hardware Considerations:: Supported hardware.
171 * USB Stick and DVD Installation:: Preparing the installation medium.
172 * Preparing for Installation:: Networking, partitioning, etc.
173 * Guided Graphical Installation:: Easy graphical installation.
174 * Manual Installation:: Manual installation for wizards.
175 * After System Installation:: When installation succeeded.
176 * Installing Guix in a VM:: Guix System playground.
177 * Building the Installation Image:: How this comes to be.
181 * Keyboard Layout and Networking and Partitioning:: Initial setup.
182 * Proceeding with the Installation:: Installing.
186 * Features:: How Guix will make your life brighter.
187 * Invoking guix package:: Package installation, removal, etc.
188 * Substitutes:: Downloading pre-built binaries.
189 * Packages with Multiple Outputs:: Single source package, multiple outputs.
190 * Invoking guix gc:: Running the garbage collector.
191 * Invoking guix pull:: Fetching the latest Guix and distribution.
192 * Channels:: Customizing the package collection.
193 * Inferiors:: Interacting with another revision of Guix.
194 * Invoking guix describe:: Display information about your Guix revision.
195 * Invoking guix archive:: Exporting and importing store files.
199 * Official Substitute Server:: One particular source of substitutes.
200 * Substitute Server Authorization:: How to enable or disable substitutes.
201 * Substitute Authentication:: How Guix verifies substitutes.
202 * Proxy Settings:: How to get substitutes via proxy.
203 * Substitution Failure:: What happens when substitution fails.
204 * On Trusting Binaries:: How can you trust that binary blob?
208 * Invoking guix environment:: Setting up development environments.
209 * Invoking guix pack:: Creating software bundles.
211 Programming Interface
213 * Package Modules:: Packages from the programmer's viewpoint.
214 * Defining Packages:: Defining new packages.
215 * Build Systems:: Specifying how packages are built.
216 * The Store:: Manipulating the package store.
217 * Derivations:: Low-level interface to package derivations.
218 * The Store Monad:: Purely functional interface to the store.
219 * G-Expressions:: Manipulating build expressions.
220 * Invoking guix repl:: Fiddling with Guix interactively.
224 * package Reference:: The package data type.
225 * origin Reference:: The origin data type.
229 * Invoking guix build:: Building packages from the command line.
230 * Invoking guix edit:: Editing package definitions.
231 * Invoking guix download:: Downloading a file and printing its hash.
232 * Invoking guix hash:: Computing the cryptographic hash of a file.
233 * Invoking guix import:: Importing package definitions.
234 * Invoking guix refresh:: Updating package definitions.
235 * Invoking guix lint:: Finding errors in package definitions.
236 * Invoking guix size:: Profiling disk usage.
237 * Invoking guix graph:: Visualizing the graph of packages.
238 * Invoking guix publish:: Sharing substitutes.
239 * Invoking guix challenge:: Challenging substitute servers.
240 * Invoking guix copy:: Copying to and from a remote store.
241 * Invoking guix container:: Process isolation.
242 * Invoking guix weather:: Assessing substitute availability.
243 * Invoking guix processes:: Listing client processes.
245 Invoking @command{guix build}
247 * Common Build Options:: Build options for most commands.
248 * Package Transformation Options:: Creating variants of packages.
249 * Additional Build Options:: Options specific to 'guix build'.
250 * Debugging Build Failures:: Real life packaging experience.
254 * Using the Configuration System:: Customizing your GNU system.
255 * operating-system Reference:: Detail of operating-system declarations.
256 * File Systems:: Configuring file system mounts.
257 * Mapped Devices:: Block device extra processing.
258 * User Accounts:: Specifying user accounts.
259 * Keyboard Layout:: How the system interprets key strokes.
260 * Locales:: Language and cultural convention settings.
261 * Services:: Specifying system services.
262 * Setuid Programs:: Programs running with root privileges.
263 * X.509 Certificates:: Authenticating HTTPS servers.
264 * Name Service Switch:: Configuring libc's name service switch.
265 * Initial RAM Disk:: Linux-Libre bootstrapping.
266 * Bootloader Configuration:: Configuring the boot loader.
267 * Invoking guix system:: Instantiating a system configuration.
268 * Running Guix in a VM:: How to run Guix System in a virtual machine.
269 * Defining Services:: Adding new service definitions.
273 * Base Services:: Essential system services.
274 * Scheduled Job Execution:: The mcron service.
275 * Log Rotation:: The rottlog service.
276 * Networking Services:: Network setup, SSH daemon, etc.
277 * X Window:: Graphical display.
278 * Printing Services:: Local and remote printer support.
279 * Desktop Services:: D-Bus and desktop services.
280 * Sound Services:: ALSA and Pulseaudio services.
281 * Database Services:: SQL databases, key-value stores, etc.
282 * Mail Services:: IMAP, POP3, SMTP, and all that.
283 * Messaging Services:: Messaging services.
284 * Telephony Services:: Telephony services.
285 * Monitoring Services:: Monitoring services.
286 * Kerberos Services:: Kerberos services.
287 * Web Services:: Web servers.
288 * Certificate Services:: TLS certificates via Let's Encrypt.
289 * DNS Services:: DNS daemons.
290 * VPN Services:: VPN daemons.
291 * Network File System:: NFS related services.
292 * Continuous Integration:: The Cuirass service.
293 * Power Management Services:: Extending battery life.
294 * Audio Services:: The MPD.
295 * Virtualization Services:: Virtualization services.
296 * Version Control Services:: Providing remote access to Git repositories.
297 * Game Services:: Game servers.
298 * Miscellaneous Services:: Other services.
302 * Service Composition:: The model for composing services.
303 * Service Types and Services:: Types and services.
304 * Service Reference:: API reference.
305 * Shepherd Services:: A particular type of service.
310 @c *********************************************************************
312 @chapter Introduction
315 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
316 using the international phonetic alphabet (IPA).} is a package
317 management tool for and distribution of the GNU system.
318 Guix makes it easy for unprivileged
319 users to install, upgrade, or remove software packages, to roll back to a
320 previous package set, to build packages from source, and generally
321 assists with the creation and maintenance of software environments.
324 @cindex GuixSD, now Guix System
325 @cindex Guix System Distribution, now Guix System
326 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
327 complements the available tools without interference (@pxref{Installation}),
328 or you can use it as a standalone operating system distribution,
329 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
330 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
331 group everything under the ``Guix'' banner since, after all, Guix System is
332 readily available through the @command{guix system} command, even if you're
333 using a different distro underneath!}. @xref{GNU Distribution}.
336 * Managing Software the Guix Way:: What's special.
337 * GNU Distribution:: The packages and tools.
340 @node Managing Software the Guix Way
341 @section Managing Software the Guix Way
343 @cindex user interfaces
344 Guix provides a command-line package management interface
345 (@pxref{Package Management}), tools to help with software development
346 (@pxref{Development}), command-line utilities for more advanced usage,
347 (@pxref{Utilities}), as well as Scheme programming interfaces
348 (@pxref{Programming Interface}).
350 Its @dfn{build daemon} is responsible for building packages on behalf of
351 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
352 binaries from authorized sources (@pxref{Substitutes}).
354 @cindex extensibility of the distribution
355 @cindex customization, of packages
356 Guix includes package definitions for many GNU and non-GNU packages, all
357 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
358 user's computing freedom}. It is @emph{extensible}: users can write
359 their own package definitions (@pxref{Defining Packages}) and make them
360 available as independent package modules (@pxref{Package Modules}). It
361 is also @emph{customizable}: users can @emph{derive} specialized package
362 definitions from existing ones, including from the command line
363 (@pxref{Package Transformation Options}).
365 @cindex functional package management
367 Under the hood, Guix implements the @dfn{functional package management}
368 discipline pioneered by Nix (@pxref{Acknowledgments}).
369 In Guix, the package build and installation process is seen
370 as a @emph{function}, in the mathematical sense. That function takes inputs,
371 such as build scripts, a compiler, and libraries, and
372 returns an installed package. As a pure function, its result depends
373 solely on its inputs---for instance, it cannot refer to software or
374 scripts that were not explicitly passed as inputs. A build function
375 always produces the same result when passed a given set of inputs. It
376 cannot alter the environment of the running system in
377 any way; for instance, it cannot create, modify, or delete files outside
378 of its build and installation directories. This is achieved by running
379 build processes in isolated environments (or @dfn{containers}), where only their
380 explicit inputs are visible.
383 The result of package build functions is @dfn{cached} in the file
384 system, in a special directory called @dfn{the store} (@pxref{The
385 Store}). Each package is installed in a directory of its own in the
386 store---by default under @file{/gnu/store}. The directory name contains
387 a hash of all the inputs used to build that package; thus, changing an
388 input yields a different directory name.
390 This approach is the foundation for the salient features of Guix: support
391 for transactional package upgrade and rollback, per-user installation, and
392 garbage collection of packages (@pxref{Features}).
395 @node GNU Distribution
396 @section GNU Distribution
399 Guix comes with a distribution of the GNU system consisting entirely of
400 free software@footnote{The term ``free'' here refers to the
401 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
402 users of that software}.}. The
403 distribution can be installed on its own (@pxref{System Installation}),
404 but it is also possible to install Guix as a package manager on top of
405 an installed GNU/Linux system (@pxref{Installation}). When we need to
406 distinguish between the two, we refer to the standalone distribution as
409 The distribution provides core GNU packages such as GNU libc, GCC, and
410 Binutils, as well as many GNU and non-GNU applications. The complete
411 list of available packages can be browsed
412 @url{http://www.gnu.org/software/guix/packages,on-line} or by
413 running @command{guix package} (@pxref{Invoking guix package}):
416 guix package --list-available
419 Our goal is to provide a practical 100% free software distribution of
420 Linux-based and other variants of GNU, with a focus on the promotion and
421 tight integration of GNU components, and an emphasis on programs and
422 tools that help users exert that freedom.
424 Packages are currently available on the following platforms:
429 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
432 Intel 32-bit architecture (IA32), Linux-Libre kernel;
435 ARMv7-A architecture with hard float, Thumb-2 and NEON,
436 using the EABI hard-float application binary interface (ABI),
437 and Linux-Libre kernel.
440 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
441 currently in an experimental stage, with limited support.
442 @xref{Contributing}, for how to help!
445 little-endian 64-bit MIPS processors, specifically the Loongson series,
446 n32 ABI, and Linux-Libre kernel.
450 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
451 configuration and Guix takes care of instantiating the configuration in a
452 transactional, reproducible, and stateless fashion (@pxref{System
453 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
454 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
455 Manual}), the well-known GNU utilities and tool chain, as well as the
456 graphical environment or system services of your choice.
458 Guix System is available on all the above platforms except
459 @code{mips64el-linux}.
462 For information on porting to other architectures or kernels,
465 Building this distribution is a cooperative effort, and you are invited
466 to join! @xref{Contributing}, for information about how you can help.
469 @c *********************************************************************
471 @chapter Installation
473 @cindex installing Guix
476 We recommend the use of this
477 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
478 shell installer script} to install Guix on top of a running GNU/Linux system,
479 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
480 with the installation of the package manager, which can be done on top of a
481 running GNU/Linux system. If, instead, you want to install the complete GNU
482 operating system, @pxref{System Installation}.} The script automates the
483 download, installation, and initial configuration of Guix. It should be run
487 @cindex foreign distro
488 @cindex directories related to foreign distro
489 When installed on a foreign distro, GNU@tie{}Guix complements the available
490 tools without interference. Its data lives exclusively in two directories,
491 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
492 such as @file{/etc}, are left untouched.
494 Once installed, Guix can be updated by running @command{guix pull}
495 (@pxref{Invoking guix pull}).
497 If you prefer to perform the installation steps manually or want to tweak
498 them, you may find the following subsections useful. They describe the
499 software requirements of Guix, as well as how to install it manually and get
503 * Binary Installation:: Getting Guix running in no time!
504 * Requirements:: Software needed to build and run Guix.
505 * Running the Test Suite:: Testing Guix.
506 * Setting Up the Daemon:: Preparing the build daemon's environment.
507 * Invoking guix-daemon:: Running the build daemon.
508 * Application Setup:: Application-specific setup.
511 @node Binary Installation
512 @section Binary Installation
514 @cindex installing Guix from binaries
515 @cindex installer script
516 This section describes how to install Guix on an arbitrary system from a
517 self-contained tarball providing binaries for Guix and for all its
518 dependencies. This is often quicker than installing from source, which
519 is described in the next sections. The only requirement is to have
522 @c Note duplicated from the ``Installation'' node.
524 We recommend the use of this
525 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
526 shell installer script}. The script automates the download, installation, and
527 initial configuration steps described below. It should be run as the root
531 Installing goes along these lines:
535 @cindex downloading Guix binary
536 Download the binary tarball from
537 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
538 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
539 already running the kernel Linux, and so on.
541 @c The following is somewhat duplicated in ``System Installation''.
542 Make sure to download the associated @file{.sig} file and to verify the
543 authenticity of the tarball against it, along these lines:
546 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
547 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
550 If that command fails because you do not have the required public key,
551 then run this command to import it:
554 $ gpg --keyserver @value{KEY-SERVER} \
555 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
559 and rerun the @code{gpg --verify} command.
560 @c end authentication part
563 Now, you need to become the @code{root} user. Depending on your distribution,
564 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
568 # tar --warning=no-timestamp -xf \
569 guix-binary-@value{VERSION}.@var{system}.tar.xz
570 # mv var/guix /var/ && mv gnu /
573 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
574 The latter contains a ready-to-use profile for @code{root} (see next
577 Do @emph{not} unpack the tarball on a working Guix system since that
578 would overwrite its own essential files.
580 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
581 not emit warnings about ``implausibly old time stamps'' (such
582 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
584 They stem from the fact that all the
585 files in the archive have their modification time set to zero (which
586 means January 1st, 1970.) This is done on purpose to make sure the
587 archive content is independent of its creation time, thus making it
591 Make the profile available under @file{~root/.config/guix/current}, which is
592 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
595 # mkdir -p ~root/.config/guix
596 # ln -sf /var/guix/profiles/per-user/root/current-guix \
597 ~root/.config/guix/current
600 Source @file{etc/profile} to augment @code{PATH} and other relevant
601 environment variables:
604 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
605 source $GUIX_PROFILE/etc/profile
609 Create the group and user accounts for build users as explained below
610 (@pxref{Build Environment Setup}).
613 Run the daemon, and set it to automatically start on boot.
615 If your host distro uses the systemd init system, this can be achieved
618 @c Versions of systemd that supported symlinked service files are not
619 @c yet widely deployed, so we should suggest that users copy the service
622 @c See this thread for more information:
623 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
626 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
628 # systemctl start guix-daemon && systemctl enable guix-daemon
631 If your host distro uses the Upstart init system:
634 # initctl reload-configuration
635 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
640 Otherwise, you can still start the daemon manually with:
643 # ~root/.config/guix/current/bin/guix-daemon \
644 --build-users-group=guixbuild
648 Make the @command{guix} command available to other users on the machine,
652 # mkdir -p /usr/local/bin
654 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
657 It is also a good idea to make the Info version of this manual available
661 # mkdir -p /usr/local/share/info
662 # cd /usr/local/share/info
663 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
667 That way, assuming @file{/usr/local/share/info} is in the search path,
668 running @command{info guix} will open this manual (@pxref{Other Info
669 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
673 @cindex substitutes, authorization thereof
674 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
675 (@pxref{Substitutes}), authorize them:
678 # guix archive --authorize < \
679 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
683 Each user may need to perform a few additional steps to make their Guix
684 environment ready for use, @pxref{Application Setup}.
687 Voilà, the installation is complete!
689 You can confirm that Guix is working by installing a sample package into
696 The binary installation tarball can be (re)produced and verified simply
697 by running the following command in the Guix source tree:
700 make guix-binary.@var{system}.tar.xz
704 ...@: which, in turn, runs:
707 guix pack -s @var{system} --localstatedir \
708 --profile-name=current-guix guix
711 @xref{Invoking guix pack}, for more info on this handy tool.
714 @section Requirements
716 This section lists requirements when building Guix from source. The
717 build procedure for Guix is the same as for other GNU software, and is
718 not covered here. Please see the files @file{README} and @file{INSTALL}
719 in the Guix source tree for additional details.
721 @cindex official website
722 GNU Guix is available for download from its website at
723 @url{https://www.gnu.org/software/guix/}.
725 GNU Guix depends on the following packages:
728 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
729 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
732 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
733 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
734 Guile,, gnutls-guile, GnuTLS-Guile});
736 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
739 @c FIXME: Specify a version number once a release has been made.
740 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
742 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
743 @item @url{http://zlib.net, zlib};
744 @item @url{http://www.gnu.org/software/make/, GNU Make}.
747 The following dependencies are optional:
751 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
752 Support for build offloading (@pxref{Daemon Offload Setup}) and
753 @command{guix copy} (@pxref{Invoking guix copy}) depends on
754 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
755 version 0.10.2 or later.
758 When @url{http://www.bzip.org, libbz2} is available,
759 @command{guix-daemon} can use it to compress build logs.
762 Unless @code{--disable-daemon} was passed to @command{configure}, the
763 following packages are also needed:
766 @item @url{http://gnupg.org/, GNU libgcrypt};
767 @item @url{http://sqlite.org, SQLite 3};
768 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
772 @cindex state directory
773 When configuring Guix on a system that already has a Guix installation,
774 be sure to specify the same state directory as the existing installation
775 using the @code{--localstatedir} option of the @command{configure}
776 script (@pxref{Directory Variables, @code{localstatedir},, standards,
777 GNU Coding Standards}). The @command{configure} script protects against
778 unintended misconfiguration of @var{localstatedir} so you do not
779 inadvertently corrupt your store (@pxref{The Store}).
781 @cindex Nix, compatibility
782 When a working installation of @url{http://nixos.org/nix/, the Nix package
783 manager} is available, you
784 can instead configure Guix with @code{--disable-daemon}. In that case,
785 Nix replaces the three dependencies above.
787 Guix is compatible with Nix, so it is possible to share the same store
788 between both. To do so, you must pass @command{configure} not only the
789 same @code{--with-store-dir} value, but also the same
790 @code{--localstatedir} value. The latter is essential because it
791 specifies where the database that stores metadata about the store is
792 located, among other things. The default values for Nix are
793 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
794 Note that @code{--disable-daemon} is not required if
795 your goal is to share the store with Nix.
797 @node Running the Test Suite
798 @section Running the Test Suite
801 After a successful @command{configure} and @code{make} run, it is a good
802 idea to run the test suite. It can help catch issues with the setup or
803 environment, or bugs in Guix itself---and really, reporting test
804 failures is a good way to help improve the software. To run the test
811 Test cases can run in parallel: you can use the @code{-j} option of
812 GNU@tie{}make to speed things up. The first run may take a few minutes
813 on a recent machine; subsequent runs will be faster because the store
814 that is created for test purposes will already have various things in
817 It is also possible to run a subset of the tests by defining the
818 @code{TESTS} makefile variable as in this example:
821 make check TESTS="tests/store.scm tests/cpio.scm"
824 By default, tests results are displayed at a file level. In order to
825 see the details of every individual test cases, it is possible to define
826 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
829 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
832 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
833 @file{test-suite.log} file. Please specify the Guix version being used
834 as well as version numbers of the dependencies (@pxref{Requirements}) in
837 Guix also comes with a whole-system test suite that tests complete
838 Guix System instances. It can only run on systems where
839 Guix is already installed, using:
846 or, again, by defining @code{TESTS} to select a subset of tests to run:
849 make check-system TESTS="basic mcron"
852 These system tests are defined in the @code{(gnu tests @dots{})}
853 modules. They work by running the operating systems under test with
854 lightweight instrumentation in a virtual machine (VM). They can be
855 computationally intensive or rather cheap, depending on whether
856 substitutes are available for their dependencies (@pxref{Substitutes}).
857 Some of them require a lot of storage space to hold VM images.
859 Again in case of test failures, please send @email{bug-guix@@gnu.org}
862 @node Setting Up the Daemon
863 @section Setting Up the Daemon
866 Operations such as building a package or running the garbage collector
867 are all performed by a specialized process, the @dfn{build daemon}, on
868 behalf of clients. Only the daemon may access the store and its
869 associated database. Thus, any operation that manipulates the store
870 goes through the daemon. For instance, command-line tools such as
871 @command{guix package} and @command{guix build} communicate with the
872 daemon (@i{via} remote procedure calls) to instruct it what to do.
874 The following sections explain how to prepare the build daemon's
875 environment. See also @ref{Substitutes}, for information on how to allow
876 the daemon to download pre-built binaries.
879 * Build Environment Setup:: Preparing the isolated build environment.
880 * Daemon Offload Setup:: Offloading builds to remote machines.
881 * SELinux Support:: Using an SELinux policy for the daemon.
884 @node Build Environment Setup
885 @subsection Build Environment Setup
887 @cindex build environment
888 In a standard multi-user setup, Guix and its daemon---the
889 @command{guix-daemon} program---are installed by the system
890 administrator; @file{/gnu/store} is owned by @code{root} and
891 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
892 Guix tools to build packages or otherwise access the store, and the
893 daemon will do it on their behalf, ensuring that the store is kept in a
894 consistent state, and allowing built packages to be shared among users.
897 When @command{guix-daemon} runs as @code{root}, you may not want package
898 build processes themselves to run as @code{root} too, for obvious
899 security reasons. To avoid that, a special pool of @dfn{build users}
900 should be created for use by build processes started by the daemon.
901 These build users need not have a shell and a home directory: they will
902 just be used when the daemon drops @code{root} privileges in build
903 processes. Having several such users allows the daemon to launch
904 distinct build processes under separate UIDs, which guarantees that they
905 do not interfere with each other---an essential feature since builds are
906 regarded as pure functions (@pxref{Introduction}).
908 On a GNU/Linux system, a build user pool may be created like this (using
909 Bash syntax and the @code{shadow} commands):
911 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
912 @c for why `-G' is needed.
914 # groupadd --system guixbuild
915 # for i in `seq -w 1 10`;
917 useradd -g guixbuild -G guixbuild \
918 -d /var/empty -s `which nologin` \
919 -c "Guix build user $i" --system \
925 The number of build users determines how many build jobs may run in
926 parallel, as specified by the @option{--max-jobs} option
927 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
928 @command{guix system vm} and related commands, you may need to add the
929 build users to the @code{kvm} group so they can access @file{/dev/kvm},
930 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
931 (@pxref{Invoking guix system}).
933 The @code{guix-daemon} program may then be run as @code{root} with the
934 following command@footnote{If your machine uses the systemd init system,
935 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
936 file in @file{/etc/systemd/system} will ensure that
937 @command{guix-daemon} is automatically started. Similarly, if your
938 machine uses the Upstart init system, drop the
939 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
940 file in @file{/etc/init}.}:
943 # guix-daemon --build-users-group=guixbuild
948 This way, the daemon starts build processes in a chroot, under one of
949 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
950 environment contains nothing but:
952 @c Keep this list in sync with libstore/build.cc! -----------------------
955 a minimal @code{/dev} directory, created mostly independently from the
956 host @code{/dev}@footnote{``Mostly'', because while the set of files
957 that appear in the chroot's @code{/dev} is fixed, most of these files
958 can only be created if the host has them.};
961 the @code{/proc} directory; it only shows the processes of the container
962 since a separate PID name space is used;
965 @file{/etc/passwd} with an entry for the current user and an entry for
969 @file{/etc/group} with an entry for the user's group;
972 @file{/etc/hosts} with an entry that maps @code{localhost} to
976 a writable @file{/tmp} directory.
979 You can influence the directory where the daemon stores build trees
980 @i{via} the @code{TMPDIR} environment variable. However, the build tree
981 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
982 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
983 This way, the value of @code{TMPDIR} does not leak inside build
984 environments, which avoids discrepancies in cases where build processes
985 capture the name of their build tree.
988 The daemon also honors the @code{http_proxy} environment variable for
989 HTTP downloads it performs, be it for fixed-output derivations
990 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
992 If you are installing Guix as an unprivileged user, it is still possible
993 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
994 However, build processes will not be isolated from one another, and not
995 from the rest of the system. Thus, build processes may interfere with
996 each other, and may access programs, libraries, and other files
997 available on the system---making it much harder to view them as
998 @emph{pure} functions.
1001 @node Daemon Offload Setup
1002 @subsection Using the Offload Facility
1006 When desired, the build daemon can @dfn{offload} derivation builds to
1007 other machines running Guix, using the @code{offload} @dfn{build
1008 hook}@footnote{This feature is available only when
1009 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1010 present.}. When that
1011 feature is enabled, a list of user-specified build machines is read from
1012 @file{/etc/guix/machines.scm}; every time a build is requested, for
1013 instance via @code{guix build}, the daemon attempts to offload it to one
1014 of the machines that satisfy the constraints of the derivation, in
1015 particular its system type---e.g., @file{x86_64-linux}. Missing
1016 prerequisites for the build are copied over SSH to the target machine,
1017 which then proceeds with the build; upon success the output(s) of the
1018 build are copied back to the initial machine.
1020 The @file{/etc/guix/machines.scm} file typically looks like this:
1023 (list (build-machine
1024 (name "eightysix.example.org")
1025 (system "x86_64-linux")
1026 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1028 (speed 2.)) ;incredibly fast!
1031 (name "meeps.example.org")
1032 (system "mips64el-linux")
1033 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1036 (string-append (getenv "HOME")
1037 "/.ssh/identity-for-guix"))))
1041 In the example above we specify a list of two build machines, one for
1042 the @code{x86_64} architecture and one for the @code{mips64el}
1045 In fact, this file is---not surprisingly!---a Scheme file that is
1046 evaluated when the @code{offload} hook is started. Its return value
1047 must be a list of @code{build-machine} objects. While this example
1048 shows a fixed list of build machines, one could imagine, say, using
1049 DNS-SD to return a list of potential build machines discovered in the
1050 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1051 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1054 @deftp {Data Type} build-machine
1055 This data type represents build machines to which the daemon may offload
1056 builds. The important fields are:
1061 The host name of the remote machine.
1064 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1067 The user account to use when connecting to the remote machine over SSH.
1068 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1069 allow non-interactive logins.
1072 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1073 This is used to authenticate the machine when we connect to it. It is a
1074 long string that looks like this:
1077 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1080 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1081 key can be found in a file such as
1082 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1084 If the machine is running the SSH daemon of GNU@tie{}lsh,
1085 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1086 similar file. It can be converted to the OpenSSH format using
1087 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1090 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1091 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1096 A number of optional fields may be specified:
1100 @item @code{port} (default: @code{22})
1101 Port number of SSH server on the machine.
1103 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1104 The SSH private key file to use when connecting to the machine, in
1105 OpenSSH format. This key must not be protected with a passphrase.
1107 Note that the default value is the private key @emph{of the root
1108 account}. Make sure it exists if you use the default.
1110 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1111 @itemx @code{compression-level} (default: @code{3})
1112 The SSH-level compression methods and compression level requested.
1114 Note that offloading relies on SSH compression to reduce bandwidth usage
1115 when transferring files to and from build machines.
1117 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1118 File name of the Unix-domain socket @command{guix-daemon} is listening
1121 @item @code{parallel-builds} (default: @code{1})
1122 The number of builds that may run in parallel on the machine.
1124 @item @code{speed} (default: @code{1.0})
1125 A ``relative speed factor''. The offload scheduler will tend to prefer
1126 machines with a higher speed factor.
1128 @item @code{features} (default: @code{'()})
1129 A list of strings denoting specific features supported by the machine.
1130 An example is @code{"kvm"} for machines that have the KVM Linux modules
1131 and corresponding hardware support. Derivations can request features by
1132 name, and they will be scheduled on matching build machines.
1137 The @command{guix} command must be in the search path on the build
1138 machines. You can check whether this is the case by running:
1141 ssh build-machine guix repl --version
1144 There is one last thing to do once @file{machines.scm} is in place. As
1145 explained above, when offloading, files are transferred back and forth
1146 between the machine stores. For this to work, you first need to
1147 generate a key pair on each machine to allow the daemon to export signed
1148 archives of files from the store (@pxref{Invoking guix archive}):
1151 # guix archive --generate-key
1155 Each build machine must authorize the key of the master machine so that
1156 it accepts store items it receives from the master:
1159 # guix archive --authorize < master-public-key.txt
1163 Likewise, the master machine must authorize the key of each build machine.
1165 All the fuss with keys is here to express pairwise mutual trust
1166 relations between the master and the build machines. Concretely, when
1167 the master receives files from a build machine (and @i{vice versa}), its
1168 build daemon can make sure they are genuine, have not been tampered
1169 with, and that they are signed by an authorized key.
1171 @cindex offload test
1172 To test whether your setup is operational, run this command on the
1179 This will attempt to connect to each of the build machines specified in
1180 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1181 available on each machine, attempt to export to the machine and import
1182 from it, and report any error in the process.
1184 If you want to test a different machine file, just specify it on the
1188 # guix offload test machines-qualif.scm
1191 Last, you can test the subset of the machines whose name matches a
1192 regular expression like this:
1195 # guix offload test machines.scm '\.gnu\.org$'
1198 @cindex offload status
1199 To display the current load of all build hosts, run this command on the
1203 # guix offload status
1207 @node SELinux Support
1208 @subsection SELinux Support
1210 @cindex SELinux, daemon policy
1211 @cindex mandatory access control, SELinux
1212 @cindex security, guix-daemon
1213 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1214 can be installed on a system where SELinux is enabled, in order to label
1215 Guix files and to specify the expected behavior of the daemon. Since
1216 Guix System does not provide an SELinux base policy, the daemon policy cannot
1217 be used on Guix System.
1219 @subsubsection Installing the SELinux policy
1220 @cindex SELinux, policy installation
1221 To install the policy run this command as root:
1224 semodule -i etc/guix-daemon.cil
1227 Then relabel the file system with @code{restorecon} or by a different
1228 mechanism provided by your system.
1230 Once the policy is installed, the file system has been relabeled, and
1231 the daemon has been restarted, it should be running in the
1232 @code{guix_daemon_t} context. You can confirm this with the following
1236 ps -Zax | grep guix-daemon
1239 Monitor the SELinux log files as you run a command like @code{guix build
1240 hello} to convince yourself that SELinux permits all necessary
1243 @subsubsection Limitations
1244 @cindex SELinux, limitations
1246 This policy is not perfect. Here is a list of limitations or quirks
1247 that should be considered when deploying the provided SELinux policy for
1252 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1253 operations involve contexts that have anything to do with
1254 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1255 but it would be preferrable to define socket rules for only this label.
1258 @code{guix gc} cannot access arbitrary links to profiles. By design,
1259 the file label of the destination of a symlink is independent of the
1260 file label of the link itself. Although all profiles under
1261 $localstatedir are labelled, the links to these profiles inherit the
1262 label of the directory they are in. For links in the user’s home
1263 directory this will be @code{user_home_t}. But for links from the root
1264 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1265 directory, etc, this won’t work. @code{guix gc} would be prevented from
1266 reading and following these links.
1269 The daemon’s feature to listen for TCP connections might no longer work.
1270 This might require extra rules, because SELinux treats network sockets
1271 differently from files.
1274 Currently all files with a name matching the regular expression
1275 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1276 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1277 that name in any profile would be permitted to run in the
1278 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1279 build a package that provides this executable and convince a user to
1280 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1281 At that point SELinux could not prevent it from accessing files that are
1282 allowed for processes in that domain.
1284 We could generate a much more restrictive policy at installation time,
1285 so that only the @emph{exact} file name of the currently installed
1286 @code{guix-daemon} executable would be labelled with
1287 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1288 The downside is that root would have to install or upgrade the policy at
1289 installation time whenever the Guix package that provides the
1290 effectively running @code{guix-daemon} executable is upgraded.
1293 @node Invoking guix-daemon
1294 @section Invoking @command{guix-daemon}
1296 The @command{guix-daemon} program implements all the functionality to
1297 access the store. This includes launching build processes, running the
1298 garbage collector, querying the availability of a build result, etc. It
1299 is normally run as @code{root} like this:
1302 # guix-daemon --build-users-group=guixbuild
1306 For details on how to set it up, @pxref{Setting Up the Daemon}.
1309 @cindex container, build environment
1310 @cindex build environment
1311 @cindex reproducible builds
1312 By default, @command{guix-daemon} launches build processes under
1313 different UIDs, taken from the build group specified with
1314 @code{--build-users-group}. In addition, each build process is run in a
1315 chroot environment that only contains the subset of the store that the
1316 build process depends on, as specified by its derivation
1317 (@pxref{Programming Interface, derivation}), plus a set of specific
1318 system directories. By default, the latter contains @file{/dev} and
1319 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1320 @dfn{container}: in addition to having its own file system tree, it has
1321 a separate mount name space, its own PID name space, network name space,
1322 etc. This helps achieve reproducible builds (@pxref{Features}).
1324 When the daemon performs a build on behalf of the user, it creates a
1325 build directory under @file{/tmp} or under the directory specified by
1326 its @code{TMPDIR} environment variable. This directory is shared with
1327 the container for the duration of the build, though within the container,
1328 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1330 The build directory is automatically deleted upon completion, unless the
1331 build failed and the client specified @option{--keep-failed}
1332 (@pxref{Invoking guix build, @option{--keep-failed}}).
1334 The daemon listens for connections and spawns one sub-process for each session
1335 started by a client (one of the @command{guix} sub-commands.) The
1336 @command{guix processes} command allows you to get an overview of the activity
1337 on your system by viewing each of the active sessions and clients.
1338 @xref{Invoking guix processes}, for more information.
1340 The following command-line options are supported:
1343 @item --build-users-group=@var{group}
1344 Take users from @var{group} to run build processes (@pxref{Setting Up
1345 the Daemon, build users}).
1347 @item --no-substitutes
1349 Do not use substitutes for build products. That is, always build things
1350 locally instead of allowing downloads of pre-built binaries
1351 (@pxref{Substitutes}).
1353 When the daemon runs with @code{--no-substitutes}, clients can still
1354 explicitly enable substitution @i{via} the @code{set-build-options}
1355 remote procedure call (@pxref{The Store}).
1357 @item --substitute-urls=@var{urls}
1358 @anchor{daemon-substitute-urls}
1359 Consider @var{urls} the default whitespace-separated list of substitute
1360 source URLs. When this option is omitted,
1361 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1363 This means that substitutes may be downloaded from @var{urls}, as long
1364 as they are signed by a trusted signature (@pxref{Substitutes}).
1367 @item --no-build-hook
1368 Do not use the @dfn{build hook}.
1370 The build hook is a helper program that the daemon can start and to
1371 which it submits build requests. This mechanism is used to offload
1372 builds to other machines (@pxref{Daemon Offload Setup}).
1374 @item --cache-failures
1375 Cache build failures. By default, only successful builds are cached.
1377 When this option is used, @command{guix gc --list-failures} can be used
1378 to query the set of store items marked as failed; @command{guix gc
1379 --clear-failures} removes store items from the set of cached failures.
1380 @xref{Invoking guix gc}.
1382 @item --cores=@var{n}
1384 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1387 The default value is @code{0}, but it may be overridden by clients, such
1388 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1391 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1392 in the build process, which can then use it to exploit internal
1393 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1395 @item --max-jobs=@var{n}
1397 Allow at most @var{n} build jobs in parallel. The default value is
1398 @code{1}. Setting it to @code{0} means that no builds will be performed
1399 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1400 Setup}), or simply fail.
1402 @item --max-silent-time=@var{seconds}
1403 When the build or substitution process remains silent for more than
1404 @var{seconds}, terminate it and report a build failure.
1406 The default value is @code{0}, which disables the timeout.
1408 The value specified here can be overridden by clients (@pxref{Common
1409 Build Options, @code{--max-silent-time}}).
1411 @item --timeout=@var{seconds}
1412 Likewise, when the build or substitution process lasts for more than
1413 @var{seconds}, terminate it and report a build failure.
1415 The default value is @code{0}, which disables the timeout.
1417 The value specified here can be overridden by clients (@pxref{Common
1418 Build Options, @code{--timeout}}).
1420 @item --rounds=@var{N}
1421 Build each derivation @var{n} times in a row, and raise an error if
1422 consecutive build results are not bit-for-bit identical. Note that this
1423 setting can be overridden by clients such as @command{guix build}
1424 (@pxref{Invoking guix build}).
1426 When used in conjunction with @option{--keep-failed}, the differing
1427 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1428 This makes it easy to look for differences between the two results.
1431 Produce debugging output.
1433 This is useful to debug daemon start-up issues, but then it may be
1434 overridden by clients, for example the @code{--verbosity} option of
1435 @command{guix build} (@pxref{Invoking guix build}).
1437 @item --chroot-directory=@var{dir}
1438 Add @var{dir} to the build chroot.
1440 Doing this may change the result of build processes---for instance if
1441 they use optional dependencies found in @var{dir} when it is available,
1442 and not otherwise. For that reason, it is not recommended to do so.
1443 Instead, make sure that each derivation declares all the inputs that it
1446 @item --disable-chroot
1447 Disable chroot builds.
1449 Using this option is not recommended since, again, it would allow build
1450 processes to gain access to undeclared dependencies. It is necessary,
1451 though, when @command{guix-daemon} is running under an unprivileged user
1454 @item --log-compression=@var{type}
1455 Compress build logs according to @var{type}, one of @code{gzip},
1456 @code{bzip2}, or @code{none}.
1458 Unless @code{--lose-logs} is used, all the build logs are kept in the
1459 @var{localstatedir}. To save space, the daemon automatically compresses
1460 them with bzip2 by default.
1462 @item --disable-deduplication
1463 @cindex deduplication
1464 Disable automatic file ``deduplication'' in the store.
1466 By default, files added to the store are automatically ``deduplicated'':
1467 if a newly added file is identical to another one found in the store,
1468 the daemon makes the new file a hard link to the other file. This can
1469 noticeably reduce disk usage, at the expense of slightly increased
1470 input/output load at the end of a build process. This option disables
1473 @item --gc-keep-outputs[=yes|no]
1474 Tell whether the garbage collector (GC) must keep outputs of live
1478 @cindex garbage collector roots
1479 When set to ``yes'', the GC will keep the outputs of any live derivation
1480 available in the store---the @code{.drv} files. The default is ``no'',
1481 meaning that derivation outputs are kept only if they are reachable from a GC
1482 root. @xref{Invoking guix gc}, for more on GC roots.
1484 @item --gc-keep-derivations[=yes|no]
1485 Tell whether the garbage collector (GC) must keep derivations
1486 corresponding to live outputs.
1488 When set to ``yes'', as is the case by default, the GC keeps
1489 derivations---i.e., @code{.drv} files---as long as at least one of their
1490 outputs is live. This allows users to keep track of the origins of
1491 items in their store. Setting it to ``no'' saves a bit of disk space.
1493 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1494 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1495 ``yes'' causes liveness to flow from derivations to outputs. When both are
1496 set to ``yes'', the effect is to keep all the build prerequisites (the
1497 sources, compiler, libraries, and other build-time tools) of live objects in
1498 the store, regardless of whether these prerequisites are reachable from a GC
1499 root. This is convenient for developers since it saves rebuilds or downloads.
1501 @item --impersonate-linux-2.6
1502 On Linux-based systems, impersonate Linux 2.6. This means that the
1503 kernel's @code{uname} system call will report 2.6 as the release number.
1505 This might be helpful to build programs that (usually wrongfully) depend
1506 on the kernel version number.
1509 Do not keep build logs. By default they are kept under
1510 @code{@var{localstatedir}/guix/log}.
1512 @item --system=@var{system}
1513 Assume @var{system} as the current system type. By default it is the
1514 architecture/kernel pair found at configure time, such as
1515 @code{x86_64-linux}.
1517 @item --listen=@var{endpoint}
1518 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1519 as the file name of a Unix-domain socket if it starts with
1520 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1521 host name or host name and port to listen to. Here are a few examples:
1524 @item --listen=/gnu/var/daemon
1525 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1526 creating it if needed.
1528 @item --listen=localhost
1529 @cindex daemon, remote access
1530 @cindex remote access to the daemon
1531 @cindex daemon, cluster setup
1532 @cindex clusters, daemon setup
1533 Listen for TCP connections on the network interface corresponding to
1534 @code{localhost}, on port 44146.
1536 @item --listen=128.0.0.42:1234
1537 Listen for TCP connections on the network interface corresponding to
1538 @code{128.0.0.42}, on port 1234.
1541 This option can be repeated multiple times, in which case
1542 @command{guix-daemon} accepts connections on all the specified
1543 endpoints. Users can tell client commands what endpoint to connect to
1544 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1545 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1548 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1549 @code{--listen=@var{host}} is suitable on local networks, such as
1550 clusters, where only trusted nodes may connect to the build daemon. In
1551 other cases where remote access to the daemon is needed, we recommend
1552 using Unix-domain sockets along with SSH.
1555 When @code{--listen} is omitted, @command{guix-daemon} listens for
1556 connections on the Unix-domain socket located at
1557 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1561 @node Application Setup
1562 @section Application Setup
1564 @cindex foreign distro
1565 When using Guix on top of GNU/Linux distribution other than Guix System---a
1566 so-called @dfn{foreign distro}---a few additional steps are needed to
1567 get everything in place. Here are some of them.
1571 @anchor{locales-and-locpath}
1572 @cindex locales, when not on Guix System
1574 @vindex GUIX_LOCPATH
1575 Packages installed @i{via} Guix will not use the locale data of the
1576 host system. Instead, you must first install one of the locale packages
1577 available with Guix and then define the @code{GUIX_LOCPATH} environment
1581 $ guix install glibc-locales
1582 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1585 Note that the @code{glibc-locales} package contains data for all the
1586 locales supported by the GNU@tie{}libc and weighs in at around
1587 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1588 limited to a few UTF-8 locales.
1590 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1591 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1592 Manual}). There are two important differences though:
1596 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1597 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1598 to make sure the programs of the foreign distro will not end up loading
1599 incompatible locale data.
1602 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1603 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1604 should your Guix profile contain a mixture of programs linked against
1605 different libc version, each libc version will only try to load locale
1606 data in the right format.
1609 This is important because the locale data format used by different libc
1610 versions may be incompatible.
1612 @subsection Name Service Switch
1614 @cindex name service switch, glibc
1615 @cindex NSS (name service switch), glibc
1616 @cindex nscd (name service caching daemon)
1617 @cindex name service caching daemon (nscd)
1618 When using Guix on a foreign distro, we @emph{strongly recommend} that
1619 the system run the GNU C library's @dfn{name service cache daemon},
1620 @command{nscd}, which should be listening on the
1621 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1622 installed with Guix may fail to look up host names or user accounts, or
1623 may even crash. The next paragraphs explain why.
1625 @cindex @file{nsswitch.conf}
1626 The GNU C library implements a @dfn{name service switch} (NSS), which is
1627 an extensible mechanism for ``name lookups'' in general: host name
1628 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1629 The GNU C Library Reference Manual}).
1631 @cindex Network information service (NIS)
1632 @cindex NIS (Network information service)
1633 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1634 lookup implementations: for example, the @code{nss-mdns} plugin allow
1635 resolution of @code{.local} host names, the @code{nis} plugin allows
1636 user account lookup using the Network information service (NIS), and so
1637 on. These extra ``lookup services'' are configured system-wide in
1638 @file{/etc/nsswitch.conf}, and all the programs running on the system
1639 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1642 When they perform a name lookup---for instance by calling the
1643 @code{getaddrinfo} function in C---applications first try to connect to
1644 the nscd; on success, nscd performs name lookups on their behalf. If
1645 the nscd is not running, then they perform the name lookup by
1646 themselves, by loading the name lookup services into their own address
1647 space and running it. These name lookup services---the
1648 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1649 the host system's C library, rather than from the C library the
1650 application is linked against (the C library coming from Guix).
1652 And this is where the problem is: if your application is linked against
1653 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1654 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1655 likely crash or have its name lookups fail unexpectedly.
1657 Running @command{nscd} on the system, among other advantages, eliminates
1658 this binary incompatibility problem because those @code{libnss_*.so}
1659 files are loaded in the @command{nscd} process, not in applications
1662 @subsection X11 Fonts
1665 The majority of graphical applications use Fontconfig to locate and
1666 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1667 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1668 by default. Thus, to allow graphical applications installed with Guix
1669 to display fonts, you have to install fonts with Guix as well.
1670 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1671 @code{font-gnu-freefont-ttf}.
1673 To display text written in Chinese languages, Japanese, or Korean in
1674 graphical applications, consider installing
1675 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1676 has multiple outputs, one per language family (@pxref{Packages with
1677 Multiple Outputs}). For instance, the following command installs fonts
1678 for Chinese languages:
1681 guix install font-adobe-source-han-sans:cn
1684 @cindex @code{xterm}
1685 Older programs such as @command{xterm} do not use Fontconfig and instead
1686 rely on server-side font rendering. Such programs require to specify a
1687 full name of a font using XLFD (X Logical Font Description), like this:
1690 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1693 To be able to use such full names for the TrueType fonts installed in
1694 your Guix profile, you need to extend the font path of the X server:
1696 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1697 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1699 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1702 @cindex @code{xlsfonts}
1703 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1704 to make sure your TrueType fonts are listed there.
1706 @cindex @code{fc-cache}
1708 After installing fonts you may have to refresh the font cache to use
1709 them in applications. The same applies when applications installed via
1710 Guix do not seem to find fonts. To force rebuilding of the font cache
1711 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1712 @code{fontconfig} package.
1714 @subsection X.509 Certificates
1716 @cindex @code{nss-certs}
1717 The @code{nss-certs} package provides X.509 certificates, which allow
1718 programs to authenticate Web servers accessed over HTTPS.
1720 When using Guix on a foreign distro, you can install this package and
1721 define the relevant environment variables so that packages know where to
1722 look for certificates. @xref{X.509 Certificates}, for detailed
1725 @subsection Emacs Packages
1727 @cindex @code{emacs}
1728 When you install Emacs packages with Guix, the elisp files may be placed
1729 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1731 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1732 directory exists because potentially there may exist thousands of Emacs
1733 packages and storing all their files in a single directory may not be
1734 reliable (because of name conflicts). So we think using a separate
1735 directory for each package is a good idea. It is very similar to how
1736 the Emacs package system organizes the file structure (@pxref{Package
1737 Files,,, emacs, The GNU Emacs Manual}).
1739 By default, Emacs (installed with Guix) ``knows'' where these packages
1740 are placed, so you do not need to perform any configuration. If, for
1741 some reason, you want to avoid auto-loading Emacs packages installed
1742 with Guix, you can do so by running Emacs with @code{--no-site-file}
1743 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1745 @subsection The GCC toolchain
1750 Guix offers individual compiler packages such as @code{gcc} but if you
1751 are in need of a complete toolchain for compiling and linking source
1752 code what you really want is the @code{gcc-toolchain} package. This
1753 package provides a complete GCC toolchain for C/C++ development,
1754 including GCC itself, the GNU C Library (headers and binaries, plus
1755 debugging symbols in the @code{debug} output), Binutils, and a linker
1758 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1759 passed to the linker, add corresponding @code{-rpath} arguments, and
1760 invoke the actual linker with this new set of arguments. You can instruct the
1761 wrapper to refuse to link against libraries not in the store by setting the
1762 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1766 @c *********************************************************************
1767 @node System Installation
1768 @chapter System Installation
1770 @cindex installing Guix System
1771 @cindex Guix System, installation
1772 This section explains how to install Guix System
1773 on a machine. Guix, as a package manager, can
1774 also be installed on top of a running GNU/Linux system,
1775 @pxref{Installation}.
1779 @c This paragraph is for people reading this from tty2 of the
1780 @c installation image.
1781 You are reading this documentation with an Info reader. For details on
1782 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1783 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1784 Info}. Hit @kbd{l} afterwards to come back here.
1786 Alternately, run @command{info info} in another tty to keep the manual
1792 * Limitations:: What you can expect.
1793 * Hardware Considerations:: Supported hardware.
1794 * USB Stick and DVD Installation:: Preparing the installation medium.
1795 * Preparing for Installation:: Networking, partitioning, etc.
1796 * Guided Graphical Installation:: Easy graphical installation.
1797 * Manual Installation:: Manual installation for wizards.
1798 * After System Installation:: When installation succeeded.
1799 * Installing Guix in a VM:: Guix System playground.
1800 * Building the Installation Image:: How this comes to be.
1804 @section Limitations
1806 We consider Guix System to be ready for a wide range of ``desktop'' and server
1807 use cases. The reliability guarantees it provides---transactional upgrades
1808 and rollbacks, reproducibility---make it a solid foundation.
1810 Nevertheless, before you proceed with the installation, be aware of the
1811 following noteworthy limitations applicable to version @value{VERSION}:
1815 Support for the Logical Volume Manager (LVM) is missing.
1818 More and more system services are provided (@pxref{Services}), but some
1822 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1823 as well as a number of X11 window managers. However, KDE is currently
1827 More than a disclaimer, this is an invitation to report issues (and success
1828 stories!), and to join us in improving it. @xref{Contributing}, for more
1832 @node Hardware Considerations
1833 @section Hardware Considerations
1835 @cindex hardware support on Guix System
1836 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1837 builds around the kernel Linux-libre, which means that only hardware for
1838 which free software drivers and firmware exist is supported. Nowadays,
1839 a wide range of off-the-shelf hardware is supported on
1840 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1841 Ethernet controllers. Unfortunately, there are still areas where
1842 hardware vendors deny users control over their own computing, and such
1843 hardware is not supported on Guix System.
1845 @cindex WiFi, hardware support
1846 One of the main areas where free drivers or firmware are lacking is WiFi
1847 devices. WiFi devices known to work include those using Atheros chips
1848 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1849 driver, and those using Broadcom/AirForce chips (BCM43xx with
1850 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1851 Linux-libre driver. Free firmware exists for both and is available
1852 out-of-the-box on Guix System, as part of @code{%base-firmware}
1853 (@pxref{operating-system Reference, @code{firmware}}).
1855 @cindex RYF, Respects Your Freedom
1856 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1857 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1858 certification program for hardware products that respect your freedom
1859 and your privacy and ensure that you have control over your device. We
1860 encourage you to check the list of RYF-certified devices.
1862 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1863 web site. It contains a catalog of hardware devices with information
1864 about their support in GNU/Linux.
1867 @node USB Stick and DVD Installation
1868 @section USB Stick and DVD Installation
1870 An ISO-9660 installation image that can be written to a USB stick or
1871 burnt to a DVD can be downloaded from
1872 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1873 where @var{system} is one of:
1877 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1880 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1883 @c start duplication of authentication part from ``Binary Installation''
1884 Make sure to download the associated @file{.sig} file and to verify the
1885 authenticity of the image against it, along these lines:
1888 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1889 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1892 If that command fails because you do not have the required public key,
1893 then run this command to import it:
1896 $ gpg --keyserver @value{KEY-SERVER} \
1897 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1901 and rerun the @code{gpg --verify} command.
1904 This image contains the tools necessary for an installation.
1905 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1907 @unnumberedsubsec Copying to a USB Stick
1909 To copy the image to a USB stick, follow these steps:
1913 Decompress the image using the @command{xz} command:
1916 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1920 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1921 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1922 copy the image with:
1925 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1929 Access to @file{/dev/sdX} usually requires root privileges.
1932 @unnumberedsubsec Burning on a DVD
1934 To copy the image to a DVD, follow these steps:
1938 Decompress the image using the @command{xz} command:
1941 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1945 Insert a blank DVD into your machine, and determine
1946 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1947 copy the image with:
1950 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1953 Access to @file{/dev/srX} usually requires root privileges.
1956 @unnumberedsubsec Booting
1958 Once this is done, you should be able to reboot the system and boot from
1959 the USB stick or DVD. The latter usually requires you to get in the
1960 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1962 @xref{Installing Guix in a VM}, if, instead, you would like to install
1963 Guix System in a virtual machine (VM).
1966 @node Preparing for Installation
1967 @section Preparing for Installation
1969 Once you have booted, you can use the guided graphical installer, which makes
1970 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1971 if you are already familiar with GNU/Linux and if you want more control than
1972 what the graphical installer provides, you can choose the ``manual''
1973 installation process (@pxref{Manual Installation}).
1975 The graphical installer is available on TTY1. You can obtain root shells on
1976 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1977 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1978 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1979 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1980 which allows you to select text with the left mouse button and to paste it
1981 with the middle button.
1984 Installation requires access to the Internet so that any missing
1985 dependencies of your system configuration can be downloaded. See the
1986 ``Networking'' section below.
1989 @node Guided Graphical Installation
1990 @section Guided Graphical Installation
1992 The graphical installer is a text-based user interface. It will guide you,
1993 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
1995 The first dialog boxes allow you to set up the system as you use it during the
1996 installation: you can choose the language, keyboard layout, and set up
1997 networking, which will be used during the installation. The image below shows
1998 the networking dialog.
2000 @image{images/installer-network,5in,, networking setup with the graphical installer}
2002 Later steps allow you to partition your hard disk, as shown in the image
2003 below, to choose whether or not to use encrypted file systems, to enter the
2004 host name and root password, and to create an additional account, among other
2007 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2009 Note that, at any time, the installer allows you to exit the current
2010 installation step and resume at a previous step, as show in the image below.
2012 @image{images/installer-resume,5in,, resuming the installation process}
2014 Once you're done, the installer produces an operating system configuration and
2015 displays it (@pxref{Using the Configuration System}). At that point you can
2016 hit ``OK'' and installation will proceed. On success, you can reboot into the
2017 new system and enjoy. @xref{After System Installation}, for what's next!
2020 @node Manual Installation
2021 @section Manual Installation
2023 This section describes how you would ``manually'' install GNU@tie{}Guix System
2024 on your machine. This option requires familiarity with GNU/Linux, with the
2025 shell, and with common administration tools. If you think this is not for
2026 you, consider using the guided graphical installer (@pxref{Guided Graphical
2029 The installation system provides root shells on TTYs 3 to 6; press
2030 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2031 many common tools needed to install the system. But it is also a full-blown
2032 Guix System, which means that you can install additional packages, should you
2033 need it, using @command{guix package} (@pxref{Invoking guix package}).
2036 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2037 * Proceeding with the Installation:: Installing.
2040 @node Keyboard Layout and Networking and Partitioning
2041 @subsection Keyboard Layout, Networking, and Partitioning
2043 Before you can install the system, you may want to adjust the keyboard layout,
2044 set up networking, and partition your target hard disk. This section will
2045 guide you through this.
2047 @subsubsection Keyboard Layout
2049 @cindex keyboard layout
2050 The installation image uses the US qwerty keyboard layout. If you want
2051 to change it, you can use the @command{loadkeys} command. For example,
2052 the following command selects the Dvorak keyboard layout:
2058 See the files under @file{/run/current-system/profile/share/keymaps} for
2059 a list of available keyboard layouts. Run @command{man loadkeys} for
2062 @subsubsection Networking
2064 Run the following command to see what your network interfaces are called:
2071 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2077 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2078 Wired interfaces have a name starting with @samp{e}; for example, the
2079 interface corresponding to the first on-board Ethernet controller is
2080 called @samp{eno1}. Wireless interfaces have a name starting with
2081 @samp{w}, like @samp{w1p2s0}.
2084 @item Wired connection
2085 To configure a wired network run the following command, substituting
2086 @var{interface} with the name of the wired interface you want to use.
2089 ifconfig @var{interface} up
2092 @item Wireless connection
2095 To configure wireless networking, you can create a configuration file
2096 for the @command{wpa_supplicant} configuration tool (its location is not
2097 important) using one of the available text editors such as
2101 nano wpa_supplicant.conf
2104 As an example, the following stanza can go to this file and will work
2105 for many wireless networks, provided you give the actual SSID and
2106 passphrase for the network you are connecting to:
2110 ssid="@var{my-ssid}"
2112 psk="the network's secret passphrase"
2116 Start the wireless service and run it in the background with the
2117 following command (substitute @var{interface} with the name of the
2118 network interface you want to use):
2121 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2124 Run @command{man wpa_supplicant} for more information.
2128 At this point, you need to acquire an IP address. On a network where IP
2129 addresses are automatically assigned @i{via} DHCP, you can run:
2132 dhclient -v @var{interface}
2135 Try to ping a server to see if networking is up and running:
2141 Setting up network access is almost always a requirement because the
2142 image does not contain all the software and tools that may be needed.
2144 @cindex installing over SSH
2145 If you want to, you can continue the installation remotely by starting
2149 herd start ssh-daemon
2152 Make sure to either set a password with @command{passwd}, or configure
2153 OpenSSH public key authentication before logging in.
2155 @subsubsection Disk Partitioning
2157 Unless this has already been done, the next step is to partition, and
2158 then format the target partition(s).
2160 The installation image includes several partitioning tools, including
2161 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2162 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2163 the partition layout you want:
2169 If your disk uses the GUID Partition Table (GPT) format and you plan to
2170 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2171 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2174 @cindex EFI, installation
2175 @cindex UEFI, installation
2176 @cindex ESP, EFI system partition
2177 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2178 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2179 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2182 parted /dev/sda set 1 esp on
2186 @vindex grub-bootloader
2187 @vindex grub-efi-bootloader
2188 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2189 @file{/sys/firmware/efi} exists in the installation image, then you should
2190 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2191 Otherwise you should use the BIOS-based GRUB, known as
2192 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2196 Once you are done partitioning the target hard disk drive, you have to
2197 create a file system on the relevant partition(s)@footnote{Currently
2198 Guix System only supports ext4 and btrfs file systems. In particular, code
2199 that reads file system UUIDs and labels only works for these file system
2200 types.}. For the ESP, if you have one and assuming it is
2201 @file{/dev/sda1}, run:
2204 mkfs.fat -F32 /dev/sda1
2207 Preferably, assign file systems a label so that you can easily and
2208 reliably refer to them in @code{file-system} declarations (@pxref{File
2209 Systems}). This is typically done using the @code{-L} option of
2210 @command{mkfs.ext4} and related commands. So, assuming the target root
2211 partition lives at @file{/dev/sda2}, a file system with the label
2212 @code{my-root} can be created with:
2215 mkfs.ext4 -L my-root /dev/sda2
2218 @cindex encrypted disk
2219 If you are instead planning to encrypt the root partition, you can use
2220 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2221 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2222 @code{man cryptsetup}} for more information.) Assuming you want to
2223 store the root partition on @file{/dev/sda2}, the command sequence would
2224 be along these lines:
2227 cryptsetup luksFormat /dev/sda2
2228 cryptsetup open --type luks /dev/sda2 my-partition
2229 mkfs.ext4 -L my-root /dev/mapper/my-partition
2232 Once that is done, mount the target file system under @file{/mnt}
2233 with a command like (again, assuming @code{my-root} is the label of the
2237 mount LABEL=my-root /mnt
2240 Also mount any other file systems you would like to use on the target
2241 system relative to this path. If you have opted for @file{/boot/efi} as an
2242 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2243 found by @code{guix system init} afterwards.
2245 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2246 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2247 sure to initialize them with @command{mkswap}. Assuming you have one
2248 swap partition on @file{/dev/sda3}, you would run:
2255 Alternatively, you may use a swap file. For example, assuming that in
2256 the new system you want to use the file @file{/swapfile} as a swap file,
2257 you would run@footnote{This example will work for many types of file
2258 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2259 btrfs), the required steps may be different. For details, see the
2260 manual pages for @command{mkswap} and @command{swapon}.}:
2263 # This is 10 GiB of swap space. Adjust "count" to change the size.
2264 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2265 # For security, make the file readable and writable only by root.
2266 chmod 600 /mnt/swapfile
2267 mkswap /mnt/swapfile
2268 swapon /mnt/swapfile
2271 Note that if you have encrypted the root partition and created a swap
2272 file in its file system as described above, then the encryption also
2273 protects the swap file, just like any other file in that file system.
2275 @node Proceeding with the Installation
2276 @subsection Proceeding with the Installation
2278 With the target partitions ready and the target root mounted on
2279 @file{/mnt}, we're ready to go. First, run:
2282 herd start cow-store /mnt
2285 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2286 during the installation phase are written to the target disk on @file{/mnt}
2287 rather than kept in memory. This is necessary because the first phase of
2288 the @command{guix system init} command (see below) entails downloads or
2289 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2291 Next, you have to edit a file and
2292 provide the declaration of the operating system to be installed. To
2293 that end, the installation system comes with three text editors. We
2294 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2295 supports syntax highlighting and parentheses matching; other editors
2296 include GNU Zile (an Emacs clone), and
2297 nvi (a clone of the original BSD @command{vi} editor).
2298 We strongly recommend storing that file on the target root file system, say,
2299 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2300 configuration file once you have rebooted into the newly-installed system.
2302 @xref{Using the Configuration System}, for an overview of the
2303 configuration file. The example configurations discussed in that
2304 section are available under @file{/etc/configuration} in the
2305 installation image. Thus, to get started with a system configuration
2306 providing a graphical display server (a ``desktop'' system), you can run
2307 something along these lines:
2311 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2312 # nano /mnt/etc/config.scm
2315 You should pay attention to what your configuration file contains, and
2320 Make sure the @code{bootloader-configuration} form refers to the target
2321 you want to install GRUB on. It should mention @code{grub-bootloader} if
2322 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2323 for newer UEFI systems. For legacy systems, the @code{target} field
2324 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2325 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2326 currently mounted and a @code{file-system} entry is specified in your
2330 Be sure that your file system labels match the value of their respective
2331 @code{device} fields in your @code{file-system} configuration, assuming
2332 your @code{file-system} configuration uses the @code{file-system-label}
2333 procedure in its @code{device} field.
2336 If there are encrypted or RAID partitions, make sure to add a
2337 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2340 Once you are done preparing the configuration file, the new system must
2341 be initialized (remember that the target root file system is mounted
2345 guix system init /mnt/etc/config.scm /mnt
2349 This copies all the necessary files and installs GRUB on
2350 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2351 more information, @pxref{Invoking guix system}. This command may trigger
2352 downloads or builds of missing packages, which can take some time.
2354 Once that command has completed---and hopefully succeeded!---you can run
2355 @command{reboot} and boot into the new system. The @code{root} password
2356 in the new system is initially empty; other users' passwords need to be
2357 initialized by running the @command{passwd} command as @code{root},
2358 unless your configuration specifies otherwise
2359 (@pxref{user-account-password, user account passwords}).
2360 @xref{After System Installation}, for what's next!
2363 @node After System Installation
2364 @section After System Installation
2366 Success, you've now booted into Guix System! From then on, you can update the
2367 system whenever you want by running, say:
2371 sudo guix system reconfigure /etc/config.scm
2375 This builds a new system generation with the latest packages and services
2376 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2377 your system includes the latest security updates (@pxref{Security Updates}).
2379 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2381 @cindex sudo vs. @command{guix pull}
2382 Note that @command{sudo guix} runs your user's @command{guix} command and
2383 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2384 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2387 Join us on @code{#guix} on the Freenode IRC network or on
2388 @email{guix-devel@@gnu.org} to share your experience!
2391 @node Installing Guix in a VM
2392 @section Installing Guix in a Virtual Machine
2394 @cindex virtual machine, Guix System installation
2395 @cindex virtual private server (VPS)
2396 @cindex VPS (virtual private server)
2397 If you'd like to install Guix System in a virtual machine (VM) or on a
2398 virtual private server (VPS) rather than on your beloved machine, this
2401 To boot a @uref{http://qemu.org/,QEMU} VM for installing Guix System in a
2402 disk image, follow these steps:
2406 First, retrieve and decompress the Guix system installation image as
2407 described previously (@pxref{USB Stick and DVD Installation}).
2410 Create a disk image that will hold the installed system. To make a
2411 qcow2-formatted disk image, use the @command{qemu-img} command:
2414 qemu-img create -f qcow2 guixsd.img 50G
2417 The resulting file will be much smaller than 50 GB (typically less than
2418 1 MB), but it will grow as the virtualized storage device is filled up.
2421 Boot the USB installation image in an VM:
2424 qemu-system-x86_64 -m 1024 -smp 1 \
2425 -net user -net nic,model=virtio -boot menu=on \
2426 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2427 -drive file=guixsd.img
2430 The ordering of the drives matters.
2432 In the VM console, quickly press the @kbd{F12} key to enter the boot
2433 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2437 You're now root in the VM, proceed with the installation process.
2438 @xref{Preparing for Installation}, and follow the instructions.
2441 Once installation is complete, you can boot the system that's on your
2442 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2445 @node Building the Installation Image
2446 @section Building the Installation Image
2448 @cindex installation image
2449 The installation image described above was built using the @command{guix
2450 system} command, specifically:
2453 guix system disk-image --file-system-type=iso9660 \
2454 gnu/system/install.scm
2457 Have a look at @file{gnu/system/install.scm} in the source tree,
2458 and see also @ref{Invoking guix system} for more information
2459 about the installation image.
2461 @section Building the Installation Image for ARM Boards
2463 Many ARM boards require a specific variant of the
2464 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2466 If you build a disk image and the bootloader is not available otherwise
2467 (on another boot drive etc), it's advisable to build an image that
2468 includes the bootloader, specifically:
2471 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2474 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2475 board, a list of possible boards will be printed.
2477 @c *********************************************************************
2478 @node Package Management
2479 @chapter Package Management
2482 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2483 remove software packages, without having to know about their build
2484 procedures or dependencies. Guix also goes beyond this obvious set of
2487 This chapter describes the main features of Guix, as well as the
2488 package management tools it provides. Along with the command-line
2489 interface described below (@pxref{Invoking guix package, @code{guix
2490 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2491 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2492 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2496 guix install emacs-guix
2500 * Features:: How Guix will make your life brighter.
2501 * Invoking guix package:: Package installation, removal, etc.
2502 * Substitutes:: Downloading pre-built binaries.
2503 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2504 * Invoking guix gc:: Running the garbage collector.
2505 * Invoking guix pull:: Fetching the latest Guix and distribution.
2506 * Channels:: Customizing the package collection.
2507 * Inferiors:: Interacting with another revision of Guix.
2508 * Invoking guix describe:: Display information about your Guix revision.
2509 * Invoking guix archive:: Exporting and importing store files.
2515 When using Guix, each package ends up in the @dfn{package store}, in its
2516 own directory---something that resembles
2517 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2519 Instead of referring to these directories, users have their own
2520 @dfn{profile}, which points to the packages that they actually want to
2521 use. These profiles are stored within each user's home directory, at
2522 @code{$HOME/.guix-profile}.
2524 For example, @code{alice} installs GCC 4.7.2. As a result,
2525 @file{/home/alice/.guix-profile/bin/gcc} points to
2526 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2527 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2528 simply continues to point to
2529 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2530 coexist on the same system without any interference.
2532 The @command{guix package} command is the central tool to manage
2533 packages (@pxref{Invoking guix package}). It operates on the per-user
2534 profiles, and can be used @emph{with normal user privileges}.
2536 @cindex transactions
2537 The command provides the obvious install, remove, and upgrade
2538 operations. Each invocation is actually a @emph{transaction}: either
2539 the specified operation succeeds, or nothing happens. Thus, if the
2540 @command{guix package} process is terminated during the transaction,
2541 or if a power outage occurs during the transaction, then the user's
2542 profile remains in its previous state, and remains usable.
2544 In addition, any package transaction may be @emph{rolled back}. So, if,
2545 for example, an upgrade installs a new version of a package that turns
2546 out to have a serious bug, users may roll back to the previous instance
2547 of their profile, which was known to work well. Similarly, the global
2548 system configuration on Guix is subject to
2549 transactional upgrades and roll-back
2550 (@pxref{Using the Configuration System}).
2552 All packages in the package store may be @emph{garbage-collected}.
2553 Guix can determine which packages are still referenced by user
2554 profiles, and remove those that are provably no longer referenced
2555 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2556 generations of their profile so that the packages they refer to can be
2559 @cindex reproducibility
2560 @cindex reproducible builds
2561 Guix takes a @dfn{purely functional} approach to package
2562 management, as described in the introduction (@pxref{Introduction}).
2563 Each @file{/gnu/store} package directory name contains a hash of all the
2564 inputs that were used to build that package---compiler, libraries, build
2565 scripts, etc. This direct correspondence allows users to make sure a
2566 given package installation matches the current state of their
2567 distribution. It also helps maximize @dfn{build reproducibility}:
2568 thanks to the isolated build environments that are used, a given build
2569 is likely to yield bit-identical files when performed on different
2570 machines (@pxref{Invoking guix-daemon, container}).
2573 This foundation allows Guix to support @dfn{transparent binary/source
2574 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2575 available from an external source---a @dfn{substitute}, Guix just
2576 downloads it and unpacks it;
2577 otherwise, it builds the package from source, locally
2578 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2579 reproducible, users do not have to trust servers that provide
2580 substitutes: they can force a local build and @emph{challenge} providers
2581 (@pxref{Invoking guix challenge}).
2583 Control over the build environment is a feature that is also useful for
2584 developers. The @command{guix environment} command allows developers of
2585 a package to quickly set up the right development environment for their
2586 package, without having to manually install the dependencies of the
2587 package into their profile (@pxref{Invoking guix environment}).
2589 @cindex replication, of software environments
2590 @cindex provenance tracking, of software artifacts
2591 All of Guix and its package definitions is version-controlled, and
2592 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2593 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2594 Guix instance on a different machine or at a later point in time, which in
2595 turn allows you to @emph{replicate complete software environments}, while
2596 retaining precise @dfn{provenance tracking} of the software.
2598 @node Invoking guix package
2599 @section Invoking @command{guix package}
2601 @cindex installing packages
2602 @cindex removing packages
2603 @cindex package installation
2604 @cindex package removal
2605 The @command{guix package} command is the tool that allows users to
2606 install, upgrade, and remove packages, as well as rolling back to
2607 previous configurations. It operates only on the user's own profile,
2608 and works with normal user privileges (@pxref{Features}). Its syntax
2612 guix package @var{options}
2615 @cindex transactions
2616 Primarily, @var{options} specifies the operations to be performed during
2617 the transaction. Upon completion, a new profile is created, but
2618 previous @dfn{generations} of the profile remain available, should the user
2621 For example, to remove @code{lua} and install @code{guile} and
2622 @code{guile-cairo} in a single transaction:
2625 guix package -r lua -i guile guile-cairo
2628 @cindex aliases, for @command{guix package}
2629 For your convenience, we also provide the following aliases:
2633 @command{guix search} is an alias for @command{guix package -s},
2635 @command{guix install} is an alias for @command{guix package -i},
2637 @command{guix remove} is an alias for @command{guix package -r},
2639 and @command{guix upgrade} is an alias for @command{guix package -u}.
2642 These aliases are less expressive than @command{guix package} and provide
2643 fewer options, so in some cases you'll probably want to use @command{guix
2646 @command{guix package} also supports a @dfn{declarative approach}
2647 whereby the user specifies the exact set of packages to be available and
2648 passes it @i{via} the @option{--manifest} option
2649 (@pxref{profile-manifest, @option{--manifest}}).
2652 For each user, a symlink to the user's default profile is automatically
2653 created in @file{$HOME/.guix-profile}. This symlink always points to the
2654 current generation of the user's default profile. Thus, users can add
2655 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2656 variable, and so on.
2657 @cindex search paths
2658 If you are not using Guix System, consider adding the
2659 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2660 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2661 shells get all the right environment variable definitions:
2664 GUIX_PROFILE="$HOME/.guix-profile" ; \
2665 source "$HOME/.guix-profile/etc/profile"
2668 In a multi-user setup, user profiles are stored in a place registered as
2669 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2670 to (@pxref{Invoking guix gc}). That directory is normally
2671 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2672 @var{localstatedir} is the value passed to @code{configure} as
2673 @code{--localstatedir}, and @var{user} is the user name. The
2674 @file{per-user} directory is created when @command{guix-daemon} is
2675 started, and the @var{user} sub-directory is created by @command{guix
2678 The @var{options} can be among the following:
2682 @item --install=@var{package} @dots{}
2683 @itemx -i @var{package} @dots{}
2684 Install the specified @var{package}s.
2686 Each @var{package} may specify either a simple package name, such as
2687 @code{guile}, or a package name followed by an at-sign and version number,
2688 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2689 case, the newest version prefixed by @code{1.8} is selected.)
2691 If no version number is specified, the
2692 newest available version will be selected. In addition, @var{package}
2693 may contain a colon, followed by the name of one of the outputs of the
2694 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2695 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2696 name (and optionally version) are searched for among the GNU
2697 distribution modules (@pxref{Package Modules}).
2699 @cindex propagated inputs
2700 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2701 that automatically get installed along with the required package
2702 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2703 @code{package} objects}, for information about propagated inputs in
2704 package definitions).
2706 @anchor{package-cmd-propagated-inputs}
2707 An example is the GNU MPC library: its C header files refer to those of
2708 the GNU MPFR library, which in turn refer to those of the GMP library.
2709 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2710 in the profile; removing MPC also removes MPFR and GMP---unless they had
2711 also been explicitly installed by the user.
2713 Besides, packages sometimes rely on the definition of environment
2714 variables for their search paths (see explanation of
2715 @code{--search-paths} below). Any missing or possibly incorrect
2716 environment variable definitions are reported here.
2718 @item --install-from-expression=@var{exp}
2720 Install the package @var{exp} evaluates to.
2722 @var{exp} must be a Scheme expression that evaluates to a
2723 @code{<package>} object. This option is notably useful to disambiguate
2724 between same-named variants of a package, with expressions such as
2725 @code{(@@ (gnu packages base) guile-final)}.
2727 Note that this option installs the first output of the specified
2728 package, which may be insufficient when needing a specific output of a
2729 multiple-output package.
2731 @item --install-from-file=@var{file}
2732 @itemx -f @var{file}
2733 Install the package that the code within @var{file} evaluates to.
2735 As an example, @var{file} might contain a definition like this
2736 (@pxref{Defining Packages}):
2739 @verbatiminclude package-hello.scm
2742 Developers may find it useful to include such a @file{guix.scm} file
2743 in the root of their project source tree that can be used to test
2744 development snapshots and create reproducible development environments
2745 (@pxref{Invoking guix environment}).
2747 @item --remove=@var{package} @dots{}
2748 @itemx -r @var{package} @dots{}
2749 Remove the specified @var{package}s.
2751 As for @code{--install}, each @var{package} may specify a version number
2752 and/or output name in addition to the package name. For instance,
2753 @code{-r glibc:debug} would remove the @code{debug} output of
2756 @item --upgrade[=@var{regexp} @dots{}]
2757 @itemx -u [@var{regexp} @dots{}]
2758 @cindex upgrading packages
2759 Upgrade all the installed packages. If one or more @var{regexp}s are
2760 specified, upgrade only installed packages whose name matches a
2761 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2763 Note that this upgrades package to the latest version of packages found
2764 in the distribution currently installed. To update your distribution,
2765 you should regularly run @command{guix pull} (@pxref{Invoking guix
2768 @item --do-not-upgrade[=@var{regexp} @dots{}]
2769 When used together with the @code{--upgrade} option, do @emph{not}
2770 upgrade any packages whose name matches a @var{regexp}. For example, to
2771 upgrade all packages in the current profile except those containing the
2772 substring ``emacs'':
2775 $ guix package --upgrade . --do-not-upgrade emacs
2778 @item @anchor{profile-manifest}--manifest=@var{file}
2779 @itemx -m @var{file}
2780 @cindex profile declaration
2781 @cindex profile manifest
2782 Create a new generation of the profile from the manifest object
2783 returned by the Scheme code in @var{file}.
2785 This allows you to @emph{declare} the profile's contents rather than
2786 constructing it through a sequence of @code{--install} and similar
2787 commands. The advantage is that @var{file} can be put under version
2788 control, copied to different machines to reproduce the same profile, and
2791 @c FIXME: Add reference to (guix profile) documentation when available.
2792 @var{file} must return a @dfn{manifest} object, which is roughly a list
2795 @findex packages->manifest
2797 (use-package-modules guile emacs)
2802 ;; Use a specific package output.
2803 (list guile-2.0 "debug")))
2806 @findex specifications->manifest
2807 In this example we have to know which modules define the @code{emacs}
2808 and @code{guile-2.0} variables to provide the right
2809 @code{use-package-modules} line, which can be cumbersome. We can
2810 instead provide regular package specifications and let
2811 @code{specifications->manifest} look up the corresponding package
2815 (specifications->manifest
2816 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2820 @cindex rolling back
2821 @cindex undoing transactions
2822 @cindex transactions, undoing
2823 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2824 the last transaction.
2826 When combined with options such as @code{--install}, roll back occurs
2827 before any other actions.
2829 When rolling back from the first generation that actually contains
2830 installed packages, the profile is made to point to the @dfn{zeroth
2831 generation}, which contains no files apart from its own metadata.
2833 After having rolled back, installing, removing, or upgrading packages
2834 overwrites previous future generations. Thus, the history of the
2835 generations in a profile is always linear.
2837 @item --switch-generation=@var{pattern}
2838 @itemx -S @var{pattern}
2840 Switch to a particular generation defined by @var{pattern}.
2842 @var{pattern} may be either a generation number or a number prefixed
2843 with ``+'' or ``-''. The latter means: move forward/backward by a
2844 specified number of generations. For example, if you want to return to
2845 the latest generation after @code{--roll-back}, use
2846 @code{--switch-generation=+1}.
2848 The difference between @code{--roll-back} and
2849 @code{--switch-generation=-1} is that @code{--switch-generation} will
2850 not make a zeroth generation, so if a specified generation does not
2851 exist, the current generation will not be changed.
2853 @item --search-paths[=@var{kind}]
2854 @cindex search paths
2855 Report environment variable definitions, in Bash syntax, that may be
2856 needed in order to use the set of installed packages. These environment
2857 variables are used to specify @dfn{search paths} for files used by some
2858 of the installed packages.
2860 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2861 environment variables to be defined so it can look for headers and
2862 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2863 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2864 library are installed in the profile, then @code{--search-paths} will
2865 suggest setting these variables to @code{@var{profile}/include} and
2866 @code{@var{profile}/lib}, respectively.
2868 The typical use case is to define these environment variables in the
2872 $ eval `guix package --search-paths`
2875 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2876 meaning that the returned environment variable definitions will either
2877 be exact settings, or prefixes or suffixes of the current value of these
2878 variables. When omitted, @var{kind} defaults to @code{exact}.
2880 This option can also be used to compute the @emph{combined} search paths
2881 of several profiles. Consider this example:
2884 $ guix package -p foo -i guile
2885 $ guix package -p bar -i guile-json
2886 $ guix package -p foo -p bar --search-paths
2889 The last command above reports about the @code{GUILE_LOAD_PATH}
2890 variable, even though, taken individually, neither @file{foo} nor
2891 @file{bar} would lead to that recommendation.
2894 @item --profile=@var{profile}
2895 @itemx -p @var{profile}
2896 Use @var{profile} instead of the user's default profile.
2898 @cindex collisions, in a profile
2899 @cindex colliding packages in profiles
2900 @cindex profile collisions
2901 @item --allow-collisions
2902 Allow colliding packages in the new profile. Use at your own risk!
2904 By default, @command{guix package} reports as an error @dfn{collisions}
2905 in the profile. Collisions happen when two or more different versions
2906 or variants of a given package end up in the profile.
2909 Use the bootstrap Guile to build the profile. This option is only
2910 useful to distribution developers.
2914 In addition to these actions, @command{guix package} supports the
2915 following options to query the current state of a profile, or the
2916 availability of packages:
2920 @item --search=@var{regexp}
2921 @itemx -s @var{regexp}
2922 @cindex searching for packages
2923 List the available packages whose name, synopsis, or description matches
2924 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2925 Print all the metadata of matching packages in
2926 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2927 GNU recutils manual}).
2929 This allows specific fields to be extracted using the @command{recsel}
2930 command, for instance:
2933 $ guix package -s malloc | recsel -p name,version,relevance
2947 Similarly, to show the name of all the packages available under the
2948 terms of the GNU@tie{}LGPL version 3:
2951 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2958 It is also possible to refine search results using several @code{-s} flags to
2959 @command{guix package}, or several arguments to @command{guix search}. For
2960 example, the following command returns a list of board games (this time using
2961 the @command{guix search} alias):
2964 $ guix search '\<board\>' game | recsel -p name
2969 If we were to omit @code{-s game}, we would also get software packages
2970 that deal with printed circuit boards; removing the angle brackets
2971 around @code{board} would further add packages that have to do with
2974 And now for a more elaborate example. The following command searches
2975 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2976 libraries, and prints the name and synopsis of the matching packages:
2979 $ guix search crypto library | \
2980 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2984 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2985 information on @dfn{selection expressions} for @code{recsel -e}.
2987 @item --show=@var{package}
2988 Show details about @var{package}, taken from the list of available packages, in
2989 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2993 $ guix package --show=python | recsel -p name,version
3001 You may also specify the full name of a package to only get details about a
3002 specific version of it:
3004 $ guix package --show=python@@3.4 | recsel -p name,version
3011 @item --list-installed[=@var{regexp}]
3012 @itemx -I [@var{regexp}]
3013 List the currently installed packages in the specified profile, with the
3014 most recently installed packages shown last. When @var{regexp} is
3015 specified, list only installed packages whose name matches @var{regexp}.
3017 For each installed package, print the following items, separated by
3018 tabs: the package name, its version string, the part of the package that
3019 is installed (for instance, @code{out} for the default output,
3020 @code{include} for its headers, etc.), and the path of this package in
3023 @item --list-available[=@var{regexp}]
3024 @itemx -A [@var{regexp}]
3025 List packages currently available in the distribution for this system
3026 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3027 installed packages whose name matches @var{regexp}.
3029 For each package, print the following items separated by tabs: its name,
3030 its version string, the parts of the package (@pxref{Packages with
3031 Multiple Outputs}), and the source location of its definition.
3033 @item --list-generations[=@var{pattern}]
3034 @itemx -l [@var{pattern}]
3036 Return a list of generations along with their creation dates; for each
3037 generation, show the installed packages, with the most recently
3038 installed packages shown last. Note that the zeroth generation is never
3041 For each installed package, print the following items, separated by
3042 tabs: the name of a package, its version string, the part of the package
3043 that is installed (@pxref{Packages with Multiple Outputs}), and the
3044 location of this package in the store.
3046 When @var{pattern} is used, the command returns only matching
3047 generations. Valid patterns include:
3050 @item @emph{Integers and comma-separated integers}. Both patterns denote
3051 generation numbers. For instance, @code{--list-generations=1} returns
3054 And @code{--list-generations=1,8,2} outputs three generations in the
3055 specified order. Neither spaces nor trailing commas are allowed.
3057 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3058 specified generations and everything in between. Note that the start of
3059 a range must be smaller than its end.
3061 It is also possible to omit the endpoint. For example,
3062 @code{--list-generations=2..}, returns all generations starting from the
3065 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3066 or months by passing an integer along with the first letter of the
3067 duration. For example, @code{--list-generations=20d} lists generations
3068 that are up to 20 days old.
3071 @item --delete-generations[=@var{pattern}]
3072 @itemx -d [@var{pattern}]
3073 When @var{pattern} is omitted, delete all generations except the current
3076 This command accepts the same patterns as @option{--list-generations}.
3077 When @var{pattern} is specified, delete the matching generations. When
3078 @var{pattern} specifies a duration, generations @emph{older} than the
3079 specified duration match. For instance, @code{--delete-generations=1m}
3080 deletes generations that are more than one month old.
3082 If the current generation matches, it is @emph{not} deleted. Also, the
3083 zeroth generation is never deleted.
3085 Note that deleting generations prevents rolling back to them.
3086 Consequently, this command must be used with care.
3090 Finally, since @command{guix package} may actually start build
3091 processes, it supports all the common build options (@pxref{Common Build
3092 Options}). It also supports package transformation options, such as
3093 @option{--with-source} (@pxref{Package Transformation Options}).
3094 However, note that package transformations are lost when upgrading; to
3095 preserve transformations across upgrades, you should define your own
3096 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3097 (@pxref{Defining Packages}).
3100 @section Substitutes
3103 @cindex pre-built binaries
3104 Guix supports transparent source/binary deployment, which means that it
3105 can either build things locally, or download pre-built items from a
3106 server, or both. We call these pre-built items @dfn{substitutes}---they
3107 are substitutes for local build results. In many cases, downloading a
3108 substitute is much faster than building things locally.
3110 Substitutes can be anything resulting from a derivation build
3111 (@pxref{Derivations}). Of course, in the common case, they are
3112 pre-built package binaries, but source tarballs, for instance, which
3113 also result from derivation builds, can be available as substitutes.
3116 * Official Substitute Server:: One particular source of substitutes.
3117 * Substitute Server Authorization:: How to enable or disable substitutes.
3118 * Substitute Authentication:: How Guix verifies substitutes.
3119 * Proxy Settings:: How to get substitutes via proxy.
3120 * Substitution Failure:: What happens when substitution fails.
3121 * On Trusting Binaries:: How can you trust that binary blob?
3124 @node Official Substitute Server
3125 @subsection Official Substitute Server
3129 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3130 that builds packages from Guix continuously for some
3131 architectures, and makes them available as substitutes. This is the
3132 default source of substitutes; it can be overridden by passing the
3133 @option{--substitute-urls} option either to @command{guix-daemon}
3134 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3135 or to client tools such as @command{guix package}
3136 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3139 Substitute URLs can be either HTTP or HTTPS.
3140 HTTPS is recommended because communications are encrypted; conversely,
3141 using HTTP makes all communications visible to an eavesdropper, who
3142 could use the information gathered to determine, for instance, whether
3143 your system has unpatched security vulnerabilities.
3145 Substitutes from the official build farm are enabled by default when
3146 using Guix System (@pxref{GNU Distribution}). However,
3147 they are disabled by default when using Guix on a foreign distribution,
3148 unless you have explicitly enabled them via one of the recommended
3149 installation steps (@pxref{Installation}). The following paragraphs
3150 describe how to enable or disable substitutes for the official build
3151 farm; the same procedure can also be used to enable substitutes for any
3152 other substitute server.
3154 @node Substitute Server Authorization
3155 @subsection Substitute Server Authorization
3158 @cindex substitutes, authorization thereof
3159 @cindex access control list (ACL), for substitutes
3160 @cindex ACL (access control list), for substitutes
3161 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3163 must add its public key to the access control list (ACL) of archive
3164 imports, using the @command{guix archive} command (@pxref{Invoking guix
3165 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3166 be compromised and to serve genuine substitutes.
3168 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3169 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3170 the installation prefix of Guix. If you installed Guix from source,
3171 make sure you checked the GPG signature of
3172 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3173 Then, you can run something like this:
3176 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3180 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3181 of an independent build farm also run by the project, reachable at
3182 @indicateurl{https://mirror.hydra.gnu.org}.
3185 Once this is in place, the output of a command like @code{guix build}
3186 should change from something like:
3189 $ guix build emacs --dry-run
3190 The following derivations would be built:
3191 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3192 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3193 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3194 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3202 $ guix build emacs --dry-run
3203 112.3 MB would be downloaded:
3204 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3205 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3206 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3207 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3212 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3213 will be downloaded, when possible, for future builds.
3215 @cindex substitutes, how to disable
3216 The substitute mechanism can be disabled globally by running
3217 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3218 guix-daemon}). It can also be disabled temporarily by passing the
3219 @code{--no-substitutes} option to @command{guix package}, @command{guix
3220 build}, and other command-line tools.
3222 @node Substitute Authentication
3223 @subsection Substitute Authentication
3225 @cindex digital signatures
3226 Guix detects and raises an error when attempting to use a substitute
3227 that has been tampered with. Likewise, it ignores substitutes that are
3228 not signed, or that are not signed by one of the keys listed in the ACL.
3230 There is one exception though: if an unauthorized server provides
3231 substitutes that are @emph{bit-for-bit identical} to those provided by
3232 an authorized server, then the unauthorized server becomes eligible for
3233 downloads. For example, assume we have chosen two substitute servers
3237 --substitute-urls="https://a.example.org https://b.example.org"
3241 @cindex reproducible builds
3242 If the ACL contains only the key for @code{b.example.org}, and if
3243 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3244 then Guix will download substitutes from @code{a.example.org} because it
3245 comes first in the list and can be considered a mirror of
3246 @code{b.example.org}. In practice, independent build machines usually
3247 produce the same binaries, thanks to bit-reproducible builds (see
3250 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3251 (in other words, the server is not authenticated), contrary to what
3252 HTTPS clients such as Web browsers usually do. This is because Guix
3253 authenticates substitute information itself, as explained above, which
3254 is what we care about (whereas X.509 certificates are about
3255 authenticating bindings between domain names and public keys.)
3257 @node Proxy Settings
3258 @subsection Proxy Settings
3261 Substitutes are downloaded over HTTP or HTTPS.
3262 The @code{http_proxy} environment
3263 variable can be set in the environment of @command{guix-daemon} and is
3264 honored for downloads of substitutes. Note that the value of
3265 @code{http_proxy} in the environment where @command{guix build},
3266 @command{guix package}, and other client commands are run has
3267 @emph{absolutely no effect}.
3269 @node Substitution Failure
3270 @subsection Substitution Failure
3272 Even when a substitute for a derivation is available, sometimes the
3273 substitution attempt will fail. This can happen for a variety of
3274 reasons: the substitute server might be offline, the substitute may
3275 recently have been deleted, the connection might have been interrupted,
3278 When substitutes are enabled and a substitute for a derivation is
3279 available, but the substitution attempt fails, Guix will attempt to
3280 build the derivation locally depending on whether or not
3281 @code{--fallback} was given (@pxref{fallback-option,, common build
3282 option @code{--fallback}}). Specifically, if @code{--fallback} was
3283 omitted, then no local build will be performed, and the derivation is
3284 considered to have failed. However, if @code{--fallback} was given,
3285 then Guix will attempt to build the derivation locally, and the success
3286 or failure of the derivation depends on the success or failure of the
3287 local build. Note that when substitutes are disabled or no substitute
3288 is available for the derivation in question, a local build will
3289 @emph{always} be performed, regardless of whether or not
3290 @code{--fallback} was given.
3292 To get an idea of how many substitutes are available right now, you can
3293 try running the @command{guix weather} command (@pxref{Invoking guix
3294 weather}). This command provides statistics on the substitutes provided
3297 @node On Trusting Binaries
3298 @subsection On Trusting Binaries
3300 @cindex trust, of pre-built binaries
3301 Today, each individual's control over their own computing is at the
3302 mercy of institutions, corporations, and groups with enough power and
3303 determination to subvert the computing infrastructure and exploit its
3304 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3305 convenient, we encourage users to also build on their own, or even run
3306 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3307 interesting target. One way to help is by publishing the software you
3308 build using @command{guix publish} so that others have one more choice
3309 of server to download substitutes from (@pxref{Invoking guix publish}).
3311 Guix has the foundations to maximize build reproducibility
3312 (@pxref{Features}). In most cases, independent builds of a given
3313 package or derivation should yield bit-identical results. Thus, through
3314 a diverse set of independent package builds, we can strengthen the
3315 integrity of our systems. The @command{guix challenge} command aims to
3316 help users assess substitute servers, and to assist developers in
3317 finding out about non-deterministic package builds (@pxref{Invoking guix
3318 challenge}). Similarly, the @option{--check} option of @command{guix
3319 build} allows users to check whether previously-installed substitutes
3320 are genuine by rebuilding them locally (@pxref{build-check,
3321 @command{guix build --check}}).
3323 In the future, we want Guix to have support to publish and retrieve
3324 binaries to/from other users, in a peer-to-peer fashion. If you would
3325 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3327 @node Packages with Multiple Outputs
3328 @section Packages with Multiple Outputs
3330 @cindex multiple-output packages
3331 @cindex package outputs
3334 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3335 source package leads to exactly one directory in the store. When running
3336 @command{guix install glibc}, one installs the default output of the
3337 GNU libc package; the default output is called @code{out}, but its name
3338 can be omitted as shown in this command. In this particular case, the
3339 default output of @code{glibc} contains all the C header files, shared
3340 libraries, static libraries, Info documentation, and other supporting
3343 Sometimes it is more appropriate to separate the various types of files
3344 produced from a single source package into separate outputs. For
3345 instance, the GLib C library (used by GTK+ and related packages)
3346 installs more than 20 MiB of reference documentation as HTML pages.
3347 To save space for users who do not need it, the documentation goes to a
3348 separate output, called @code{doc}. To install the main GLib output,
3349 which contains everything but the documentation, one would run:
3355 @cindex documentation
3356 The command to install its documentation is:
3359 guix install glib:doc
3362 Some packages install programs with different ``dependency footprints''.
3363 For instance, the WordNet package installs both command-line tools and
3364 graphical user interfaces (GUIs). The former depend solely on the C
3365 library, whereas the latter depend on Tcl/Tk and the underlying X
3366 libraries. In this case, we leave the command-line tools in the default
3367 output, whereas the GUIs are in a separate output. This allows users
3368 who do not need the GUIs to save space. The @command{guix size} command
3369 can help find out about such situations (@pxref{Invoking guix size}).
3370 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3372 There are several such multiple-output packages in the GNU distribution.
3373 Other conventional output names include @code{lib} for libraries and
3374 possibly header files, @code{bin} for stand-alone programs, and
3375 @code{debug} for debugging information (@pxref{Installing Debugging
3376 Files}). The outputs of a packages are listed in the third column of
3377 the output of @command{guix package --list-available} (@pxref{Invoking
3381 @node Invoking guix gc
3382 @section Invoking @command{guix gc}
3384 @cindex garbage collector
3386 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3387 The @command{guix gc} command allows users to explicitly run the garbage
3388 collector to reclaim space from the @file{/gnu/store} directory. It is
3389 the @emph{only} way to remove files from @file{/gnu/store}---removing
3390 files or directories manually may break it beyond repair!
3393 @cindex garbage collector roots
3394 The garbage collector has a set of known @dfn{roots}: any file under
3395 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3396 cannot be deleted; any other file is considered @dfn{dead} and may be
3397 deleted. The set of garbage collector roots (``GC roots'' for short)
3398 includes default user profiles; by default, the symlinks under
3399 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3400 added with @command{guix build --root}, for example (@pxref{Invoking
3401 guix build}). The @command{guix gc --list-roots} command lists them.
3403 Prior to running @code{guix gc --collect-garbage} to make space, it is
3404 often useful to remove old generations from user profiles; that way, old
3405 package builds referenced by those generations can be reclaimed. This
3406 is achieved by running @code{guix package --delete-generations}
3407 (@pxref{Invoking guix package}).
3409 Our recommendation is to run a garbage collection periodically, or when
3410 you are short on disk space. For instance, to guarantee that at least
3411 5@tie{}GB are available on your disk, simply run:
3417 It is perfectly safe to run as a non-interactive periodic job
3418 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3419 Running @command{guix gc} with no arguments will collect as
3420 much garbage as it can, but that is often inconvenient: you may find
3421 yourself having to rebuild or re-download software that is ``dead'' from
3422 the GC viewpoint but that is necessary to build other pieces of
3423 software---e.g., the compiler tool chain.
3425 The @command{guix gc} command has three modes of operation: it can be
3426 used to garbage-collect any dead files (the default), to delete specific
3427 files (the @code{--delete} option), to print garbage-collector
3428 information, or for more advanced queries. The garbage collection
3429 options are as follows:
3432 @item --collect-garbage[=@var{min}]
3433 @itemx -C [@var{min}]
3434 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3435 sub-directories. This is the default operation when no option is
3438 When @var{min} is given, stop once @var{min} bytes have been collected.
3439 @var{min} may be a number of bytes, or it may include a unit as a
3440 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3441 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3443 When @var{min} is omitted, collect all the garbage.
3445 @item --free-space=@var{free}
3446 @itemx -F @var{free}
3447 Collect garbage until @var{free} space is available under
3448 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3449 as @code{500MiB}, as described above.
3451 When @var{free} or more is already available in @file{/gnu/store}, do
3452 nothing and exit immediately.
3454 @item --delete-generations[=@var{duration}]
3455 @itemx -d [@var{duration}]
3456 Before starting the garbage collection process, delete all the generations
3457 older than @var{duration}, for all the user profiles; when run as root, this
3458 applies to all the profiles @emph{of all the users}.
3460 For example, this command deletes all the generations of all your profiles
3461 that are older than 2 months (except generations that are current), and then
3462 proceeds to free space until at least 10 GiB are available:
3465 guix gc -d 2m -F 10G
3470 Attempt to delete all the store files and directories specified as
3471 arguments. This fails if some of the files are not in the store, or if
3472 they are still live.
3474 @item --list-failures
3475 List store items corresponding to cached build failures.
3477 This prints nothing unless the daemon was started with
3478 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3479 @option{--cache-failures}}).
3482 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3485 @item --clear-failures
3486 Remove the specified store items from the failed-build cache.
3488 Again, this option only makes sense when the daemon is started with
3489 @option{--cache-failures}. Otherwise, it does nothing.
3492 Show the list of dead files and directories still present in the
3493 store---i.e., files and directories no longer reachable from any root.
3496 Show the list of live store files and directories.
3500 In addition, the references among existing store files can be queried:
3506 @cindex package dependencies
3507 List the references (respectively, the referrers) of store files given
3513 List the requisites of the store files passed as arguments. Requisites
3514 include the store files themselves, their references, and the references
3515 of these, recursively. In other words, the returned list is the
3516 @dfn{transitive closure} of the store files.
3518 @xref{Invoking guix size}, for a tool to profile the size of the closure
3519 of an element. @xref{Invoking guix graph}, for a tool to visualize
3520 the graph of references.
3524 Return the derivation(s) leading to the given store items
3525 (@pxref{Derivations}).
3527 For example, this command:
3530 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3534 returns the @file{.drv} file(s) leading to the @code{emacs} package
3535 installed in your profile.
3537 Note that there may be zero matching @file{.drv} files, for instance
3538 because these files have been garbage-collected. There can also be more
3539 than one matching @file{.drv} due to fixed-output derivations.
3542 Lastly, the following options allow you to check the integrity of the
3543 store and to control disk usage.
3547 @item --verify[=@var{options}]
3548 @cindex integrity, of the store
3549 @cindex integrity checking
3550 Verify the integrity of the store.
3552 By default, make sure that all the store items marked as valid in the
3553 database of the daemon actually exist in @file{/gnu/store}.
3555 When provided, @var{options} must be a comma-separated list containing one
3556 or more of @code{contents} and @code{repair}.
3558 When passing @option{--verify=contents}, the daemon computes the
3559 content hash of each store item and compares it against its hash in the
3560 database. Hash mismatches are reported as data corruptions. Because it
3561 traverses @emph{all the files in the store}, this command can take a
3562 long time, especially on systems with a slow disk drive.
3564 @cindex repairing the store
3565 @cindex corruption, recovering from
3566 Using @option{--verify=repair} or @option{--verify=contents,repair}
3567 causes the daemon to try to repair corrupt store items by fetching
3568 substitutes for them (@pxref{Substitutes}). Because repairing is not
3569 atomic, and thus potentially dangerous, it is available only to the
3570 system administrator. A lightweight alternative, when you know exactly
3571 which items in the store are corrupt, is @command{guix build --repair}
3572 (@pxref{Invoking guix build}).
3575 @cindex deduplication
3576 Optimize the store by hard-linking identical files---this is
3577 @dfn{deduplication}.
3579 The daemon performs deduplication after each successful build or archive
3580 import, unless it was started with @code{--disable-deduplication}
3581 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3582 this option is primarily useful when the daemon was running with
3583 @code{--disable-deduplication}.
3587 @node Invoking guix pull
3588 @section Invoking @command{guix pull}
3590 @cindex upgrading Guix
3591 @cindex updating Guix
3592 @cindex @command{guix pull}
3594 Packages are installed or upgraded to the latest version available in
3595 the distribution currently available on your local machine. To update
3596 that distribution, along with the Guix tools, you must run @command{guix
3597 pull}: the command downloads the latest Guix source code and package
3598 descriptions, and deploys it. Source code is downloaded from a
3599 @uref{https://git-scm.com, Git} repository, by default the official
3600 GNU@tie{}Guix repository, though this can be customized.
3602 On completion, @command{guix package} will use packages and package
3603 versions from this just-retrieved copy of Guix. Not only that, but all
3604 the Guix commands and Scheme modules will also be taken from that latest
3605 version. New @command{guix} sub-commands added by the update also
3608 Any user can update their Guix copy using @command{guix pull}, and the
3609 effect is limited to the user who run @command{guix pull}. For
3610 instance, when user @code{root} runs @command{guix pull}, this has no
3611 effect on the version of Guix that user @code{alice} sees, and vice
3614 The result of running @command{guix pull} is a @dfn{profile} available
3615 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3616 make sure to add it to the beginning of your search path so that you use
3617 the latest version, and similarly for the Info manual
3618 (@pxref{Documentation}):
3621 export PATH="$HOME/.config/guix/current/bin:$PATH"
3622 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3625 The @code{--list-generations} or @code{-l} option lists past generations
3626 produced by @command{guix pull}, along with details about their provenance:
3630 Generation 1 Jun 10 2018 00:18:18
3632 repository URL: https://git.savannah.gnu.org/git/guix.git
3633 branch: origin/master
3634 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3636 Generation 2 Jun 11 2018 11:02:49
3638 repository URL: https://git.savannah.gnu.org/git/guix.git
3639 branch: origin/master
3640 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3641 2 new packages: keepalived, libnfnetlink
3642 6 packages upgraded: emacs-nix-mode@@2.0.4,
3643 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3644 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3646 Generation 3 Jun 13 2018 23:31:07 (current)
3648 repository URL: https://git.savannah.gnu.org/git/guix.git
3649 branch: origin/master
3650 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3651 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3652 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3655 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3656 describe the current status of Guix.
3658 This @code{~/.config/guix/current} profile works like any other profile
3659 created by @command{guix package} (@pxref{Invoking guix package}). That
3660 is, you can list generations, roll back to the previous
3661 generation---i.e., the previous Guix---and so on:
3664 $ guix package -p ~/.config/guix/current --roll-back
3665 switched from generation 3 to 2
3666 $ guix package -p ~/.config/guix/current --delete-generations=1
3667 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3670 The @command{guix pull} command is usually invoked with no arguments,
3671 but it supports the following options:
3674 @item --url=@var{url}
3675 @itemx --commit=@var{commit}
3676 @itemx --branch=@var{branch}
3677 Download code for the @code{guix} channel from the specified @var{url}, at the
3678 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3679 string), or @var{branch}.
3681 @cindex @file{channels.scm}, configuration file
3682 @cindex configuration file for channels
3683 These options are provided for convenience, but you can also specify your
3684 configuration in the @file{~/.config/guix/channels.scm} file or using the
3685 @option{--channels} option (see below).
3687 @item --channels=@var{file}
3688 @itemx -C @var{file}
3689 Read the list of channels from @var{file} instead of
3690 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3691 evaluates to a list of channel objects. @xref{Channels}, for more
3696 Display the list of packages added or upgraded since the previous generation.
3698 This is the same information as displayed upon @command{guix pull} completion,
3699 but without ellipses; it is also similar to the output of @command{guix pull
3700 -l} for the last generation (see below).
3702 @item --list-generations[=@var{pattern}]
3703 @itemx -l [@var{pattern}]
3704 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3705 is provided, the subset of generations that match @var{pattern}.
3706 The syntax of @var{pattern} is the same as with @code{guix package
3707 --list-generations} (@pxref{Invoking guix package}).
3709 @xref{Invoking guix describe}, for a way to display information about the
3710 current generation only.
3712 @item --profile=@var{profile}
3713 @itemx -p @var{profile}
3714 Use @var{profile} instead of @file{~/.config/guix/current}.
3718 Show which channel commit(s) would be used and what would be built or
3719 substituted but do not actually do it.
3721 @item --system=@var{system}
3722 @itemx -s @var{system}
3723 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3724 the system type of the build host.
3727 Produce verbose output, writing build logs to the standard error output.
3730 Use the bootstrap Guile to build the latest Guix. This option is only
3731 useful to Guix developers.
3734 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3735 repository and branch to pull from, as well as @emph{additional} repositories
3736 containing package modules that should be deployed. @xref{Channels}, for more
3739 In addition, @command{guix pull} supports all the common build options
3740 (@pxref{Common Build Options}).
3746 @cindex @file{channels.scm}, configuration file
3747 @cindex configuration file for channels
3748 @cindex @command{guix pull}, configuration file
3749 @cindex configuration of @command{guix pull}
3750 Guix and its package collection are updated by running @command{guix pull}
3751 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3752 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3753 customized by defining @dfn{channels} in the
3754 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3755 of a Git repository to be deployed, and @command{guix pull} can be instructed
3756 to pull from one or more channels. In other words, channels can be used to
3757 @emph{customize} and to @emph{extend} Guix, as we will see below.
3759 @subsection Using a Custom Guix Channel
3761 The channel called @code{guix} specifies where Guix itself---its command-line
3762 tools as well as its package collection---should be downloaded. For instance,
3763 suppose you want to update from your own copy of the Guix repository at
3764 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3765 write in @code{~/.config/guix/channels.scm} this specification:
3768 ;; Tell 'guix pull' to use my own repo.
3771 (url "https://example.org/my-guix.git")
3772 (branch "super-hacks")))
3776 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3777 branch of the repository at @code{example.org}.
3779 @subsection Specifying Additional Channels
3781 @cindex extending the package collection (channels)
3782 @cindex personal packages (channels)
3783 @cindex channels, for personal packages
3784 You can also specify @emph{additional channels} to pull from. Let's say you
3785 have a bunch of custom package variants or personal packages that you think
3786 would make little sense to contribute to the Guix project, but would like to
3787 have these packages transparently available to you at the command line. You
3788 would first write modules containing those package definitions (@pxref{Package
3789 Modules}), maintain them in a Git repository, and then you and anyone else can
3790 use it as an additional channel to get packages from. Neat, no?
3792 @c What follows stems from discussions at
3793 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3794 @c earlier discussions on guix-devel@gnu.org.
3796 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3797 publish your personal channel to the world, we would like to share a few words
3802 Before publishing a channel, please consider contributing your package
3803 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3804 to free software of all sorts, and packages in Guix proper are readily
3805 available to all Guix users and benefit from the project's quality assurance
3809 When you maintain package definitions outside Guix, we, Guix developers,
3810 consider that @emph{the compatibility burden is on you}. Remember that
3811 package modules and package definitions are just Scheme code that uses various
3812 programming interfaces (APIs). We want to remain free to change these APIs to
3813 keep improving Guix, possibly in ways that break your channel. We never
3814 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3818 Corollary: if you're using an external channel and that channel breaks, please
3819 @emph{report the issue to the channel authors}, not to the Guix project.
3822 You've been warned! Having said this, we believe external channels are a
3823 practical way to exert your freedom to augment Guix' package collection and to
3824 share your improvements, which are basic tenets of
3825 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3826 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3829 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3830 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3833 @vindex %default-channels
3835 ;; Add my personal packages to those Guix provides.
3837 (name 'my-personal-packages)
3838 (url "https://example.org/personal-packages.git"))
3843 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3844 add a channel the list of channels that the variable @code{%default-channels}
3845 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3846 Manual}). With this file in place, @command{guix pull} builds not only Guix
3847 but also the package modules from your own repository. The result in
3848 @file{~/.config/guix/current} is the union of Guix with your own package
3852 $ guix pull --list-generations
3854 Generation 19 Aug 27 2018 16:20:48
3856 repository URL: https://git.savannah.gnu.org/git/guix.git
3858 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3859 my-personal-packages dd3df5e
3860 repository URL: https://example.org/personal-packages.git
3862 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3863 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3864 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3868 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3869 both Guix and packages from the @code{my-personal-packages} channel. Among
3870 the new and upgraded packages that are listed, some like @code{my-gimp} and
3871 @code{my-emacs-with-cool-features} might come from
3872 @code{my-personal-packages}, while others come from the Guix default channel.
3874 To create a channel, create a Git repository containing your own package
3875 modules and make it available. The repository can contain anything, but a
3876 useful channel will contain Guile modules that export packages. Once you
3877 start using a channel, Guix will behave as if the root directory of that
3878 channel's Git repository has been added to the Guile load path (@pxref{Load
3879 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3880 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3881 module, then the module will be available under the name @code{(my-packages
3882 my-tools)}, and you will be able to use it like any other module
3883 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3885 @cindex dependencies, channels
3886 @cindex meta-data, channels
3887 @subsection Declaring Channel Dependencies
3889 Channel authors may decide to augment a package collection provided by other
3890 channels. They can declare their channel to be dependent on other channels in
3891 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3892 the channel repository.
3894 The meta-data file should contain a simple S-expression like this:
3901 (name some-collection)
3902 (url "https://example.org/first-collection.git"))
3904 (name some-other-collection)
3905 (url "https://example.org/second-collection.git")
3906 (branch "testing"))))
3909 In the above example this channel is declared to depend on two other channels,
3910 which will both be fetched automatically. The modules provided by the channel
3911 will be compiled in an environment where the modules of all these declared
3912 channels are available.
3914 For the sake of reliability and maintainability, you should avoid dependencies
3915 on channels that you don't control, and you should aim to keep the number of
3916 dependencies to a minimum.
3918 @subsection Replicating Guix
3920 @cindex pinning, channels
3921 @cindex replicating Guix
3922 @cindex reproducibility, of Guix
3923 The @command{guix pull --list-generations} output above shows precisely which
3924 commits were used to build this instance of Guix. We can thus replicate it,
3925 say, on another machine, by providing a channel specification in
3926 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3929 ;; Deploy specific commits of my channels of interest.
3932 (url "https://git.savannah.gnu.org/git/guix.git")
3933 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3935 (name 'my-personal-packages)
3936 (url "https://example.org/personal-packages.git")
3937 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3940 The @command{guix describe --format=channels} command can even generate this
3941 list of channels directly (@pxref{Invoking guix describe}).
3943 At this point the two machines run the @emph{exact same Guix}, with access to
3944 the @emph{exact same packages}. The output of @command{guix build gimp} on
3945 one machine will be exactly the same, bit for bit, as the output of the same
3946 command on the other machine. It also means both machines have access to all
3947 the source code of Guix and, transitively, to all the source code of every
3950 This gives you super powers, allowing you to track the provenance of binary
3951 artifacts with very fine grain, and to reproduce software environments at
3952 will---some sort of ``meta reproducibility'' capabilities, if you will.
3953 @xref{Inferiors}, for another way to take advantage of these super powers.
3958 @c TODO: Remove this once we're more confident about API stability.
3960 The functionality described here is a ``technology preview'' as of version
3961 @value{VERSION}. As such, the interface is subject to change.
3965 @cindex composition of Guix revisions
3966 Sometimes you might need to mix packages from the revision of Guix you're
3967 currently running with packages available in a different revision of Guix.
3968 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3969 revisions in arbitrary ways.
3971 @cindex inferior packages
3972 Technically, an ``inferior'' is essentially a separate Guix process connected
3973 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3974 @code{(guix inferior)} module allows you to create inferiors and to
3975 communicate with them. It also provides a high-level interface to browse and
3976 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3978 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3979 to interact with a separate revision of Guix. For example, let's assume you
3980 want to install in your profile the current @code{guile} package, along with
3981 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3982 because the newer @code{guile-json} has an incompatible API and you want to
3983 run your code against the old API@. To do that, you could write a manifest for
3984 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3985 manifest, you would create an inferior for that old Guix revision you care
3986 about, and you would look up the @code{guile-json} package in the inferior:
3989 (use-modules (guix inferior) (guix channels)
3990 (srfi srfi-1)) ;for 'first'
3993 ;; This is the old revision from which we want to
3994 ;; extract guile-json.
3997 (url "https://git.savannah.gnu.org/git/guix.git")
3999 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4002 ;; An inferior representing the above revision.
4003 (inferior-for-channels channels))
4005 ;; Now create a manifest with the current "guile" package
4006 ;; and the old "guile-json" package.
4008 (list (first (lookup-inferior-packages inferior "guile-json"))
4009 (specification->package "guile")))
4012 On its first run, @command{guix package --manifest} might have to build the
4013 channel you specified before it can create the inferior; subsequent runs will
4014 be much faster because the Guix revision will be cached.
4016 The @code{(guix inferior)} module provides the following procedures to open an
4019 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4020 [#:cache-directory] [#:ttl]
4021 Return an inferior for @var{channels}, a list of channels. Use the cache at
4022 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4023 This procedure opens a new connection to the build daemon.
4025 As a side effect, this procedure may build or substitute binaries for
4026 @var{channels}, which can take time.
4029 @deffn {Scheme Procedure} open-inferior @var{directory} @
4030 [#:command "bin/guix"]
4031 Open the inferior Guix in @var{directory}, running
4032 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4033 the inferior could not be launched.
4036 @cindex inferior packages
4037 The procedures listed below allow you to obtain and manipulate inferior
4040 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4041 Return the list of packages known to @var{inferior}.
4044 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4046 Return the sorted list of inferior packages matching @var{name} in
4047 @var{inferior}, with highest version numbers first. If @var{version} is true,
4048 return only packages with a version number prefixed by @var{version}.
4051 @deffn {Scheme Procedure} inferior-package? @var{obj}
4052 Return true if @var{obj} is an inferior package.
4055 @deffn {Scheme Procedure} inferior-package-name @var{package}
4056 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4057 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4058 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4059 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4060 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4061 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4062 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4063 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4064 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4065 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4066 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4067 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4068 These procedures are the counterpart of package record accessors
4069 (@pxref{package Reference}). Most of them work by querying the inferior
4070 @var{package} comes from, so the inferior must still be live when you call
4074 Inferior packages can be used transparently like any other package or
4075 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4076 transparently handled by the @code{packages->manifest} procedure, which is
4077 commonly use in manifests (@pxref{Invoking guix package, the
4078 @option{--manifest} option of @command{guix package}}). Thus you can insert
4079 an inferior package pretty much anywhere you would insert a regular package:
4080 in manifests, in the @code{packages} field of your @code{operating-system}
4081 declaration, and so on.
4083 @node Invoking guix describe
4084 @section Invoking @command{guix describe}
4086 @cindex reproducibility
4087 @cindex replicating Guix
4088 Often you may want to answer questions like: ``Which revision of Guix am I
4089 using?'' or ``Which channels am I using?'' This is useful information in many
4090 situations: if you want to @emph{replicate} an environment on a different
4091 machine or user account, if you want to report a bug or to determine what
4092 change in the channels you are using caused it, or if you want to record your
4093 system state for reproducibility purposes. The @command{guix describe}
4094 command answers these questions.
4096 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4097 displays the channel(s) that it was built from, including their repository URL
4098 and commit IDs (@pxref{Channels}):
4102 Generation 10 Sep 03 2018 17:32:44 (current)
4104 repository URL: https://git.savannah.gnu.org/git/guix.git
4106 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4109 If you're familiar with the Git version control system, this is similar in
4110 spirit to @command{git describe}; the output is also similar to that of
4111 @command{guix pull --list-generations}, but limited to the current generation
4112 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4113 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4114 information is all it takes to describe the revision of Guix you're using, and
4115 also to replicate it.
4117 To make it easier to replicate Guix, @command{guix describe} can also be asked
4118 to return a list of channels instead of the human-readable description above:
4121 $ guix describe -f channels
4124 (url "https://git.savannah.gnu.org/git/guix.git")
4126 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4130 You can save this to a file and feed it to @command{guix pull -C} on some
4131 other machine or at a later point in time, which will instantiate @emph{this
4132 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4133 From there on, since you're able to deploy the same revision of Guix, you can
4134 just as well @emph{replicate a complete software environment}. We humbly
4135 think that this is @emph{awesome}, and we hope you'll like it too!
4137 The details of the options supported by @command{guix describe} are as
4141 @item --format=@var{format}
4142 @itemx -f @var{format}
4143 Produce output in the specified @var{format}, one of:
4147 produce human-readable output;
4149 produce a list of channel specifications that can be passed to @command{guix
4150 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4154 produce a list of channel specifications in JSON format;
4156 produce a list of channel specifications in Recutils format.
4159 @item --profile=@var{profile}
4160 @itemx -p @var{profile}
4161 Display information about @var{profile}.
4164 @node Invoking guix archive
4165 @section Invoking @command{guix archive}
4167 @cindex @command{guix archive}
4169 The @command{guix archive} command allows users to @dfn{export} files
4170 from the store into a single archive, and to later @dfn{import} them on
4171 a machine that runs Guix.
4172 In particular, it allows store files to be transferred from one machine
4173 to the store on another machine.
4176 If you're looking for a way to produce archives in a format suitable for
4177 tools other than Guix, @pxref{Invoking guix pack}.
4180 @cindex exporting store items
4181 To export store files as an archive to standard output, run:
4184 guix archive --export @var{options} @var{specifications}...
4187 @var{specifications} may be either store file names or package
4188 specifications, as for @command{guix package} (@pxref{Invoking guix
4189 package}). For instance, the following command creates an archive
4190 containing the @code{gui} output of the @code{git} package and the main
4191 output of @code{emacs}:
4194 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4197 If the specified packages are not built yet, @command{guix archive}
4198 automatically builds them. The build process may be controlled with the
4199 common build options (@pxref{Common Build Options}).
4201 To transfer the @code{emacs} package to a machine connected over SSH,
4205 guix archive --export -r emacs | ssh the-machine guix archive --import
4209 Similarly, a complete user profile may be transferred from one machine
4210 to another like this:
4213 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4214 ssh the-machine guix-archive --import
4218 However, note that, in both examples, all of @code{emacs} and the
4219 profile as well as all of their dependencies are transferred (due to
4220 @code{-r}), regardless of what is already available in the store on the
4221 target machine. The @code{--missing} option can help figure out which
4222 items are missing from the target store. The @command{guix copy}
4223 command simplifies and optimizes this whole process, so this is probably
4224 what you should use in this case (@pxref{Invoking guix copy}).
4226 @cindex nar, archive format
4227 @cindex normalized archive (nar)
4228 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4229 comparable in spirit to `tar', but with differences
4230 that make it more appropriate for our purposes. First, rather than
4231 recording all Unix metadata for each file, the nar format only mentions
4232 the file type (regular, directory, or symbolic link); Unix permissions
4233 and owner/group are dismissed. Second, the order in which directory
4234 entries are stored always follows the order of file names according to
4235 the C locale collation order. This makes archive production fully
4238 When exporting, the daemon digitally signs the contents of the archive,
4239 and that digital signature is appended. When importing, the daemon
4240 verifies the signature and rejects the import in case of an invalid
4241 signature or if the signing key is not authorized.
4242 @c FIXME: Add xref to daemon doc about signatures.
4244 The main options are:
4248 Export the specified store files or packages (see below.) Write the
4249 resulting archive to the standard output.
4251 Dependencies are @emph{not} included in the output, unless
4252 @code{--recursive} is passed.
4256 When combined with @code{--export}, this instructs @command{guix
4257 archive} to include dependencies of the given items in the archive.
4258 Thus, the resulting archive is self-contained: it contains the closure
4259 of the exported store items.
4262 Read an archive from the standard input, and import the files listed
4263 therein into the store. Abort if the archive has an invalid digital
4264 signature, or if it is signed by a public key not among the authorized
4265 keys (see @code{--authorize} below.)
4268 Read a list of store file names from the standard input, one per line,
4269 and write on the standard output the subset of these files missing from
4272 @item --generate-key[=@var{parameters}]
4273 @cindex signing, archives
4274 Generate a new key pair for the daemon. This is a prerequisite before
4275 archives can be exported with @code{--export}. Note that this operation
4276 usually takes time, because it needs to gather enough entropy to
4277 generate the key pair.
4279 The generated key pair is typically stored under @file{/etc/guix}, in
4280 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4281 key, which must be kept secret.) When @var{parameters} is omitted,
4282 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4283 versions before 1.6.0, it is a 4096-bit RSA key.
4284 Alternatively, @var{parameters} can specify
4285 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4286 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4287 Libgcrypt Reference Manual}).
4290 @cindex authorizing, archives
4291 Authorize imports signed by the public key passed on standard input.
4292 The public key must be in ``s-expression advanced format''---i.e., the
4293 same format as the @file{signing-key.pub} file.
4295 The list of authorized keys is kept in the human-editable file
4296 @file{/etc/guix/acl}. The file contains
4297 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4298 s-expressions''} and is structured as an access-control list in the
4299 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4302 @item --extract=@var{directory}
4303 @itemx -x @var{directory}
4304 Read a single-item archive as served by substitute servers
4305 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4306 low-level operation needed in only very narrow use cases; see below.
4308 For example, the following command extracts the substitute for Emacs
4309 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4313 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4314 | bunzip2 | guix archive -x /tmp/emacs
4317 Single-item archives are different from multiple-item archives produced
4318 by @command{guix archive --export}; they contain a single store item,
4319 and they do @emph{not} embed a signature. Thus this operation does
4320 @emph{no} signature verification and its output should be considered
4323 The primary purpose of this operation is to facilitate inspection of
4324 archive contents coming from possibly untrusted substitute servers.
4329 @c *********************************************************************
4331 @chapter Development
4333 @cindex software development
4334 If you are a software developer, Guix provides tools that you should find
4335 helpful---independently of the language you're developing in. This is what
4336 this chapter is about.
4338 The @command{guix environment} command provides a convenient way to set up
4339 @dfn{development environments} containing all the dependencies and tools
4340 necessary to work on the software package of your choice. The @command{guix
4341 pack} command allows you to create @dfn{application bundles} that can be
4342 easily distributed to users who do not run Guix.
4345 * Invoking guix environment:: Setting up development environments.
4346 * Invoking guix pack:: Creating software bundles.
4349 @node Invoking guix environment
4350 @section Invoking @command{guix environment}
4352 @cindex reproducible build environments
4353 @cindex development environments
4354 @cindex @command{guix environment}
4355 @cindex environment, package build environment
4356 The purpose of @command{guix environment} is to assist hackers in
4357 creating reproducible development environments without polluting their
4358 package profile. The @command{guix environment} tool takes one or more
4359 packages, builds all of their inputs, and creates a shell
4360 environment to use them.
4362 The general syntax is:
4365 guix environment @var{options} @var{package}@dots{}
4368 The following example spawns a new shell set up for the development of
4372 guix environment guile
4375 If the needed dependencies are not built yet, @command{guix environment}
4376 automatically builds them. The environment of the new shell is an augmented
4377 version of the environment that @command{guix environment} was run in.
4378 It contains the necessary search paths for building the given package
4379 added to the existing environment variables. To create a ``pure''
4380 environment, in which the original environment variables have been unset,
4381 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4382 environment variables such as @code{PATH} in their @file{~/.bashrc}
4383 file. As a consequence, when @code{guix environment} launches it, Bash
4384 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4385 environment variables. It is an error to define such environment
4386 variables in @file{.bashrc}; instead, they should be defined in
4387 @file{.bash_profile}, which is sourced only by log-in shells.
4388 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4389 details on Bash start-up files.}.
4391 @vindex GUIX_ENVIRONMENT
4392 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4393 variable in the shell it spawns; its value is the file name of the
4394 profile of this environment. This allows users to, say, define a
4395 specific prompt for development environments in their @file{.bashrc}
4396 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4399 if [ -n "$GUIX_ENVIRONMENT" ]
4401 export PS1="\u@@\h \w [dev]\$ "
4406 ...@: or to browse the profile:
4409 $ ls "$GUIX_ENVIRONMENT/bin"
4412 Additionally, more than one package may be specified, in which case the
4413 union of the inputs for the given packages are used. For example, the
4414 command below spawns a shell where all of the dependencies of both Guile
4415 and Emacs are available:
4418 guix environment guile emacs
4421 Sometimes an interactive shell session is not desired. An arbitrary
4422 command may be invoked by placing the @code{--} token to separate the
4423 command from the rest of the arguments:
4426 guix environment guile -- make -j4
4429 In other situations, it is more convenient to specify the list of
4430 packages needed in the environment. For example, the following command
4431 runs @command{python} from an environment containing Python@tie{}2.7 and
4435 guix environment --ad-hoc python2-numpy python-2.7 -- python
4438 Furthermore, one might want the dependencies of a package and also some
4439 additional packages that are not build-time or runtime dependencies, but
4440 are useful when developing nonetheless. Because of this, the
4441 @code{--ad-hoc} flag is positional. Packages appearing before
4442 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4443 added to the environment. Packages appearing after are interpreted as
4444 packages that will be added to the environment directly. For example,
4445 the following command creates a Guix development environment that
4446 additionally includes Git and strace:
4449 guix environment guix --ad-hoc git strace
4452 Sometimes it is desirable to isolate the environment as much as
4453 possible, for maximal purity and reproducibility. In particular, when
4454 using Guix on a host distro that is not Guix System, it is desirable to
4455 prevent access to @file{/usr/bin} and other system-wide resources from
4456 the development environment. For example, the following command spawns
4457 a Guile REPL in a ``container'' where only the store and the current
4458 working directory are mounted:
4461 guix environment --ad-hoc --container guile -- guile
4465 The @code{--container} option requires Linux-libre 3.19 or newer.
4468 The available options are summarized below.
4471 @item --root=@var{file}
4472 @itemx -r @var{file}
4473 @cindex persistent environment
4474 @cindex garbage collector root, for environments
4475 Make @var{file} a symlink to the profile for this environment, and
4476 register it as a garbage collector root.
4478 This is useful if you want to protect your environment from garbage
4479 collection, to make it ``persistent''.
4481 When this option is omitted, the environment is protected from garbage
4482 collection only for the duration of the @command{guix environment}
4483 session. This means that next time you recreate the same environment,
4484 you could have to rebuild or re-download packages. @xref{Invoking guix
4485 gc}, for more on GC roots.
4487 @item --expression=@var{expr}
4488 @itemx -e @var{expr}
4489 Create an environment for the package or list of packages that
4490 @var{expr} evaluates to.
4492 For example, running:
4495 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4498 starts a shell with the environment for this specific variant of the
4504 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4507 starts a shell with all the base system packages available.
4509 The above commands only use the default output of the given packages.
4510 To select other outputs, two element tuples can be specified:
4513 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4516 @item --load=@var{file}
4517 @itemx -l @var{file}
4518 Create an environment for the package or list of packages that the code
4519 within @var{file} evaluates to.
4521 As an example, @var{file} might contain a definition like this
4522 (@pxref{Defining Packages}):
4525 @verbatiminclude environment-gdb.scm
4528 @item --manifest=@var{file}
4529 @itemx -m @var{file}
4530 Create an environment for the packages contained in the manifest object
4531 returned by the Scheme code in @var{file}.
4533 This is similar to the same-named option in @command{guix package}
4534 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4538 Include all specified packages in the resulting environment, as if an
4539 @i{ad hoc} package were defined with them as inputs. This option is
4540 useful for quickly creating an environment without having to write a
4541 package expression to contain the desired inputs.
4543 For instance, the command:
4546 guix environment --ad-hoc guile guile-sdl -- guile
4549 runs @command{guile} in an environment where Guile and Guile-SDL are
4552 Note that this example implicitly asks for the default output of
4553 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4554 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4555 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4557 This option may be composed with the default behavior of @command{guix
4558 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4559 as packages whose dependencies will be added to the environment, the
4560 default behavior. Packages appearing after are interpreted as packages
4561 that will be added to the environment directly.
4564 Unset existing environment variables when building the new environment, except
4565 those specified with @option{--preserve} (see below.) This has the effect of
4566 creating an environment in which search paths only contain package inputs.
4568 @item --preserve=@var{regexp}
4569 @itemx -E @var{regexp}
4570 When used alongside @option{--pure}, preserve the environment variables
4571 matching @var{regexp}---in other words, put them on a ``white list'' of
4572 environment variables that must be preserved. This option can be repeated
4576 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4580 This example runs @command{mpirun} in a context where the only environment
4581 variables defined are @code{PATH}, environment variables whose name starts
4582 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4585 @item --search-paths
4586 Display the environment variable definitions that make up the
4589 @item --system=@var{system}
4590 @itemx -s @var{system}
4591 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4596 Run @var{command} within an isolated container. The current working
4597 directory outside the container is mapped inside the container.
4598 Additionally, unless overridden with @code{--user}, a dummy home
4599 directory is created that matches the current user's home directory, and
4600 @file{/etc/passwd} is configured accordingly.
4602 The spawned process runs as the current user outside the container. Inside
4603 the container, it has the same UID and GID as the current user, unless
4604 @option{--user} is passed (see below.)
4608 For containers, share the network namespace with the host system.
4609 Containers created without this flag only have access to the loopback
4612 @item --link-profile
4614 For containers, link the environment profile to
4615 @file{~/.guix-profile} within the container. This is equivalent to
4616 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4617 within the container. Linking will fail and abort the environment if
4618 the directory already exists, which will certainly be the case if
4619 @command{guix environment} was invoked in the user's home directory.
4621 Certain packages are configured to look in
4622 @code{~/.guix-profile} for configuration files and data;@footnote{For
4623 example, the @code{fontconfig} package inspects
4624 @file{~/.guix-profile/share/fonts} for additional fonts.}
4625 @code{--link-profile} allows these programs to behave as expected within
4628 @item --user=@var{user}
4629 @itemx -u @var{user}
4630 For containers, use the username @var{user} in place of the current
4631 user. The generated @file{/etc/passwd} entry within the container will
4632 contain the name @var{user}, the home directory will be
4633 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4634 the UID and GID inside the container are 1000. @var{user}
4635 need not exist on the system.
4637 Additionally, any shared or exposed path (see @code{--share} and
4638 @code{--expose} respectively) whose target is within the current user's
4639 home directory will be remapped relative to @file{/home/USER}; this
4640 includes the automatic mapping of the current working directory.
4643 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4645 guix environment --container --user=foo \
4646 --expose=$HOME/test \
4647 --expose=/tmp/target=$HOME/target
4650 While this will limit the leaking of user identity through home paths
4651 and each of the user fields, this is only one useful component of a
4652 broader privacy/anonymity solution---not one in and of itself.
4654 @item --expose=@var{source}[=@var{target}]
4655 For containers, expose the file system @var{source} from the host system
4656 as the read-only file system @var{target} within the container. If
4657 @var{target} is not specified, @var{source} is used as the target mount
4658 point in the container.
4660 The example below spawns a Guile REPL in a container in which the user's
4661 home directory is accessible read-only via the @file{/exchange}
4665 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4668 @item --share=@var{source}[=@var{target}]
4669 For containers, share the file system @var{source} from the host system
4670 as the writable file system @var{target} within the container. If
4671 @var{target} is not specified, @var{source} is used as the target mount
4672 point in the container.
4674 The example below spawns a Guile REPL in a container in which the user's
4675 home directory is accessible for both reading and writing via the
4676 @file{/exchange} directory:
4679 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4683 @command{guix environment}
4684 also supports all of the common build options that @command{guix
4685 build} supports (@pxref{Common Build Options}) as well as package
4686 transformation options (@pxref{Package Transformation Options}).
4688 @node Invoking guix pack
4689 @section Invoking @command{guix pack}
4691 Occasionally you want to pass software to people who are not (yet!)
4692 lucky enough to be using Guix. You'd tell them to run @command{guix
4693 package -i @var{something}}, but that's not possible in this case. This
4694 is where @command{guix pack} comes in.
4697 If you are looking for ways to exchange binaries among machines that
4698 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4699 publish}, and @ref{Invoking guix archive}.
4704 @cindex application bundle
4705 @cindex software bundle
4706 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4707 @dfn{software bundle}: it creates a tarball or some other archive
4708 containing the binaries of the software you're interested in, and all
4709 its dependencies. The resulting archive can be used on any machine that
4710 does not have Guix, and people can run the exact same binaries as those
4711 you have with Guix. The pack itself is created in a bit-reproducible
4712 fashion, so anyone can verify that it really contains the build results
4713 that you pretend to be shipping.
4715 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4716 their dependencies, you can run:
4719 $ guix pack guile emacs geiser
4721 /gnu/store/@dots{}-pack.tar.gz
4724 The result here is a tarball containing a @file{/gnu/store} directory
4725 with all the relevant packages. The resulting tarball contains a
4726 @dfn{profile} with the three packages of interest; the profile is the
4727 same as would be created by @command{guix package -i}. It is this
4728 mechanism that is used to create Guix's own standalone binary tarball
4729 (@pxref{Binary Installation}).
4731 Users of this pack would have to run
4732 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4733 find inconvenient. To work around it, you can create, say, a
4734 @file{/opt/gnu/bin} symlink to the profile:
4737 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4741 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4743 @cindex relocatable binaries, with @command{guix pack}
4744 What if the recipient of your pack does not have root privileges on
4745 their machine, and thus cannot unpack it in the root file system? In
4746 that case, you will want to use the @code{--relocatable} option (see
4747 below). This option produces @dfn{relocatable binaries}, meaning they
4748 they can be placed anywhere in the file system hierarchy: in the example
4749 above, users can unpack your tarball in their home directory and
4750 directly run @file{./opt/gnu/bin/guile}.
4752 @cindex Docker, build an image with guix pack
4753 Alternatively, you can produce a pack in the Docker image format using
4754 the following command:
4757 guix pack -f docker guile emacs geiser
4761 The result is a tarball that can be passed to the @command{docker load}
4763 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4764 documentation} for more information.
4766 @cindex Singularity, build an image with guix pack
4767 @cindex SquashFS, build an image with guix pack
4768 Yet another option is to produce a SquashFS image with the following
4772 guix pack -f squashfs guile emacs geiser
4776 The result is a SquashFS file system image that can either be mounted or
4777 directly be used as a file system container image with the
4778 @uref{http://singularity.lbl.gov, Singularity container execution
4779 environment}, using commands like @command{singularity shell} or
4780 @command{singularity exec}.
4782 Several command-line options allow you to customize your pack:
4785 @item --format=@var{format}
4786 @itemx -f @var{format}
4787 Produce a pack in the given @var{format}.
4789 The available formats are:
4793 This is the default format. It produces a tarball containing all the
4794 specified binaries and symlinks.
4797 This produces a tarball that follows the
4798 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4799 Docker Image Specification}.
4802 This produces a SquashFS image containing all the specified binaries and
4803 symlinks, as well as empty mount points for virtual file systems like
4807 @cindex relocatable binaries
4810 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4811 anywhere in the file system hierarchy and run from there.
4813 When this option is passed once, the resulting binaries require support for
4814 @dfn{user namespaces} in the kernel Linux; when passed
4815 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4816 PRoot support, can be thought of as the abbreviation of ``Really
4817 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4818 if user namespaces are unavailable, and essentially work anywhere---see below
4819 for the implications.
4821 For example, if you create a pack containing Bash with:
4824 guix pack -RR -S /mybin=bin bash
4828 ...@: you can copy that pack to a machine that lacks Guix, and from your
4829 home directory as a normal user, run:
4837 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4838 @file{/gnu/store} shows up and contains all the dependencies of
4839 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4840 altogether! That is probably the simplest way to deploy Guix-built
4841 software on a non-Guix machine.
4844 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4845 the kernel Linux, which allows unprivileged users to mount or change root.
4846 Old versions of Linux did not support it, and some GNU/Linux distributions
4849 To produce relocatable binaries that work even in the absence of user
4850 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4851 case, binaries will try user namespace support and fall back to PRoot if user
4852 namespaces are not supported.
4854 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4855 support for file system virtualization. It achieves that by using the
4856 @code{ptrace} system call on the running program. This approach has the
4857 advantage to work without requiring special kernel support, but it incurs
4858 run-time overhead every time a system call is made.
4861 @item --expression=@var{expr}
4862 @itemx -e @var{expr}
4863 Consider the package @var{expr} evaluates to.
4865 This has the same purpose as the same-named option in @command{guix
4866 build} (@pxref{Additional Build Options, @code{--expression} in
4867 @command{guix build}}).
4869 @item --manifest=@var{file}
4870 @itemx -m @var{file}
4871 Use the packages contained in the manifest object returned by the Scheme
4874 This has a similar purpose as the same-named option in @command{guix
4875 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4876 same manifest files. It allows you to define a collection of packages
4877 once and use it both for creating profiles and for creating archives
4878 for use on machines that do not have Guix installed. Note that you can
4879 specify @emph{either} a manifest file @emph{or} a list of packages,
4882 @item --system=@var{system}
4883 @itemx -s @var{system}
4884 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4885 the system type of the build host.
4887 @item --target=@var{triplet}
4888 @cindex cross-compilation
4889 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4890 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4891 configuration triplets,, autoconf, Autoconf}).
4893 @item --compression=@var{tool}
4894 @itemx -C @var{tool}
4895 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4896 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4898 @item --symlink=@var{spec}
4899 @itemx -S @var{spec}
4900 Add the symlinks specified by @var{spec} to the pack. This option can
4901 appear several times.
4903 @var{spec} has the form @code{@var{source}=@var{target}}, where
4904 @var{source} is the symlink that will be created and @var{target} is the
4907 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4908 symlink pointing to the @file{bin} sub-directory of the profile.
4910 @item --save-provenance
4911 Save provenance information for the packages passed on the command line.
4912 Provenance information includes the URL and commit of the channels in use
4915 Provenance information is saved in the
4916 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4917 usual package metadata---the name and version of each package, their
4918 propagated inputs, and so on. It is useful information to the recipient of
4919 the pack, who then knows how the pack was (supposedly) obtained.
4921 This option is not enabled by default because, like timestamps, provenance
4922 information contributes nothing to the build process. In other words, there
4923 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4924 Recording such ``silent'' metadata in the output thus potentially breaks the
4925 source-to-binary bitwise reproducibility property.
4927 @item --localstatedir
4928 @itemx --profile-name=@var{name}
4929 Include the ``local state directory'', @file{/var/guix}, in the resulting
4930 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4931 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4932 @file{~root/.guix-profile}.
4934 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4935 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4936 the pack means that the store is ``complete'' and manageable by Guix;
4937 not providing it pack means that the store is ``dead'': items cannot be
4938 added to it or removed from it after extraction of the pack.
4940 One use case for this is the Guix self-contained binary tarball
4941 (@pxref{Binary Installation}).
4944 Use the bootstrap binaries to build the pack. This option is only
4945 useful to Guix developers.
4948 In addition, @command{guix pack} supports all the common build options
4949 (@pxref{Common Build Options}) and all the package transformation
4950 options (@pxref{Package Transformation Options}).
4953 @c *********************************************************************
4954 @node Programming Interface
4955 @chapter Programming Interface
4957 GNU Guix provides several Scheme programming interfaces (APIs) to
4958 define, build, and query packages. The first interface allows users to
4959 write high-level package definitions. These definitions refer to
4960 familiar packaging concepts, such as the name and version of a package,
4961 its build system, and its dependencies. These definitions can then be
4962 turned into concrete build actions.
4964 Build actions are performed by the Guix daemon, on behalf of users. In a
4965 standard setup, the daemon has write access to the store---the
4966 @file{/gnu/store} directory---whereas users do not. The recommended
4967 setup also has the daemon perform builds in chroots, under a specific
4968 build users, to minimize interference with the rest of the system.
4971 Lower-level APIs are available to interact with the daemon and the
4972 store. To instruct the daemon to perform a build action, users actually
4973 provide it with a @dfn{derivation}. A derivation is a low-level
4974 representation of the build actions to be taken, and the environment in
4975 which they should occur---derivations are to package definitions what
4976 assembly is to C programs. The term ``derivation'' comes from the fact
4977 that build results @emph{derive} from them.
4979 This chapter describes all these APIs in turn, starting from high-level
4980 package definitions.
4983 * Package Modules:: Packages from the programmer's viewpoint.
4984 * Defining Packages:: Defining new packages.
4985 * Build Systems:: Specifying how packages are built.
4986 * The Store:: Manipulating the package store.
4987 * Derivations:: Low-level interface to package derivations.
4988 * The Store Monad:: Purely functional interface to the store.
4989 * G-Expressions:: Manipulating build expressions.
4990 * Invoking guix repl:: Fiddling with Guix interactively.
4993 @node Package Modules
4994 @section Package Modules
4996 From a programming viewpoint, the package definitions of the
4997 GNU distribution are provided by Guile modules in the @code{(gnu packages
4998 @dots{})} name space@footnote{Note that packages under the @code{(gnu
4999 packages @dots{})} module name space are not necessarily ``GNU
5000 packages''. This module naming scheme follows the usual Guile module
5001 naming convention: @code{gnu} means that these modules are distributed
5002 as part of the GNU system, and @code{packages} identifies modules that
5003 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5004 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5005 module exports a variable named @code{emacs}, which is bound to a
5006 @code{<package>} object (@pxref{Defining Packages}).
5008 The @code{(gnu packages @dots{})} module name space is
5009 automatically scanned for packages by the command-line tools. For
5010 instance, when running @code{guix install emacs}, all the @code{(gnu
5011 packages @dots{})} modules are scanned until one that exports a package
5012 object whose name is @code{emacs} is found. This package search
5013 facility is implemented in the @code{(gnu packages)} module.
5015 @cindex customization, of packages
5016 @cindex package module search path
5017 Users can store package definitions in modules with different
5018 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5019 name and module name must match. For instance, the @code{(my-packages
5020 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5021 relative to the load path specified with @option{--load-path} or
5022 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5023 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5024 these package definitions visible to the user interfaces:
5028 By adding the directory containing your package modules to the search path
5029 with the @code{-L} flag of @command{guix package} and other commands
5030 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5031 environment variable described below.
5034 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5035 pulls from it. A channel is essentially a Git repository containing package
5036 modules. @xref{Channels}, for more information on how to define and use
5040 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5042 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5043 This is a colon-separated list of directories to search for additional
5044 package modules. Directories listed in this variable take precedence
5045 over the own modules of the distribution.
5048 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5049 each package is built based solely on other packages in the
5050 distribution. The root of this dependency graph is a small set of
5051 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5052 bootstrap)} module. For more information on bootstrapping,
5053 @pxref{Bootstrapping}.
5055 @node Defining Packages
5056 @section Defining Packages
5058 The high-level interface to package definitions is implemented in the
5059 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5060 example, the package definition, or @dfn{recipe}, for the GNU Hello
5061 package looks like this:
5064 (define-module (gnu packages hello)
5065 #:use-module (guix packages)
5066 #:use-module (guix download)
5067 #:use-module (guix build-system gnu)
5068 #:use-module (guix licenses)
5069 #:use-module (gnu packages gawk))
5071 (define-public hello
5077 (uri (string-append "mirror://gnu/hello/hello-" version
5081 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5082 (build-system gnu-build-system)
5083 (arguments '(#:configure-flags '("--enable-silent-rules")))
5084 (inputs `(("gawk" ,gawk)))
5085 (synopsis "Hello, GNU world: An example GNU package")
5086 (description "Guess what GNU Hello prints!")
5087 (home-page "http://www.gnu.org/software/hello/")
5092 Without being a Scheme expert, the reader may have guessed the meaning
5093 of the various fields here. This expression binds the variable
5094 @code{hello} to a @code{<package>} object, which is essentially a record
5095 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5096 This package object can be inspected using procedures found in the
5097 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5098 returns---surprise!---@code{"hello"}.
5100 With luck, you may be able to import part or all of the definition of
5101 the package you are interested in from another repository, using the
5102 @code{guix import} command (@pxref{Invoking guix import}).
5104 In the example above, @var{hello} is defined in a module of its own,
5105 @code{(gnu packages hello)}. Technically, this is not strictly
5106 necessary, but it is convenient to do so: all the packages defined in
5107 modules under @code{(gnu packages @dots{})} are automatically known to
5108 the command-line tools (@pxref{Package Modules}).
5110 There are a few points worth noting in the above package definition:
5114 The @code{source} field of the package is an @code{<origin>} object
5115 (@pxref{origin Reference}, for the complete reference).
5116 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5117 meaning that the source is a file to be downloaded over FTP or HTTP.
5119 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5120 the GNU mirrors defined in @code{(guix download)}.
5122 The @code{sha256} field specifies the expected SHA256 hash of the file
5123 being downloaded. It is mandatory, and allows Guix to check the
5124 integrity of the file. The @code{(base32 @dots{})} form introduces the
5125 base32 representation of the hash. You can obtain this information with
5126 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5127 hash} (@pxref{Invoking guix hash}).
5130 When needed, the @code{origin} form can also have a @code{patches} field
5131 listing patches to be applied, and a @code{snippet} field giving a
5132 Scheme expression to modify the source code.
5135 @cindex GNU Build System
5136 The @code{build-system} field specifies the procedure to build the
5137 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5138 represents the familiar GNU Build System, where packages may be
5139 configured, built, and installed with the usual @code{./configure &&
5140 make && make check && make install} command sequence.
5143 The @code{arguments} field specifies options for the build system
5144 (@pxref{Build Systems}). Here it is interpreted by
5145 @var{gnu-build-system} as a request run @file{configure} with the
5146 @code{--enable-silent-rules} flag.
5152 What about these quote (@code{'}) characters? They are Scheme syntax to
5153 introduce a literal list; @code{'} is synonymous with @code{quote}.
5154 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5155 for details. Here the value of the @code{arguments} field is a list of
5156 arguments passed to the build system down the road, as with @code{apply}
5157 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5160 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5161 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5162 @code{#:configure-flags} is a keyword used to pass a keyword argument
5163 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5167 The @code{inputs} field specifies inputs to the build process---i.e.,
5168 build-time or run-time dependencies of the package. Here, we define an
5169 input called @code{"gawk"} whose value is that of the @var{gawk}
5170 variable; @var{gawk} is itself bound to a @code{<package>} object.
5172 @cindex backquote (quasiquote)
5175 @cindex comma (unquote)
5179 @findex unquote-splicing
5180 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5181 us to introduce a literal list in the @code{inputs} field, while
5182 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5183 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5186 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5187 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5188 of ensuring that they are present (@pxref{Build Systems}).
5190 However, any other dependencies need to be specified in the
5191 @code{inputs} field. Any dependency not specified here will simply be
5192 unavailable to the build process, possibly leading to a build failure.
5195 @xref{package Reference}, for a full description of possible fields.
5197 Once a package definition is in place, the
5198 package may actually be built using the @code{guix build} command-line
5199 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5200 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5201 package definition using the @command{guix edit} command
5202 (@pxref{Invoking guix edit}).
5203 @xref{Packaging Guidelines}, for
5204 more information on how to test package definitions, and
5205 @ref{Invoking guix lint}, for information on how to check a definition
5206 for style conformance.
5207 @vindex GUIX_PACKAGE_PATH
5208 Lastly, @pxref{Channels}, for information
5209 on how to extend the distribution by adding your own package definitions
5212 Finally, updating the package definition to a new upstream version
5213 can be partly automated by the @command{guix refresh} command
5214 (@pxref{Invoking guix refresh}).
5216 Behind the scenes, a derivation corresponding to the @code{<package>}
5217 object is first computed by the @code{package-derivation} procedure.
5218 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5219 The build actions it prescribes may then be realized by using the
5220 @code{build-derivations} procedure (@pxref{The Store}).
5222 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5223 Return the @code{<derivation>} object of @var{package} for @var{system}
5224 (@pxref{Derivations}).
5226 @var{package} must be a valid @code{<package>} object, and @var{system}
5227 must be a string denoting the target system type---e.g.,
5228 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5229 must be a connection to the daemon, which operates on the store
5230 (@pxref{The Store}).
5234 @cindex cross-compilation
5235 Similarly, it is possible to compute a derivation that cross-builds a
5236 package for some other system:
5238 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5239 @var{package} @var{target} [@var{system}]
5240 Return the @code{<derivation>} object of @var{package} cross-built from
5241 @var{system} to @var{target}.
5243 @var{target} must be a valid GNU triplet denoting the target hardware
5244 and operating system, such as @code{"mips64el-linux-gnu"}
5245 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
5246 Configure and Build System}).
5249 @cindex package transformations
5250 @cindex input rewriting
5251 @cindex dependency tree rewriting
5252 Packages can be manipulated in arbitrary ways. An example of a useful
5253 transformation is @dfn{input rewriting}, whereby the dependency tree of
5254 a package is rewritten by replacing specific inputs by others:
5256 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5257 [@var{rewrite-name}]
5258 Return a procedure that, when passed a package, replaces its direct and
5259 indirect dependencies (but not its implicit inputs) according to
5260 @var{replacements}. @var{replacements} is a list of package pairs; the
5261 first element of each pair is the package to replace, and the second one
5264 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5265 the name of a package and returns its new name after rewrite.
5269 Consider this example:
5272 (define libressl-instead-of-openssl
5273 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5275 (package-input-rewriting `((,openssl . ,libressl))))
5277 (define git-with-libressl
5278 (libressl-instead-of-openssl git))
5282 Here we first define a rewriting procedure that replaces @var{openssl}
5283 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5284 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5285 This is exactly what the @option{--with-input} command-line option does
5286 (@pxref{Package Transformation Options, @option{--with-input}}).
5288 The following variant of @code{package-input-rewriting} can match packages to
5289 be replaced by name rather than by identity.
5291 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5292 Return a procedure that, given a package, applies the given @var{replacements} to
5293 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5294 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5295 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5296 replacement for that package.
5299 The example above could be rewritten this way:
5302 (define libressl-instead-of-openssl
5303 ;; Replace all the packages called "openssl" with LibreSSL.
5304 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5307 The key difference here is that, this time, packages are matched by spec and
5308 not by identity. In other words, any package in the graph that is called
5309 @code{openssl} will be replaced.
5311 A more generic procedure to rewrite a package dependency graph is
5312 @code{package-mapping}: it supports arbitrary changes to nodes in the
5315 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5316 Return a procedure that, given a package, applies @var{proc} to all the packages
5317 depended on and returns the resulting package. The procedure stops recursion
5318 when @var{cut?} returns true for a given package.
5322 * package Reference:: The package data type.
5323 * origin Reference:: The origin data type.
5327 @node package Reference
5328 @subsection @code{package} Reference
5330 This section summarizes all the options available in @code{package}
5331 declarations (@pxref{Defining Packages}).
5333 @deftp {Data Type} package
5334 This is the data type representing a package recipe.
5338 The name of the package, as a string.
5340 @item @code{version}
5341 The version of the package, as a string.
5344 An object telling how the source code for the package should be
5345 acquired. Most of the time, this is an @code{origin} object, which
5346 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5347 can also be any other ``file-like'' object such as a @code{local-file},
5348 which denotes a file from the local file system (@pxref{G-Expressions,
5349 @code{local-file}}).
5351 @item @code{build-system}
5352 The build system that should be used to build the package (@pxref{Build
5355 @item @code{arguments} (default: @code{'()})
5356 The arguments that should be passed to the build system. This is a
5357 list, typically containing sequential keyword-value pairs.
5359 @item @code{inputs} (default: @code{'()})
5360 @itemx @code{native-inputs} (default: @code{'()})
5361 @itemx @code{propagated-inputs} (default: @code{'()})
5362 @cindex inputs, of packages
5363 These fields list dependencies of the package. Each one is a list of
5364 tuples, where each tuple has a label for the input (a string) as its
5365 first element, a package, origin, or derivation as its second element,
5366 and optionally the name of the output thereof that should be used, which
5367 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5368 more on package outputs). For example, the list below specifies three
5372 `(("libffi" ,libffi)
5373 ("libunistring" ,libunistring)
5374 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5377 @cindex cross compilation, package dependencies
5378 The distinction between @code{native-inputs} and @code{inputs} is
5379 necessary when considering cross-compilation. When cross-compiling,
5380 dependencies listed in @code{inputs} are built for the @emph{target}
5381 architecture; conversely, dependencies listed in @code{native-inputs}
5382 are built for the architecture of the @emph{build} machine.
5384 @code{native-inputs} is typically used to list tools needed at
5385 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5386 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5387 this area (@pxref{Invoking guix lint}).
5389 @anchor{package-propagated-inputs}
5390 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5391 specified packages will be automatically installed alongside the package
5392 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5393 package}}, for information on how @command{guix package} deals with
5396 For example this is necessary when a C/C++ library needs headers of
5397 another library to compile, or when a pkg-config file refers to another
5398 one @i{via} its @code{Requires} field.
5400 Another example where @code{propagated-inputs} is useful is for languages
5401 that lack a facility to record the run-time search path akin to the
5402 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5403 more. To ensure that libraries written in those languages can find
5404 library code they depend on at run time, run-time dependencies must be
5405 listed in @code{propagated-inputs} rather than @code{inputs}.
5407 @item @code{outputs} (default: @code{'("out")})
5408 The list of output names of the package. @xref{Packages with Multiple
5409 Outputs}, for typical uses of additional outputs.
5411 @item @code{native-search-paths} (default: @code{'()})
5412 @itemx @code{search-paths} (default: @code{'()})
5413 A list of @code{search-path-specification} objects describing
5414 search-path environment variables honored by the package.
5416 @item @code{replacement} (default: @code{#f})
5417 This must be either @code{#f} or a package object that will be used as a
5418 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5421 @item @code{synopsis}
5422 A one-line description of the package.
5424 @item @code{description}
5425 A more elaborate description of the package.
5427 @item @code{license}
5428 @cindex license, of packages
5429 The license of the package; a value from @code{(guix licenses)},
5430 or a list of such values.
5432 @item @code{home-page}
5433 The URL to the home-page of the package, as a string.
5435 @item @code{supported-systems} (default: @var{%supported-systems})
5436 The list of systems supported by the package, as strings of the form
5437 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5439 @item @code{maintainers} (default: @code{'()})
5440 The list of maintainers of the package, as @code{maintainer} objects.
5442 @item @code{location} (default: source location of the @code{package} form)
5443 The source location of the package. It is useful to override this when
5444 inheriting from another package, in which case this field is not
5445 automatically corrected.
5449 @deffn {Scheme Syntax} this-package
5450 When used in the @emph{lexical scope} of a package field definition, this
5451 identifier resolves to the package being defined.
5453 The example below shows how to add a package as a native input of itself when
5461 ;; When cross-compiled, Guile, for example, depends on
5462 ;; a native version of itself. Add it here.
5463 (native-inputs (if (%current-target-system)
5464 `(("self" ,this-package))
5468 It is an error to refer to @code{this-package} outside a package definition.
5471 @node origin Reference
5472 @subsection @code{origin} Reference
5474 This section summarizes all the options available in @code{origin}
5475 declarations (@pxref{Defining Packages}).
5477 @deftp {Data Type} origin
5478 This is the data type representing a source code origin.
5482 An object containing the URI of the source. The object type depends on
5483 the @code{method} (see below). For example, when using the
5484 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5485 values are: a URL represented as a string, or a list thereof.
5488 A procedure that handles the URI.
5493 @item @var{url-fetch} from @code{(guix download)}
5494 download a file from the HTTP, HTTPS, or FTP URL specified in the
5498 @item @var{git-fetch} from @code{(guix git-download)}
5499 clone the Git version control repository, and check out the revision
5500 specified in the @code{uri} field as a @code{git-reference} object; a
5501 @code{git-reference} looks like this:
5505 (url "git://git.debian.org/git/pkg-shadow/shadow")
5506 (commit "v4.1.5.1"))
5511 A bytevector containing the SHA-256 hash of the source. Typically the
5512 @code{base32} form is used here to generate the bytevector from a
5515 You can obtain this information using @code{guix download}
5516 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5519 @item @code{file-name} (default: @code{#f})
5520 The file name under which the source code should be saved. When this is
5521 @code{#f}, a sensible default value will be used in most cases. In case
5522 the source is fetched from a URL, the file name from the URL will be
5523 used. For version control checkouts, it is recommended to provide the
5524 file name explicitly because the default is not very descriptive.
5526 @item @code{patches} (default: @code{'()})
5527 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5528 file-like objects}) pointing to patches to be applied to the source.
5530 This list of patches must be unconditional. In particular, it cannot
5531 depend on the value of @code{%current-system} or
5532 @code{%current-target-system}.
5534 @item @code{snippet} (default: @code{#f})
5535 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5536 in the source directory. This is a convenient way to modify the source,
5537 sometimes more convenient than a patch.
5539 @item @code{patch-flags} (default: @code{'("-p1")})
5540 A list of command-line flags that should be passed to the @code{patch}
5543 @item @code{patch-inputs} (default: @code{#f})
5544 Input packages or derivations to the patching process. When this is
5545 @code{#f}, the usual set of inputs necessary for patching are provided,
5546 such as GNU@tie{}Patch.
5548 @item @code{modules} (default: @code{'()})
5549 A list of Guile modules that should be loaded during the patching
5550 process and while running the code in the @code{snippet} field.
5552 @item @code{patch-guile} (default: @code{#f})
5553 The Guile package that should be used in the patching process. When
5554 this is @code{#f}, a sensible default is used.
5560 @section Build Systems
5562 @cindex build system
5563 Each package definition specifies a @dfn{build system} and arguments for
5564 that build system (@pxref{Defining Packages}). This @code{build-system}
5565 field represents the build procedure of the package, as well as implicit
5566 dependencies of that build procedure.
5568 Build systems are @code{<build-system>} objects. The interface to
5569 create and manipulate them is provided by the @code{(guix build-system)}
5570 module, and actual build systems are exported by specific modules.
5572 @cindex bag (low-level package representation)
5573 Under the hood, build systems first compile package objects to
5574 @dfn{bags}. A @dfn{bag} is like a package, but with less
5575 ornamentation---in other words, a bag is a lower-level representation of
5576 a package, which includes all the inputs of that package, including some
5577 that were implicitly added by the build system. This intermediate
5578 representation is then compiled to a derivation (@pxref{Derivations}).
5580 Build systems accept an optional list of @dfn{arguments}. In package
5581 definitions, these are passed @i{via} the @code{arguments} field
5582 (@pxref{Defining Packages}). They are typically keyword arguments
5583 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5584 Guile Reference Manual}). The value of these arguments is usually
5585 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5586 by the daemon (@pxref{Derivations}).
5588 The main build system is @var{gnu-build-system}, which implements the
5589 standard build procedure for GNU and many other packages. It
5590 is provided by the @code{(guix build-system gnu)} module.
5592 @defvr {Scheme Variable} gnu-build-system
5593 @var{gnu-build-system} represents the GNU Build System, and variants
5594 thereof (@pxref{Configuration, configuration and makefile conventions,,
5595 standards, GNU Coding Standards}).
5597 @cindex build phases
5598 In a nutshell, packages using it are configured, built, and installed with
5599 the usual @code{./configure && make && make check && make install}
5600 command sequence. In practice, a few additional steps are often needed.
5601 All these steps are split up in separate @dfn{phases},
5602 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5603 modules for more details about the build phases.}:
5607 Unpack the source tarball, and change the current directory to the
5608 extracted source tree. If the source is actually a directory, copy it
5609 to the build tree, and enter that directory.
5611 @item patch-source-shebangs
5612 Patch shebangs encountered in source files so they refer to the right
5613 store file names. For instance, this changes @code{#!/bin/sh} to
5614 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5617 Run the @file{configure} script with a number of default options, such
5618 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5619 by the @code{#:configure-flags} argument.
5622 Run @code{make} with the list of flags specified with
5623 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5624 (the default), build with @code{make -j}.
5627 Run @code{make check}, or some other target specified with
5628 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5629 @code{#:parallel-tests?} argument is true (the default), run @code{make
5633 Run @code{make install} with the flags listed in @code{#:make-flags}.
5635 @item patch-shebangs
5636 Patch shebangs on the installed executable files.
5639 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5640 is false), copying them to the @code{debug} output when available
5641 (@pxref{Installing Debugging Files}).
5644 @vindex %standard-phases
5645 The build-side module @code{(guix build gnu-build-system)} defines
5646 @var{%standard-phases} as the default list of build phases.
5647 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5648 procedure implements the actual phase.
5650 The list of phases used for a particular package can be changed with the
5651 @code{#:phases} parameter. For instance, passing:
5654 #:phases (modify-phases %standard-phases (delete 'configure))
5657 means that all the phases described above will be used, except the
5658 @code{configure} phase.
5660 In addition, this build system ensures that the ``standard'' environment
5661 for GNU packages is available. This includes tools such as GCC, libc,
5662 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5663 build-system gnu)} module for a complete list). We call these the
5664 @dfn{implicit inputs} of a package, because package definitions do not
5665 have to mention them.
5668 Other @code{<build-system>} objects are defined to support other
5669 conventions and tools used by free software packages. They inherit most
5670 of @var{gnu-build-system}, and differ mainly in the set of inputs
5671 implicitly added to the build process, and in the list of phases
5672 executed. Some of these build systems are listed below.
5674 @defvr {Scheme Variable} ant-build-system
5675 This variable is exported by @code{(guix build-system ant)}. It
5676 implements the build procedure for Java packages that can be built with
5677 @url{http://ant.apache.org/, Ant build tool}.
5679 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5680 provided by the @code{icedtea} package to the set of inputs. Different
5681 packages can be specified with the @code{#:ant} and @code{#:jdk}
5682 parameters, respectively.
5684 When the original package does not provide a suitable Ant build file,
5685 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5686 build file @file{build.xml} with tasks to build the specified jar
5687 archive. In this case the parameter @code{#:source-dir} can be used to
5688 specify the source sub-directory, defaulting to ``src''.
5690 The @code{#:main-class} parameter can be used with the minimal ant
5691 buildfile to specify the main class of the resulting jar. This makes the
5692 jar file executable. The @code{#:test-include} parameter can be used to
5693 specify the list of junit tests to run. It defaults to
5694 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5695 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5696 because abstract classes cannot be run as tests.
5698 The parameter @code{#:build-target} can be used to specify the Ant task
5699 that should be run during the @code{build} phase. By default the
5700 ``jar'' task will be run.
5704 @defvr {Scheme Variable} android-ndk-build-system
5705 @cindex Android distribution
5706 @cindex Android NDK build system
5707 This variable is exported by @code{(guix build-system android-ndk)}. It
5708 implements a build procedure for Android NDK (native development kit)
5709 packages using a Guix-specific build process.
5711 The build system assumes that packages install their public interface
5712 (header) files to the subdirectory "include" of the "out" output and
5713 their libraries to the subdirectory "lib" of the "out" output.
5715 It's also assumed that the union of all the dependencies of a package
5716 has no conflicting files.
5718 For the time being, cross-compilation is not supported - so right now
5719 the libraries and header files are assumed to be host tools.
5723 @defvr {Scheme Variable} asdf-build-system/source
5724 @defvrx {Scheme Variable} asdf-build-system/sbcl
5725 @defvrx {Scheme Variable} asdf-build-system/ecl
5727 These variables, exported by @code{(guix build-system asdf)}, implement
5728 build procedures for Common Lisp packages using
5729 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5730 definition facility for Common Lisp programs and libraries.
5732 The @code{asdf-build-system/source} system installs the packages in
5733 source form, and can be loaded using any common lisp implementation, via
5734 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5735 systems in the format which a particular implementation understands.
5736 These build systems can also be used to produce executable programs, or
5737 lisp images which contain a set of packages pre-loaded.
5739 The build system uses naming conventions. For binary packages, the
5740 package name should be prefixed with the lisp implementation, such as
5741 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5743 Additionally, the corresponding source package should be labeled using
5744 the same convention as python packages (see @ref{Python Modules}), using
5745 the @code{cl-} prefix.
5747 For binary packages, each system should be defined as a Guix package.
5748 If one package @code{origin} contains several systems, package variants
5749 can be created in order to build all the systems. Source packages,
5750 which use @code{asdf-build-system/source}, may contain several systems.
5752 In order to create executable programs and images, the build-side
5753 procedures @code{build-program} and @code{build-image} can be used.
5754 They should be called in a build phase after the @code{create-symlinks}
5755 phase, so that the system which was just built can be used within the
5756 resulting image. @code{build-program} requires a list of Common Lisp
5757 expressions to be passed as the @code{#:entry-program} argument.
5759 If the system is not defined within its own @code{.asd} file of the same
5760 name, then the @code{#:asd-file} parameter should be used to specify
5761 which file the system is defined in. Furthermore, if the package
5762 defines a system for its tests in a separate file, it will be loaded
5763 before the tests are run if it is specified by the
5764 @code{#:test-asd-file} parameter. If it is not set, the files
5765 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5766 and @code{test.asd} will be tried if they exist.
5768 If for some reason the package must be named in a different way than the
5769 naming conventions suggest, the @code{#:asd-system-name} parameter can
5770 be used to specify the name of the system.
5774 @defvr {Scheme Variable} cargo-build-system
5775 @cindex Rust programming language
5776 @cindex Cargo (Rust build system)
5777 This variable is exported by @code{(guix build-system cargo)}. It
5778 supports builds of packages using Cargo, the build tool of the
5779 @uref{https://www.rust-lang.org, Rust programming language}.
5781 In its @code{configure} phase, this build system replaces dependencies
5782 specified in the @file{Carto.toml} file with inputs to the Guix package.
5783 The @code{install} phase installs the binaries, and it also installs the
5784 source code and @file{Cargo.toml} file.
5787 @cindex Clojure (programming language)
5788 @cindex simple Clojure build system
5789 @defvr {Scheme Variable} clojure-build-system
5790 This variable is exported by @code{(guix build-system clojure)}. It implements
5791 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5792 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5795 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5796 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5797 @code{#:zip} parameters, respectively.
5799 A list of source directories, test directories and jar names can be specified
5800 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5801 parameters, respectively. Compile directory and main class can be specified
5802 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5803 Other parameters are documented below.
5805 This build system is an extension of @var{ant-build-system}, but with the
5806 following phases changed:
5811 This phase calls @code{compile} in Clojure to compile source files and runs
5812 @command{jar} to create jars from both source files and compiled files
5813 according to the include list and exclude list specified in
5814 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5815 has priority over the include list. These lists consist of symbols
5816 representing Clojure libraries or the special keyword @code{#:all} representing
5817 all Clojure libraries found under the source directories. The parameter
5818 @code{#:omit-source?} decides if source should be included into the jars.
5821 This phase runs tests according to the include list and exclude list specified
5822 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5823 meanings are analogous to that of @code{#:aot-include} and
5824 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5825 stands for all Clojure libraries found under the test directories. The
5826 parameter @code{#:tests?} decides if tests should be run.
5829 This phase installs all jars built previously.
5832 Apart from the above, this build system also contains an additional phase:
5837 This phase installs all top-level files with base name matching
5838 @var{%doc-regex}. A different regex can be specified with the
5839 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5840 directories specified in @code{#:doc-dirs} are installed as well.
5844 @defvr {Scheme Variable} cmake-build-system
5845 This variable is exported by @code{(guix build-system cmake)}. It
5846 implements the build procedure for packages using the
5847 @url{http://www.cmake.org, CMake build tool}.
5849 It automatically adds the @code{cmake} package to the set of inputs.
5850 Which package is used can be specified with the @code{#:cmake}
5853 The @code{#:configure-flags} parameter is taken as a list of flags
5854 passed to the @command{cmake} command. The @code{#:build-type}
5855 parameter specifies in abstract terms the flags passed to the compiler;
5856 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5857 debugging information''), which roughly means that code is compiled with
5858 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5861 @defvr {Scheme Variable} dune-build-system
5862 This variable is exported by @code{(guix build-system dune)}. It
5863 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5864 tool for the OCaml programming language. It is implemented as an extension
5865 of the @code{ocaml-build-system} which is described below. As such, the
5866 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5869 It automatically adds the @code{dune} package to the set of inputs.
5870 Which package is used can be specified with the @code{#:dune}
5873 There is no @code{configure} phase because dune packages typically don't
5874 need to be configured. The @code{#:build-flags} parameter is taken as a
5875 list of flags passed to the @code{dune} command during the build.
5877 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5878 command instead of the more recent @code{dune} command while building
5879 a package. Its default value is @code{#f}.
5881 The @code{#:package} parameter can be passed to specify a package name, which
5882 is useful when a package contains multiple packages and you want to build
5883 only one of them. This is equivalent to passing the @code{-p} argument to
5887 @defvr {Scheme Variable} go-build-system
5888 This variable is exported by @code{(guix build-system go)}. It
5889 implements a build procedure for Go packages using the standard
5890 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5891 Go build mechanisms}.
5893 The user is expected to provide a value for the key @code{#:import-path}
5894 and, in some cases, @code{#:unpack-path}. The
5895 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5896 corresponds to the file system path expected by the package's build
5897 scripts and any referring packages, and provides a unique way to
5898 refer to a Go package. It is typically based on a combination of the
5899 package source code's remote URI and file system hierarchy structure. In
5900 some cases, you will need to unpack the package's source code to a
5901 different directory structure than the one indicated by the import path,
5902 and @code{#:unpack-path} should be used in such cases.
5904 Packages that provide Go libraries should install their source code into
5905 the built output. The key @code{#:install-source?}, which defaults to
5906 @code{#t}, controls whether or not the source code is installed. It can
5907 be set to @code{#f} for packages that only provide executable files.
5910 @defvr {Scheme Variable} glib-or-gtk-build-system
5911 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5912 is intended for use with packages making use of GLib or GTK+.
5914 This build system adds the following two phases to the ones defined by
5915 @var{gnu-build-system}:
5918 @item glib-or-gtk-wrap
5919 The phase @code{glib-or-gtk-wrap} ensures that programs in
5920 @file{bin/} are able to find GLib ``schemas'' and
5921 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5922 modules}. This is achieved by wrapping the programs in launch scripts
5923 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5924 environment variables.
5926 It is possible to exclude specific package outputs from that wrapping
5927 process by listing their names in the
5928 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5929 when an output is known not to contain any GLib or GTK+ binaries, and
5930 where wrapping would gratuitously add a dependency of that output on
5933 @item glib-or-gtk-compile-schemas
5934 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5935 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5936 GSettings schemas} of GLib are compiled. Compilation is performed by the
5937 @command{glib-compile-schemas} program. It is provided by the package
5938 @code{glib:bin} which is automatically imported by the build system.
5939 The @code{glib} package providing @command{glib-compile-schemas} can be
5940 specified with the @code{#:glib} parameter.
5943 Both phases are executed after the @code{install} phase.
5946 @defvr {Scheme Variable} guile-build-system
5947 This build system is for Guile packages that consist exclusively of Scheme
5948 code and that are so lean that they don't even have a makefile, let alone a
5949 @file{configure} script. It compiles Scheme code using @command{guild
5950 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5951 installs the @file{.scm} and @file{.go} files in the right place. It also
5952 installs documentation.
5954 This build system supports cross-compilation by using the @code{--target}
5955 option of @command{guild compile}.
5957 Packages built with @code{guile-build-system} must provide a Guile package in
5958 their @code{native-inputs} field.
5961 @defvr {Scheme Variable} minify-build-system
5962 This variable is exported by @code{(guix build-system minify)}. It
5963 implements a minification procedure for simple JavaScript packages.
5965 It adds @code{uglify-js} to the set of inputs and uses it to compress
5966 all JavaScript files in the @file{src} directory. A different minifier
5967 package can be specified with the @code{#:uglify-js} parameter, but it
5968 is expected that the package writes the minified code to the standard
5971 When the input JavaScript files are not all located in the @file{src}
5972 directory, the parameter @code{#:javascript-files} can be used to
5973 specify a list of file names to feed to the minifier.
5976 @defvr {Scheme Variable} ocaml-build-system
5977 This variable is exported by @code{(guix build-system ocaml)}. It implements
5978 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
5979 of choosing the correct set of commands to run for each package. OCaml
5980 packages can expect many different commands to be run. This build system will
5983 When the package has a @file{setup.ml} file present at the top-level, it will
5984 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
5985 @code{ocaml setup.ml -install}. The build system will assume that this file
5986 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
5987 care of setting the prefix and enabling tests if they are not disabled. You
5988 can pass configure and build flags with the @code{#:configure-flags} and
5989 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
5990 set of flags used to enable tests. The @code{#:use-make?} key can be used to
5991 bypass this system in the build and install phases.
5993 When the package has a @file{configure} file, it is assumed that it is a
5994 hand-made configure script that requires a different argument format than
5995 in the @code{gnu-build-system}. You can add more flags with the
5996 @code{#:configure-flags} key.
5998 When the package has a @file{Makefile} file (or @code{#:use-make?} is
5999 @code{#t}), it will be used and more flags can be passed to the build and
6000 install phases with the @code{#:make-flags} key.
6002 Finally, some packages do not have these files and use a somewhat standard
6003 location for its build system. In that case, the build system will run
6004 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6005 providing the path to the required findlib module. Additional flags can
6006 be passed via the @code{#:build-flags} key. Install is taken care of by
6007 @command{opam-installer}. In this case, the @code{opam} package must
6008 be added to the @code{native-inputs} field of the package definition.
6010 Note that most OCaml packages assume they will be installed in the same
6011 directory as OCaml, which is not what we want in guix. In particular, they
6012 will install @file{.so} files in their module's directory, which is usually
6013 fine because it is in the OCaml compiler directory. In guix though, these
6014 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6015 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6016 @file{.so} libraries should be installed.
6019 @defvr {Scheme Variable} python-build-system
6020 This variable is exported by @code{(guix build-system python)}. It
6021 implements the more or less standard build procedure used by Python
6022 packages, which consists in running @code{python setup.py build} and
6023 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6025 For packages that install stand-alone Python programs under @code{bin/},
6026 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6027 environment variable points to all the Python libraries they depend on.
6029 Which Python package is used to perform the build can be specified with
6030 the @code{#:python} parameter. This is a useful way to force a package
6031 to be built for a specific version of the Python interpreter, which
6032 might be necessary if the package is only compatible with a single
6033 interpreter version.
6035 By default guix calls @code{setup.py} under control of
6036 @code{setuptools}, much like @command{pip} does. Some packages are not
6037 compatible with setuptools (and pip), thus you can disable this by
6038 setting the @code{#:use-setuptools} parameter to @code{#f}.
6041 @defvr {Scheme Variable} perl-build-system
6042 This variable is exported by @code{(guix build-system perl)}. It
6043 implements the standard build procedure for Perl packages, which either
6044 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6045 followed by @code{Build} and @code{Build install}; or in running
6046 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6047 @code{make} and @code{make install}, depending on which of
6048 @code{Build.PL} or @code{Makefile.PL} is present in the package
6049 distribution. Preference is given to the former if both @code{Build.PL}
6050 and @code{Makefile.PL} exist in the package distribution. This
6051 preference can be reversed by specifying @code{#t} for the
6052 @code{#:make-maker?} parameter.
6054 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6055 passes flags specified by the @code{#:make-maker-flags} or
6056 @code{#:module-build-flags} parameter, respectively.
6058 Which Perl package is used can be specified with @code{#:perl}.
6061 @defvr {Scheme Variable} r-build-system
6062 This variable is exported by @code{(guix build-system r)}. It
6063 implements the build procedure used by @uref{http://r-project.org, R}
6064 packages, which essentially is little more than running @code{R CMD
6065 INSTALL --library=/gnu/store/@dots{}} in an environment where
6066 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6067 are run after installation using the R function
6068 @code{tools::testInstalledPackage}.
6071 @defvr {Scheme Variable} rakudo-build-system
6072 This variable is exported by @code{(guix build-system rakudo)} It
6073 implements the build procedure used by @uref{https://rakudo.org/,
6074 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6075 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6076 installs the binaries, library files and the resources, as well as wrap
6077 the files under the @code{bin/} directory. Tests can be skipped by
6078 passing @code{#f} to the @code{tests?} parameter.
6080 Which rakudo package is used can be specified with @code{rakudo}.
6081 Which perl6-tap-harness package used for the tests can be specified with
6082 @code{#:prove6} or removed by passing @code{#f} to the
6083 @code{with-prove6?} parameter.
6084 Which perl6-zef package used for tests and installing can be specified
6085 with @code{#:zef} or removed by passing @code{#f} to the
6086 @code{with-zef?} parameter.
6089 @defvr {Scheme Variable} texlive-build-system
6090 This variable is exported by @code{(guix build-system texlive)}. It is
6091 used to build TeX packages in batch mode with a specified engine. The
6092 build system sets the @code{TEXINPUTS} variable to find all TeX source
6093 files in the inputs.
6095 By default it runs @code{luatex} on all files ending on @code{ins}. A
6096 different engine and format can be specified with the
6097 @code{#:tex-format} argument. Different build targets can be specified
6098 with the @code{#:build-targets} argument, which expects a list of file
6099 names. The build system adds only @code{texlive-bin} and
6100 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6101 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6102 and @code{#:texlive-latex-base}, respectively.
6104 The @code{#:tex-directory} parameter tells the build system where to
6105 install the built files under the texmf tree.
6108 @defvr {Scheme Variable} ruby-build-system
6109 This variable is exported by @code{(guix build-system ruby)}. It
6110 implements the RubyGems build procedure used by Ruby packages, which
6111 involves running @code{gem build} followed by @code{gem install}.
6113 The @code{source} field of a package that uses this build system
6114 typically references a gem archive, since this is the format that Ruby
6115 developers use when releasing their software. The build system unpacks
6116 the gem archive, potentially patches the source, runs the test suite,
6117 repackages the gem, and installs it. Additionally, directories and
6118 tarballs may be referenced to allow building unreleased gems from Git or
6119 a traditional source release tarball.
6121 Which Ruby package is used can be specified with the @code{#:ruby}
6122 parameter. A list of additional flags to be passed to the @command{gem}
6123 command can be specified with the @code{#:gem-flags} parameter.
6126 @defvr {Scheme Variable} waf-build-system
6127 This variable is exported by @code{(guix build-system waf)}. It
6128 implements a build procedure around the @code{waf} script. The common
6129 phases---@code{configure}, @code{build}, and @code{install}---are
6130 implemented by passing their names as arguments to the @code{waf}
6133 The @code{waf} script is executed by the Python interpreter. Which
6134 Python package is used to run the script can be specified with the
6135 @code{#:python} parameter.
6138 @defvr {Scheme Variable} scons-build-system
6139 This variable is exported by @code{(guix build-system scons)}. It
6140 implements the build procedure used by the SCons software construction
6141 tool. This build system runs @code{scons} to build the package,
6142 @code{scons test} to run tests, and then @code{scons install} to install
6145 Additional flags to be passed to @code{scons} can be specified with the
6146 @code{#:scons-flags} parameter. The version of Python used to run SCons
6147 can be specified by selecting the appropriate SCons package with the
6148 @code{#:scons} parameter.
6151 @defvr {Scheme Variable} haskell-build-system
6152 This variable is exported by @code{(guix build-system haskell)}. It
6153 implements the Cabal build procedure used by Haskell packages, which
6154 involves running @code{runhaskell Setup.hs configure
6155 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6156 Instead of installing the package by running @code{runhaskell Setup.hs
6157 install}, to avoid trying to register libraries in the read-only
6158 compiler store directory, the build system uses @code{runhaskell
6159 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6160 addition, the build system generates the package documentation by
6161 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6162 is passed. Optional Haddock parameters can be passed with the help of
6163 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6164 not found, the build system looks for @code{Setup.lhs} instead.
6166 Which Haskell compiler is used can be specified with the @code{#:haskell}
6167 parameter which defaults to @code{ghc}.
6170 @defvr {Scheme Variable} dub-build-system
6171 This variable is exported by @code{(guix build-system dub)}. It
6172 implements the Dub build procedure used by D packages, which
6173 involves running @code{dub build} and @code{dub run}.
6174 Installation is done by copying the files manually.
6176 Which D compiler is used can be specified with the @code{#:ldc}
6177 parameter which defaults to @code{ldc}.
6180 @defvr {Scheme Variable} emacs-build-system
6181 This variable is exported by @code{(guix build-system emacs)}. It
6182 implements an installation procedure similar to the packaging system
6183 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6185 It first creates the @code{@var{package}-autoloads.el} file, then it
6186 byte compiles all Emacs Lisp files. Differently from the Emacs
6187 packaging system, the Info documentation files are moved to the standard
6188 documentation directory and the @file{dir} file is deleted. Each
6189 package is installed in its own directory under
6190 @file{share/emacs/site-lisp/guix.d}.
6193 @defvr {Scheme Variable} font-build-system
6194 This variable is exported by @code{(guix build-system font)}. It
6195 implements an installation procedure for font packages where upstream
6196 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6197 need to be copied into place. It copies font files to standard
6198 locations in the output directory.
6201 @defvr {Scheme Variable} meson-build-system
6202 This variable is exported by @code{(guix build-system meson)}. It
6203 implements the build procedure for packages that use
6204 @url{http://mesonbuild.com, Meson} as their build system.
6206 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6207 of inputs, and they can be changed with the parameters @code{#:meson}
6208 and @code{#:ninja} if needed. The default Meson is
6209 @code{meson-for-build}, which is special because it doesn't clear the
6210 @code{RUNPATH} of binaries and libraries when they are installed.
6212 This build system is an extension of @var{gnu-build-system}, but with the
6213 following phases changed to some specific for Meson:
6218 The phase runs @code{meson} with the flags specified in
6219 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6220 @code{plain} unless something else is specified in @code{#:build-type}.
6223 The phase runs @code{ninja} to build the package in parallel by default, but
6224 this can be changed with @code{#:parallel-build?}.
6227 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6228 which is @code{"test"} by default.
6231 The phase runs @code{ninja install} and can not be changed.
6234 Apart from that, the build system also adds the following phases:
6239 This phase ensures that all binaries can find the libraries they need.
6240 It searches for required libraries in subdirectories of the package being
6241 built, and adds those to @code{RUNPATH} where needed. It also removes
6242 references to libraries left over from the build phase by
6243 @code{meson-for-build}, such as test dependencies, that aren't actually
6244 required for the program to run.
6246 @item glib-or-gtk-wrap
6247 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6248 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6250 @item glib-or-gtk-compile-schemas
6251 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6252 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6256 @defvr {Scheme Variable} linux-module-build-system
6257 @var{linux-module-build-system} allows building Linux kernel modules.
6259 @cindex build phases
6260 This build system is an extension of @var{gnu-build-system}, but with the
6261 following phases changed:
6266 This phase configures the environment so that the Linux kernel's Makefile
6267 can be used to build the external kernel module.
6270 This phase uses the Linux kernel's Makefile in order to build the external
6274 This phase uses the Linux kernel's Makefile in order to install the external
6278 It is possible and useful to specify the Linux kernel to use for building
6279 the module (in the "arguments" form of a package using the
6280 linux-module-build-system, use the key #:linux to specify it).
6283 Lastly, for packages that do not need anything as sophisticated, a
6284 ``trivial'' build system is provided. It is trivial in the sense that
6285 it provides basically no support: it does not pull any implicit inputs,
6286 and does not have a notion of build phases.
6288 @defvr {Scheme Variable} trivial-build-system
6289 This variable is exported by @code{(guix build-system trivial)}.
6291 This build system requires a @code{#:builder} argument. This argument
6292 must be a Scheme expression that builds the package output(s)---as
6293 with @code{build-expression->derivation} (@pxref{Derivations,
6294 @code{build-expression->derivation}}).
6304 Conceptually, the @dfn{store} is the place where derivations that have
6305 been built successfully are stored---by default, @file{/gnu/store}.
6306 Sub-directories in the store are referred to as @dfn{store items} or
6307 sometimes @dfn{store paths}. The store has an associated database that
6308 contains information such as the store paths referred to by each store
6309 path, and the list of @emph{valid} store items---results of successful
6310 builds. This database resides in @file{@var{localstatedir}/guix/db},
6311 where @var{localstatedir} is the state directory specified @i{via}
6312 @option{--localstatedir} at configure time, usually @file{/var}.
6314 The store is @emph{always} accessed by the daemon on behalf of its clients
6315 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6316 connect to the daemon over a Unix-domain socket, send requests to it,
6317 and read the result---these are remote procedure calls, or RPCs.
6320 Users must @emph{never} modify files under @file{/gnu/store} directly.
6321 This would lead to inconsistencies and break the immutability
6322 assumptions of Guix's functional model (@pxref{Introduction}).
6324 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6325 how to check the integrity of the store and attempt recovery from
6326 accidental modifications.
6329 The @code{(guix store)} module provides procedures to connect to the
6330 daemon, and to perform RPCs. These are described below. By default,
6331 @code{open-connection}, and thus all the @command{guix} commands,
6332 connect to the local daemon or to the URI specified by the
6333 @code{GUIX_DAEMON_SOCKET} environment variable.
6335 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6336 When set, the value of this variable should be a file name or a URI
6337 designating the daemon endpoint. When it is a file name, it denotes a
6338 Unix-domain socket to connect to. In addition to file names, the
6339 supported URI schemes are:
6344 These are for Unix-domain sockets.
6345 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6346 @file{/var/guix/daemon-socket/socket}.
6349 @cindex daemon, remote access
6350 @cindex remote access to the daemon
6351 @cindex daemon, cluster setup
6352 @cindex clusters, daemon setup
6353 These URIs denote connections over TCP/IP, without encryption nor
6354 authentication of the remote host. The URI must specify the host name
6355 and optionally a port number (by default port 44146 is used):
6358 guix://master.guix.example.org:1234
6361 This setup is suitable on local networks, such as clusters, where only
6362 trusted nodes may connect to the build daemon at
6363 @code{master.guix.example.org}.
6365 The @code{--listen} option of @command{guix-daemon} can be used to
6366 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6370 @cindex SSH access to build daemons
6371 These URIs allow you to connect to a remote daemon over
6372 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6373 A typical URL might look like this:
6376 ssh://charlie@@guix.example.org:22
6379 As for @command{guix copy}, the usual OpenSSH client configuration files
6380 are honored (@pxref{Invoking guix copy}).
6383 Additional URI schemes may be supported in the future.
6385 @c XXX: Remove this note when the protocol incurs fewer round trips
6386 @c and when (guix derivations) no longer relies on file system access.
6388 The ability to connect to remote build daemons is considered
6389 experimental as of @value{VERSION}. Please get in touch with us to
6390 share any problems or suggestions you may have (@pxref{Contributing}).
6394 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6395 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6396 @var{reserve-space?} is true, instruct it to reserve a little bit of
6397 extra space on the file system so that the garbage collector can still
6398 operate should the disk become full. Return a server object.
6400 @var{file} defaults to @var{%default-socket-path}, which is the normal
6401 location given the options that were passed to @command{configure}.
6404 @deffn {Scheme Procedure} close-connection @var{server}
6405 Close the connection to @var{server}.
6408 @defvr {Scheme Variable} current-build-output-port
6409 This variable is bound to a SRFI-39 parameter, which refers to the port
6410 where build and error logs sent by the daemon should be written.
6413 Procedures that make RPCs all take a server object as their first
6416 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6417 @cindex invalid store items
6418 Return @code{#t} when @var{path} designates a valid store item and
6419 @code{#f} otherwise (an invalid item may exist on disk but still be
6420 invalid, for instance because it is the result of an aborted or failed
6423 A @code{&store-protocol-error} condition is raised if @var{path} is not
6424 prefixed by the store directory (@file{/gnu/store}).
6427 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6428 Add @var{text} under file @var{name} in the store, and return its store
6429 path. @var{references} is the list of store paths referred to by the
6430 resulting store path.
6433 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
6434 Build @var{derivations} (a list of @code{<derivation>} objects or
6435 derivation paths), and return when the worker is done building them.
6436 Return @code{#t} on success.
6439 Note that the @code{(guix monads)} module provides a monad as well as
6440 monadic versions of the above procedures, with the goal of making it
6441 more convenient to work with code that accesses the store (@pxref{The
6445 @i{This section is currently incomplete.}
6448 @section Derivations
6451 Low-level build actions and the environment in which they are performed
6452 are represented by @dfn{derivations}. A derivation contains the
6453 following pieces of information:
6457 The outputs of the derivation---derivations produce at least one file or
6458 directory in the store, but may produce more.
6461 @cindex build-time dependencies
6462 @cindex dependencies, build-time
6463 The inputs of the derivations---i.e., its build-time dependencies---which may
6464 be other derivations or plain files in the store (patches, build scripts,
6468 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6471 The file name of a build script in the store, along with the arguments
6475 A list of environment variables to be defined.
6479 @cindex derivation path
6480 Derivations allow clients of the daemon to communicate build actions to
6481 the store. They exist in two forms: as an in-memory representation,
6482 both on the client- and daemon-side, and as files in the store whose
6483 name end in @code{.drv}---these files are referred to as @dfn{derivation
6484 paths}. Derivations paths can be passed to the @code{build-derivations}
6485 procedure to perform the build actions they prescribe (@pxref{The
6488 @cindex fixed-output derivations
6489 Operations such as file downloads and version-control checkouts for
6490 which the expected content hash is known in advance are modeled as
6491 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6492 of a fixed-output derivation are independent of its inputs---e.g., a
6493 source code download produces the same result regardless of the download
6494 method and tools being used.
6497 @cindex run-time dependencies
6498 @cindex dependencies, run-time
6499 The outputs of derivations---i.e., the build results---have a set of
6500 @dfn{references}, as reported by the @code{references} RPC or the
6501 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6502 are the set of run-time dependencies of the build results. References are a
6503 subset of the inputs of the derivation; this subset is automatically computed
6504 by the build daemon by scanning all the files in the outputs.
6506 The @code{(guix derivations)} module provides a representation of
6507 derivations as Scheme objects, along with procedures to create and
6508 otherwise manipulate derivations. The lowest-level primitive to create
6509 a derivation is the @code{derivation} procedure:
6511 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6512 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6513 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6514 [#:system (%current-system)] [#:references-graphs #f] @
6515 [#:allowed-references #f] [#:disallowed-references #f] @
6516 [#:leaked-env-vars #f] [#:local-build? #f] @
6517 [#:substitutable? #t] [#:properties '()]
6518 Build a derivation with the given arguments, and return the resulting
6519 @code{<derivation>} object.
6521 When @var{hash} and @var{hash-algo} are given, a
6522 @dfn{fixed-output derivation} is created---i.e., one whose result is
6523 known in advance, such as a file download. If, in addition,
6524 @var{recursive?} is true, then that fixed output may be an executable
6525 file or a directory and @var{hash} must be the hash of an archive
6526 containing this output.
6528 When @var{references-graphs} is true, it must be a list of file
6529 name/store path pairs. In that case, the reference graph of each store
6530 path is exported in the build environment in the corresponding file, in
6531 a simple text format.
6533 When @var{allowed-references} is true, it must be a list of store items
6534 or outputs that the derivation's output may refer to. Likewise,
6535 @var{disallowed-references}, if true, must be a list of things the
6536 outputs may @emph{not} refer to.
6538 When @var{leaked-env-vars} is true, it must be a list of strings
6539 denoting environment variables that are allowed to ``leak'' from the
6540 daemon's environment to the build environment. This is only applicable
6541 to fixed-output derivations---i.e., when @var{hash} is true. The main
6542 use is to allow variables such as @code{http_proxy} to be passed to
6543 derivations that download files.
6545 When @var{local-build?} is true, declare that the derivation is not a
6546 good candidate for offloading and should rather be built locally
6547 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6548 where the costs of data transfers would outweigh the benefits.
6550 When @var{substitutable?} is false, declare that substitutes of the
6551 derivation's output should not be used (@pxref{Substitutes}). This is
6552 useful, for instance, when building packages that capture details of the
6553 host CPU instruction set.
6555 @var{properties} must be an association list describing ``properties'' of the
6556 derivation. It is kept as-is, uninterpreted, in the derivation.
6560 Here's an example with a shell script as its builder, assuming
6561 @var{store} is an open connection to the daemon, and @var{bash} points
6562 to a Bash executable in the store:
6565 (use-modules (guix utils)
6569 (let ((builder ; add the Bash script to the store
6570 (add-text-to-store store "my-builder.sh"
6571 "echo hello world > $out\n" '())))
6572 (derivation store "foo"
6573 bash `("-e" ,builder)
6574 #:inputs `((,bash) (,builder))
6575 #:env-vars '(("HOME" . "/homeless"))))
6576 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6579 As can be guessed, this primitive is cumbersome to use directly. A
6580 better approach is to write build scripts in Scheme, of course! The
6581 best course of action for that is to write the build code as a
6582 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6583 information, @pxref{G-Expressions}.
6585 Once upon a time, @code{gexp->derivation} did not exist and constructing
6586 derivations with build code written in Scheme was achieved with
6587 @code{build-expression->derivation}, documented below. This procedure
6588 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6590 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6591 @var{name} @var{exp} @
6592 [#:system (%current-system)] [#:inputs '()] @
6593 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6594 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6595 [#:references-graphs #f] [#:allowed-references #f] @
6596 [#:disallowed-references #f] @
6597 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6598 Return a derivation that executes Scheme expression @var{exp} as a
6599 builder for derivation @var{name}. @var{inputs} must be a list of
6600 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6601 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6602 modules from the current search path to be copied in the store,
6603 compiled, and made available in the load path during the execution of
6604 @var{exp}---e.g., @code{((guix build utils) (guix build
6605 gnu-build-system))}.
6607 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6608 to a list of output/path pairs, and where @code{%build-inputs} is bound
6609 to a list of string/output-path pairs made from @var{inputs}.
6610 Optionally, @var{env-vars} is a list of string pairs specifying the name
6611 and value of environment variables visible to the builder. The builder
6612 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6613 @var{exp} returns @code{#f}, the build is considered to have failed.
6615 @var{exp} is built using @var{guile-for-build} (a derivation). When
6616 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6617 @code{%guile-for-build} fluid is used instead.
6619 See the @code{derivation} procedure for the meaning of
6620 @var{references-graphs}, @var{allowed-references},
6621 @var{disallowed-references}, @var{local-build?}, and
6622 @var{substitutable?}.
6626 Here's an example of a single-output derivation that creates a directory
6627 containing one file:
6630 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6631 (mkdir out) ; create /gnu/store/@dots{}-goo
6632 (call-with-output-file (string-append out "/test")
6634 (display '(hello guix) p))))))
6635 (build-expression->derivation store "goo" builder))
6637 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6641 @node The Store Monad
6642 @section The Store Monad
6646 The procedures that operate on the store described in the previous
6647 sections all take an open connection to the build daemon as their first
6648 argument. Although the underlying model is functional, they either have
6649 side effects or depend on the current state of the store.
6651 The former is inconvenient: the connection to the build daemon has to be
6652 carried around in all those functions, making it impossible to compose
6653 functions that do not take that parameter with functions that do. The
6654 latter can be problematic: since store operations have side effects
6655 and/or depend on external state, they have to be properly sequenced.
6657 @cindex monadic values
6658 @cindex monadic functions
6659 This is where the @code{(guix monads)} module comes in. This module
6660 provides a framework for working with @dfn{monads}, and a particularly
6661 useful monad for our uses, the @dfn{store monad}. Monads are a
6662 construct that allows two things: associating ``context'' with values
6663 (in our case, the context is the store), and building sequences of
6664 computations (here computations include accesses to the store). Values
6665 in a monad---values that carry this additional context---are called
6666 @dfn{monadic values}; procedures that return such values are called
6667 @dfn{monadic procedures}.
6669 Consider this ``normal'' procedure:
6672 (define (sh-symlink store)
6673 ;; Return a derivation that symlinks the 'bash' executable.
6674 (let* ((drv (package-derivation store bash))
6675 (out (derivation->output-path drv))
6676 (sh (string-append out "/bin/bash")))
6677 (build-expression->derivation store "sh"
6678 `(symlink ,sh %output))))
6681 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6682 as a monadic function:
6685 (define (sh-symlink)
6686 ;; Same, but return a monadic value.
6687 (mlet %store-monad ((drv (package->derivation bash)))
6688 (gexp->derivation "sh"
6689 #~(symlink (string-append #$drv "/bin/bash")
6693 There are several things to note in the second version: the @code{store}
6694 parameter is now implicit and is ``threaded'' in the calls to the
6695 @code{package->derivation} and @code{gexp->derivation} monadic
6696 procedures, and the monadic value returned by @code{package->derivation}
6697 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6699 As it turns out, the call to @code{package->derivation} can even be
6700 omitted since it will take place implicitly, as we will see later
6701 (@pxref{G-Expressions}):
6704 (define (sh-symlink)
6705 (gexp->derivation "sh"
6706 #~(symlink (string-append #$bash "/bin/bash")
6711 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6712 @c for the funny quote.
6713 Calling the monadic @code{sh-symlink} has no effect. As someone once
6714 said, ``you exit a monad like you exit a building on fire: by running''.
6715 So, to exit the monad and get the desired effect, one must use
6716 @code{run-with-store}:
6719 (run-with-store (open-connection) (sh-symlink))
6720 @result{} /gnu/store/...-sh-symlink
6723 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6724 new ``meta-commands'' to make it easier to deal with monadic procedures:
6725 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6726 to ``run'' a single monadic value through the store:
6729 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6730 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6733 The latter enters a recursive REPL, where all the return values are
6734 automatically run through the store:
6737 scheme@@(guile-user)> ,enter-store-monad
6738 store-monad@@(guile-user) [1]> (package->derivation hello)
6739 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6740 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6741 $3 = "/gnu/store/@dots{}-foo"
6742 store-monad@@(guile-user) [1]> ,q
6743 scheme@@(guile-user)>
6747 Note that non-monadic values cannot be returned in the
6748 @code{store-monad} REPL.
6750 The main syntactic forms to deal with monads in general are provided by
6751 the @code{(guix monads)} module and are described below.
6753 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6754 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6758 @deffn {Scheme Syntax} return @var{val}
6759 Return a monadic value that encapsulates @var{val}.
6762 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6763 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6764 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6765 referred to as ``bind'', but that name denotes an unrelated procedure in
6766 Guile. Thus we use this somewhat cryptic symbol inherited from the
6767 Haskell language.}. There can be one @var{mproc} or several of them, as
6772 (with-monad %state-monad
6774 (lambda (x) (return (+ 1 x)))
6775 (lambda (x) (return (* 2 x)))))
6779 @result{} some-state
6783 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6785 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6787 Bind the variables @var{var} to the monadic values @var{mval} in
6788 @var{body}, which is a sequence of expressions. As with the bind
6789 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6790 value ``contained'' in @var{mval} and making @var{var} refer to that
6791 raw, non-monadic value within the scope of the @var{body}. The form
6792 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6793 @var{val}, as per @code{let}. The binding operations occur in sequence
6794 from left to right. The last expression of @var{body} must be a monadic
6795 expression, and its result will become the result of the @code{mlet} or
6796 @code{mlet*} when run in the @var{monad}.
6798 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6799 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6802 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6803 Bind @var{mexp} and the following monadic expressions in sequence,
6804 returning the result of the last expression. Every expression in the
6805 sequence must be a monadic expression.
6807 This is akin to @code{mlet}, except that the return values of the
6808 monadic expressions are ignored. In that sense, it is analogous to
6809 @code{begin}, but applied to monadic expressions.
6812 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6813 When @var{condition} is true, evaluate the sequence of monadic
6814 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6815 @var{condition} is false, return @code{*unspecified*} in the current
6816 monad. Every expression in the sequence must be a monadic expression.
6819 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6820 When @var{condition} is false, evaluate the sequence of monadic
6821 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6822 @var{condition} is true, return @code{*unspecified*} in the current
6823 monad. Every expression in the sequence must be a monadic expression.
6827 The @code{(guix monads)} module provides the @dfn{state monad}, which
6828 allows an additional value---the state---to be @emph{threaded} through
6829 monadic procedure calls.
6831 @defvr {Scheme Variable} %state-monad
6832 The state monad. Procedures in the state monad can access and change
6833 the state that is threaded.
6835 Consider the example below. The @code{square} procedure returns a value
6836 in the state monad. It returns the square of its argument, but also
6837 increments the current state value:
6841 (mlet %state-monad ((count (current-state)))
6842 (mbegin %state-monad
6843 (set-current-state (+ 1 count))
6846 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6851 When ``run'' through @var{%state-monad}, we obtain that additional state
6852 value, which is the number of @code{square} calls.
6855 @deffn {Monadic Procedure} current-state
6856 Return the current state as a monadic value.
6859 @deffn {Monadic Procedure} set-current-state @var{value}
6860 Set the current state to @var{value} and return the previous state as a
6864 @deffn {Monadic Procedure} state-push @var{value}
6865 Push @var{value} to the current state, which is assumed to be a list,
6866 and return the previous state as a monadic value.
6869 @deffn {Monadic Procedure} state-pop
6870 Pop a value from the current state and return it as a monadic value.
6871 The state is assumed to be a list.
6874 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6875 Run monadic value @var{mval} starting with @var{state} as the initial
6876 state. Return two values: the resulting value, and the resulting state.
6879 The main interface to the store monad, provided by the @code{(guix
6880 store)} module, is as follows.
6882 @defvr {Scheme Variable} %store-monad
6883 The store monad---an alias for @var{%state-monad}.
6885 Values in the store monad encapsulate accesses to the store. When its
6886 effect is needed, a value of the store monad must be ``evaluated'' by
6887 passing it to the @code{run-with-store} procedure (see below.)
6890 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6891 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6892 open store connection.
6895 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6896 Return as a monadic value the absolute file name in the store of the file
6897 containing @var{text}, a string. @var{references} is a list of store items that the
6898 resulting text file refers to; it defaults to the empty list.
6901 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6902 Return as a monadic value the absolute file name in the store of the file
6903 containing @var{data}, a bytevector. @var{references} is a list of store
6904 items that the resulting binary file refers to; it defaults to the empty list.
6907 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6908 [#:recursive? #t] [#:select? (const #t)]
6909 Return the name of @var{file} once interned in the store. Use
6910 @var{name} as its store name, or the basename of @var{file} if
6911 @var{name} is omitted.
6913 When @var{recursive?} is true, the contents of @var{file} are added
6914 recursively; if @var{file} designates a flat file and @var{recursive?}
6915 is true, its contents are added, and its permission bits are kept.
6917 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6918 @var{stat})} for each directory entry, where @var{file} is the entry's
6919 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6920 entries for which @var{select?} does not return true.
6922 The example below adds a file to the store, under two different names:
6925 (run-with-store (open-connection)
6926 (mlet %store-monad ((a (interned-file "README"))
6927 (b (interned-file "README" "LEGU-MIN")))
6928 (return (list a b))))
6930 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6935 The @code{(guix packages)} module exports the following package-related
6938 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6939 [#:system (%current-system)] [#:target #f] @
6942 value in the absolute file name of @var{file} within the @var{output}
6943 directory of @var{package}. When @var{file} is omitted, return the name
6944 of the @var{output} directory of @var{package}. When @var{target} is
6945 true, use it as a cross-compilation target triplet.
6948 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6949 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6950 @var{target} [@var{system}]
6951 Monadic version of @code{package-derivation} and
6952 @code{package-cross-derivation} (@pxref{Defining Packages}).
6957 @section G-Expressions
6959 @cindex G-expression
6960 @cindex build code quoting
6961 So we have ``derivations'', which represent a sequence of build actions
6962 to be performed to produce an item in the store (@pxref{Derivations}).
6963 These build actions are performed when asking the daemon to actually
6964 build the derivations; they are run by the daemon in a container
6965 (@pxref{Invoking guix-daemon}).
6967 @cindex strata of code
6968 It should come as no surprise that we like to write these build actions
6969 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
6970 code@footnote{The term @dfn{stratum} in this context was coined by
6971 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
6972 Kiselyov, who has written insightful
6973 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
6974 on this topic}, refers to this kind of code generation as
6975 @dfn{staging}.}: the ``host code''---code that defines packages, talks
6976 to the daemon, etc.---and the ``build code''---code that actually
6977 performs build actions, such as making directories, invoking
6978 @command{make}, etc.
6980 To describe a derivation and its build actions, one typically needs to
6981 embed build code inside host code. It boils down to manipulating build
6982 code as data, and the homoiconicity of Scheme---code has a direct
6983 representation as data---comes in handy for that. But we need more than
6984 the normal @code{quasiquote} mechanism in Scheme to construct build
6987 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
6988 S-expressions adapted to build expressions. G-expressions, or
6989 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
6990 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
6991 @code{#$}, and @code{#$@@}), which are comparable to
6992 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
6993 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
6994 GNU Guile Reference Manual}). However, there are major differences:
6998 Gexps are meant to be written to a file and run or manipulated by other
7002 When a high-level object such as a package or derivation is unquoted
7003 inside a gexp, the result is as if its output file name had been
7007 Gexps carry information about the packages or derivations they refer to,
7008 and these dependencies are automatically added as inputs to the build
7009 processes that use them.
7012 @cindex lowering, of high-level objects in gexps
7013 This mechanism is not limited to package and derivation
7014 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7015 derivations or files in the store can be defined,
7016 such that these objects can also be inserted
7017 into gexps. For example, a useful type of high-level objects that can be
7018 inserted in a gexp is ``file-like objects'', which make it easy to
7019 add files to the store and to refer to them in
7020 derivations and such (see @code{local-file} and @code{plain-file}
7023 To illustrate the idea, here is an example of a gexp:
7030 (symlink (string-append #$coreutils "/bin/ls")
7034 This gexp can be passed to @code{gexp->derivation}; we obtain a
7035 derivation that builds a directory containing exactly one symlink to
7036 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7039 (gexp->derivation "the-thing" build-exp)
7042 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7043 substituted to the reference to the @var{coreutils} package in the
7044 actual build code, and @var{coreutils} is automatically made an input to
7045 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7046 output)}) is replaced by a string containing the directory name of the
7047 output of the derivation.
7049 @cindex cross compilation
7050 In a cross-compilation context, it is useful to distinguish between
7051 references to the @emph{native} build of a package---that can run on the
7052 host---versus references to cross builds of a package. To that end, the
7053 @code{#+} plays the same role as @code{#$}, but is a reference to a
7054 native package build:
7057 (gexp->derivation "vi"
7060 (system* (string-append #+coreutils "/bin/ln")
7062 (string-append #$emacs "/bin/emacs")
7063 (string-append #$output "/bin/vi")))
7064 #:target "mips64el-linux-gnu")
7068 In the example above, the native build of @var{coreutils} is used, so
7069 that @command{ln} can actually run on the host; but then the
7070 cross-compiled build of @var{emacs} is referenced.
7072 @cindex imported modules, for gexps
7073 @findex with-imported-modules
7074 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7075 able to use certain Guile modules from the ``host environment'' in the
7076 gexp, so those modules should be imported in the ``build environment''.
7077 The @code{with-imported-modules} form allows you to express that:
7080 (let ((build (with-imported-modules '((guix build utils))
7082 (use-modules (guix build utils))
7083 (mkdir-p (string-append #$output "/bin"))))))
7084 (gexp->derivation "empty-dir"
7087 (display "success!\n")
7092 In this example, the @code{(guix build utils)} module is automatically
7093 pulled into the isolated build environment of our gexp, such that
7094 @code{(use-modules (guix build utils))} works as expected.
7096 @cindex module closure
7097 @findex source-module-closure
7098 Usually you want the @emph{closure} of the module to be imported---i.e.,
7099 the module itself and all the modules it depends on---rather than just
7100 the module; failing to do that, attempts to use the module will fail
7101 because of missing dependent modules. The @code{source-module-closure}
7102 procedure computes the closure of a module by looking at its source file
7103 headers, which comes in handy in this case:
7106 (use-modules (guix modules)) ;for 'source-module-closure'
7108 (with-imported-modules (source-module-closure
7109 '((guix build utils)
7111 (gexp->derivation "something-with-vms"
7113 (use-modules (guix build utils)
7118 @cindex extensions, for gexps
7119 @findex with-extensions
7120 In the same vein, sometimes you want to import not just pure-Scheme
7121 modules, but also ``extensions'' such as Guile bindings to C libraries
7122 or other ``full-blown'' packages. Say you need the @code{guile-json}
7123 package available on the build side, here's how you would do it:
7126 (use-modules (gnu packages guile)) ;for 'guile-json'
7128 (with-extensions (list guile-json)
7129 (gexp->derivation "something-with-json"
7131 (use-modules (json))
7135 The syntactic form to construct gexps is summarized below.
7137 @deffn {Scheme Syntax} #~@var{exp}
7138 @deffnx {Scheme Syntax} (gexp @var{exp})
7139 Return a G-expression containing @var{exp}. @var{exp} may contain one
7140 or more of the following forms:
7144 @itemx (ungexp @var{obj})
7145 Introduce a reference to @var{obj}. @var{obj} may have one of the
7146 supported types, for example a package or a
7147 derivation, in which case the @code{ungexp} form is replaced by its
7148 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7150 If @var{obj} is a list, it is traversed and references to supported
7151 objects are substituted similarly.
7153 If @var{obj} is another gexp, its contents are inserted and its
7154 dependencies are added to those of the containing gexp.
7156 If @var{obj} is another kind of object, it is inserted as is.
7158 @item #$@var{obj}:@var{output}
7159 @itemx (ungexp @var{obj} @var{output})
7160 This is like the form above, but referring explicitly to the
7161 @var{output} of @var{obj}---this is useful when @var{obj} produces
7162 multiple outputs (@pxref{Packages with Multiple Outputs}).
7165 @itemx #+@var{obj}:output
7166 @itemx (ungexp-native @var{obj})
7167 @itemx (ungexp-native @var{obj} @var{output})
7168 Same as @code{ungexp}, but produces a reference to the @emph{native}
7169 build of @var{obj} when used in a cross compilation context.
7171 @item #$output[:@var{output}]
7172 @itemx (ungexp output [@var{output}])
7173 Insert a reference to derivation output @var{output}, or to the main
7174 output when @var{output} is omitted.
7176 This only makes sense for gexps passed to @code{gexp->derivation}.
7179 @itemx (ungexp-splicing @var{lst})
7180 Like the above, but splices the contents of @var{lst} inside the
7184 @itemx (ungexp-native-splicing @var{lst})
7185 Like the above, but refers to native builds of the objects listed in
7190 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7191 of the @code{gexp?} type (see below.)
7194 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7195 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7196 in their execution environment.
7198 Each item in @var{modules} can be the name of a module, such as
7199 @code{(guix build utils)}, or it can be a module name, followed by an
7200 arrow, followed by a file-like object:
7203 `((guix build utils)
7205 ((guix config) => ,(scheme-file "config.scm"
7206 #~(define-module @dots{}))))
7210 In the example above, the first two modules are taken from the search
7211 path, and the last one is created from the given file-like object.
7213 This form has @emph{lexical} scope: it has an effect on the gexps
7214 directly defined in @var{body}@dots{}, but not on those defined, say, in
7215 procedures called from @var{body}@dots{}.
7218 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7219 Mark the gexps defined in @var{body}@dots{} as requiring
7220 @var{extensions} in their build and execution environment.
7221 @var{extensions} is typically a list of package objects such as those
7222 defined in the @code{(gnu packages guile)} module.
7224 Concretely, the packages listed in @var{extensions} are added to the
7225 load path while compiling imported modules in @var{body}@dots{}; they
7226 are also added to the load path of the gexp returned by
7230 @deffn {Scheme Procedure} gexp? @var{obj}
7231 Return @code{#t} if @var{obj} is a G-expression.
7234 G-expressions are meant to be written to disk, either as code building
7235 some derivation, or as plain files in the store. The monadic procedures
7236 below allow you to do that (@pxref{The Store Monad}, for more
7237 information about monads.)
7239 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7240 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7241 [#:hash #f] [#:hash-algo #f] @
7242 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7243 [#:module-path @var{%load-path}] @
7244 [#:effective-version "2.2"] @
7245 [#:references-graphs #f] [#:allowed-references #f] @
7246 [#:disallowed-references #f] @
7247 [#:leaked-env-vars #f] @
7248 [#:script-name (string-append @var{name} "-builder")] @
7249 [#:deprecation-warnings #f] @
7250 [#:local-build? #f] [#:substitutable? #t] @
7251 [#:properties '()] [#:guile-for-build #f]
7252 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7253 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7254 stored in a file called @var{script-name}. When @var{target} is true,
7255 it is used as the cross-compilation target triplet for packages referred
7258 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7260 make @var{modules} available in the evaluation context of @var{exp};
7261 @var{modules} is a list of names of Guile modules searched in
7262 @var{module-path} to be copied in the store, compiled, and made available in
7263 the load path during the execution of @var{exp}---e.g., @code{((guix
7264 build utils) (guix build gnu-build-system))}.
7266 @var{effective-version} determines the string to use when adding extensions of
7267 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7269 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7272 When @var{references-graphs} is true, it must be a list of tuples of one of the
7276 (@var{file-name} @var{package})
7277 (@var{file-name} @var{package} @var{output})
7278 (@var{file-name} @var{derivation})
7279 (@var{file-name} @var{derivation} @var{output})
7280 (@var{file-name} @var{store-item})
7283 The right-hand-side of each element of @var{references-graphs} is automatically made
7284 an input of the build process of @var{exp}. In the build environment, each
7285 @var{file-name} contains the reference graph of the corresponding item, in a simple
7288 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7289 In the latter case, the list denotes store items that the result is allowed to
7290 refer to. Any reference to another store item will lead to a build error.
7291 Similarly for @var{disallowed-references}, which can list items that must not be
7292 referenced by the outputs.
7294 @var{deprecation-warnings} determines whether to show deprecation warnings while
7295 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7297 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7300 @cindex file-like objects
7301 The @code{local-file}, @code{plain-file}, @code{computed-file},
7302 @code{program-file}, and @code{scheme-file} procedures below return
7303 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7304 these objects lead to a file in the store. Consider this G-expression:
7307 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7308 #$(local-file "/tmp/my-nscd.conf"))
7311 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7312 to the store. Once expanded, for instance @i{via}
7313 @code{gexp->derivation}, the G-expression refers to that copy under
7314 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7315 does not have any effect on what the G-expression does.
7316 @code{plain-file} can be used similarly; it differs in that the file
7317 content is directly passed as a string.
7319 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7320 [#:recursive? #f] [#:select? (const #t)]
7321 Return an object representing local file @var{file} to add to the store; this
7322 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7323 up relative to the source file where this form appears. @var{file} will be added to
7324 the store under @var{name}--by default the base name of @var{file}.
7326 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7327 designates a flat file and @var{recursive?} is true, its contents are added, and its
7328 permission bits are kept.
7330 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7331 @var{stat})} for each directory entry, where @var{file} is the entry's
7332 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7333 entries for which @var{select?} does not return true.
7335 This is the declarative counterpart of the @code{interned-file} monadic
7336 procedure (@pxref{The Store Monad, @code{interned-file}}).
7339 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7340 Return an object representing a text file called @var{name} with the given
7341 @var{content} (a string or a bytevector) to be added to the store.
7343 This is the declarative counterpart of @code{text-file}.
7346 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7347 [#:options '(#:local-build? #t)]
7348 Return an object representing the store item @var{name}, a file or
7349 directory computed by @var{gexp}. @var{options}
7350 is a list of additional arguments to pass to @code{gexp->derivation}.
7352 This is the declarative counterpart of @code{gexp->derivation}.
7355 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7356 [#:guile (default-guile)] [#:module-path %load-path]
7357 Return an executable script @var{name} that runs @var{exp} using
7358 @var{guile}, with @var{exp}'s imported modules in its search path.
7359 Look up @var{exp}'s modules in @var{module-path}.
7361 The example below builds a script that simply invokes the @command{ls}
7365 (use-modules (guix gexp) (gnu packages base))
7367 (gexp->script "list-files"
7368 #~(execl #$(file-append coreutils "/bin/ls")
7372 When ``running'' it through the store (@pxref{The Store Monad,
7373 @code{run-with-store}}), we obtain a derivation that produces an
7374 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7377 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7379 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7383 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7384 [#:guile #f] [#:module-path %load-path]
7385 Return an object representing the executable store item @var{name} that
7386 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7387 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7389 This is the declarative counterpart of @code{gexp->script}.
7392 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7393 [#:set-load-path? #t] [#:module-path %load-path] @
7395 [#:guile (default-guile)]
7396 Return a derivation that builds a file @var{name} containing @var{exp}.
7397 When @var{splice?} is true, @var{exp} is considered to be a list of
7398 expressions that will be spliced in the resulting file.
7400 When @var{set-load-path?} is true, emit code in the resulting file to
7401 set @code{%load-path} and @code{%load-compiled-path} to honor
7402 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7405 The resulting file holds references to all the dependencies of @var{exp}
7406 or a subset thereof.
7409 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7410 Return an object representing the Scheme file @var{name} that contains
7413 This is the declarative counterpart of @code{gexp->file}.
7416 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7417 Return as a monadic value a derivation that builds a text file
7418 containing all of @var{text}. @var{text} may list, in addition to
7419 strings, objects of any type that can be used in a gexp: packages,
7420 derivations, local file objects, etc. The resulting store file holds
7421 references to all these.
7423 This variant should be preferred over @code{text-file} anytime the file
7424 to create will reference items from the store. This is typically the
7425 case when building a configuration file that embeds store file names,
7429 (define (profile.sh)
7430 ;; Return the name of a shell script in the store that
7431 ;; initializes the 'PATH' environment variable.
7432 (text-file* "profile.sh"
7433 "export PATH=" coreutils "/bin:"
7434 grep "/bin:" sed "/bin\n"))
7437 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7438 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7439 preventing them from being garbage-collected during its lifetime.
7442 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7443 Return an object representing store file @var{name} containing
7444 @var{text}. @var{text} is a sequence of strings and file-like objects,
7448 (mixed-text-file "profile"
7449 "export PATH=" coreutils "/bin:" grep "/bin")
7452 This is the declarative counterpart of @code{text-file*}.
7455 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7456 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7457 Each item in @var{files} must be a two-element list where the first element is the
7458 file name to use in the new directory, and the second element is a gexp
7459 denoting the target file. Here's an example:
7463 `(("hosts" ,(plain-file "hosts"
7464 "127.0.0.1 localhost"))
7465 ("bashrc" ,(plain-file "bashrc"
7466 "alias ls='ls --color=auto'"))))
7469 This yields an @code{etc} directory containing these two files.
7472 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7473 Return a directory that is the union of @var{things}, where @var{things} is a list of
7474 file-like objects denoting directories. For example:
7477 (directory-union "guile+emacs" (list guile emacs))
7480 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7483 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7484 Return a file-like object that expands to the concatenation of @var{obj}
7485 and @var{suffix}, where @var{obj} is a lowerable object and each
7486 @var{suffix} is a string.
7488 As an example, consider this gexp:
7491 (gexp->script "run-uname"
7492 #~(system* #$(file-append coreutils
7496 The same effect could be achieved with:
7499 (gexp->script "run-uname"
7500 #~(system* (string-append #$coreutils
7504 There is one difference though: in the @code{file-append} case, the
7505 resulting script contains the absolute file name as a string, whereas in
7506 the second case, the resulting script contains a @code{(string-append
7507 @dots{})} expression to construct the file name @emph{at run time}.
7511 Of course, in addition to gexps embedded in ``host'' code, there are
7512 also modules containing build tools. To make it clear that they are
7513 meant to be used in the build stratum, these modules are kept in the
7514 @code{(guix build @dots{})} name space.
7516 @cindex lowering, of high-level objects in gexps
7517 Internally, high-level objects are @dfn{lowered}, using their compiler,
7518 to either derivations or store items. For instance, lowering a package
7519 yields a derivation, and lowering a @code{plain-file} yields a store
7520 item. This is achieved using the @code{lower-object} monadic procedure.
7522 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7524 Return as a value in @var{%store-monad} the derivation or store item
7525 corresponding to @var{obj} for @var{system}, cross-compiling for
7526 @var{target} if @var{target} is true. @var{obj} must be an object that
7527 has an associated gexp compiler, such as a @code{<package>}.
7530 @node Invoking guix repl
7531 @section Invoking @command{guix repl}
7533 @cindex REPL, read-eval-print loop
7534 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7535 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7536 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7537 command, @command{guix repl} guarantees that all the Guix modules and all its
7538 dependencies are available in the search path. You can use it this way:
7542 scheme@@(guile-user)> ,use (gnu packages base)
7543 scheme@@(guile-user)> coreutils
7544 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7548 In addition, @command{guix repl} implements a simple machine-readable REPL
7549 protocol for use by @code{(guix inferior)}, a facility to interact with
7550 @dfn{inferiors}, separate processes running a potentially different revision
7553 The available options are as follows:
7556 @item --type=@var{type}
7557 @itemx -t @var{type}
7558 Start a REPL of the given @var{TYPE}, which can be one of the following:
7562 This is default, and it spawns a standard full-featured Guile REPL.
7564 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7565 that the @code{(guix inferior)} module speaks.
7568 @item --listen=@var{endpoint}
7569 By default, @command{guix repl} reads from standard input and writes to
7570 standard output. When this option is passed, it will instead listen for
7571 connections on @var{endpoint}. Here are examples of valid options:
7574 @item --listen=tcp:37146
7575 Accept connections on localhost on port 37146.
7577 @item --listen=unix:/tmp/socket
7578 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7582 @c *********************************************************************
7586 This section describes Guix command-line utilities. Some of them are
7587 primarily targeted at developers and users who write new package
7588 definitions, while others are more generally useful. They complement
7589 the Scheme programming interface of Guix in a convenient way.
7592 * Invoking guix build:: Building packages from the command line.
7593 * Invoking guix edit:: Editing package definitions.
7594 * Invoking guix download:: Downloading a file and printing its hash.
7595 * Invoking guix hash:: Computing the cryptographic hash of a file.
7596 * Invoking guix import:: Importing package definitions.
7597 * Invoking guix refresh:: Updating package definitions.
7598 * Invoking guix lint:: Finding errors in package definitions.
7599 * Invoking guix size:: Profiling disk usage.
7600 * Invoking guix graph:: Visualizing the graph of packages.
7601 * Invoking guix publish:: Sharing substitutes.
7602 * Invoking guix challenge:: Challenging substitute servers.
7603 * Invoking guix copy:: Copying to and from a remote store.
7604 * Invoking guix container:: Process isolation.
7605 * Invoking guix weather:: Assessing substitute availability.
7606 * Invoking guix processes:: Listing client processes.
7609 @node Invoking guix build
7610 @section Invoking @command{guix build}
7612 @cindex package building
7613 @cindex @command{guix build}
7614 The @command{guix build} command builds packages or derivations and
7615 their dependencies, and prints the resulting store paths. Note that it
7616 does not modify the user's profile---this is the job of the
7617 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7618 it is mainly useful for distribution developers.
7620 The general syntax is:
7623 guix build @var{options} @var{package-or-derivation}@dots{}
7626 As an example, the following command builds the latest versions of Emacs
7627 and of Guile, displays their build logs, and finally displays the
7628 resulting directories:
7631 guix build emacs guile
7634 Similarly, the following command builds all the available packages:
7637 guix build --quiet --keep-going \
7638 `guix package -A | cut -f1,2 --output-delimiter=@@`
7641 @var{package-or-derivation} may be either the name of a package found in
7642 the software distribution such as @code{coreutils} or
7643 @code{coreutils@@8.20}, or a derivation such as
7644 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7645 package with the corresponding name (and optionally version) is searched
7646 for among the GNU distribution modules (@pxref{Package Modules}).
7648 Alternatively, the @code{--expression} option may be used to specify a
7649 Scheme expression that evaluates to a package; this is useful when
7650 disambiguating among several same-named packages or package variants is
7653 There may be zero or more @var{options}. The available options are
7654 described in the subsections below.
7657 * Common Build Options:: Build options for most commands.
7658 * Package Transformation Options:: Creating variants of packages.
7659 * Additional Build Options:: Options specific to 'guix build'.
7660 * Debugging Build Failures:: Real life packaging experience.
7663 @node Common Build Options
7664 @subsection Common Build Options
7666 A number of options that control the build process are common to
7667 @command{guix build} and other commands that can spawn builds, such as
7668 @command{guix package} or @command{guix archive}. These are the
7673 @item --load-path=@var{directory}
7674 @itemx -L @var{directory}
7675 Add @var{directory} to the front of the package module search path
7676 (@pxref{Package Modules}).
7678 This allows users to define their own packages and make them visible to
7679 the command-line tools.
7683 Keep the build tree of failed builds. Thus, if a build fails, its build
7684 tree is kept under @file{/tmp}, in a directory whose name is shown at
7685 the end of the build log. This is useful when debugging build issues.
7686 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7689 This option has no effect when connecting to a remote daemon with a
7690 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7695 Keep going when some of the derivations fail to build; return only once
7696 all the builds have either completed or failed.
7698 The default behavior is to stop as soon as one of the specified
7699 derivations has failed.
7703 Do not build the derivations.
7705 @anchor{fallback-option}
7707 When substituting a pre-built binary fails, fall back to building
7708 packages locally (@pxref{Substitution Failure}).
7710 @item --substitute-urls=@var{urls}
7711 @anchor{client-substitute-urls}
7712 Consider @var{urls} the whitespace-separated list of substitute source
7713 URLs, overriding the default list of URLs of @command{guix-daemon}
7714 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7716 This means that substitutes may be downloaded from @var{urls}, provided
7717 they are signed by a key authorized by the system administrator
7718 (@pxref{Substitutes}).
7720 When @var{urls} is the empty string, substitutes are effectively
7723 @item --no-substitutes
7724 Do not use substitutes for build products. That is, always build things
7725 locally instead of allowing downloads of pre-built binaries
7726 (@pxref{Substitutes}).
7729 Do not ``graft'' packages. In practice, this means that package updates
7730 available as grafts are not applied. @xref{Security Updates}, for more
7731 information on grafts.
7733 @item --rounds=@var{n}
7734 Build each derivation @var{n} times in a row, and raise an error if
7735 consecutive build results are not bit-for-bit identical.
7737 This is a useful way to detect non-deterministic builds processes.
7738 Non-deterministic build processes are a problem because they make it
7739 practically impossible for users to @emph{verify} whether third-party
7740 binaries are genuine. @xref{Invoking guix challenge}, for more.
7742 Note that, currently, the differing build results are not kept around,
7743 so you will have to manually investigate in case of an error---e.g., by
7744 stashing one of the build results with @code{guix archive --export}
7745 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7748 @item --no-build-hook
7749 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7750 (@pxref{Daemon Offload Setup}). That is, always build things locally
7751 instead of offloading builds to remote machines.
7753 @item --max-silent-time=@var{seconds}
7754 When the build or substitution process remains silent for more than
7755 @var{seconds}, terminate it and report a build failure.
7757 By default, the daemon's setting is honored (@pxref{Invoking
7758 guix-daemon, @code{--max-silent-time}}).
7760 @item --timeout=@var{seconds}
7761 Likewise, when the build or substitution process lasts for more than
7762 @var{seconds}, terminate it and report a build failure.
7764 By default, the daemon's setting is honored (@pxref{Invoking
7765 guix-daemon, @code{--timeout}}).
7767 @c Note: This option is actually not part of %standard-build-options but
7768 @c most programs honor it.
7769 @cindex verbosity, of the command-line tools
7770 @cindex build logs, verbosity
7771 @item -v @var{level}
7772 @itemx --verbosity=@var{level}
7773 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7774 output is produced, 1 is for quiet output, and 2 shows all the build log
7775 output on standard error.
7777 @item --cores=@var{n}
7779 Allow the use of up to @var{n} CPU cores for the build. The special
7780 value @code{0} means to use as many CPU cores as available.
7782 @item --max-jobs=@var{n}
7784 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7785 guix-daemon, @code{--max-jobs}}, for details about this option and the
7786 equivalent @command{guix-daemon} option.
7788 @item --debug=@var{level}
7789 Produce debugging output coming from the build daemon. @var{level} must be an
7790 integer between 0 and 5; higher means more verbose output. Setting a level of
7791 4 or more may be helpful when debugging setup issues with the build daemon.
7795 Behind the scenes, @command{guix build} is essentially an interface to
7796 the @code{package-derivation} procedure of the @code{(guix packages)}
7797 module, and to the @code{build-derivations} procedure of the @code{(guix
7798 derivations)} module.
7800 In addition to options explicitly passed on the command line,
7801 @command{guix build} and other @command{guix} commands that support
7802 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7804 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7805 Users can define this variable to a list of command line options that
7806 will automatically be used by @command{guix build} and other
7807 @command{guix} commands that can perform builds, as in the example
7811 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7814 These options are parsed independently, and the result is appended to
7815 the parsed command-line options.
7819 @node Package Transformation Options
7820 @subsection Package Transformation Options
7822 @cindex package variants
7823 Another set of command-line options supported by @command{guix build}
7824 and also @command{guix package} are @dfn{package transformation
7825 options}. These are options that make it possible to define @dfn{package
7826 variants}---for instance, packages built from different source code.
7827 This is a convenient way to create customized packages on the fly
7828 without having to type in the definitions of package variants
7829 (@pxref{Defining Packages}).
7833 @item --with-source=@var{source}
7834 @itemx --with-source=@var{package}=@var{source}
7835 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7836 Use @var{source} as the source of @var{package}, and @var{version} as
7838 @var{source} must be a file name or a URL, as for @command{guix
7839 download} (@pxref{Invoking guix download}).
7841 When @var{package} is omitted,
7842 it is taken to be the package name specified on the
7843 command line that matches the base of @var{source}---e.g.,
7844 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7845 package is @code{guile}.
7847 Likewise, when @var{version} is omitted, the version string is inferred from
7848 @var{source}; in the previous example, it is @code{2.0.10}.
7850 This option allows users to try out versions of packages other than the
7851 one provided by the distribution. The example below downloads
7852 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7853 the @code{ed} package:
7856 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7859 As a developer, @code{--with-source} makes it easy to test release
7863 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7866 @dots{} or to build from a checkout in a pristine environment:
7869 $ git clone git://git.sv.gnu.org/guix.git
7870 $ guix build guix --with-source=guix@@1.0=./guix
7873 @item --with-input=@var{package}=@var{replacement}
7874 Replace dependency on @var{package} by a dependency on
7875 @var{replacement}. @var{package} must be a package name, and
7876 @var{replacement} must be a package specification such as @code{guile}
7877 or @code{guile@@1.8}.
7879 For instance, the following command builds Guix, but replaces its
7880 dependency on the current stable version of Guile with a dependency on
7881 the legacy version of Guile, @code{guile@@2.0}:
7884 guix build --with-input=guile=guile@@2.0 guix
7887 This is a recursive, deep replacement. So in this example, both
7888 @code{guix} and its dependency @code{guile-json} (which also depends on
7889 @code{guile}) get rebuilt against @code{guile@@2.0}.
7891 This is implemented using the @code{package-input-rewriting} Scheme
7892 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7894 @item --with-graft=@var{package}=@var{replacement}
7895 This is similar to @code{--with-input} but with an important difference:
7896 instead of rebuilding the whole dependency chain, @var{replacement} is
7897 built and then @dfn{grafted} onto the binaries that were initially
7898 referring to @var{package}. @xref{Security Updates}, for more
7899 information on grafts.
7901 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7902 and all its dependencies, replacing references to the version of GnuTLS
7903 they currently refer to:
7906 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7909 This has the advantage of being much faster than rebuilding everything.
7910 But there is a caveat: it works if and only if @var{package} and
7911 @var{replacement} are strictly compatible---for example, if they provide
7912 a library, the application binary interface (ABI) of those libraries
7913 must be compatible. If @var{replacement} is somehow incompatible with
7914 @var{package}, then the resulting package may be unusable. Use with
7917 @item --with-git-url=@var{package}=@var{url}
7918 @cindex Git, using the latest commit
7919 @cindex latest commit, building
7920 Build @var{package} from the latest commit of the @code{master} branch of the
7921 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7924 For example, the following command builds the NumPy Python library against the
7925 latest commit of the master branch of Python itself:
7928 guix build python-numpy \
7929 --with-git-url=python=https://github.com/python/cpython
7932 This option can also be combined with @code{--with-branch} or
7933 @code{--with-commit} (see below).
7935 @cindex continuous integration
7936 Obviously, since it uses the latest commit of the given branch, the result of
7937 such a command varies over time. Nevertheless it is a convenient way to
7938 rebuild entire software stacks against the latest commit of one or more
7939 packages. This is particularly useful in the context of continuous
7942 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7943 consecutive accesses to the same repository. You may want to clean it up once
7944 in a while to save disk space.
7946 @item --with-branch=@var{package}=@var{branch}
7947 Build @var{package} from the latest commit of @var{branch}. If the
7948 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7949 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7950 repository URL is taken from that @code{source}. Otherwise you have to use
7951 @code{--with-git-url} to specify the URL of the Git repository.
7953 For instance, the following command builds @code{guile-sqlite3} from the
7954 latest commit of its @code{master} branch, and then builds @code{guix} (which
7955 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
7956 specific @code{guile-sqlite3} build:
7959 guix build --with-branch=guile-sqlite3=master cuirass
7962 @item --with-commit=@var{package}=@var{commit}
7963 This is similar to @code{--with-branch}, except that it builds from
7964 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
7965 Git commit SHA1 identifier.
7968 @node Additional Build Options
7969 @subsection Additional Build Options
7971 The command-line options presented below are specific to @command{guix
7978 Build quietly, without displaying the build log; this is equivalent to
7979 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
7980 (or similar) and can always be retrieved using the @option{--log-file} option.
7982 @item --file=@var{file}
7983 @itemx -f @var{file}
7984 Build the package, derivation, or other file-like object that the code within
7985 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
7987 As an example, @var{file} might contain a package definition like this
7988 (@pxref{Defining Packages}):
7991 @verbatiminclude package-hello.scm
7994 @item --expression=@var{expr}
7995 @itemx -e @var{expr}
7996 Build the package or derivation @var{expr} evaluates to.
7998 For example, @var{expr} may be @code{(@@ (gnu packages guile)
7999 guile-1.8)}, which unambiguously designates this specific variant of
8000 version 1.8 of Guile.
8002 Alternatively, @var{expr} may be a G-expression, in which case it is used
8003 as a build program passed to @code{gexp->derivation}
8004 (@pxref{G-Expressions}).
8006 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8007 (@pxref{The Store Monad}). The procedure must return a derivation as a
8008 monadic value, which is then passed through @code{run-with-store}.
8012 Build the source derivations of the packages, rather than the packages
8015 For instance, @code{guix build -S gcc} returns something like
8016 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8019 The returned source tarball is the result of applying any patches and
8020 code snippets specified in the package @code{origin} (@pxref{Defining
8024 Fetch and return the source of @var{package-or-derivation} and all their
8025 dependencies, recursively. This is a handy way to obtain a local copy
8026 of all the source code needed to build @var{packages}, allowing you to
8027 eventually build them even without network access. It is an extension
8028 of the @code{--source} option and can accept one of the following
8029 optional argument values:
8033 This value causes the @code{--sources} option to behave in the same way
8034 as the @code{--source} option.
8037 Build the source derivations of all packages, including any source that
8038 might be listed as @code{inputs}. This is the default value.
8041 $ guix build --sources tzdata
8042 The following derivations will be built:
8043 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8044 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8048 Build the source derivations of all packages, as well of all transitive
8049 inputs to the packages. This can be used e.g.@: to
8050 prefetch package source for later offline building.
8053 $ guix build --sources=transitive tzdata
8054 The following derivations will be built:
8055 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8056 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8057 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8058 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8059 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8060 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8066 @item --system=@var{system}
8067 @itemx -s @var{system}
8068 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8069 the system type of the build host. The @command{guix build} command allows
8070 you to repeat this option several times, in which case it builds for all the
8071 specified systems; other commands ignore extraneous @option{-s} options.
8074 The @code{--system} flag is for @emph{native} compilation and must not
8075 be confused with cross-compilation. See @code{--target} below for
8076 information on cross-compilation.
8079 An example use of this is on Linux-based systems, which can emulate
8080 different personalities. For instance, passing
8081 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8082 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8083 to build packages in a complete 32-bit environment.
8086 Building for an @code{armhf-linux} system is unconditionally enabled on
8087 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8088 allow for this functionality, notably the ThunderX.
8091 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8092 is enabled (@pxref{Virtualization Services,
8093 @code{qemu-binfmt-service-type}}), you can build for any system for
8094 which a QEMU @code{binfmt_misc} handler is installed.
8096 Builds for a system other than that of the machine you are using can
8097 also be offloaded to a remote machine of the right architecture.
8098 @xref{Daemon Offload Setup}, for more information on offloading.
8100 @item --target=@var{triplet}
8101 @cindex cross-compilation
8102 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8103 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
8104 configuration triplets,, autoconf, Autoconf}).
8106 @anchor{build-check}
8108 @cindex determinism, checking
8109 @cindex reproducibility, checking
8110 Rebuild @var{package-or-derivation}, which are already available in the
8111 store, and raise an error if the build results are not bit-for-bit
8114 This mechanism allows you to check whether previously installed
8115 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8116 of a package is deterministic. @xref{Invoking guix challenge}, for more
8117 background information and tools.
8119 When used in conjunction with @option{--keep-failed}, the differing
8120 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8121 This makes it easy to look for differences between the two results.
8124 @cindex repairing store items
8125 @cindex corruption, recovering from
8126 Attempt to repair the specified store items, if they are corrupt, by
8127 re-downloading or rebuilding them.
8129 This operation is not atomic and thus restricted to @code{root}.
8133 Return the derivation paths, not the output paths, of the given
8136 @item --root=@var{file}
8137 @itemx -r @var{file}
8138 @cindex GC roots, adding
8139 @cindex garbage collector roots, adding
8140 Make @var{file} a symlink to the result, and register it as a garbage
8143 Consequently, the results of this @command{guix build} invocation are
8144 protected from garbage collection until @var{file} is removed. When
8145 that option is omitted, build results are eligible for garbage
8146 collection as soon as the build completes. @xref{Invoking guix gc}, for
8150 @cindex build logs, access
8151 Return the build log file names or URLs for the given
8152 @var{package-or-derivation}, or raise an error if build logs are
8155 This works regardless of how packages or derivations are specified. For
8156 instance, the following invocations are equivalent:
8159 guix build --log-file `guix build -d guile`
8160 guix build --log-file `guix build guile`
8161 guix build --log-file guile
8162 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8165 If a log is unavailable locally, and unless @code{--no-substitutes} is
8166 passed, the command looks for a corresponding log on one of the
8167 substitute servers (as specified with @code{--substitute-urls}.)
8169 So for instance, imagine you want to see the build log of GDB on MIPS,
8170 but you are actually on an @code{x86_64} machine:
8173 $ guix build --log-file gdb -s mips64el-linux
8174 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8177 You can freely access a huge library of build logs!
8180 @node Debugging Build Failures
8181 @subsection Debugging Build Failures
8183 @cindex build failures, debugging
8184 When defining a new package (@pxref{Defining Packages}), you will
8185 probably find yourself spending some time debugging and tweaking the
8186 build until it succeeds. To do that, you need to operate the build
8187 commands yourself in an environment as close as possible to the one the
8190 To that end, the first thing to do is to use the @option{--keep-failed}
8191 or @option{-K} option of @command{guix build}, which will keep the
8192 failed build tree in @file{/tmp} or whatever directory you specified as
8193 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8195 From there on, you can @command{cd} to the failed build tree and source
8196 the @file{environment-variables} file, which contains all the
8197 environment variable definitions that were in place when the build
8198 failed. So let's say you're debugging a build failure in package
8199 @code{foo}; a typical session would look like this:
8203 @dots{} @i{build fails}
8204 $ cd /tmp/guix-build-foo.drv-0
8205 $ source ./environment-variables
8209 Now, you can invoke commands as if you were the daemon (almost) and
8210 troubleshoot your build process.
8212 Sometimes it happens that, for example, a package's tests pass when you
8213 run them manually but they fail when the daemon runs them. This can
8214 happen because the daemon runs builds in containers where, unlike in our
8215 environment above, network access is missing, @file{/bin/sh} does not
8216 exist, etc. (@pxref{Build Environment Setup}).
8218 In such cases, you may need to run inspect the build process from within
8219 a container similar to the one the build daemon creates:
8224 $ cd /tmp/guix-build-foo.drv-0
8225 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8226 [env]# source ./environment-variables
8230 Here, @command{guix environment -C} creates a container and spawns a new
8231 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8232 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8233 the container, which would may find handy while debugging. The
8234 @option{--no-grafts} option makes sure we get the exact same
8235 environment, with ungrafted packages (@pxref{Security Updates}, for more
8238 To get closer to a container like that used by the build daemon, we can
8239 remove @file{/bin/sh}:
8245 (Don't worry, this is harmless: this is all happening in the throw-away
8246 container created by @command{guix environment}.)
8248 The @command{strace} command is probably not in the search path, but we
8252 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8255 In this way, not only you will have reproduced the environment variables
8256 the daemon uses, you will also be running the build process in a container
8257 similar to the one the daemon uses.
8260 @node Invoking guix edit
8261 @section Invoking @command{guix edit}
8263 @cindex @command{guix edit}
8264 @cindex package definition, editing
8265 So many packages, so many source files! The @command{guix edit} command
8266 facilitates the life of users and packagers by pointing their editor at
8267 the source file containing the definition of the specified packages.
8271 guix edit gcc@@4.9 vim
8275 launches the program specified in the @code{VISUAL} or in the
8276 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8279 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8280 have created your own packages on @code{GUIX_PACKAGE_PATH}
8281 (@pxref{Package Modules}), you will be able to edit the package
8282 recipes. In other cases, you will be able to examine the read-only recipes
8283 for packages currently in the store.
8286 @node Invoking guix download
8287 @section Invoking @command{guix download}
8289 @cindex @command{guix download}
8290 @cindex downloading package sources
8291 When writing a package definition, developers typically need to download
8292 a source tarball, compute its SHA256 hash, and write that
8293 hash in the package definition (@pxref{Defining Packages}). The
8294 @command{guix download} tool helps with this task: it downloads a file
8295 from the given URI, adds it to the store, and prints both its file name
8296 in the store and its SHA256 hash.
8298 The fact that the downloaded file is added to the store saves bandwidth:
8299 when the developer eventually tries to build the newly defined package
8300 with @command{guix build}, the source tarball will not have to be
8301 downloaded again because it is already in the store. It is also a
8302 convenient way to temporarily stash files, which may be deleted
8303 eventually (@pxref{Invoking guix gc}).
8305 The @command{guix download} command supports the same URIs as used in
8306 package definitions. In particular, it supports @code{mirror://} URIs.
8307 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8308 Guile bindings for GnuTLS are available in the user's environment; when
8309 they are not available, an error is raised. @xref{Guile Preparations,
8310 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8311 GnuTLS-Guile}, for more information.
8313 @command{guix download} verifies HTTPS server certificates by loading
8314 the certificates of X.509 authorities from the directory pointed to by
8315 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8316 Certificates}), unless @option{--no-check-certificate} is used.
8318 The following options are available:
8321 @item --format=@var{fmt}
8323 Write the hash in the format specified by @var{fmt}. For more
8324 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8326 @item --no-check-certificate
8327 Do not validate the X.509 certificates of HTTPS servers.
8329 When using this option, you have @emph{absolutely no guarantee} that you
8330 are communicating with the authentic server responsible for the given
8331 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8333 @item --output=@var{file}
8334 @itemx -o @var{file}
8335 Save the downloaded file to @var{file} instead of adding it to the
8339 @node Invoking guix hash
8340 @section Invoking @command{guix hash}
8342 @cindex @command{guix hash}
8343 The @command{guix hash} command computes the SHA256 hash of a file.
8344 It is primarily a convenience tool for anyone contributing to the
8345 distribution: it computes the cryptographic hash of a file, which can be
8346 used in the definition of a package (@pxref{Defining Packages}).
8348 The general syntax is:
8351 guix hash @var{option} @var{file}
8354 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8355 hash of data read from standard input. @command{guix hash} has the
8360 @item --format=@var{fmt}
8362 Write the hash in the format specified by @var{fmt}.
8364 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8365 (@code{hex} and @code{hexadecimal} can be used as well).
8367 If the @option{--format} option is not specified, @command{guix hash}
8368 will output the hash in @code{nix-base32}. This representation is used
8369 in the definitions of packages.
8373 Compute the hash on @var{file} recursively.
8375 In this case, the hash is computed on an archive containing @var{file},
8376 including its children if it is a directory. Some of the metadata of
8377 @var{file} is part of the archive; for instance, when @var{file} is a
8378 regular file, the hash is different depending on whether @var{file} is
8379 executable or not. Metadata such as time stamps has no impact on the
8380 hash (@pxref{Invoking guix archive}).
8381 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8386 When combined with @option{--recursive}, exclude version control system
8387 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8390 As an example, here is how you would compute the hash of a Git checkout,
8391 which is useful when using the @code{git-fetch} method (@pxref{origin
8395 $ git clone http://example.org/foo.git
8401 @node Invoking guix import
8402 @section Invoking @command{guix import}
8404 @cindex importing packages
8405 @cindex package import
8406 @cindex package conversion
8407 @cindex Invoking @command{guix import}
8408 The @command{guix import} command is useful for people who would like to
8409 add a package to the distribution with as little work as
8410 possible---a legitimate demand. The command knows of a few
8411 repositories from which it can ``import'' package metadata. The result
8412 is a package definition, or a template thereof, in the format we know
8413 (@pxref{Defining Packages}).
8415 The general syntax is:
8418 guix import @var{importer} @var{options}@dots{}
8421 @var{importer} specifies the source from which to import package
8422 metadata, and @var{options} specifies a package identifier and other
8423 options specific to @var{importer}. Currently, the available
8428 Import metadata for the given GNU package. This provides a template
8429 for the latest version of that GNU package, including the hash of its
8430 source tarball, and its canonical synopsis and description.
8432 Additional information such as the package dependencies and its
8433 license needs to be figured out manually.
8435 For example, the following command returns a package definition for
8439 guix import gnu hello
8442 Specific command-line options are:
8445 @item --key-download=@var{policy}
8446 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8447 keys when verifying the package signature. @xref{Invoking guix
8448 refresh, @code{--key-download}}.
8453 Import metadata from the @uref{https://pypi.python.org/, Python Package
8454 Index}. Information is taken from the JSON-formatted description
8455 available at @code{pypi.python.org} and usually includes all the relevant
8456 information, including package dependencies. For maximum efficiency, it
8457 is recommended to install the @command{unzip} utility, so that the
8458 importer can unzip Python wheels and gather data from them.
8460 The command below imports metadata for the @code{itsdangerous} Python
8464 guix import pypi itsdangerous
8470 Traverse the dependency graph of the given upstream package recursively
8471 and generate package expressions for all those packages that are not yet
8477 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8478 is taken from the JSON-formatted description available at
8479 @code{rubygems.org} and includes most relevant information, including
8480 runtime dependencies. There are some caveats, however. The metadata
8481 doesn't distinguish between synopses and descriptions, so the same string
8482 is used for both fields. Additionally, the details of non-Ruby
8483 dependencies required to build native extensions is unavailable and left
8484 as an exercise to the packager.
8486 The command below imports metadata for the @code{rails} Ruby package:
8489 guix import gem rails
8495 Traverse the dependency graph of the given upstream package recursively
8496 and generate package expressions for all those packages that are not yet
8502 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8503 Information is taken from the JSON-formatted metadata provided through
8504 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8505 relevant information, such as module dependencies. License information
8506 should be checked closely. If Perl is available in the store, then the
8507 @code{corelist} utility will be used to filter core modules out of the
8508 list of dependencies.
8510 The command command below imports metadata for the @code{Acme::Boolean}
8514 guix import cpan Acme::Boolean
8519 @cindex Bioconductor
8520 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8521 central repository for the @uref{http://r-project.org, GNU@tie{}R
8522 statistical and graphical environment}.
8524 Information is extracted from the @code{DESCRIPTION} file of the package.
8526 The command command below imports metadata for the @code{Cairo}
8530 guix import cran Cairo
8533 When @code{--recursive} is added, the importer will traverse the
8534 dependency graph of the given upstream package recursively and generate
8535 package expressions for all those packages that are not yet in Guix.
8537 When @code{--archive=bioconductor} is added, metadata is imported from
8538 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8539 packages for for the analysis and comprehension of high-throughput
8540 genomic data in bioinformatics.
8542 Information is extracted from the @code{DESCRIPTION} file of a package
8543 published on the web interface of the Bioconductor SVN repository.
8545 The command below imports metadata for the @code{GenomicRanges}
8549 guix import cran --archive=bioconductor GenomicRanges
8555 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
8556 comprehensive TeX archive network for TeX packages that are part of the
8557 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8559 Information about the package is obtained through the XML API provided
8560 by CTAN, while the source code is downloaded from the SVN repository of
8561 the Tex Live project. This is done because the CTAN does not keep
8564 The command command below imports metadata for the @code{fontspec}
8568 guix import texlive fontspec
8571 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8572 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8573 tree in the TeX Live SVN repository, but from the specified sibling
8574 directory under the same root.
8576 The command below imports metadata for the @code{ifxetex} package from
8577 CTAN while fetching the sources from the directory
8578 @file{texmf/source/generic}:
8581 guix import texlive --archive=generic ifxetex
8585 @cindex JSON, import
8586 Import package metadata from a local JSON file. Consider the following
8587 example package definition in JSON format:
8593 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8594 "build-system": "gnu",
8595 "home-page": "https://www.gnu.org/software/hello/",
8596 "synopsis": "Hello, GNU world: An example GNU package",
8597 "description": "GNU Hello prints a greeting.",
8598 "license": "GPL-3.0+",
8599 "native-inputs": ["gcc@@6"]
8603 The field names are the same as for the @code{<package>} record
8604 (@xref{Defining Packages}). References to other packages are provided
8605 as JSON lists of quoted package specification strings such as
8606 @code{guile} or @code{guile@@2.0}.
8608 The importer also supports a more explicit source definition using the
8609 common fields for @code{<origin>} records:
8615 "method": "url-fetch",
8616 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8618 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8625 The command below reads metadata from the JSON file @code{hello.json}
8626 and outputs a package expression:
8629 guix import json hello.json
8633 Import metadata from a local copy of the source of the
8634 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8635 relies on the @command{nix-instantiate} command of
8636 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8637 typically written in a mixture of Nix-language and Bash code. This
8638 command only imports the high-level package structure that is written in
8639 the Nix language. It normally includes all the basic fields of a
8642 When importing a GNU package, the synopsis and descriptions are replaced
8643 by their canonical upstream variant.
8645 Usually, you will first need to do:
8648 export NIX_REMOTE=daemon
8652 so that @command{nix-instantiate} does not try to open the Nix database.
8654 As an example, the command below imports the package definition of
8655 LibreOffice (more precisely, it imports the definition of the package
8656 bound to the @code{libreoffice} top-level attribute):
8659 guix import nix ~/path/to/nixpkgs libreoffice
8664 Import metadata from the Haskell community's central package archive
8665 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8666 Cabal files and includes all the relevant information, including package
8669 Specific command-line options are:
8674 Read a Cabal file from standard input.
8675 @item --no-test-dependencies
8677 Do not include dependencies required only by the test suites.
8678 @item --cabal-environment=@var{alist}
8679 @itemx -e @var{alist}
8680 @var{alist} is a Scheme alist defining the environment in which the
8681 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8682 @code{arch}, @code{impl} and a string representing the name of a flag.
8683 The value associated with a flag has to be either the symbol
8684 @code{true} or @code{false}. The value associated with other keys
8685 has to conform to the Cabal file format definition. The default value
8686 associated with the keys @code{os}, @code{arch} and @code{impl} is
8687 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8690 Traverse the dependency graph of the given upstream package recursively
8691 and generate package expressions for all those packages that are not yet
8695 The command below imports metadata for the latest version of the
8696 @code{HTTP} Haskell package without including test dependencies and
8697 specifying the value of the flag @samp{network-uri} as @code{false}:
8700 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8703 A specific package version may optionally be specified by following the
8704 package name by an at-sign and a version number as in the following example:
8707 guix import hackage mtl@@2.1.3.1
8712 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8713 It takes a package name, looks up the package version included in a
8714 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8715 release and uses the @code{hackage} importer to retrieve its metadata.
8716 Note that it is up to you to select an LTS release compatible with the
8717 GHC compiler used by Guix.
8719 Specific command-line options are:
8722 @item --no-test-dependencies
8724 Do not include dependencies required only by the test suites.
8725 @item --lts-version=@var{version}
8726 @itemx -l @var{version}
8727 @var{version} is the desired LTS release version. If omitted the latest
8731 Traverse the dependency graph of the given upstream package recursively
8732 and generate package expressions for all those packages that are not yet
8736 The command below imports metadata for the @code{HTTP} Haskell package
8737 included in the LTS Stackage release version 7.18:
8740 guix import stackage --lts-version=7.18 HTTP
8745 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8746 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8748 Specific command-line options are:
8751 @item --archive=@var{repo}
8752 @itemx -a @var{repo}
8753 @var{repo} identifies the archive repository from which to retrieve the
8754 information. Currently the supported repositories and their identifiers
8758 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8759 identifier. This is the default.
8761 Packages from @code{elpa.gnu.org} are signed with one of the keys
8762 contained in the GnuPG keyring at
8763 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8764 @code{emacs} package (@pxref{Package Installation, ELPA package
8765 signatures,, emacs, The GNU Emacs Manual}).
8768 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
8769 @code{melpa-stable} identifier.
8772 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
8778 Traverse the dependency graph of the given upstream package recursively
8779 and generate package expressions for all those packages that are not yet
8785 Import metadata from the crates.io Rust package repository
8786 @uref{https://crates.io, crates.io}.
8791 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8792 repository used by the OCaml community.
8795 The structure of the @command{guix import} code is modular. It would be
8796 useful to have more importers for other package formats, and your help
8797 is welcome here (@pxref{Contributing}).
8799 @node Invoking guix refresh
8800 @section Invoking @command{guix refresh}
8802 @cindex @command {guix refresh}
8803 The primary audience of the @command{guix refresh} command is developers
8804 of the GNU software distribution. By default, it reports any packages
8805 provided by the distribution that are outdated compared to the latest
8806 upstream version, like this:
8810 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8811 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8814 Alternately, one can specify packages to consider, in which case a
8815 warning is emitted for packages that lack an updater:
8818 $ guix refresh coreutils guile guile-ssh
8819 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8820 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8823 @command{guix refresh} browses the upstream repository of each package and determines
8824 the highest version number of the releases therein. The command
8825 knows how to update specific types of packages: GNU packages, ELPA
8826 packages, etc.---see the documentation for @option{--type} below. There
8827 are many packages, though, for which it lacks a method to determine
8828 whether a new upstream release is available. However, the mechanism is
8829 extensible, so feel free to get in touch with us to add a new method!
8834 Consider the packages specified, and all the packages upon which they depend.
8837 $ guix refresh --recursive coreutils
8838 gnu/packages/acl.scm:35:2: warning: no updater for acl
8839 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8840 gnu/packages/xml.scm:68:2: warning: no updater for expat
8841 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8847 Sometimes the upstream name differs from the package name used in Guix,
8848 and @command{guix refresh} needs a little help. Most updaters honor the
8849 @code{upstream-name} property in package definitions, which can be used
8853 (define-public network-manager
8855 (name "network-manager")
8857 (properties '((upstream-name . "NetworkManager")))))
8860 When passed @code{--update}, it modifies distribution source files to
8861 update the version numbers and source tarball hashes of those package
8862 recipes (@pxref{Defining Packages}). This is achieved by downloading
8863 each package's latest source tarball and its associated OpenPGP
8864 signature, authenticating the downloaded tarball against its signature
8865 using @command{gpg}, and finally computing its hash. When the public
8866 key used to sign the tarball is missing from the user's keyring, an
8867 attempt is made to automatically retrieve it from a public key server;
8868 when this is successful, the key is added to the user's keyring; otherwise,
8869 @command{guix refresh} reports an error.
8871 The following options are supported:
8875 @item --expression=@var{expr}
8876 @itemx -e @var{expr}
8877 Consider the package @var{expr} evaluates to.
8879 This is useful to precisely refer to a package, as in this example:
8882 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8885 This command lists the dependents of the ``final'' libc (essentially all
8890 Update distribution source files (package recipes) in place. This is
8891 usually run from a checkout of the Guix source tree (@pxref{Running
8892 Guix Before It Is Installed}):
8895 $ ./pre-inst-env guix refresh -s non-core -u
8898 @xref{Defining Packages}, for more information on package definitions.
8900 @item --select=[@var{subset}]
8901 @itemx -s @var{subset}
8902 Select all the packages in @var{subset}, one of @code{core} or
8905 The @code{core} subset refers to all the packages at the core of the
8906 distribution---i.e., packages that are used to build ``everything
8907 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8908 changing one of these packages in the distribution entails a rebuild of
8909 all the others. Thus, such updates are an inconvenience to users in
8910 terms of build time or bandwidth used to achieve the upgrade.
8912 The @code{non-core} subset refers to the remaining packages. It is
8913 typically useful in cases where an update of the core packages would be
8916 @item --manifest=@var{file}
8917 @itemx -m @var{file}
8918 Select all the packages from the manifest in @var{file}. This is useful to
8919 check if any packages of the user manifest can be updated.
8921 @item --type=@var{updater}
8922 @itemx -t @var{updater}
8923 Select only packages handled by @var{updater} (may be a comma-separated
8924 list of updaters). Currently, @var{updater} may be one of:
8928 the updater for GNU packages;
8930 the updater for GNOME packages;
8932 the updater for KDE packages;
8934 the updater for X.org packages;
8936 the updater for packages hosted on kernel.org;
8938 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
8940 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8942 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8944 the updater for @uref{http://www.cpan.org/, CPAN} packages;
8946 the updater for @uref{https://pypi.python.org, PyPI} packages.
8948 the updater for @uref{https://rubygems.org, RubyGems} packages.
8950 the updater for @uref{https://github.com, GitHub} packages.
8952 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
8954 the updater for @uref{https://www.stackage.org, Stackage} packages.
8956 the updater for @uref{https://crates.io, Crates} packages.
8958 the updater for @uref{https://launchpad.net, Launchpad} packages.
8961 For instance, the following command only checks for updates of Emacs
8962 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
8965 $ guix refresh --type=elpa,cran
8966 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
8967 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
8972 In addition, @command{guix refresh} can be passed one or more package
8973 names, as in this example:
8976 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
8980 The command above specifically updates the @code{emacs} and
8981 @code{idutils} packages. The @code{--select} option would have no
8982 effect in this case.
8984 When considering whether to upgrade a package, it is sometimes
8985 convenient to know which packages would be affected by the upgrade and
8986 should be checked for compatibility. For this the following option may
8987 be used when passing @command{guix refresh} one or more package names:
8991 @item --list-updaters
8993 List available updaters and exit (see @option{--type} above.)
8995 For each updater, display the fraction of packages it covers; at the
8996 end, display the fraction of packages covered by all these updaters.
8998 @item --list-dependent
9000 List top-level dependent packages that would need to be rebuilt as a
9001 result of upgrading one or more packages.
9003 @xref{Invoking guix graph, the @code{reverse-package} type of
9004 @command{guix graph}}, for information on how to visualize the list of
9005 dependents of a package.
9009 Be aware that the @code{--list-dependent} option only
9010 @emph{approximates} the rebuilds that would be required as a result of
9011 an upgrade. More rebuilds might be required under some circumstances.
9014 $ guix refresh --list-dependent flex
9015 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9016 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9019 The command above lists a set of packages that could be built to check
9020 for compatibility with an upgraded @code{flex} package.
9024 @item --list-transitive
9025 List all the packages which one or more packages depend upon.
9028 $ guix refresh --list-transitive flex
9029 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9030 bison@@3.0.5 indent@@2.2.10 tar@@1.30 gzip@@1.9 bzip2@@1.0.6 xz@@5.2.4 file@@5.33 @dots{}
9035 The command above lists a set of packages which, when changed, would cause
9036 @code{flex} to be rebuilt.
9038 The following options can be used to customize GnuPG operation:
9042 @item --gpg=@var{command}
9043 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9044 for in @code{$PATH}.
9046 @item --keyring=@var{file}
9047 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9048 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9049 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9050 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9051 information on a tool to manipulate keybox files).
9053 When this option is omitted, @command{guix refresh} uses
9054 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9055 signing keys. OpenPGP signatures are checked against keys from this keyring;
9056 missing keys are downloaded to this keyring as well (see
9057 @option{--key-download} below.)
9059 You can export keys from your default GPG keyring into a keybox file using
9060 commands like this one:
9063 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9066 Likewise, you can fetch keys to a specific keybox file like this:
9069 gpg --no-default-keyring --keyring mykeyring.kbx \
9070 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9073 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9074 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9076 @item --key-download=@var{policy}
9077 Handle missing OpenPGP keys according to @var{policy}, which may be one
9082 Always download missing OpenPGP keys from the key server, and add them
9083 to the user's GnuPG keyring.
9086 Never try to download missing OpenPGP keys. Instead just bail out.
9089 When a package signed with an unknown OpenPGP key is encountered, ask
9090 the user whether to download it or not. This is the default behavior.
9093 @item --key-server=@var{host}
9094 Use @var{host} as the OpenPGP key server when importing a public key.
9098 The @code{github} updater uses the
9099 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9100 releases. When used repeatedly e.g.@: when refreshing all packages,
9101 GitHub will eventually refuse to answer any further API requests. By
9102 default 60 API requests per hour are allowed, and a full refresh on all
9103 GitHub packages in Guix requires more than this. Authentication with
9104 GitHub through the use of an API token alleviates these limits. To use
9105 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9106 token procured from @uref{https://github.com/settings/tokens} or
9110 @node Invoking guix lint
9111 @section Invoking @command{guix lint}
9113 @cindex @command{guix lint}
9114 @cindex package, checking for errors
9115 The @command{guix lint} command is meant to help package developers avoid
9116 common errors and use a consistent style. It runs a number of checks on
9117 a given set of packages in order to find common mistakes in their
9118 definitions. Available @dfn{checkers} include (see
9119 @code{--list-checkers} for a complete list):
9124 Validate certain typographical and stylistic rules about package
9125 descriptions and synopses.
9127 @item inputs-should-be-native
9128 Identify inputs that should most likely be native inputs.
9134 @itemx source-file-name
9135 Probe @code{home-page} and @code{source} URLs and report those that are
9136 invalid. Suggest a @code{mirror://} URL when applicable. If the
9137 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9138 URL. Check that the source file name is meaningful, e.g.@: is not just a
9139 version number or ``git-checkout'', without a declared @code{file-name}
9140 (@pxref{origin Reference}).
9142 @item source-unstable-tarball
9143 Parse the @code{source} URL to determine if a tarball from GitHub is
9144 autogenerated or if it is a release tarball. Unfortunately GitHub's
9145 autogenerated tarballs are sometimes regenerated.
9148 @cindex security vulnerabilities
9149 @cindex CVE, Common Vulnerabilities and Exposures
9150 Report known vulnerabilities found in the Common Vulnerabilities and
9151 Exposures (CVE) databases of the current and past year
9152 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9155 To view information about a particular vulnerability, visit pages such as:
9159 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9161 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9165 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9166 @code{CVE-2015-7554}.
9168 Package developers can specify in package recipes the
9169 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9170 name and version of the package when they differ from the name or version
9171 that Guix uses, as in this example:
9177 ;; CPE calls this package "grub2".
9178 (properties '((cpe-name . "grub2")
9179 (cpe-version . "2.3")))
9182 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
9183 Some entries in the CVE database do not specify which version of a
9184 package they apply to, and would thus ``stick around'' forever. Package
9185 developers who found CVE alerts and verified they can be ignored can
9186 declare them as in this example:
9192 ;; These CVEs no longer apply and can be safely ignored.
9193 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9196 "CVE-2011-5244")))))
9200 Warn about obvious source code formatting issues: trailing white space,
9201 use of tabulations, etc.
9204 The general syntax is:
9207 guix lint @var{options} @var{package}@dots{}
9210 If no package is given on the command line, then all packages are checked.
9211 The @var{options} may be zero or more of the following:
9214 @item --list-checkers
9216 List and describe all the available checkers that will be run on packages
9221 Only enable the checkers specified in a comma-separated list using the
9222 names returned by @code{--list-checkers}.
9226 @node Invoking guix size
9227 @section Invoking @command{guix size}
9230 @cindex package size
9232 @cindex @command{guix size}
9233 The @command{guix size} command helps package developers profile the
9234 disk usage of packages. It is easy to overlook the impact of an
9235 additional dependency added to a package, or the impact of using a
9236 single output for a package that could easily be split (@pxref{Packages
9237 with Multiple Outputs}). Such are the typical issues that
9238 @command{guix size} can highlight.
9240 The command can be passed one or more package specifications
9241 such as @code{gcc@@4.8}
9242 or @code{guile:debug}, or a file name in the store. Consider this
9246 $ guix size coreutils
9247 store item total self
9248 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9249 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9250 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9251 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9252 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9253 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9254 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9255 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9260 The store items listed here constitute the @dfn{transitive closure} of
9261 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9262 would be returned by:
9265 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9268 Here the output shows three columns next to store items. The first column,
9269 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9270 the store item---that is, its own size plus the size of all its
9271 dependencies. The next column, labeled ``self'', shows the size of the
9272 item itself. The last column shows the ratio of the size of the item
9273 itself to the space occupied by all the items listed here.
9275 In this example, we see that the closure of Coreutils weighs in at
9276 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9277 libraries. (That libc and GCC's libraries represent a large fraction of
9278 the closure is not a problem @i{per se} because they are always available
9279 on the system anyway.)
9281 When the package(s) passed to @command{guix size} are available in the
9282 store@footnote{More precisely, @command{guix size} looks for the
9283 @emph{ungrafted} variant of the given package(s), as returned by
9284 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9285 for information on grafts.}, @command{guix size} queries the daemon to determine its
9286 dependencies, and measures its size in the store, similar to @command{du
9287 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9290 When the given packages are @emph{not} in the store, @command{guix size}
9291 reports information based on the available substitutes
9292 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9293 store items that are not even on disk, only available remotely.
9295 You can also specify several package names:
9298 $ guix size coreutils grep sed bash
9299 store item total self
9300 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9301 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9302 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9303 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9309 In this example we see that the combination of the four packages takes
9310 102.3@tie{}MiB in total, which is much less than the sum of each closure
9311 since they have a lot of dependencies in common.
9313 The available options are:
9317 @item --substitute-urls=@var{urls}
9318 Use substitute information from @var{urls}.
9319 @xref{client-substitute-urls, the same option for @code{guix build}}.
9321 @item --sort=@var{key}
9322 Sort lines according to @var{key}, one of the following options:
9326 the size of each item (the default);
9328 the total size of the item's closure.
9331 @item --map-file=@var{file}
9332 Write a graphical map of disk usage in PNG format to @var{file}.
9334 For the example above, the map looks like this:
9336 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9337 produced by @command{guix size}}
9339 This option requires that
9340 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
9341 installed and visible in Guile's module search path. When that is not
9342 the case, @command{guix size} fails as it tries to load it.
9344 @item --system=@var{system}
9345 @itemx -s @var{system}
9346 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9350 @node Invoking guix graph
9351 @section Invoking @command{guix graph}
9354 @cindex @command{guix graph}
9355 @cindex package dependencies
9356 Packages and their dependencies form a @dfn{graph}, specifically a
9357 directed acyclic graph (DAG). It can quickly become difficult to have a
9358 mental model of the package DAG, so the @command{guix graph} command
9359 provides a visual representation of the DAG. By default,
9360 @command{guix graph} emits a DAG representation in the input format of
9361 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
9362 directly to the @command{dot} command of Graphviz. It can also emit an
9363 HTML page with embedded JavaScript code to display a ``chord diagram''
9364 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9365 emit Cypher queries to construct a graph in a graph database supporting
9366 the @uref{http://www.opencypher.org/, openCypher} query language.
9367 The general syntax is:
9370 guix graph @var{options} @var{package}@dots{}
9373 For example, the following command generates a PDF file representing the
9374 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9378 guix graph coreutils | dot -Tpdf > dag.pdf
9381 The output looks like this:
9383 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9385 Nice little graph, no?
9387 But there is more than one graph! The one above is concise: it is the
9388 graph of package objects, omitting implicit inputs such as GCC, libc,
9389 grep, etc. It is often useful to have such a concise graph, but
9390 sometimes one may want to see more details. @command{guix graph} supports
9391 several types of graphs, allowing you to choose the level of detail:
9395 This is the default type used in the example above. It shows the DAG of
9396 package objects, excluding implicit dependencies. It is concise, but
9397 filters out many details.
9399 @item reverse-package
9400 This shows the @emph{reverse} DAG of packages. For example:
9403 guix graph --type=reverse-package ocaml
9406 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9407 you are also interested in cases where OCaml is an implicit dependency, see
9408 @code{reverse-bag} below.)
9410 Note that for core packages this can yield huge graphs. If all you want
9411 is to know the number of packages that depend on a given package, use
9412 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9413 @option{--list-dependent}}).
9416 This is the package DAG, @emph{including} implicit inputs.
9418 For instance, the following command:
9421 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9424 ...@: yields this bigger graph:
9426 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9428 At the bottom of the graph, we see all the implicit inputs of
9429 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9431 Now, note that the dependencies of these implicit inputs---that is, the
9432 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9433 here, for conciseness.
9436 Similar to @code{bag-emerged}, but this time including all the bootstrap
9439 @item bag-with-origins
9440 Similar to @code{bag}, but also showing origins and their dependencies.
9443 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9444 it also takes implicit dependencies into account. For example:
9447 guix graph -t reverse-bag dune
9451 ...@: yields the graph of all packages that depend on Dune, directly or
9452 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9453 @i{via} @code{dune-build-system}, this shows a large number of packages,
9454 whereas @code{reverse-package} would show very few if any.
9457 This is the most detailed representation: It shows the DAG of
9458 derivations (@pxref{Derivations}) and plain store items. Compared to
9459 the above representation, many additional nodes are visible, including
9460 build scripts, patches, Guile modules, etc.
9462 For this type of graph, it is also possible to pass a @file{.drv} file
9463 name instead of a package name, as in:
9466 guix graph -t derivation `guix system build -d my-config.scm`
9470 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9471 For example, the following command shows the graph for the package
9472 module that defines the @code{guile} package:
9475 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9479 All the types above correspond to @emph{build-time dependencies}. The
9480 following graph type represents the @emph{run-time dependencies}:
9484 This is the graph of @dfn{references} of a package output, as returned
9485 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9487 If the given package output is not available in the store, @command{guix
9488 graph} attempts to obtain dependency information from substitutes.
9490 Here you can also pass a store file name instead of a package name. For
9491 example, the command below produces the reference graph of your profile
9492 (which can be big!):
9495 guix graph -t references `readlink -f ~/.guix-profile`
9499 This is the graph of the @dfn{referrers} of a store item, as returned by
9500 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9502 This relies exclusively on local information from your store. For
9503 instance, let us suppose that the current Inkscape is available in 10
9504 profiles on your machine; @command{guix graph -t referrers inkscape}
9505 will show a graph rooted at Inkscape and with those 10 profiles linked
9508 It can help determine what is preventing a store item from being garbage
9513 The available options are the following:
9516 @item --type=@var{type}
9517 @itemx -t @var{type}
9518 Produce a graph output of @var{type}, where @var{type} must be one of
9519 the values listed above.
9522 List the supported graph types.
9524 @item --backend=@var{backend}
9525 @itemx -b @var{backend}
9526 Produce a graph using the selected @var{backend}.
9528 @item --list-backends
9529 List the supported graph backends.
9531 Currently, the available backends are Graphviz and d3.js.
9533 @item --expression=@var{expr}
9534 @itemx -e @var{expr}
9535 Consider the package @var{expr} evaluates to.
9537 This is useful to precisely refer to a package, as in this example:
9540 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9543 @item --system=@var{system}
9544 @itemx -s @var{system}
9545 Display the graph for @var{system}---e.g., @code{i686-linux}.
9547 The package dependency graph is largely architecture-independent, but there
9548 are some architecture-dependent bits that this option allows you to visualize.
9553 @node Invoking guix publish
9554 @section Invoking @command{guix publish}
9556 @cindex @command{guix publish}
9557 The purpose of @command{guix publish} is to enable users to easily share
9558 their store with others, who can then use it as a substitute server
9559 (@pxref{Substitutes}).
9561 When @command{guix publish} runs, it spawns an HTTP server which allows
9562 anyone with network access to obtain substitutes from it. This means
9563 that any machine running Guix can also act as if it were a build farm,
9564 since the HTTP interface is compatible with Hydra, the software behind
9565 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9567 For security, each substitute is signed, allowing recipients to check
9568 their authenticity and integrity (@pxref{Substitutes}). Because
9569 @command{guix publish} uses the signing key of the system, which is only
9570 readable by the system administrator, it must be started as root; the
9571 @code{--user} option makes it drop root privileges early on.
9573 The signing key pair must be generated before @command{guix publish} is
9574 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9577 The general syntax is:
9580 guix publish @var{options}@dots{}
9583 Running @command{guix publish} without any additional arguments will
9584 spawn an HTTP server on port 8080:
9590 Once a publishing server has been authorized (@pxref{Invoking guix
9591 archive}), the daemon may download substitutes from it:
9594 guix-daemon --substitute-urls=http://example.org:8080
9597 By default, @command{guix publish} compresses archives on the fly as it
9598 serves them. This ``on-the-fly'' mode is convenient in that it requires
9599 no setup and is immediately available. However, when serving lots of
9600 clients, we recommend using the @option{--cache} option, which enables
9601 caching of the archives before they are sent to clients---see below for
9602 details. The @command{guix weather} command provides a handy way to
9603 check what a server provides (@pxref{Invoking guix weather}).
9605 As a bonus, @command{guix publish} also serves as a content-addressed
9606 mirror for source files referenced in @code{origin} records
9607 (@pxref{origin Reference}). For instance, assuming @command{guix
9608 publish} is running on @code{example.org}, the following URL returns the
9609 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9610 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9613 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9616 Obviously, these URLs only work for files that are in the store; in
9617 other cases, they return 404 (``Not Found'').
9619 @cindex build logs, publication
9620 Build logs are available from @code{/log} URLs like:
9623 http://example.org/log/gwspk@dots{}-guile-2.2.3
9627 When @command{guix-daemon} is configured to save compressed build logs,
9628 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9629 URLs return the compressed log as-is, with an appropriate
9630 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9631 running @command{guix-daemon} with @code{--log-compression=gzip} since
9632 Web browsers can automatically decompress it, which is not the case with
9635 The following options are available:
9638 @item --port=@var{port}
9639 @itemx -p @var{port}
9640 Listen for HTTP requests on @var{port}.
9642 @item --listen=@var{host}
9643 Listen on the network interface for @var{host}. The default is to
9644 accept connections from any interface.
9646 @item --user=@var{user}
9647 @itemx -u @var{user}
9648 Change privileges to @var{user} as soon as possible---i.e., once the
9649 server socket is open and the signing key has been read.
9651 @item --compression[=@var{level}]
9652 @itemx -C [@var{level}]
9653 Compress data using the given @var{level}. When @var{level} is zero,
9654 disable compression. The range 1 to 9 corresponds to different gzip
9655 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
9658 Unless @option{--cache} is used, compression occurs on the fly and
9659 the compressed streams are not
9660 cached. Thus, to reduce load on the machine that runs @command{guix
9661 publish}, it may be a good idea to choose a low compression level, to
9662 run @command{guix publish} behind a caching proxy, or to use
9663 @option{--cache}. Using @option{--cache} has the advantage that it
9664 allows @command{guix publish} to add @code{Content-Length} HTTP header
9667 @item --cache=@var{directory}
9668 @itemx -c @var{directory}
9669 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9670 and only serve archives that are in cache.
9672 When this option is omitted, archives and meta-data are created
9673 on-the-fly. This can reduce the available bandwidth, especially when
9674 compression is enabled, since this may become CPU-bound. Another
9675 drawback of the default mode is that the length of archives is not known
9676 in advance, so @command{guix publish} does not add a
9677 @code{Content-Length} HTTP header to its responses, which in turn
9678 prevents clients from knowing the amount of data being downloaded.
9680 Conversely, when @option{--cache} is used, the first request for a store
9681 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9682 background process to @dfn{bake} the archive---computing its
9683 @code{.narinfo} and compressing the archive, if needed. Once the
9684 archive is cached in @var{directory}, subsequent requests succeed and
9685 are served directly from the cache, which guarantees that clients get
9686 the best possible bandwidth.
9688 The ``baking'' process is performed by worker threads. By default, one
9689 thread per CPU core is created, but this can be customized. See
9690 @option{--workers} below.
9692 When @option{--ttl} is used, cached entries are automatically deleted
9693 when they have expired.
9695 @item --workers=@var{N}
9696 When @option{--cache} is used, request the allocation of @var{N} worker
9697 threads to ``bake'' archives.
9699 @item --ttl=@var{ttl}
9700 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9701 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9702 days, @code{1m} means 1 month, and so on.
9704 This allows the user's Guix to keep substitute information in cache for
9705 @var{ttl}. However, note that @code{guix publish} does not itself
9706 guarantee that the store items it provides will indeed remain available
9707 for as long as @var{ttl}.
9709 Additionally, when @option{--cache} is used, cached entries that have
9710 not been accessed for @var{ttl} and that no longer have a corresponding
9711 item in the store, may be deleted.
9713 @item --nar-path=@var{path}
9714 Use @var{path} as the prefix for the URLs of ``nar'' files
9715 (@pxref{Invoking guix archive, normalized archives}).
9717 By default, nars are served at a URL such as
9718 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9719 change the @code{/nar} part to @var{path}.
9721 @item --public-key=@var{file}
9722 @itemx --private-key=@var{file}
9723 Use the specific @var{file}s as the public/private key pair used to sign
9724 the store items being published.
9726 The files must correspond to the same key pair (the private key is used
9727 for signing and the public key is merely advertised in the signature
9728 metadata). They must contain keys in the canonical s-expression format
9729 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9730 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9731 @file{/etc/guix/signing-key.sec} are used.
9733 @item --repl[=@var{port}]
9734 @itemx -r [@var{port}]
9735 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9736 Reference Manual}) on @var{port} (37146 by default). This is used
9737 primarily for debugging a running @command{guix publish} server.
9740 Enabling @command{guix publish} on Guix System is a one-liner: just
9741 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9742 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9743 @code{guix-publish-service-type}}).
9745 If you are instead running Guix on a ``foreign distro'', follow these
9750 If your host distro uses the systemd init system:
9753 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9754 /etc/systemd/system/
9755 # systemctl start guix-publish && systemctl enable guix-publish
9759 If your host distro uses the Upstart init system:
9762 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9763 # start guix-publish
9767 Otherwise, proceed similarly with your distro's init system.
9770 @node Invoking guix challenge
9771 @section Invoking @command{guix challenge}
9773 @cindex reproducible builds
9774 @cindex verifiable builds
9775 @cindex @command{guix challenge}
9777 Do the binaries provided by this server really correspond to the source
9778 code it claims to build? Is a package build process deterministic?
9779 These are the questions the @command{guix challenge} command attempts to
9782 The former is obviously an important question: Before using a substitute
9783 server (@pxref{Substitutes}), one had better @emph{verify} that it
9784 provides the right binaries, and thus @emph{challenge} it. The latter
9785 is what enables the former: If package builds are deterministic, then
9786 independent builds of the package should yield the exact same result,
9787 bit for bit; if a server provides a binary different from the one
9788 obtained locally, it may be either corrupt or malicious.
9790 We know that the hash that shows up in @file{/gnu/store} file names is
9791 the hash of all the inputs of the process that built the file or
9792 directory---compilers, libraries, build scripts,
9793 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9794 one store file name should map to exactly one build output.
9795 @command{guix challenge} checks whether there is, indeed, a single
9796 mapping by comparing the build outputs of several independent builds of
9797 any given store item.
9799 The command output looks like this:
9802 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9803 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9804 updating list of substitutes from 'https://guix.example.org'... 100.0%
9805 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9806 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9807 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9808 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9809 /gnu/store/@dots{}-git-2.5.0 contents differ:
9810 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9811 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9812 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9813 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9814 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9815 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9816 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9820 6,406 store items were analyzed:
9821 - 4,749 (74.1%) were identical
9822 - 525 (8.2%) differed
9823 - 1,132 (17.7%) were inconclusive
9827 In this example, @command{guix challenge} first scans the store to
9828 determine the set of locally-built derivations---as opposed to store
9829 items that were downloaded from a substitute server---and then queries
9830 all the substitute servers. It then reports those store items for which
9831 the servers obtained a result different from the local build.
9833 @cindex non-determinism, in package builds
9834 As an example, @code{guix.example.org} always gets a different answer.
9835 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9836 case of Git. This might indicate that the build process of Git is
9837 non-deterministic, meaning that its output varies as a function of
9838 various things that Guix does not fully control, in spite of building
9839 packages in isolated environments (@pxref{Features}). Most common
9840 sources of non-determinism include the addition of timestamps in build
9841 results, the inclusion of random numbers, and directory listings sorted
9842 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9845 To find out what is wrong with this Git binary, we can do something along
9846 these lines (@pxref{Invoking guix archive}):
9849 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9850 | guix archive -x /tmp/git
9851 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9854 This command shows the difference between the files resulting from the
9855 local build, and the files resulting from the build on
9856 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9857 diffutils, Comparing and Merging Files}). The @command{diff} command
9858 works great for text files. When binary files differ, a better option
9859 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9860 visualize differences for all kinds of files.
9862 Once you have done that work, you can tell whether the differences are due
9863 to a non-deterministic build process or to a malicious server. We try
9864 hard to remove sources of non-determinism in packages to make it easier
9865 to verify substitutes, but of course, this is a process that
9866 involves not just Guix, but a large part of the free software community.
9867 In the meantime, @command{guix challenge} is one tool to help address
9870 If you are writing packages for Guix, you are encouraged to check
9871 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9872 same build result as you did with:
9875 $ guix challenge @var{package}
9879 where @var{package} is a package specification such as
9880 @code{guile@@2.0} or @code{glibc:debug}.
9882 The general syntax is:
9885 guix challenge @var{options} [@var{packages}@dots{}]
9888 When a difference is found between the hash of a locally-built item and
9889 that of a server-provided substitute, or among substitutes provided by
9890 different servers, the command displays it as in the example above and
9891 its exit code is 2 (other non-zero exit codes denote other kinds of
9894 The one option that matters is:
9898 @item --substitute-urls=@var{urls}
9899 Consider @var{urls} the whitespace-separated list of substitute source
9904 Show details about matches (identical contents) in addition to
9905 information about mismatches.
9909 @node Invoking guix copy
9910 @section Invoking @command{guix copy}
9912 @cindex copy, of store items, over SSH
9913 @cindex SSH, copy of store items
9914 @cindex sharing store items across machines
9915 @cindex transferring store items across machines
9916 The @command{guix copy} command copies items from the store of one
9917 machine to that of another machine over a secure shell (SSH)
9918 connection@footnote{This command is available only when Guile-SSH was
9919 found. @xref{Requirements}, for details.}. For example, the following
9920 command copies the @code{coreutils} package, the user's profile, and all
9921 their dependencies over to @var{host}, logged in as @var{user}:
9924 guix copy --to=@var{user}@@@var{host} \
9925 coreutils `readlink -f ~/.guix-profile`
9928 If some of the items to be copied are already present on @var{host},
9929 they are not actually sent.
9931 The command below retrieves @code{libreoffice} and @code{gimp} from
9932 @var{host}, assuming they are available there:
9935 guix copy --from=@var{host} libreoffice gimp
9938 The SSH connection is established using the Guile-SSH client, which is
9939 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
9940 @file{~/.ssh/config}, and uses the SSH agent for authentication.
9942 The key used to sign items that are sent must be accepted by the remote
9943 machine. Likewise, the key used by the remote machine to sign items you
9944 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
9945 own daemon. @xref{Invoking guix archive}, for more information about
9946 store item authentication.
9948 The general syntax is:
9951 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
9954 You must always specify one of the following options:
9957 @item --to=@var{spec}
9958 @itemx --from=@var{spec}
9959 Specify the host to send to or receive from. @var{spec} must be an SSH
9960 spec such as @code{example.org}, @code{charlie@@example.org}, or
9961 @code{charlie@@example.org:2222}.
9964 The @var{items} can be either package names, such as @code{gimp}, or
9965 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
9967 When specifying the name of a package to send, it is first built if
9968 needed, unless @option{--dry-run} was specified. Common build options
9969 are supported (@pxref{Common Build Options}).
9972 @node Invoking guix container
9973 @section Invoking @command{guix container}
9975 @cindex @command{guix container}
9977 As of version @value{VERSION}, this tool is experimental. The interface
9978 is subject to radical change in the future.
9981 The purpose of @command{guix container} is to manipulate processes
9982 running within an isolated environment, commonly known as a
9983 ``container'', typically created by the @command{guix environment}
9984 (@pxref{Invoking guix environment}) and @command{guix system container}
9985 (@pxref{Invoking guix system}) commands.
9987 The general syntax is:
9990 guix container @var{action} @var{options}@dots{}
9993 @var{action} specifies the operation to perform with a container, and
9994 @var{options} specifies the context-specific arguments for the action.
9996 The following actions are available:
10000 Execute a command within the context of a running container.
10005 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10008 @var{pid} specifies the process ID of the running container.
10009 @var{program} specifies an executable file name within the root file
10010 system of the container. @var{arguments} are the additional options that
10011 will be passed to @var{program}.
10013 The following command launches an interactive login shell inside a
10014 Guix system container, started by @command{guix system container}, and whose
10015 process ID is 9001:
10018 guix container exec 9001 /run/current-system/profile/bin/bash --login
10021 Note that the @var{pid} cannot be the parent process of a container. It
10022 must be PID 1 of the container or one of its child processes.
10026 @node Invoking guix weather
10027 @section Invoking @command{guix weather}
10029 Occasionally you're grumpy because substitutes are lacking and you end
10030 up building packages by yourself (@pxref{Substitutes}). The
10031 @command{guix weather} command reports on substitute availability on the
10032 specified servers so you can have an idea of whether you'll be grumpy
10033 today. It can sometimes be useful info as a user, but it is primarily
10034 useful to people running @command{guix publish} (@pxref{Invoking guix
10037 @cindex statistics, for substitutes
10038 @cindex availability of substitutes
10039 @cindex substitute availability
10040 @cindex weather, substitute availability
10041 Here's a sample run:
10044 $ guix weather --substitute-urls=https://guix.example.org
10045 computing 5,872 package derivations for x86_64-linux...
10046 looking for 6,128 store items on https://guix.example.org..
10047 updating list of substitutes from 'https://guix.example.org'... 100.0%
10048 https://guix.example.org
10049 43.4% substitutes available (2,658 out of 6,128)
10050 7,032.5 MiB of nars (compressed)
10051 19,824.2 MiB on disk (uncompressed)
10052 0.030 seconds per request (182.9 seconds in total)
10053 33.5 requests per second
10055 9.8% (342 out of 3,470) of the missing items are queued
10057 x86_64-linux: 518 (59.7%)
10058 i686-linux: 221 (25.5%)
10059 aarch64-linux: 128 (14.8%)
10060 build rate: 23.41 builds per hour
10061 x86_64-linux: 11.16 builds per hour
10062 i686-linux: 6.03 builds per hour
10063 aarch64-linux: 6.41 builds per hour
10066 @cindex continuous integration, statistics
10067 As you can see, it reports the fraction of all the packages for which
10068 substitutes are available on the server---regardless of whether
10069 substitutes are enabled, and regardless of whether this server's signing
10070 key is authorized. It also reports the size of the compressed archives
10071 (``nars'') provided by the server, the size the corresponding store
10072 items occupy in the store (assuming deduplication is turned off), and
10073 the server's throughput. The second part gives continuous integration
10074 (CI) statistics, if the server supports it. In addition, using the
10075 @option{--coverage} option, @command{guix weather} can list ``important''
10076 package substitutes missing on the server (see below).
10078 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10079 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10080 challenge}, it ignores signatures on those substitutes, which is
10081 innocuous since the command only gathers statistics and cannot install
10084 Among other things, it is possible to query specific system types and
10085 specific package sets. The available options are listed below.
10088 @item --substitute-urls=@var{urls}
10089 @var{urls} is the space-separated list of substitute server URLs to
10090 query. When this option is omitted, the default set of substitute
10091 servers is queried.
10093 @item --system=@var{system}
10094 @itemx -s @var{system}
10095 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10096 option can be repeated, in which case @command{guix weather} will query
10097 substitutes for several system types.
10099 @item --manifest=@var{file}
10100 Instead of querying substitutes for all the packages, only ask for those
10101 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10102 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10105 @item --coverage[=@var{count}]
10106 @itemx -c [@var{count}]
10107 Report on substitute coverage for packages: list packages with at least
10108 @var{count} dependents (zero by default) for which substitutes are
10109 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10110 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10111 @var{b} usually lacks substitutes as well. The result looks like this:
10114 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10115 computing 8,983 package derivations for x86_64-linux...
10116 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10117 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10118 @value{SUBSTITUTE-URL}
10119 64.7% substitutes available (6,047 out of 9,343)
10121 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10122 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10123 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10124 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10128 What this example shows is that @code{kcoreaddons} and presumably the 58
10129 packages that depend on it have no substitutes at @code{ci.guix.info};
10130 likewise for @code{qgpgme} and the 46 packages that depend on it.
10132 If you are a Guix developer, or if you are taking care of this build farm,
10133 you'll probably want to have a closer look at these packages: they may simply
10137 @node Invoking guix processes
10138 @section Invoking @command{guix processes}
10140 The @command{guix processes} command can be useful to developers and system
10141 administrators, especially on multi-user machines and on build farms: it lists
10142 the current sessions (connections to the daemon), as well as information about
10143 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10144 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10145 listed.}. Here's an example of the information it returns:
10148 $ sudo guix processes
10151 ClientCommand: guix environment --ad-hoc python
10155 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10159 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10160 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10161 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10162 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10163 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10164 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10165 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10168 In this example we see that @command{guix-daemon} has three clients:
10169 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10170 integration tool; their process identifier (PID) is given by the
10171 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10172 @command{guix-daemon} sub-process of this particular session.
10174 The @code{LockHeld} fields show which store items are currently locked by this
10175 session, which corresponds to store items being built or substituted (the
10176 @code{LockHeld} field is not displayed when @command{guix processes} is not
10177 running as root.) Last, by looking at the @code{ChildProcess} field, we
10178 understand that these three builds are being offloaded (@pxref{Daemon Offload
10181 The output is in Recutils format so we can use the handy @command{recsel}
10182 command to select sessions of interest (@pxref{Selection Expressions,,,
10183 recutils, GNU recutils manual}). As an example, the command shows the command
10184 line and PID of the client that triggered the build of a Perl package:
10187 $ sudo guix processes | \
10188 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10190 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10194 @node System Configuration
10195 @chapter System Configuration
10197 @cindex system configuration
10198 Guix System supports a consistent whole-system configuration
10199 mechanism. By that we mean that all aspects of the global system
10200 configuration---such as the available system services, timezone and
10201 locale settings, user accounts---are declared in a single place. Such
10202 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10204 One of the advantages of putting all the system configuration under the
10205 control of Guix is that it supports transactional system upgrades, and
10206 makes it possible to roll back to a previous system instantiation,
10207 should something go wrong with the new one (@pxref{Features}). Another
10208 advantage is that it makes it easy to replicate the exact same configuration
10209 across different machines, or at different points in time, without
10210 having to resort to additional administration tools layered on top of
10211 the own tools of the system.
10212 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10214 This section describes this mechanism. First we focus on the system
10215 administrator's viewpoint---explaining how the system is configured and
10216 instantiated. Then we show how this mechanism can be extended, for
10217 instance to support new system services.
10220 * Using the Configuration System:: Customizing your GNU system.
10221 * operating-system Reference:: Detail of operating-system declarations.
10222 * File Systems:: Configuring file system mounts.
10223 * Mapped Devices:: Block device extra processing.
10224 * User Accounts:: Specifying user accounts.
10225 * Keyboard Layout:: How the system interprets key strokes.
10226 * Locales:: Language and cultural convention settings.
10227 * Services:: Specifying system services.
10228 * Setuid Programs:: Programs running with root privileges.
10229 * X.509 Certificates:: Authenticating HTTPS servers.
10230 * Name Service Switch:: Configuring libc's name service switch.
10231 * Initial RAM Disk:: Linux-Libre bootstrapping.
10232 * Bootloader Configuration:: Configuring the boot loader.
10233 * Invoking guix system:: Instantiating a system configuration.
10234 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10235 * Defining Services:: Adding new service definitions.
10238 @node Using the Configuration System
10239 @section Using the Configuration System
10241 The operating system is configured by providing an
10242 @code{operating-system} declaration in a file that can then be passed to
10243 the @command{guix system} command (@pxref{Invoking guix system}). A
10244 simple setup, with the default system services, the default Linux-Libre
10245 kernel, initial RAM disk, and boot loader looks like this:
10247 @findex operating-system
10249 @include os-config-bare-bones.texi
10252 This example should be self-describing. Some of the fields defined
10253 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10254 Others, such as @code{packages} and @code{services}, can be omitted, in
10255 which case they get a default value.
10257 Below we discuss the effect of some of the most important fields
10258 (@pxref{operating-system Reference}, for details about all the available
10259 fields), and how to @dfn{instantiate} the operating system using
10260 @command{guix system}.
10262 @unnumberedsubsec Bootloader
10264 @cindex legacy boot, on Intel machines
10265 @cindex BIOS boot, on Intel machines
10268 The @code{bootloader} field describes the method that will be used to boot
10269 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10270 mode, as in the example above. However, more recent machines rely instead on
10271 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10272 the @code{bootloader} field should contain something along these lines:
10275 (bootloader-configuration
10276 (bootloader grub-efi-bootloader)
10277 (target "/boot/efi"))
10280 @xref{Bootloader Configuration}, for more information on the available
10281 configuration options.
10283 @unnumberedsubsec Globally-Visible Packages
10285 @vindex %base-packages
10286 The @code{packages} field lists packages that will be globally visible
10287 on the system, for all user accounts---i.e., in every user's @code{PATH}
10288 environment variable---in addition to the per-user profiles
10289 (@pxref{Invoking guix package}). The @var{%base-packages} variable
10290 provides all the tools one would expect for basic user and administrator
10291 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10292 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10293 etc. The example above adds GNU@tie{}Screen to those,
10294 taken from the @code{(gnu packages screen)}
10295 module (@pxref{Package Modules}). The
10296 @code{(list package output)} syntax can be used to add a specific output
10300 (use-modules (gnu packages))
10301 (use-modules (gnu packages dns))
10305 (packages (cons (list bind "utils")
10309 @findex specification->package
10310 Referring to packages by variable name, like @code{bind} above, has
10311 the advantage of being unambiguous; it also allows typos and such to be
10312 diagnosed right away as ``unbound variables''. The downside is that one
10313 needs to know which module defines which package, and to augment the
10314 @code{use-package-modules} line accordingly. To avoid that, one can use
10315 the @code{specification->package} procedure of the @code{(gnu packages)}
10316 module, which returns the best package for a given name or name and
10320 (use-modules (gnu packages))
10324 (packages (append (map specification->package
10325 '("tcpdump" "htop" "gnupg@@2.0"))
10329 @unnumberedsubsec System Services
10332 @vindex %base-services
10333 The @code{services} field lists @dfn{system services} to be made
10334 available when the system starts (@pxref{Services}).
10335 The @code{operating-system} declaration above specifies that, in
10336 addition to the basic services, we want the OpenSSH secure shell
10337 daemon listening on port 2222 (@pxref{Networking Services,
10338 @code{openssh-service-type}}). Under the hood,
10339 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10340 right command-line options, possibly with supporting configuration files
10341 generated as needed (@pxref{Defining Services}).
10343 @cindex customization, of services
10344 @findex modify-services
10345 Occasionally, instead of using the base services as is, you will want to
10346 customize them. To do this, use @code{modify-services} (@pxref{Service
10347 Reference, @code{modify-services}}) to modify the list.
10349 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10350 (the console log-in) in the @var{%base-services} list (@pxref{Base
10351 Services, @code{%base-services}}). To do that, you can write the
10352 following in your operating system declaration:
10355 (define %my-services
10356 ;; My very own list of services.
10357 (modify-services %base-services
10358 (guix-service-type config =>
10359 (guix-configuration
10361 (use-substitutes? #f)
10362 (extra-options '("--gc-keep-derivations"))))
10363 (mingetty-service-type config =>
10364 (mingetty-configuration
10365 (inherit config)))))
10369 (services %my-services))
10372 This changes the configuration---i.e., the service parameters---of the
10373 @code{guix-service-type} instance, and that of all the
10374 @code{mingetty-service-type} instances in the @var{%base-services} list.
10375 Observe how this is accomplished: first, we arrange for the original
10376 configuration to be bound to the identifier @code{config} in the
10377 @var{body}, and then we write the @var{body} so that it evaluates to the
10378 desired configuration. In particular, notice how we use @code{inherit}
10379 to create a new configuration which has the same values as the old
10380 configuration, but with a few modifications.
10382 @cindex encrypted disk
10383 The configuration for a typical ``desktop'' usage, with an encrypted
10384 root partition, the X11 display
10385 server, GNOME and Xfce (users can choose which of these desktop
10386 environments to use at the log-in screen by pressing @kbd{F1}), network
10387 management, power management, and more, would look like this:
10390 @include os-config-desktop.texi
10393 A graphical system with a choice of lightweight window managers
10394 instead of full-blown desktop environments would look like this:
10397 @include os-config-lightweight-desktop.texi
10400 This example refers to the @file{/boot/efi} file system by its UUID,
10401 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10402 as returned by the @command{blkid} command.
10404 @xref{Desktop Services}, for the exact list of services provided by
10405 @var{%desktop-services}. @xref{X.509 Certificates}, for background
10406 information about the @code{nss-certs} package that is used here.
10408 Again, @var{%desktop-services} is just a list of service objects. If
10409 you want to remove services from there, you can do so using the
10410 procedures for list filtering (@pxref{SRFI-1 Filtering and
10411 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10412 following expression returns a list that contains all the services in
10413 @var{%desktop-services} minus the Avahi service:
10416 (remove (lambda (service)
10417 (eq? (service-kind service) avahi-service-type))
10421 @unnumberedsubsec Instantiating the System
10423 Assuming the @code{operating-system} declaration
10424 is stored in the @file{my-system-config.scm}
10425 file, the @command{guix system reconfigure my-system-config.scm} command
10426 instantiates that configuration, and makes it the default GRUB boot
10427 entry (@pxref{Invoking guix system}).
10429 The normal way to change the system configuration is by updating this
10430 file and re-running @command{guix system reconfigure}. One should never
10431 have to touch files in @file{/etc} or to run commands that modify the
10432 system state such as @command{useradd} or @command{grub-install}. In
10433 fact, you must avoid that since that would not only void your warranty
10434 but also prevent you from rolling back to previous versions of your
10435 system, should you ever need to.
10437 @cindex roll-back, of the operating system
10438 Speaking of roll-back, each time you run @command{guix system
10439 reconfigure}, a new @dfn{generation} of the system is created---without
10440 modifying or deleting previous generations. Old system generations get
10441 an entry in the bootloader boot menu, allowing you to boot them in case
10442 something went wrong with the latest generation. Reassuring, no? The
10443 @command{guix system list-generations} command lists the system
10444 generations available on disk. It is also possible to roll back the
10445 system via the commands @command{guix system roll-back} and
10446 @command{guix system switch-generation}.
10448 Although the @command{guix system reconfigure} command will not modify
10449 previous generations, you must take care when the current generation is not
10450 the latest (e.g., after invoking @command{guix system roll-back}), since
10451 the operation might overwrite a later generation (@pxref{Invoking guix
10454 @unnumberedsubsec The Programming Interface
10456 At the Scheme level, the bulk of an @code{operating-system} declaration
10457 is instantiated with the following monadic procedure (@pxref{The Store
10460 @deffn {Monadic Procedure} operating-system-derivation os
10461 Return a derivation that builds @var{os}, an @code{operating-system}
10462 object (@pxref{Derivations}).
10464 The output of the derivation is a single directory that refers to all
10465 the packages, configuration files, and other supporting files needed to
10466 instantiate @var{os}.
10469 This procedure is provided by the @code{(gnu system)} module. Along
10470 with @code{(gnu services)} (@pxref{Services}), this module contains the
10471 guts of Guix System. Make sure to visit it!
10474 @node operating-system Reference
10475 @section @code{operating-system} Reference
10477 This section summarizes all the options available in
10478 @code{operating-system} declarations (@pxref{Using the Configuration
10481 @deftp {Data Type} operating-system
10482 This is the data type representing an operating system configuration.
10483 By that, we mean all the global system configuration, not per-user
10484 configuration (@pxref{Using the Configuration System}).
10487 @item @code{kernel} (default: @var{linux-libre})
10488 The package object of the operating system kernel to use@footnote{Currently
10489 only the Linux-libre kernel is supported. In the future, it will be
10490 possible to use the GNU@tie{}Hurd.}.
10492 @item @code{kernel-arguments} (default: @code{'("quiet")})
10493 List of strings or gexps representing additional arguments to pass on
10494 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10496 @item @code{bootloader}
10497 The system bootloader configuration object. @xref{Bootloader Configuration}.
10500 This is the label (a string) as it appears in the bootloader's menu entry.
10501 The default label includes the kernel name and version.
10503 @item @code{keyboard-layout} (default: @code{#f})
10504 This field specifies the keyboard layout to use in the console. It can be
10505 either @code{#f}, in which case the default keyboard layout is used (usually
10506 US English), or a @code{<keyboard-layout>} record.
10508 This keyboard layout is in effect as soon as the kernel has booted. For
10509 instance, it is the keyboard layout in effect when you type a passphrase if
10510 your root file system is on a @code{luks-device-mapping} mapped device
10511 (@pxref{Mapped Devices}).
10514 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10515 that used by the graphical display server. @xref{Bootloader Configuration},
10516 for information on how to specify the bootloader's keyboard layout. @xref{X
10517 Window}, for information on how to specify the keyboard layout used by the X
10521 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10523 @cindex initial RAM disk
10524 The list of Linux kernel modules that need to be available in the
10525 initial RAM disk. @xref{Initial RAM Disk}.
10527 @item @code{initrd} (default: @code{base-initrd})
10528 A procedure that returns an initial RAM disk for the Linux
10529 kernel. This field is provided to support low-level customization and
10530 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10532 @item @code{firmware} (default: @var{%base-firmware})
10534 List of firmware packages loadable by the operating system kernel.
10536 The default includes firmware needed for Atheros- and Broadcom-based
10537 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10538 respectively). @xref{Hardware Considerations}, for more info on
10539 supported hardware.
10541 @item @code{host-name}
10544 @item @code{hosts-file}
10546 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10547 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10548 Reference Manual}). The default is a file with entries for
10549 @code{localhost} and @var{host-name}.
10551 @item @code{mapped-devices} (default: @code{'()})
10552 A list of mapped devices. @xref{Mapped Devices}.
10554 @item @code{file-systems}
10555 A list of file systems. @xref{File Systems}.
10557 @item @code{swap-devices} (default: @code{'()})
10558 @cindex swap devices
10559 A list of strings identifying devices or files to be used for ``swap
10560 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10561 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10562 It is possible to specify a swap file in a file system on a mapped
10563 device, provided that the necessary device mapping and file system are
10564 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10566 @item @code{users} (default: @code{%base-user-accounts})
10567 @itemx @code{groups} (default: @var{%base-groups})
10568 List of user accounts and groups. @xref{User Accounts}.
10570 If the @code{users} list lacks a user account with UID@tie{}0, a
10571 ``root'' account with UID@tie{}0 is automatically added.
10573 @item @code{skeletons} (default: @code{(default-skeletons)})
10574 A list target file name/file-like object tuples (@pxref{G-Expressions,
10575 file-like objects}). These are the skeleton files that will be added to
10576 the home directory of newly-created user accounts.
10578 For instance, a valid value may look like this:
10581 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10582 (".guile" ,(plain-file "guile"
10583 "(use-modules (ice-9 readline))
10584 (activate-readline)")))
10587 @item @code{issue} (default: @var{%default-issue})
10588 A string denoting the contents of the @file{/etc/issue} file, which is
10589 displayed when users log in on a text console.
10591 @item @code{packages} (default: @var{%base-packages})
10592 The set of packages installed in the global profile, which is accessible
10593 at @file{/run/current-system/profile}.
10595 The default set includes core utilities and it is good practice to
10596 install non-core utilities in user profiles (@pxref{Invoking guix
10599 @item @code{timezone}
10600 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10602 You can run the @command{tzselect} command to find out which timezone
10603 string corresponds to your region. Choosing an invalid timezone name
10604 causes @command{guix system} to fail.
10606 @item @code{locale} (default: @code{"en_US.utf8"})
10607 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10608 Library Reference Manual}). @xref{Locales}, for more information.
10610 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10611 The list of locale definitions to be compiled and that may be used at
10612 run time. @xref{Locales}.
10614 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10615 The list of GNU@tie{}libc packages whose locale data and tools are used
10616 to build the locale definitions. @xref{Locales}, for compatibility
10617 considerations that justify this option.
10619 @item @code{name-service-switch} (default: @var{%default-nss})
10620 Configuration of the libc name service switch (NSS)---a
10621 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10624 @item @code{services} (default: @var{%base-services})
10625 A list of service objects denoting system services. @xref{Services}.
10627 @cindex essential services
10628 @item @code{essential-services} (default: ...)
10629 The list of ``essential services''---i.e., things like instances of
10630 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10631 Reference}), which are derived from the operating system definition itself.
10632 As a user you should @emph{never} need to touch this field.
10634 @item @code{pam-services} (default: @code{(base-pam-services)})
10636 @cindex pluggable authentication modules
10637 Linux @dfn{pluggable authentication module} (PAM) services.
10638 @c FIXME: Add xref to PAM services section.
10640 @item @code{setuid-programs} (default: @var{%setuid-programs})
10641 List of string-valued G-expressions denoting setuid programs.
10642 @xref{Setuid Programs}.
10644 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10645 @cindex sudoers file
10646 The contents of the @file{/etc/sudoers} file as a file-like object
10647 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10649 This file specifies which users can use the @command{sudo} command, what
10650 they are allowed to do, and what privileges they may gain. The default
10651 is that only @code{root} and members of the @code{wheel} group may use
10656 @deffn {Scheme Syntax} this-operating-system
10657 When used in the @emph{lexical scope} of an operating system field definition,
10658 this identifier resolves to the operating system being defined.
10660 The example below shows how to refer to the operating system being defined in
10661 the definition of the @code{label} field:
10664 (use-modules (gnu) (guix))
10668 (label (package-full-name
10669 (operating-system-kernel this-operating-system))))
10672 It is an error to refer to @code{this-operating-system} outside an operating
10679 @section File Systems
10681 The list of file systems to be mounted is specified in the
10682 @code{file-systems} field of the operating system declaration
10683 (@pxref{Using the Configuration System}). Each file system is declared
10684 using the @code{file-system} form, like this:
10688 (mount-point "/home")
10689 (device "/dev/sda3")
10693 As usual, some of the fields are mandatory---those shown in the example
10694 above---while others can be omitted. These are described below.
10696 @deftp {Data Type} file-system
10697 Objects of this type represent file systems to be mounted. They
10698 contain the following members:
10702 This is a string specifying the type of the file system---e.g.,
10705 @item @code{mount-point}
10706 This designates the place where the file system is to be mounted.
10708 @item @code{device}
10709 This names the ``source'' of the file system. It can be one of three
10710 things: a file system label, a file system UUID, or the name of a
10711 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10712 systems without having to hard-code their actual device
10713 name@footnote{Note that, while it is tempting to use
10714 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10715 result, this is not recommended: These special device nodes are created
10716 by the udev daemon and may be unavailable at the time the device is
10719 @findex file-system-label
10720 File system labels are created using the @code{file-system-label}
10721 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10722 plain strings. Here's an example of a file system referred to by its
10723 label, as shown by the @command{e2label} command:
10727 (mount-point "/home")
10729 (device (file-system-label "my-home")))
10733 UUIDs are converted from their string representation (as shown by the
10734 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10735 @code{uuid} form expects 16-byte UUIDs as defined in
10736 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10737 form of UUID used by the ext2 family of file systems and others, but it
10738 is different from ``UUIDs'' found in FAT file systems, for instance.},
10743 (mount-point "/home")
10745 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10748 When the source of a file system is a mapped device (@pxref{Mapped
10749 Devices}), its @code{device} field @emph{must} refer to the mapped
10750 device name---e.g., @file{"/dev/mapper/root-partition"}.
10751 This is required so that
10752 the system knows that mounting the file system depends on having the
10753 corresponding device mapping established.
10755 @item @code{flags} (default: @code{'()})
10756 This is a list of symbols denoting mount flags. Recognized flags
10757 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10758 access to special files), @code{no-suid} (ignore setuid and setgid
10759 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10760 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10761 Library Reference Manual}, for more information on these flags.
10763 @item @code{options} (default: @code{#f})
10764 This is either @code{#f}, or a string denoting mount options passed to the
10765 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10766 Reference Manual}, for details and run @command{man 8 mount} for options for
10767 various file systems.
10769 @item @code{mount?} (default: @code{#t})
10770 This value indicates whether to automatically mount the file system when
10771 the system is brought up. When set to @code{#f}, the file system gets
10772 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10773 is not automatically mounted.
10775 @item @code{needed-for-boot?} (default: @code{#f})
10776 This Boolean value indicates whether the file system is needed when
10777 booting. If that is true, then the file system is mounted when the
10778 initial RAM disk (initrd) is loaded. This is always the case, for
10779 instance, for the root file system.
10781 @item @code{check?} (default: @code{#t})
10782 This Boolean indicates whether the file system needs to be checked for
10783 errors before being mounted.
10785 @item @code{create-mount-point?} (default: @code{#f})
10786 When true, the mount point is created if it does not exist yet.
10788 @item @code{dependencies} (default: @code{'()})
10789 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10790 representing file systems that must be mounted or mapped devices that
10791 must be opened before (and unmounted or closed after) this one.
10793 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10794 a dependency of @file{/sys/fs/cgroup/cpu} and
10795 @file{/sys/fs/cgroup/memory}.
10797 Another example is a file system that depends on a mapped device, for
10798 example for an encrypted partition (@pxref{Mapped Devices}).
10802 The @code{(gnu system file-systems)} exports the following useful
10805 @defvr {Scheme Variable} %base-file-systems
10806 These are essential file systems that are required on normal systems,
10807 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10808 below.) Operating system declarations should always contain at least
10812 @defvr {Scheme Variable} %pseudo-terminal-file-system
10813 This is the file system to be mounted as @file{/dev/pts}. It supports
10814 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10815 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10816 Manual}). Pseudo-terminals are used by terminal emulators such as
10820 @defvr {Scheme Variable} %shared-memory-file-system
10821 This file system is mounted as @file{/dev/shm} and is used to support
10822 memory sharing across processes (@pxref{Memory-mapped I/O,
10823 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10826 @defvr {Scheme Variable} %immutable-store
10827 This file system performs a read-only ``bind mount'' of
10828 @file{/gnu/store}, making it read-only for all the users including
10829 @code{root}. This prevents against accidental modification by software
10830 running as @code{root} or by system administrators.
10832 The daemon itself is still able to write to the store: it remounts it
10833 read-write in its own ``name space.''
10836 @defvr {Scheme Variable} %binary-format-file-system
10837 The @code{binfmt_misc} file system, which allows handling of arbitrary
10838 executable file types to be delegated to user space. This requires the
10839 @code{binfmt.ko} kernel module to be loaded.
10842 @defvr {Scheme Variable} %fuse-control-file-system
10843 The @code{fusectl} file system, which allows unprivileged users to mount
10844 and unmount user-space FUSE file systems. This requires the
10845 @code{fuse.ko} kernel module to be loaded.
10848 @node Mapped Devices
10849 @section Mapped Devices
10851 @cindex device mapping
10852 @cindex mapped devices
10853 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10854 such as a hard disk partition, can be @dfn{mapped} into another device,
10855 usually in @code{/dev/mapper/},
10856 with additional processing over the data that flows through
10857 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10858 concept of a ``mapped device'' and that of a file system: both boil down
10859 to @emph{translating} input/output operations made on a file to
10860 operations on its backing store. Thus, the Hurd implements mapped
10861 devices, like file systems, using the generic @dfn{translator} mechanism
10862 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10863 typical example is encryption device mapping: all writes to the mapped
10864 device are encrypted, and all reads are deciphered, transparently.
10865 Guix extends this notion by considering any device or set of devices that
10866 are @dfn{transformed} in some way to create a new device; for instance,
10867 RAID devices are obtained by @dfn{assembling} several other devices, such
10868 as hard disks or partitions, into a new one that behaves as one partition.
10869 Other examples, not yet implemented, are LVM logical volumes.
10871 Mapped devices are declared using the @code{mapped-device} form,
10872 defined as follows; for examples, see below.
10874 @deftp {Data Type} mapped-device
10875 Objects of this type represent device mappings that will be made when
10876 the system boots up.
10880 This is either a string specifying the name of the block device to be mapped,
10881 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10882 need to be assembled for creating a new one.
10885 This string specifies the name of the resulting mapped device. For
10886 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10887 specifying @code{"my-partition"} leads to the creation of
10888 the @code{"/dev/mapper/my-partition"} device.
10889 For RAID devices of type @code{raid-device-mapping}, the full device name
10890 such as @code{"/dev/md0"} needs to be given.
10893 This must be a @code{mapped-device-kind} object, which specifies how
10894 @var{source} is mapped to @var{target}.
10898 @defvr {Scheme Variable} luks-device-mapping
10899 This defines LUKS block device encryption using the @command{cryptsetup}
10900 command from the package with the same name. It relies on the
10901 @code{dm-crypt} Linux kernel module.
10904 @defvr {Scheme Variable} raid-device-mapping
10905 This defines a RAID device, which is assembled using the @code{mdadm}
10906 command from the package with the same name. It requires a Linux kernel
10907 module for the appropriate RAID level to be loaded, such as @code{raid456}
10908 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10911 @cindex disk encryption
10913 The following example specifies a mapping from @file{/dev/sda3} to
10914 @file{/dev/mapper/home} using LUKS---the
10915 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10916 standard mechanism for disk encryption.
10917 The @file{/dev/mapper/home}
10918 device can then be used as the @code{device} of a @code{file-system}
10919 declaration (@pxref{File Systems}).
10923 (source "/dev/sda3")
10925 (type luks-device-mapping))
10928 Alternatively, to become independent of device numbering, one may obtain
10929 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10933 cryptsetup luksUUID /dev/sda3
10936 and use it as follows:
10940 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10942 (type luks-device-mapping))
10945 @cindex swap encryption
10946 It is also desirable to encrypt swap space, since swap space may contain
10947 sensitive data. One way to accomplish that is to use a swap file in a
10948 file system on a device mapped via LUKS encryption. In this way, the
10949 swap file is encrypted because the entire device is encrypted.
10950 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10952 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10953 may be declared as follows:
10957 (source (list "/dev/sda1" "/dev/sdb1"))
10958 (target "/dev/md0")
10959 (type raid-device-mapping))
10962 The @file{/dev/md0} device can then be used as the @code{device} of a
10963 @code{file-system} declaration (@pxref{File Systems}).
10964 Note that the RAID level need not be given; it is chosen during the
10965 initial creation and formatting of the RAID device and is determined
10966 automatically later.
10969 @node User Accounts
10970 @section User Accounts
10974 @cindex user accounts
10975 User accounts and groups are entirely managed through the
10976 @code{operating-system} declaration. They are specified with the
10977 @code{user-account} and @code{user-group} forms:
10983 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10984 "audio" ;sound card
10985 "video" ;video devices such as webcams
10986 "cdrom")) ;the good ol' CD-ROM
10987 (comment "Bob's sister")
10988 (home-directory "/home/alice"))
10991 When booting or upon completion of @command{guix system reconfigure},
10992 the system ensures that only the user accounts and groups specified in
10993 the @code{operating-system} declaration exist, and with the specified
10994 properties. Thus, account or group creations or modifications made by
10995 directly invoking commands such as @command{useradd} are lost upon
10996 reconfiguration or reboot. This ensures that the system remains exactly
10999 @deftp {Data Type} user-account
11000 Objects of this type represent user accounts. The following members may
11005 The name of the user account.
11009 This is the name (a string) or identifier (a number) of the user group
11010 this account belongs to.
11012 @item @code{supplementary-groups} (default: @code{'()})
11013 Optionally, this can be defined as a list of group names that this
11014 account belongs to.
11016 @item @code{uid} (default: @code{#f})
11017 This is the user ID for this account (a number), or @code{#f}. In the
11018 latter case, a number is automatically chosen by the system when the
11019 account is created.
11021 @item @code{comment} (default: @code{""})
11022 A comment about the account, such as the account owner's full name.
11024 @item @code{home-directory}
11025 This is the name of the home directory for the account.
11027 @item @code{create-home-directory?} (default: @code{#t})
11028 Indicates whether the home directory of this account should be created
11029 if it does not exist yet.
11031 @item @code{shell} (default: Bash)
11032 This is a G-expression denoting the file name of a program to be used as
11033 the shell (@pxref{G-Expressions}).
11035 @item @code{system?} (default: @code{#f})
11036 This Boolean value indicates whether the account is a ``system''
11037 account. System accounts are sometimes treated specially; for instance,
11038 graphical login managers do not list them.
11040 @anchor{user-account-password}
11041 @cindex password, for user accounts
11042 @item @code{password} (default: @code{#f})
11043 You would normally leave this field to @code{#f}, initialize user
11044 passwords as @code{root} with the @command{passwd} command, and then let
11045 users change it with @command{passwd}. Passwords set with
11046 @command{passwd} are of course preserved across reboot and
11049 If you @emph{do} want to set an initial password for an account, then
11050 this field must contain the encrypted password, as a string. You can use the
11051 @code{crypt} procedure for this purpose:
11058 ;; Specify a SHA-512-hashed initial password.
11059 (password (crypt "InitialPassword!" "$6$abc")))
11063 The hash of this initial password will be available in a file in
11064 @file{/gnu/store}, readable by all the users, so this method must be used with
11068 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11069 more information on password encryption, and @ref{Encryption,,, guile, GNU
11070 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11076 User group declarations are even simpler:
11079 (user-group (name "students"))
11082 @deftp {Data Type} user-group
11083 This type is for, well, user groups. There are just a few fields:
11087 The name of the group.
11089 @item @code{id} (default: @code{#f})
11090 The group identifier (a number). If @code{#f}, a new number is
11091 automatically allocated when the group is created.
11093 @item @code{system?} (default: @code{#f})
11094 This Boolean value indicates whether the group is a ``system'' group.
11095 System groups have low numerical IDs.
11097 @item @code{password} (default: @code{#f})
11098 What, user groups can have a password? Well, apparently yes. Unless
11099 @code{#f}, this field specifies the password of the group.
11104 For convenience, a variable lists all the basic user groups one may
11107 @defvr {Scheme Variable} %base-groups
11108 This is the list of basic user groups that users and/or packages expect
11109 to be present on the system. This includes groups such as ``root'',
11110 ``wheel'', and ``users'', as well as groups used to control access to
11111 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11114 @defvr {Scheme Variable} %base-user-accounts
11115 This is the list of basic system accounts that programs may expect to
11116 find on a GNU/Linux system, such as the ``nobody'' account.
11118 Note that the ``root'' account is not included here. It is a
11119 special-case and is automatically added whether or not it is specified.
11122 @node Keyboard Layout
11123 @section Keyboard Layout
11125 @cindex keyboard layout
11127 To specify what each key of your keyboard does, you need to tell the operating
11128 system what @dfn{keyboard layout} you want to use. The default, when nothing
11129 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11130 However, German speakers will usually prefer the German QWERTZ layout, French
11131 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11132 or bépo, and they might even want to further customize the effect of some of
11133 the keys. This section explains how to get that done.
11135 @cindex keyboard layout, definition
11136 There are three components that will want to know about your keyboard layout:
11140 The @emph{bootloader} may want to know what keyboard layout you want to use
11141 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11142 you want, for instance, to make sure that you can type the passphrase of your
11143 encrypted root partition using the right layout.
11146 The @emph{operating system kernel}, Linux, will need that so that the console
11147 is properly configured (@pxref{operating-system Reference,
11148 @code{keyboard-layout}}).
11151 The @emph{graphical display server}, usually Xorg, also has its own idea of
11152 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11155 Guix allows you to configure all three separately but, fortunately, it allows
11156 you to share the same keyboard layout for all three components.
11158 @cindex XKB, keyboard layouts
11159 Keyboard layouts are represented by records created by the
11160 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11161 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11162 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11163 optional variant name, an optional keyboard model name, and a possibly empty
11164 list of additional options. In most cases the layout name is all you care
11165 about. Here are a few example:
11168 ;; The German QWERTZ layout. Here we assume a standard
11169 ;; "pc105" keyboard model.
11170 (keyboard-layout "de")
11172 ;; The bépo variant of the French layout.
11173 (keyboard-layout "fr" "bepo")
11175 ;; The Catalan layout.
11176 (keyboard-layout "es" "cat")
11178 ;; The Latin American Spanish layout. In addition, the
11179 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11180 ;; and the "Menu" key is used as a "Compose" key to enter
11181 ;; accented letters.
11182 (keyboard-layout "latam"
11183 #:options '("ctrl:nocaps" "compose:menu"))
11185 ;; The Russian layout for a ThinkPad keyboard.
11186 (keyboard-layout "ru" #:model "thinkpad")
11188 ;; The "US international" layout, which is the US layout plus
11189 ;; dead keys to enter accented characters. This is for an
11190 ;; Apple MacBook keyboard.
11191 (keyboard-layout "us" "intl" #:model "macbook78")
11194 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11195 for a complete list of supported layouts, variants, and models.
11197 @cindex keyboard layout, configuration
11198 Let's say you want your system to use the Turkish keyboard layout throughout
11199 your system---bootloader, console, and Xorg. Here's what your system
11200 configuration would look like:
11202 @findex set-xorg-configuration
11204 ;; Using the Turkish layout for the bootloader, the console,
11209 (keyboard-layout (keyboard-layout "tr")) ;for the console
11210 (bootloader (bootloader-configuration
11211 (bootloader grub-efi-bootloader)
11212 (target "/boot/efi")
11213 (keyboard-layout keyboard-layout))) ;for GRUB
11214 (services (cons (set-xorg-configuration
11215 (xorg-configuration ;for Xorg
11216 (keyboard-layout keyboard-layout)))
11217 %desktop-services)))
11220 In the example above, for GRUB and for Xorg, we just refer to the
11221 @code{keyboard-layout} field defined above, but we could just as well refer to
11222 a different layout. The @code{set-xorg-configuration} procedure communicates
11223 the desired Xorg configuration to the graphical log-in manager, by default
11226 We've discussed how to specify the @emph{default} keyboard layout of your
11227 system when it starts, but you can also adjust it at run time:
11231 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11232 where you can select one or more keyboard layouts.
11235 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11236 allows you to change the current layout. For example, this is how you would
11237 change the layout to US Dvorak:
11240 setxkbmap us dvorak
11244 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11245 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11246 keyboard layout categorization described above. The command below loads the
11247 French bépo layout:
11258 A @dfn{locale} defines cultural conventions for a particular language
11259 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11260 Reference Manual}). Each locale has a name that typically has the form
11261 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11262 @code{fr_LU.utf8} designates the locale for the French language, with
11263 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11265 @cindex locale definition
11266 Usually, you will want to specify the default locale for the machine
11267 using the @code{locale} field of the @code{operating-system} declaration
11268 (@pxref{operating-system Reference, @code{locale}}).
11270 The selected locale is automatically added to the @dfn{locale
11271 definitions} known to the system if needed, with its codeset inferred
11272 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11273 @code{UTF-8} codeset. Additional locale definitions can be specified in
11274 the @code{locale-definitions} slot of @code{operating-system}---this is
11275 useful, for instance, if the codeset could not be inferred from the
11276 locale name. The default set of locale definitions includes some widely
11277 used locales, but not all the available locales, in order to save space.
11279 For instance, to add the North Frisian locale for Germany, the value of
11283 (cons (locale-definition
11284 (name "fy_DE.utf8") (source "fy_DE"))
11285 %default-locale-definitions)
11288 Likewise, to save space, one might want @code{locale-definitions} to
11289 list only the locales that are actually used, as in:
11292 (list (locale-definition
11293 (name "ja_JP.eucjp") (source "ja_JP")
11294 (charset "EUC-JP")))
11298 The compiled locale definitions are available at
11299 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11300 version, which is the default location where the GNU@tie{}libc provided
11301 by Guix looks for locale data. This can be overridden using the
11302 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11303 @code{LOCPATH} and locale packages}).
11305 The @code{locale-definition} form is provided by the @code{(gnu system
11306 locale)} module. Details are given below.
11308 @deftp {Data Type} locale-definition
11309 This is the data type of a locale definition.
11314 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11315 Reference Manual}, for more information on locale names.
11317 @item @code{source}
11318 The name of the source for that locale. This is typically the
11319 @code{@var{language}_@var{territory}} part of the locale name.
11321 @item @code{charset} (default: @code{"UTF-8"})
11322 The ``character set'' or ``code set'' for that locale,
11323 @uref{http://www.iana.org/assignments/character-sets, as defined by
11329 @defvr {Scheme Variable} %default-locale-definitions
11330 A list of commonly used UTF-8 locales, used as the default
11331 value of the @code{locale-definitions} field of @code{operating-system}
11334 @cindex locale name
11335 @cindex normalized codeset in locale names
11336 These locale definitions use the @dfn{normalized codeset} for the part
11337 that follows the dot in the name (@pxref{Using gettextized software,
11338 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11339 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11340 @code{uk_UA.UTF-8}.
11343 @subsection Locale Data Compatibility Considerations
11345 @cindex incompatibility, of locale data
11346 @code{operating-system} declarations provide a @code{locale-libcs} field
11347 to specify the GNU@tie{}libc packages that are used to compile locale
11348 declarations (@pxref{operating-system Reference}). ``Why would I
11349 care?'', you may ask. Well, it turns out that the binary format of
11350 locale data is occasionally incompatible from one libc version to
11353 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11354 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11355 For instance, a program linked against libc version 2.21 is unable to
11356 read locale data produced with libc 2.22; worse, that program
11357 @emph{aborts} instead of simply ignoring the incompatible locale
11358 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11359 the incompatible locale data, which is already an improvement.}.
11360 Similarly, a program linked against libc 2.22 can read most, but not
11361 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11362 data is incompatible); thus calls to @code{setlocale} may fail, but
11363 programs will not abort.
11365 The ``problem'' with Guix is that users have a lot of freedom: They can
11366 choose whether and when to upgrade software in their profiles, and might
11367 be using a libc version different from the one the system administrator
11368 used to build the system-wide locale data.
11370 Fortunately, unprivileged users can also install their own locale data
11371 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11372 @code{GUIX_LOCPATH} and locale packages}).
11374 Still, it is best if the system-wide locale data at
11375 @file{/run/current-system/locale} is built for all the libc versions
11376 actually in use on the system, so that all the programs can access
11377 it---this is especially crucial on a multi-user system. To do that, the
11378 administrator can specify several libc packages in the
11379 @code{locale-libcs} field of @code{operating-system}:
11382 (use-package-modules base)
11386 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11389 This example would lead to a system containing locale definitions for
11390 both libc 2.21 and the current version of libc in
11391 @file{/run/current-system/locale}.
11397 @cindex system services
11398 An important part of preparing an @code{operating-system} declaration is
11399 listing @dfn{system services} and their configuration (@pxref{Using the
11400 Configuration System}). System services are typically daemons launched
11401 when the system boots, or other actions needed at that time---e.g.,
11402 configuring network access.
11404 Guix has a broad definition of ``service'' (@pxref{Service
11405 Composition}), but many services are managed by the GNU@tie{}Shepherd
11406 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11407 command allows you to list the available services, show their status,
11408 start and stop them, or do other specific operations (@pxref{Jump
11409 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11415 The above command, run as @code{root}, lists the currently defined
11416 services. The @command{herd doc} command shows a synopsis of the given
11417 service and its associated actions:
11421 Run libc's name service cache daemon (nscd).
11423 # herd doc nscd action invalidate
11424 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11427 The @command{start}, @command{stop}, and @command{restart} sub-commands
11428 have the effect you would expect. For instance, the commands below stop
11429 the nscd service and restart the Xorg display server:
11433 Service nscd has been stopped.
11434 # herd restart xorg-server
11435 Service xorg-server has been stopped.
11436 Service xorg-server has been started.
11439 The following sections document the available services, starting with
11440 the core services, that may be used in an @code{operating-system}
11444 * Base Services:: Essential system services.
11445 * Scheduled Job Execution:: The mcron service.
11446 * Log Rotation:: The rottlog service.
11447 * Networking Services:: Network setup, SSH daemon, etc.
11448 * X Window:: Graphical display.
11449 * Printing Services:: Local and remote printer support.
11450 * Desktop Services:: D-Bus and desktop services.
11451 * Sound Services:: ALSA and Pulseaudio services.
11452 * Database Services:: SQL databases, key-value stores, etc.
11453 * Mail Services:: IMAP, POP3, SMTP, and all that.
11454 * Messaging Services:: Messaging services.
11455 * Telephony Services:: Telephony services.
11456 * Monitoring Services:: Monitoring services.
11457 * Kerberos Services:: Kerberos services.
11458 * LDAP Services:: LDAP services.
11459 * Web Services:: Web servers.
11460 * Certificate Services:: TLS certificates via Let's Encrypt.
11461 * DNS Services:: DNS daemons.
11462 * VPN Services:: VPN daemons.
11463 * Network File System:: NFS related services.
11464 * Continuous Integration:: The Cuirass service.
11465 * Power Management Services:: Extending battery life.
11466 * Audio Services:: The MPD.
11467 * Virtualization Services:: Virtualization services.
11468 * Version Control Services:: Providing remote access to Git repositories.
11469 * Game Services:: Game servers.
11470 * Miscellaneous Services:: Other services.
11473 @node Base Services
11474 @subsection Base Services
11476 The @code{(gnu services base)} module provides definitions for the basic
11477 services that one expects from the system. The services exported by
11478 this module are listed below.
11480 @defvr {Scheme Variable} %base-services
11481 This variable contains a list of basic services (@pxref{Service Types
11482 and Services}, for more information on service objects) one would
11483 expect from the system: a login service (mingetty) on each tty, syslogd,
11484 the libc name service cache daemon (nscd), the udev device manager, and
11487 This is the default value of the @code{services} field of
11488 @code{operating-system} declarations. Usually, when customizing a
11489 system, you will want to append services to @var{%base-services}, like
11493 (append (list (service avahi-service-type)
11494 (service openssh-service-type))
11499 @defvr {Scheme Variable} special-files-service-type
11500 This is the service that sets up ``special files'' such as
11501 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11503 The value associated with @code{special-files-service-type} services
11504 must be a list of tuples where the first element is the ``special file''
11505 and the second element is its target. By default it is:
11507 @cindex @file{/bin/sh}
11508 @cindex @file{sh}, in @file{/bin}
11510 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11513 @cindex @file{/usr/bin/env}
11514 @cindex @file{env}, in @file{/usr/bin}
11515 If you want to add, say, @code{/usr/bin/env} to your system, you can
11519 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11520 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11523 Since this is part of @code{%base-services}, you can use
11524 @code{modify-services} to customize the set of special files
11525 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11526 to add a special file is @i{via} the @code{extra-special-file} procedure
11530 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11531 Use @var{target} as the ``special file'' @var{file}.
11533 For example, adding the following lines to the @code{services} field of
11534 your operating system declaration leads to a @file{/usr/bin/env}
11538 (extra-special-file "/usr/bin/env"
11539 (file-append coreutils "/bin/env"))
11543 @deffn {Scheme Procedure} host-name-service @var{name}
11544 Return a service that sets the host name to @var{name}.
11547 @deffn {Scheme Procedure} login-service @var{config}
11548 Return a service to run login according to @var{config}, a
11549 @code{<login-configuration>} object, which specifies the message of the day,
11550 among other things.
11553 @deftp {Data Type} login-configuration
11554 This is the data type representing the configuration of login.
11559 @cindex message of the day
11560 A file-like object containing the ``message of the day''.
11562 @item @code{allow-empty-passwords?} (default: @code{#t})
11563 Allow empty passwords by default so that first-time users can log in when
11564 the 'root' account has just been created.
11569 @deffn {Scheme Procedure} mingetty-service @var{config}
11570 Return a service to run mingetty according to @var{config}, a
11571 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11575 @deftp {Data Type} mingetty-configuration
11576 This is the data type representing the configuration of Mingetty, which
11577 provides the default implementation of virtual console log-in.
11582 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11584 @item @code{auto-login} (default: @code{#f})
11585 When true, this field must be a string denoting the user name under
11586 which the system automatically logs in. When it is @code{#f}, a
11587 user name and password must be entered to log in.
11589 @item @code{login-program} (default: @code{#f})
11590 This must be either @code{#f}, in which case the default log-in program
11591 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11592 the name of the log-in program.
11594 @item @code{login-pause?} (default: @code{#f})
11595 When set to @code{#t} in conjunction with @var{auto-login}, the user
11596 will have to press a key before the log-in shell is launched.
11598 @item @code{mingetty} (default: @var{mingetty})
11599 The Mingetty package to use.
11604 @deffn {Scheme Procedure} agetty-service @var{config}
11605 Return a service to run agetty according to @var{config}, an
11606 @code{<agetty-configuration>} object, which specifies the tty to run,
11607 among other things.
11610 @deftp {Data Type} agetty-configuration
11611 This is the data type representing the configuration of agetty, which
11612 implements virtual and serial console log-in. See the @code{agetty(8)}
11613 man page for more information.
11618 The name of the console this agetty runs on, as a string---e.g.,
11619 @code{"ttyS0"}. This argument is optional, it will default to
11620 a reasonable default serial port used by the kernel Linux.
11622 For this, if there is a value for an option @code{agetty.tty} in the kernel
11623 command line, agetty will extract the device name of the serial port
11624 from it and use that.
11626 If not and if there is a value for an option @code{console} with a tty in
11627 the Linux command line, agetty will extract the device name of the
11628 serial port from it and use that.
11630 In both cases, agetty will leave the other serial device settings
11631 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11634 @item @code{baud-rate} (default: @code{#f})
11635 A string containing a comma-separated list of one or more baud rates, in
11638 @item @code{term} (default: @code{#f})
11639 A string containing the value used for the @code{TERM} environment
11642 @item @code{eight-bits?} (default: @code{#f})
11643 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11646 @item @code{auto-login} (default: @code{#f})
11647 When passed a login name, as a string, the specified user will be logged
11648 in automatically without prompting for their login name or password.
11650 @item @code{no-reset?} (default: @code{#f})
11651 When @code{#t}, don't reset terminal cflags (control modes).
11653 @item @code{host} (default: @code{#f})
11654 This accepts a string containing the "login_host", which will be written
11655 into the @file{/var/run/utmpx} file.
11657 @item @code{remote?} (default: @code{#f})
11658 When set to @code{#t} in conjunction with @var{host}, this will add an
11659 @code{-r} fakehost option to the command line of the login program
11660 specified in @var{login-program}.
11662 @item @code{flow-control?} (default: @code{#f})
11663 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11665 @item @code{no-issue?} (default: @code{#f})
11666 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11667 not be displayed before presenting the login prompt.
11669 @item @code{init-string} (default: @code{#f})
11670 This accepts a string that will be sent to the tty or modem before
11671 sending anything else. It can be used to initialize a modem.
11673 @item @code{no-clear?} (default: @code{#f})
11674 When set to @code{#t}, agetty will not clear the screen before showing
11677 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11678 This must be either a gexp denoting the name of a log-in program, or
11679 unset, in which case the default value is the @command{login} from the
11682 @item @code{local-line} (default: @code{#f})
11683 Control the CLOCAL line flag. This accepts one of three symbols as
11684 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11685 the default value chosen by agetty is @code{'auto}.
11687 @item @code{extract-baud?} (default: @code{#f})
11688 When set to @code{#t}, instruct agetty to try to extract the baud rate
11689 from the status messages produced by certain types of modems.
11691 @item @code{skip-login?} (default: @code{#f})
11692 When set to @code{#t}, do not prompt the user for a login name. This
11693 can be used with @var{login-program} field to use non-standard login
11696 @item @code{no-newline?} (default: @code{#f})
11697 When set to @code{#t}, do not print a newline before printing the
11698 @file{/etc/issue} file.
11700 @c Is this dangerous only when used with login-program, or always?
11701 @item @code{login-options} (default: @code{#f})
11702 This option accepts a string containing options that are passed to the
11703 login program. When used with the @var{login-program}, be aware that a
11704 malicious user could try to enter a login name containing embedded
11705 options that could be parsed by the login program.
11707 @item @code{login-pause} (default: @code{#f})
11708 When set to @code{#t}, wait for any key before showing the login prompt.
11709 This can be used in conjunction with @var{auto-login} to save memory by
11710 lazily spawning shells.
11712 @item @code{chroot} (default: @code{#f})
11713 Change root to the specified directory. This option accepts a directory
11716 @item @code{hangup?} (default: @code{#f})
11717 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11718 specified terminal.
11720 @item @code{keep-baud?} (default: @code{#f})
11721 When set to @code{#t}, try to keep the existing baud rate. The baud
11722 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11725 @item @code{timeout} (default: @code{#f})
11726 When set to an integer value, terminate if no user name could be read
11727 within @var{timeout} seconds.
11729 @item @code{detect-case?} (default: @code{#f})
11730 When set to @code{#t}, turn on support for detecting an uppercase-only
11731 terminal. This setting will detect a login name containing only
11732 uppercase letters as indicating an uppercase-only terminal and turn on
11733 some upper-to-lower case conversions. Note that this will not support
11734 Unicode characters.
11736 @item @code{wait-cr?} (default: @code{#f})
11737 When set to @code{#t}, wait for the user or modem to send a
11738 carriage-return or linefeed character before displaying
11739 @file{/etc/issue} or login prompt. This is typically used with the
11740 @var{init-string} option.
11742 @item @code{no-hints?} (default: @code{#f})
11743 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11746 @item @code{no-hostname?} (default: @code{#f})
11747 By default, the hostname is printed. When this option is set to
11748 @code{#t}, no hostname will be shown at all.
11750 @item @code{long-hostname?} (default: @code{#f})
11751 By default, the hostname is only printed until the first dot. When this
11752 option is set to @code{#t}, the fully qualified hostname by
11753 @code{gethostname} or @code{getaddrinfo} is shown.
11755 @item @code{erase-characters} (default: @code{#f})
11756 This option accepts a string of additional characters that should be
11757 interpreted as backspace when the user types their login name.
11759 @item @code{kill-characters} (default: @code{#f})
11760 This option accepts a string that should be interpreted to mean "ignore
11761 all previous characters" (also called a "kill" character) when the types
11764 @item @code{chdir} (default: @code{#f})
11765 This option accepts, as a string, a directory path that will be changed
11768 @item @code{delay} (default: @code{#f})
11769 This options accepts, as an integer, the number of seconds to sleep
11770 before opening the tty and displaying the login prompt.
11772 @item @code{nice} (default: @code{#f})
11773 This option accepts, as an integer, the nice value with which to run the
11774 @command{login} program.
11776 @item @code{extra-options} (default: @code{'()})
11777 This option provides an "escape hatch" for the user to provide arbitrary
11778 command-line arguments to @command{agetty} as a list of strings.
11783 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11784 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11785 according to @var{config}, a @code{<kmscon-configuration>} object, which
11786 specifies the tty to run, among other things.
11789 @deftp {Data Type} kmscon-configuration
11790 This is the data type representing the configuration of Kmscon, which
11791 implements virtual console log-in.
11795 @item @code{virtual-terminal}
11796 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11798 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11799 A gexp denoting the name of the log-in program. The default log-in program is
11800 @command{login} from the Shadow tool suite.
11802 @item @code{login-arguments} (default: @code{'("-p")})
11803 A list of arguments to pass to @command{login}.
11805 @item @code{auto-login} (default: @code{#f})
11806 When passed a login name, as a string, the specified user will be logged
11807 in automatically without prompting for their login name or password.
11809 @item @code{hardware-acceleration?} (default: #f)
11810 Whether to use hardware acceleration.
11812 @item @code{kmscon} (default: @var{kmscon})
11813 The Kmscon package to use.
11818 @cindex name service cache daemon
11820 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11821 [#:name-services '()]
11822 Return a service that runs the libc name service cache daemon (nscd) with the
11823 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11824 Service Switch}, for an example.
11826 For convenience, the Shepherd service for nscd provides the following actions:
11830 @cindex cache invalidation, nscd
11831 @cindex nscd, cache invalidation
11832 This invalidate the given cache. For instance, running:
11835 herd invalidate nscd hosts
11839 invalidates the host name lookup cache of nscd.
11842 Running @command{herd statistics nscd} displays information about nscd usage
11848 @defvr {Scheme Variable} %nscd-default-configuration
11849 This is the default @code{<nscd-configuration>} value (see below) used
11850 by @code{nscd-service}. It uses the caches defined by
11851 @var{%nscd-default-caches}; see below.
11854 @deftp {Data Type} nscd-configuration
11855 This is the data type representing the name service cache daemon (nscd)
11860 @item @code{name-services} (default: @code{'()})
11861 List of packages denoting @dfn{name services} that must be visible to
11862 the nscd---e.g., @code{(list @var{nss-mdns})}.
11864 @item @code{glibc} (default: @var{glibc})
11865 Package object denoting the GNU C Library providing the @command{nscd}
11868 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11869 Name of the nscd log file. This is where debugging output goes when
11870 @code{debug-level} is strictly positive.
11872 @item @code{debug-level} (default: @code{0})
11873 Integer denoting the debugging levels. Higher numbers mean that more
11874 debugging output is logged.
11876 @item @code{caches} (default: @var{%nscd-default-caches})
11877 List of @code{<nscd-cache>} objects denoting things to be cached; see
11883 @deftp {Data Type} nscd-cache
11884 Data type representing a cache database of nscd and its parameters.
11888 @item @code{database}
11889 This is a symbol representing the name of the database to be cached.
11890 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11891 @code{services}, which designate the corresponding NSS database
11892 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11894 @item @code{positive-time-to-live}
11895 @itemx @code{negative-time-to-live} (default: @code{20})
11896 A number representing the number of seconds during which a positive or
11897 negative lookup result remains in cache.
11899 @item @code{check-files?} (default: @code{#t})
11900 Whether to check for updates of the files corresponding to
11903 For instance, when @var{database} is @code{hosts}, setting this flag
11904 instructs nscd to check for updates in @file{/etc/hosts} and to take
11907 @item @code{persistent?} (default: @code{#t})
11908 Whether the cache should be stored persistently on disk.
11910 @item @code{shared?} (default: @code{#t})
11911 Whether the cache should be shared among users.
11913 @item @code{max-database-size} (default: 32@tie{}MiB)
11914 Maximum size in bytes of the database cache.
11916 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11917 @c settings, so leave them out.
11922 @defvr {Scheme Variable} %nscd-default-caches
11923 List of @code{<nscd-cache>} objects used by default by
11924 @code{nscd-configuration} (see above).
11926 It enables persistent and aggressive caching of service and host name
11927 lookups. The latter provides better host name lookup performance,
11928 resilience in the face of unreliable name servers, and also better
11929 privacy---often the result of host name lookups is in local cache, so
11930 external name servers do not even need to be queried.
11933 @anchor{syslog-configuration-type}
11936 @deftp {Data Type} syslog-configuration
11937 This data type represents the configuration of the syslog daemon.
11940 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11941 The syslog daemon to use.
11943 @item @code{config-file} (default: @code{%default-syslog.conf})
11944 The syslog configuration file to use.
11949 @anchor{syslog-service}
11951 @deffn {Scheme Procedure} syslog-service @var{config}
11952 Return a service that runs a syslog daemon according to @var{config}.
11954 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11955 information on the configuration file syntax.
11958 @defvr {Scheme Variable} guix-service-type
11959 This is the type of the service that runs the build daemon,
11960 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11961 @code{guix-configuration} record as described below.
11964 @anchor{guix-configuration-type}
11965 @deftp {Data Type} guix-configuration
11966 This data type represents the configuration of the Guix build daemon.
11967 @xref{Invoking guix-daemon}, for more information.
11970 @item @code{guix} (default: @var{guix})
11971 The Guix package to use.
11973 @item @code{build-group} (default: @code{"guixbuild"})
11974 Name of the group for build user accounts.
11976 @item @code{build-accounts} (default: @code{10})
11977 Number of build user accounts to create.
11979 @item @code{authorize-key?} (default: @code{#t})
11980 @cindex substitutes, authorization thereof
11981 Whether to authorize the substitute keys listed in
11982 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11983 (@pxref{Substitutes}).
11985 @vindex %default-authorized-guix-keys
11986 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11987 The list of authorized key files for archive imports, as a list of
11988 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11989 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11991 @item @code{use-substitutes?} (default: @code{#t})
11992 Whether to use substitutes.
11994 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11995 The list of URLs where to look for substitutes by default.
11997 @item @code{max-silent-time} (default: @code{0})
11998 @itemx @code{timeout} (default: @code{0})
11999 The number of seconds of silence and the number of seconds of activity,
12000 respectively, after which a build process times out. A value of zero
12001 disables the timeout.
12003 @item @code{log-compression} (default: @code{'bzip2})
12004 The type of compression used for build logs---one of @code{gzip},
12005 @code{bzip2}, or @code{none}.
12007 @item @code{extra-options} (default: @code{'()})
12008 List of extra command-line options for @command{guix-daemon}.
12010 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12011 File where @command{guix-daemon}'s standard output and standard error
12014 @item @code{http-proxy} (default: @code{#f})
12015 The HTTP proxy used for downloading fixed-output derivations and
12018 @item @code{tmpdir} (default: @code{#f})
12019 A directory path where the @command{guix-daemon} will perform builds.
12024 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12025 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12026 udev rules can be provided as a list of files through the @var{rules}
12027 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
12028 @code{(gnu services base)} simplify the creation of such rule files.
12031 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12032 Return a udev-rule file named @var{file-name} containing the rules
12033 defined by the @var{contents} literal.
12035 In the following example, a rule for a USB device is defined to be
12036 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12037 upon detecting a USB device with a given product identifier.
12040 (define %example-udev-rule
12042 "90-usb-thing.rules"
12043 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12044 "ATTR@{product@}==\"Example\", "
12045 "RUN+=\"/path/to/script\"")))
12048 The @command{herd rules udev} command, as root, returns the name of the
12049 directory containing all the active udev rules.
12052 Here we show how the default @var{udev-service} can be extended with it.
12058 (modify-services %desktop-services
12059 (udev-service-type config =>
12060 (udev-configuration (inherit config)
12061 (rules (append (udev-configuration-rules config)
12062 (list %example-udev-rule))))))))
12065 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12066 Return a udev file named @var{file-name} containing the rules defined
12067 within @var{file}, a file-like object.
12069 The following example showcases how we can use an existing rule file.
12072 (use-modules (guix download) ;for url-fetch
12073 (guix packages) ;for origin
12076 (define %android-udev-rules
12078 "51-android-udev.rules"
12079 (let ((version "20170910"))
12082 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12083 "android-udev-rules/" version "/51-android.rules"))
12085 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12089 Additionally, Guix package definitions can be included in @var{rules} in
12090 order to extend the udev rules with the definitions found under their
12091 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12092 @var{file->udev-rule} example, we could have used the
12093 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12094 packages android)} module.
12096 The following example shows how to use the @var{android-udev-rules}
12097 package so that the Android tool @command{adb} can detect devices
12098 without root privileges. It also details how to create the
12099 @code{adbusers} group, which is required for the proper functioning of
12100 the rules defined within the @var{android-udev-rules} package. To
12101 create such a group, we must define it both as part of the
12102 @var{supplementary-groups} of our @var{user-account} declaration, as
12103 well as in the @var{groups} field of the @var{operating-system} record.
12106 (use-modules (gnu packages android) ;for android-udev-rules
12107 (gnu system shadow) ;for user-group
12112 (users (cons (user-acount
12114 (supplementary-groups
12115 '("adbusers" ;for adb
12116 "wheel" "netdev" "audio" "video"))
12119 (groups (cons (user-group (system? #t) (name "adbusers"))
12125 (modify-services %desktop-services
12128 (udev-configuration (inherit config)
12129 (rules (cons android-udev-rules
12130 (udev-configuration-rules config))))))))
12133 @defvr {Scheme Variable} urandom-seed-service-type
12134 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12135 when rebooting. It also tries to seed @file{/dev/urandom} from
12136 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12140 @defvr {Scheme Variable} %random-seed-file
12141 This is the name of the file where some random bytes are saved by
12142 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12143 It defaults to @file{/var/lib/random-seed}.
12148 @defvr {Scheme Variable} gpm-service-type
12149 This is the type of the service that runs GPM, the @dfn{general-purpose
12150 mouse daemon}, which provides mouse support to the Linux console. GPM
12151 allows users to use the mouse in the console, notably to select, copy,
12154 The value for services of this type must be a @code{gpm-configuration}
12155 (see below). This service is not part of @var{%base-services}.
12158 @deftp {Data Type} gpm-configuration
12159 Data type representing the configuration of GPM.
12162 @item @code{options} (default: @code{%default-gpm-options})
12163 Command-line options passed to @command{gpm}. The default set of
12164 options instruct @command{gpm} to listen to mouse events on
12165 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12168 @item @code{gpm} (default: @code{gpm})
12169 The GPM package to use.
12174 @anchor{guix-publish-service-type}
12175 @deffn {Scheme Variable} guix-publish-service-type
12176 This is the service type for @command{guix publish} (@pxref{Invoking
12177 guix publish}). Its value must be a @code{guix-configuration}
12178 object, as described below.
12180 This assumes that @file{/etc/guix} already contains a signing key pair as
12181 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12182 archive}). If that is not the case, the service will fail to start.
12185 @deftp {Data Type} guix-publish-configuration
12186 Data type representing the configuration of the @code{guix publish}
12190 @item @code{guix} (default: @code{guix})
12191 The Guix package to use.
12193 @item @code{port} (default: @code{80})
12194 The TCP port to listen for connections.
12196 @item @code{host} (default: @code{"localhost"})
12197 The host (and thus, network interface) to listen to. Use
12198 @code{"0.0.0.0"} to listen on all the network interfaces.
12200 @item @code{compression-level} (default: @code{3})
12201 The gzip compression level at which substitutes are compressed. Use
12202 @code{0} to disable compression altogether, and @code{9} to get the best
12203 compression ratio at the expense of increased CPU usage.
12205 @item @code{nar-path} (default: @code{"nar"})
12206 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12207 publish, @code{--nar-path}}, for details.
12209 @item @code{cache} (default: @code{#f})
12210 When it is @code{#f}, disable caching and instead generate archives on
12211 demand. Otherwise, this should be the name of a directory---e.g.,
12212 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12213 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12214 @option{--cache}}, for more information on the tradeoffs involved.
12216 @item @code{workers} (default: @code{#f})
12217 When it is an integer, this is the number of worker threads used for
12218 caching; when @code{#f}, the number of processors is used.
12219 @xref{Invoking guix publish, @option{--workers}}, for more information.
12221 @item @code{ttl} (default: @code{#f})
12222 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12223 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12224 for more information.
12228 @anchor{rngd-service}
12229 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12230 [#:device "/dev/hwrng"]
12231 Return a service that runs the @command{rngd} program from @var{rng-tools}
12232 to add @var{device} to the kernel's entropy pool. The service will fail if
12233 @var{device} does not exist.
12236 @anchor{pam-limits-service}
12237 @cindex session limits
12242 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12244 Return a service that installs a configuration file for the
12245 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12246 @code{pam_limits} module}. The procedure optionally takes a list of
12247 @code{pam-limits-entry} values, which can be used to specify
12248 @code{ulimit} limits and nice priority limits to user sessions.
12250 The following limits definition sets two hard and soft limits for all
12251 login sessions of users in the @code{realtime} group:
12254 (pam-limits-service
12256 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12257 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12260 The first entry increases the maximum realtime priority for
12261 non-privileged processes; the second entry lifts any restriction of the
12262 maximum address space that can be locked in memory. These settings are
12263 commonly used for real-time audio systems.
12266 @node Scheduled Job Execution
12267 @subsection Scheduled Job Execution
12271 @cindex scheduling jobs
12272 The @code{(gnu services mcron)} module provides an interface to
12273 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12274 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12275 Unix @command{cron} daemon; the main difference is that it is
12276 implemented in Guile Scheme, which provides a lot of flexibility when
12277 specifying the scheduling of jobs and their actions.
12279 The example below defines an operating system that runs the
12280 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12281 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12282 well as the @command{mkid} command on behalf of an unprivileged user
12283 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12284 gexps to introduce job definitions that are passed to mcron
12285 (@pxref{G-Expressions}).
12288 (use-modules (guix) (gnu) (gnu services mcron))
12289 (use-package-modules base idutils)
12291 (define updatedb-job
12292 ;; Run 'updatedb' at 3AM every day. Here we write the
12293 ;; job's action as a Scheme procedure.
12294 #~(job '(next-hour '(3))
12296 (execl (string-append #$findutils "/bin/updatedb")
12298 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12300 (define garbage-collector-job
12301 ;; Collect garbage 5 minutes after midnight every day.
12302 ;; The job's action is a shell command.
12303 #~(job "5 0 * * *" ;Vixie cron syntax
12306 (define idutils-job
12307 ;; Update the index database as user "charlie" at 12:15PM
12308 ;; and 19:15PM. This runs from the user's home directory.
12309 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12310 (string-append #$idutils "/bin/mkid src")
12315 (services (cons (service mcron-service-type
12316 (mcron-configuration
12317 (jobs (list garbage-collector-job
12323 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12324 for more information on mcron job specifications. Below is the
12325 reference of the mcron service.
12327 On a running system, you can use the @code{schedule} action of the service to
12328 visualize the mcron jobs that will be executed next:
12331 # herd schedule mcron
12335 The example above lists the next five tasks that will be executed, but you can
12336 also specify the number of tasks to display:
12339 # herd schedule mcron 10
12342 @defvr {Scheme Variable} mcron-service-type
12343 This is the type of the @code{mcron} service, whose value is an
12344 @code{mcron-configuration} object.
12346 This service type can be the target of a service extension that provides
12347 it additional job specifications (@pxref{Service Composition}). In
12348 other words, it is possible to define services that provide additional
12352 @deftp {Data Type} mcron-configuration
12353 Data type representing the configuration of mcron.
12356 @item @code{mcron} (default: @var{mcron})
12357 The mcron package to use.
12360 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12361 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12362 specifications,, mcron, GNU@tie{}mcron}).
12368 @subsection Log Rotation
12371 @cindex log rotation
12373 Log files such as those found in @file{/var/log} tend to grow endlessly,
12374 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12375 their contents in separate files, possibly compressed. The @code{(gnu
12376 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12377 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12379 The example below defines an operating system that provides log rotation
12380 with the default settings, for commonly encountered log files.
12383 (use-modules (guix) (gnu))
12384 (use-service-modules admin mcron)
12385 (use-package-modules base idutils)
12389 (services (cons (service rottlog-service-type)
12393 @defvr {Scheme Variable} rottlog-service-type
12394 This is the type of the Rottlog service, whose value is a
12395 @code{rottlog-configuration} object.
12397 Other services can extend this one with new @code{log-rotation} objects
12398 (see below), thereby augmenting the set of files to be rotated.
12400 This service type can define mcron jobs (@pxref{Scheduled Job
12401 Execution}) to run the rottlog service.
12404 @deftp {Data Type} rottlog-configuration
12405 Data type representing the configuration of rottlog.
12408 @item @code{rottlog} (default: @code{rottlog})
12409 The Rottlog package to use.
12411 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12412 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12413 rottlog, GNU Rot[t]log Manual}).
12415 @item @code{rotations} (default: @code{%default-rotations})
12416 A list of @code{log-rotation} objects as defined below.
12419 This is a list of gexps where each gexp corresponds to an mcron job
12420 specification (@pxref{Scheduled Job Execution}).
12424 @deftp {Data Type} log-rotation
12425 Data type representing the rotation of a group of log files.
12427 Taking an example from the Rottlog manual (@pxref{Period Related File
12428 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12434 (files '("/var/log/apache/*"))
12435 (options '("storedir apache-archives"
12441 The list of fields is as follows:
12444 @item @code{frequency} (default: @code{'weekly})
12445 The log rotation frequency, a symbol.
12448 The list of files or file glob patterns to rotate.
12450 @item @code{options} (default: @code{'()})
12451 The list of rottlog options for this rotation (@pxref{Configuration
12452 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12454 @item @code{post-rotate} (default: @code{#f})
12455 Either @code{#f} or a gexp to execute once the rotation has completed.
12459 @defvr {Scheme Variable} %default-rotations
12460 Specifies weekly rotation of @var{%rotated-files} and
12461 a couple of other files.
12464 @defvr {Scheme Variable} %rotated-files
12465 The list of syslog-controlled files to be rotated. By default it is:
12466 @code{'("/var/log/messages" "/var/log/secure")}.
12469 @node Networking Services
12470 @subsection Networking Services
12472 The @code{(gnu services networking)} module provides services to configure
12473 the network interface.
12475 @cindex DHCP, networking service
12476 @defvr {Scheme Variable} dhcp-client-service-type
12477 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12478 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12479 is the DHCP client package to use, @code{isc-dhcp} by default.
12482 @deffn {Scheme Procedure} dhcpd-service-type
12483 This type defines a service that runs a DHCP daemon. To create a
12484 service of this type, you must supply a @code{<dhcpd-configuration>}.
12488 (service dhcpd-service-type
12489 (dhcpd-configuration
12490 (config-file (local-file "my-dhcpd.conf"))
12491 (interfaces '("enp0s25"))))
12495 @deftp {Data Type} dhcpd-configuration
12497 @item @code{package} (default: @code{isc-dhcp})
12498 The package that provides the DHCP daemon. This package is expected to
12499 provide the daemon at @file{sbin/dhcpd} relative to its output
12500 directory. The default package is the
12501 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
12502 @item @code{config-file} (default: @code{#f})
12503 The configuration file to use. This is required. It will be passed to
12504 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12505 object (@pxref{G-Expressions, file-like objects}). See @code{man
12506 dhcpd.conf} for details on the configuration file syntax.
12507 @item @code{version} (default: @code{"4"})
12508 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12509 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12510 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12512 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12513 The run directory to use. At service activation time, this directory
12514 will be created if it does not exist.
12515 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12516 The PID file to use. This corresponds to the @code{-pf} option of
12517 @code{dhcpd}. See @code{man dhcpd} for details.
12518 @item @code{interfaces} (default: @code{'()})
12519 The names of the network interfaces on which dhcpd should listen for
12520 broadcasts. If this list is not empty, then its elements (which must be
12521 strings) will be appended to the @code{dhcpd} invocation when starting
12522 the daemon. It may not be necessary to explicitly specify any
12523 interfaces here; see @code{man dhcpd} for details.
12527 @defvr {Scheme Variable} static-networking-service-type
12528 This is the type for statically-configured network interfaces.
12529 @c TODO Document <static-networking> data structures.
12532 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12533 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12534 [#:requirement @code{'(udev)}]
12535 Return a service that starts @var{interface} with address @var{ip}. If
12536 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12537 it must be a string specifying the default network gateway. @var{requirement}
12538 can be used to declare a dependency on another service before configuring the
12541 This procedure can be called several times, one for each network
12542 interface of interest. Behind the scenes what it does is extend
12543 @code{static-networking-service-type} with additional network interfaces
12549 (static-networking-service "eno1" "192.168.1.82"
12550 #:gateway "192.168.1.2"
12551 #:name-servers '("192.168.1.2"))
12558 @cindex network management
12559 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12560 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12561 management daemon that aims to simplify wired and wireless networking.
12563 This service adds the @var{wicd} package to the global profile, providing
12564 several commands to interact with the daemon and configure networking:
12565 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12566 and @command{wicd-curses} user interfaces.
12569 @cindex ModemManager
12571 @defvr {Scheme Variable} modem-manager-service-type
12572 This is the service type for the
12573 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12574 service. The value for this service type is a
12575 @code{modem-manager-configuration} record.
12577 This service is part of @code{%desktop-services} (@pxref{Desktop
12581 @deftp {Data Type} modem-manager-configuration
12582 Data type representing the configuration of ModemManager.
12585 @item @code{modem-manager} (default: @code{modem-manager})
12586 The ModemManager package to use.
12591 @cindex NetworkManager
12593 @defvr {Scheme Variable} network-manager-service-type
12594 This is the service type for the
12595 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12596 service. The value for this service type is a
12597 @code{network-manager-configuration} record.
12599 This service is part of @code{%desktop-services} (@pxref{Desktop
12603 @deftp {Data Type} network-manager-configuration
12604 Data type representing the configuration of NetworkManager.
12607 @item @code{network-manager} (default: @code{network-manager})
12608 The NetworkManager package to use.
12610 @item @code{dns} (default: @code{"default"})
12611 Processing mode for DNS, which affects how NetworkManager uses the
12612 @code{resolv.conf} configuration file.
12616 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12617 provided by currently active connections.
12620 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12621 using a "split DNS" configuration if you are connected to a VPN, and
12622 then update @code{resolv.conf} to point to the local nameserver.
12625 NetworkManager will not modify @code{resolv.conf}.
12628 @item @code{vpn-plugins} (default: @code{'()})
12629 This is the list of available plugins for virtual private networks
12630 (VPNs). An example of this is the @code{network-manager-openvpn}
12631 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12637 @deffn {Scheme Variable} connman-service-type
12638 This is the service type to run @url{https://01.org/connman,Connman},
12639 a network connection manager.
12641 Its value must be an
12642 @code{connman-configuration} record as in this example:
12645 (service connman-service-type
12646 (connman-configuration
12647 (disable-vpn? #t)))
12650 See below for details about @code{connman-configuration}.
12653 @deftp {Data Type} connman-configuration
12654 Data Type representing the configuration of connman.
12657 @item @code{connman} (default: @var{connman})
12658 The connman package to use.
12660 @item @code{disable-vpn?} (default: @code{#f})
12661 When true, disable connman's vpn plugin.
12665 @cindex WPA Supplicant
12666 @defvr {Scheme Variable} wpa-supplicant-service-type
12667 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12668 supplicant}, an authentication daemon required to authenticate against
12669 encrypted WiFi or ethernet networks.
12672 @deftp {Data Type} wpa-supplicant-configuration
12673 Data type representing the configuration of WPA Supplicant.
12675 It takes the following parameters:
12678 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12679 The WPA Supplicant package to use.
12681 @item @code{dbus?} (default: @code{#t})
12682 Whether to listen for requests on D-Bus.
12684 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12685 Where to store the PID file.
12687 @item @code{interface} (default: @code{#f})
12688 If this is set, it must specify the name of a network interface that
12689 WPA supplicant will control.
12691 @item @code{config-file} (default: @code{#f})
12692 Optional configuration file to use.
12694 @item @code{extra-options} (default: @code{'()})
12695 List of additional command-line arguments to pass to the daemon.
12700 @defvr {Scheme Variable} iptables-service-type
12701 This is the service type to set up an iptables configuration. iptables is a
12702 packet filtering framework supported by the Linux kernel. This service
12703 supports configuring iptables for both IPv4 and IPv6. A simple example
12704 configuration rejecting all incoming connections except those to the ssh port
12708 (service iptables-service-type
12709 (iptables-configuration
12710 (ipv4-rules (plain-file "iptables.rules" "*filter
12714 -A INPUT -p tcp --dport 22 -j ACCEPT
12715 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12718 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12722 -A INPUT -p tcp --dport 22 -j ACCEPT
12723 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12729 @deftp {Data Type} iptables-configuration
12730 The data type representing the configuration of iptables.
12733 @item @code{iptables} (default: @code{iptables})
12734 The iptables package that provides @code{iptables-restore} and
12735 @code{ip6tables-restore}.
12736 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12737 The iptables rules to use. It will be passed to @code{iptables-restore}.
12738 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12740 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12741 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12742 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12747 @cindex NTP (Network Time Protocol), service
12748 @cindex real time clock
12749 @defvr {Scheme Variable} ntp-service-type
12750 This is the type of the service running the @uref{http://www.ntp.org,
12751 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12752 system clock synchronized with that of the specified NTP servers.
12754 The value of this service is an @code{ntpd-configuration} object, as described
12758 @deftp {Data Type} ntp-configuration
12759 This is the data type for the NTP service configuration.
12762 @item @code{servers} (default: @code{%ntp-servers})
12763 This is the list of servers (host names) with which @command{ntpd} will be
12766 @item @code{allow-large-adjustment?} (default: @code{#f})
12767 This determines whether @command{ntpd} is allowed to make an initial
12768 adjustment of more than 1,000 seconds.
12770 @item @code{ntp} (default: @code{ntp})
12771 The NTP package to use.
12775 @defvr {Scheme Variable} %ntp-servers
12776 List of host names used as the default NTP servers. These are servers of the
12777 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12781 @deffn {Scheme Procedure} openntpd-service-type
12782 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12783 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12784 clock synchronized with that of the given servers.
12788 openntpd-service-type
12789 (openntpd-configuration
12790 (listen-on '("127.0.0.1" "::1"))
12791 (sensor '("udcf0 correction 70000"))
12792 (constraint-from '("www.gnu.org"))
12793 (constraints-from '("https://www.google.com/"))
12794 (allow-large-adjustment? #t)))
12799 @deftp {Data Type} openntpd-configuration
12801 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12802 The openntpd executable to use.
12803 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12804 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12805 @item @code{query-from} (default: @code{'()})
12806 A list of local IP address the ntpd daemon should use for outgoing queries.
12807 @item @code{sensor} (default: @code{'()})
12808 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12809 will listen to each sensor that acutally exists and ignore non-existant ones.
12810 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12812 @item @code{server} (default: @var{%ntp-servers})
12813 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12814 @item @code{servers} (default: @code{'()})
12815 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12816 @item @code{constraint-from} (default: @code{'()})
12817 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12818 This time information is not used for precision but acts as an authenticated
12819 constraint, thereby reducing the impact of unauthenticated NTP
12820 man-in-the-middle attacks.
12821 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12823 @item @code{constraints-from} (default: @code{'()})
12824 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12825 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12826 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12827 @item @code{allow-large-adjustment?} (default: @code{#f})
12828 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12834 @deffn {Scheme variable} inetd-service-type
12835 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12836 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12837 connections on internet sockets, and lazily starts the specified server
12838 program when a connection is made on one of these sockets.
12840 The value of this service is an @code{inetd-configuration} object. The
12841 following example configures the @command{inetd} daemon to provide the
12842 built-in @command{echo} service, as well as an smtp service which
12843 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12844 gateway @code{hostname}:
12849 (inetd-configuration
12853 (socket-type 'stream)
12860 (socket-type 'stream)
12864 (program (file-append openssh "/bin/ssh"))
12866 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12867 "-W" "smtp-server:25" "user@@hostname")))))
12870 See below for more details about @code{inetd-configuration}.
12873 @deftp {Data Type} inetd-configuration
12874 Data type representing the configuration of @command{inetd}.
12877 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12878 The @command{inetd} executable to use.
12880 @item @code{entries} (default: @code{'()})
12881 A list of @command{inetd} service entries. Each entry should be created
12882 by the @code{inetd-entry} constructor.
12886 @deftp {Data Type} inetd-entry
12887 Data type representing an entry in the @command{inetd} configuration.
12888 Each entry corresponds to a socket where @command{inetd} will listen for
12892 @item @code{node} (default: @code{#f})
12893 Optional string, a comma-separated list of local addresses
12894 @command{inetd} should use when listening for this service.
12895 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12896 description of all options.
12898 A string, the name must correspond to an entry in @code{/etc/services}.
12899 @item @code{socket-type}
12900 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12902 @item @code{protocol}
12903 A string, must correspond to an entry in @code{/etc/protocols}.
12904 @item @code{wait?} (default: @code{#t})
12905 Whether @command{inetd} should wait for the server to exit before
12906 listening to new service requests.
12908 A string containing the user (and, optionally, group) name of the user
12909 as whom the server should run. The group name can be specified in a
12910 suffix, separated by a colon or period, i.e.@: @code{"user"},
12911 @code{"user:group"} or @code{"user.group"}.
12912 @item @code{program} (default: @code{"internal"})
12913 The server program which will serve the requests, or @code{"internal"}
12914 if @command{inetd} should use a built-in service.
12915 @item @code{arguments} (default: @code{'()})
12916 A list strings or file-like objects, which are the server program's
12917 arguments, starting with the zeroth argument, i.e.@: the name of the
12918 program itself. For @command{inetd}'s internal services, this entry
12919 must be @code{'()} or @code{'("internal")}.
12922 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12923 detailed discussion of each configuration field.
12927 @defvr {Scheme Variable} tor-service-type
12928 This is the type for a service that runs the @uref{https://torproject.org,
12929 Tor} anonymous networking daemon. The service is configured using a
12930 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12931 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12935 @deftp {Data Type} tor-configuration
12937 @item @code{tor} (default: @code{tor})
12938 The package that provides the Tor daemon. This package is expected to provide
12939 the daemon at @file{bin/tor} relative to its output directory. The default
12940 package is the @uref{https://www.torproject.org, Tor Project's}
12943 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12944 The configuration file to use. It will be appended to a default configuration
12945 file, and the final configuration file will be passed to @code{tor} via its
12946 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12947 file-like objects}). See @code{man tor} for details on the configuration file
12950 @item @code{hidden-services} (default: @code{'()})
12951 The list of @code{<hidden-service>} records to use. For any hidden service
12952 you include in this list, appropriate configuration to enable the hidden
12953 service will be automatically added to the default configuration file. You
12954 may conveniently create @code{<hidden-service>} records using the
12955 @code{tor-hidden-service} procedure described below.
12957 @item @code{socks-socket-type} (default: @code{'tcp})
12958 The default socket type that Tor should use for its SOCKS socket. This must
12959 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12960 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12961 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12962 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12965 If you want to customize the SOCKS socket in more detail, leave
12966 @code{socks-socket-type} at its default value of @code{'tcp} and use
12967 @code{config-file} to override the default by providing your own
12968 @code{SocksPort} option.
12972 @cindex hidden service
12973 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12974 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12975 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12978 '((22 "127.0.0.1:22")
12979 (80 "127.0.0.1:8080"))
12982 In this example, port 22 of the hidden service is mapped to local port 22, and
12983 port 80 is mapped to local port 8080.
12985 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12986 the @file{hostname} file contains the @code{.onion} host name for the hidden
12989 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12990 project's documentation} for more information.
12993 The @code{(gnu services rsync)} module provides the following services:
12995 You might want an rsync daemon if you have files that you want available
12996 so anyone (or just yourself) can download existing files or upload new
12999 @deffn {Scheme Variable} rsync-service-type
13000 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
13001 @command{rsync-configuration} record as in this example:
13004 (service rsync-service-type)
13007 See below for details about @code{rsync-configuration}.
13010 @deftp {Data Type} rsync-configuration
13011 Data type representing the configuration for @code{rsync-service}.
13014 @item @code{package} (default: @var{rsync})
13015 @code{rsync} package to use.
13017 @item @code{port-number} (default: @code{873})
13018 TCP port on which @command{rsync} listens for incoming connections. If port
13019 is less than @code{1024} @command{rsync} needs to be started as the
13020 @code{root} user and group.
13022 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13023 Name of the file where @command{rsync} writes its PID.
13025 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13026 Name of the file where @command{rsync} writes its lock file.
13028 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13029 Name of the file where @command{rsync} writes its log file.
13031 @item @code{use-chroot?} (default: @var{#t})
13032 Whether to use chroot for @command{rsync} shared directory.
13034 @item @code{share-path} (default: @file{/srv/rsync})
13035 Location of the @command{rsync} shared directory.
13037 @item @code{share-comment} (default: @code{"Rsync share"})
13038 Comment of the @command{rsync} shared directory.
13040 @item @code{read-only?} (default: @var{#f})
13041 Read-write permissions to shared directory.
13043 @item @code{timeout} (default: @code{300})
13044 I/O timeout in seconds.
13046 @item @code{user} (default: @var{"root"})
13047 Owner of the @code{rsync} process.
13049 @item @code{group} (default: @var{"root"})
13050 Group of the @code{rsync} process.
13052 @item @code{uid} (default: @var{"rsyncd"})
13053 User name or user ID that file transfers to and from that module should take
13054 place as when the daemon was run as @code{root}.
13056 @item @code{gid} (default: @var{"rsyncd"})
13057 Group name or group ID that will be used when accessing the module.
13062 Furthermore, @code{(gnu services ssh)} provides the following services.
13066 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13067 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13068 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13069 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13070 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13071 [#:public-key-authentication? #t] [#:initialize? #t]
13072 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13073 @var{host-key} must designate a file containing the host key, and readable
13076 When @var{daemonic?} is true, @command{lshd} will detach from the
13077 controlling terminal and log its output to syslogd, unless one sets
13078 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13079 depend on existence of syslogd service. When @var{pid-file?} is true,
13080 @command{lshd} writes its PID to the file called @var{pid-file}.
13082 When @var{initialize?} is true, automatically create the seed and host key
13083 upon service activation if they do not exist yet. This may take long and
13084 require interaction.
13086 When @var{initialize?} is false, it is up to the user to initialize the
13087 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13088 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13089 basics,,, lsh, LSH Manual}).
13091 When @var{interfaces} is empty, lshd listens for connections on all the
13092 network interfaces; otherwise, @var{interfaces} must be a list of host names
13095 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13096 passwords, and @var{root-login?} specifies whether to accept log-ins as
13099 The other options should be self-descriptive.
13104 @deffn {Scheme Variable} openssh-service-type
13105 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13106 shell daemon, @command{sshd}. Its value must be an
13107 @code{openssh-configuration} record as in this example:
13110 (service openssh-service-type
13111 (openssh-configuration
13112 (x11-forwarding? #t)
13113 (permit-root-login 'without-password)
13115 `(("alice" ,(local-file "alice.pub"))
13116 ("bob" ,(local-file "bob.pub"))))))
13119 See below for details about @code{openssh-configuration}.
13121 This service can be extended with extra authorized keys, as in this
13125 (service-extension openssh-service-type
13126 (const `(("charlie"
13127 ,(local-file "charlie.pub")))))
13131 @deftp {Data Type} openssh-configuration
13132 This is the configuration record for OpenSSH's @command{sshd}.
13135 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13136 Name of the file where @command{sshd} writes its PID.
13138 @item @code{port-number} (default: @code{22})
13139 TCP port on which @command{sshd} listens for incoming connections.
13141 @item @code{permit-root-login} (default: @code{#f})
13142 This field determines whether and when to allow logins as root. If
13143 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13144 If it's the symbol @code{'without-password}, then root logins are
13145 permitted but not with password-based authentication.
13147 @item @code{allow-empty-passwords?} (default: @code{#f})
13148 When true, users with empty passwords may log in. When false, they may
13151 @item @code{password-authentication?} (default: @code{#t})
13152 When true, users may log in with their password. When false, they have
13153 other authentication methods.
13155 @item @code{public-key-authentication?} (default: @code{#t})
13156 When true, users may log in using public key authentication. When
13157 false, users have to use other authentication method.
13159 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13160 This is used only by protocol version 2.
13162 @item @code{x11-forwarding?} (default: @code{#f})
13163 When true, forwarding of X11 graphical client connections is
13164 enabled---in other words, @command{ssh} options @option{-X} and
13165 @option{-Y} will work.
13167 @item @code{allow-agent-forwarding?} (default: @code{#t})
13168 Whether to allow agent forwarding.
13170 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13171 Whether to allow TCP forwarding.
13173 @item @code{gateway-ports?} (default: @code{#f})
13174 Whether to allow gateway ports.
13176 @item @code{challenge-response-authentication?} (default: @code{#f})
13177 Specifies whether challenge response authentication is allowed (e.g.@: via
13180 @item @code{use-pam?} (default: @code{#t})
13181 Enables the Pluggable Authentication Module interface. If set to
13182 @code{#t}, this will enable PAM authentication using
13183 @code{challenge-response-authentication?} and
13184 @code{password-authentication?}, in addition to PAM account and session
13185 module processing for all authentication types.
13187 Because PAM challenge response authentication usually serves an
13188 equivalent role to password authentication, you should disable either
13189 @code{challenge-response-authentication?} or
13190 @code{password-authentication?}.
13192 @item @code{print-last-log?} (default: @code{#t})
13193 Specifies whether @command{sshd} should print the date and time of the
13194 last user login when a user logs in interactively.
13196 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13197 Configures external subsystems (e.g.@: file transfer daemon).
13199 This is a list of two-element lists, each of which containing the
13200 subsystem name and a command (with optional arguments) to execute upon
13203 The command @command{internal-sftp} implements an in-process SFTP
13204 server. Alternately, one can specify the @command{sftp-server} command:
13206 (service openssh-service-type
13207 (openssh-configuration
13209 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13212 @item @code{accepted-environment} (default: @code{'()})
13213 List of strings describing which environment variables may be exported.
13215 Each string gets on its own line. See the @code{AcceptEnv} option in
13216 @code{man sshd_config}.
13218 This example allows ssh-clients to export the @code{COLORTERM} variable.
13219 It is set by terminal emulators, which support colors. You can use it in
13220 your shell's ressource file to enable colors for the prompt and commands
13221 if this variable is set.
13224 (service openssh-service-type
13225 (openssh-configuration
13226 (accepted-environment '("COLORTERM"))))
13229 @item @code{authorized-keys} (default: @code{'()})
13230 @cindex authorized keys, SSH
13231 @cindex SSH authorized keys
13232 This is the list of authorized keys. Each element of the list is a user
13233 name followed by one or more file-like objects that represent SSH public
13237 (openssh-configuration
13239 `(("rekado" ,(local-file "rekado.pub"))
13240 ("chris" ,(local-file "chris.pub"))
13241 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13245 registers the specified public keys for user accounts @code{rekado},
13246 @code{chris}, and @code{root}.
13248 Additional authorized keys can be specified @i{via}
13249 @code{service-extension}.
13251 Note that this does @emph{not} interfere with the use of
13252 @file{~/.ssh/authorized_keys}.
13254 @item @code{log-level} (default: @code{'info})
13255 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13256 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13257 page for @file{sshd_config} for the full list of level names.
13259 @item @code{extra-content} (default: @code{""})
13260 This field can be used to append arbitrary text to the configuration file. It
13261 is especially useful for elaborate configurations that cannot be expressed
13262 otherwise. This configuration, for example, would generally disable root
13263 logins, but permit them from one specific IP address:
13266 (openssh-configuration
13268 Match Address 192.168.0.1
13269 PermitRootLogin yes"))
13275 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13276 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13277 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13280 For example, to specify a Dropbear service listening on port 1234, add
13281 this call to the operating system's @code{services} field:
13284 (dropbear-service (dropbear-configuration
13285 (port-number 1234)))
13289 @deftp {Data Type} dropbear-configuration
13290 This data type represents the configuration of a Dropbear SSH daemon.
13293 @item @code{dropbear} (default: @var{dropbear})
13294 The Dropbear package to use.
13296 @item @code{port-number} (default: 22)
13297 The TCP port where the daemon waits for incoming connections.
13299 @item @code{syslog-output?} (default: @code{#t})
13300 Whether to enable syslog output.
13302 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13303 File name of the daemon's PID file.
13305 @item @code{root-login?} (default: @code{#f})
13306 Whether to allow @code{root} logins.
13308 @item @code{allow-empty-passwords?} (default: @code{#f})
13309 Whether to allow empty passwords.
13311 @item @code{password-authentication?} (default: @code{#t})
13312 Whether to enable password-based authentication.
13316 @defvr {Scheme Variable} %facebook-host-aliases
13317 This variable contains a string for use in @file{/etc/hosts}
13318 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13319 line contains a entry that maps a known server name of the Facebook
13320 on-line service---e.g., @code{www.facebook.com}---to the local
13321 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13323 This variable is typically used in the @code{hosts-file} field of an
13324 @code{operating-system} declaration (@pxref{operating-system Reference,
13325 @file{/etc/hosts}}):
13328 (use-modules (gnu) (guix))
13331 (host-name "mymachine")
13334 ;; Create a /etc/hosts file with aliases for "localhost"
13335 ;; and "mymachine", as well as for Facebook servers.
13336 (plain-file "hosts"
13337 (string-append (local-host-aliases host-name)
13338 %facebook-host-aliases))))
13341 This mechanism can prevent programs running locally, such as Web
13342 browsers, from accessing Facebook.
13345 The @code{(gnu services avahi)} provides the following definition.
13347 @defvr {Scheme Variable} avahi-service-type
13348 This is the service that runs @command{avahi-daemon}, a system-wide
13349 mDNS/DNS-SD responder that allows for service discovery and
13350 ``zero-configuration'' host name lookups (see @uref{http://avahi.org/}).
13351 Its value must be a @code{zero-configuration} record---see below.
13353 This service extends the name service cache daemon (nscd) so that it can
13354 resolve @code{.local} host names using
13355 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13356 Service Switch}, for information on host name resolution.
13358 Additionally, add the @var{avahi} package to the system profile so that
13359 commands such as @command{avahi-browse} are directly usable.
13362 @deftp {Data Type} avahi-configuration
13363 Data type representation the configuration for Avahi.
13367 @item @code{host-name} (default: @code{#f})
13368 If different from @code{#f}, use that as the host name to
13369 publish for this machine; otherwise, use the machine's actual host name.
13371 @item @code{publish?} (default: @code{#t})
13372 When true, allow host names and services to be published (broadcast) over the
13375 @item @code{publish-workstation?} (default: @code{#t})
13376 When true, @command{avahi-daemon} publishes the machine's host name and IP
13377 address via mDNS on the local network. To view the host names published on
13378 your local network, you can run:
13381 avahi-browse _workstation._tcp
13384 @item @code{wide-area?} (default: @code{#f})
13385 When true, DNS-SD over unicast DNS is enabled.
13387 @item @code{ipv4?} (default: @code{#t})
13388 @itemx @code{ipv6?} (default: @code{#t})
13389 These fields determine whether to use IPv4/IPv6 sockets.
13391 @item @code{domains-to-browse} (default: @code{'()})
13392 This is a list of domains to browse.
13396 @deffn {Scheme Variable} openvswitch-service-type
13397 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
13398 service, whose value should be an @code{openvswitch-configuration}
13402 @deftp {Data Type} openvswitch-configuration
13403 Data type representing the configuration of Open vSwitch, a multilayer
13404 virtual switch which is designed to enable massive network automation
13405 through programmatic extension.
13408 @item @code{package} (default: @var{openvswitch})
13409 Package object of the Open vSwitch.
13415 @subsection X Window
13418 @cindex X Window System
13419 @cindex login manager
13420 Support for the X Window graphical display system---specifically
13421 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13422 there is no @code{xorg-service} procedure. Instead, the X server is
13423 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13426 @cindex GNOME, login manager
13427 GDM of course allows users to log in into window managers and desktop
13428 environments other than GNOME; for those using GNOME, GDM is required for
13429 features such as automatic screen locking.
13431 @cindex window manager
13432 To use X11, you must install at least one @dfn{window manager}---for
13433 example the @code{windowmaker} or @code{openbox} packages---preferably
13434 by adding it to the @code{packages} field of your operating system
13435 definition (@pxref{operating-system Reference, system-wide packages}).
13437 @defvr {Scheme Variable} gdm-service-type
13438 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13439 Desktop Manager} (GDM), a program that manages graphical display servers and
13440 handles graphical user logins. Its value must be a @code{gdm-configuration}
13443 @cindex session types (X11)
13444 @cindex X11 session types
13445 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13446 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13447 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13448 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13449 set of packages automatically makes them available at the log-in screen.
13451 In addition, @file{~/.xsession} files are honored. When available,
13452 @file{~/.xsession} must be an executable that starts a window manager
13453 and/or other X clients.
13456 @deftp {Data Type} gdm-configuration
13458 @item @code{auto-login?} (default: @code{#f})
13459 @itemx @code{default-user} (default: @code{#f})
13460 When @code{auto-login?} is false, GDM presents a log-in screen.
13462 When @code{auto-login?} is true, GDM logs in directly as
13463 @code{default-user}.
13465 @item @code{gnome-shell-assets} (default: ...)
13466 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13468 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13469 Configuration of the Xorg graphical server.
13471 @item @code{xsession} (default: @code{(xinitrc)})
13472 Script to run before starting a X session.
13474 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13475 File name of the @code{dbus-daemon} executable.
13477 @item @code{gdm} (default: @code{gdm})
13478 The GDM package to use.
13482 @defvr {Scheme Variable} slim-service-type
13483 This is the type for the SLiM graphical login manager for X11.
13485 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13486 allows users to choose a session from the log-in screen using @kbd{F1}. It
13487 also honors @file{~/.xsession} files.
13490 @deftp {Data Type} slim-configuration
13491 Data type representing the configuration of @code{slim-service-type}.
13494 @item @code{allow-empty-passwords?} (default: @code{#t})
13495 Whether to allow logins with empty passwords.
13497 @item @code{auto-login?} (default: @code{#f})
13498 @itemx @code{default-user} (default: @code{""})
13499 When @code{auto-login?} is false, SLiM presents a log-in screen.
13501 When @code{auto-login?} is true, SLiM logs in directly as
13502 @code{default-user}.
13504 @item @code{theme} (default: @code{%default-slim-theme})
13505 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13506 The graphical theme to use and its name.
13508 @item @code{auto-login-session} (default: @code{#f})
13509 If true, this must be the name of the executable to start as the default
13510 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13512 If false, a session described by one of the available @file{.desktop}
13513 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13517 You must install at least one window manager in the system profile or in
13518 your user profile. Failing to do that, if @code{auto-login-session} is
13519 false, you will be unable to log in.
13522 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13523 Configuration of the Xorg graphical server.
13525 @item @code{xauth} (default: @code{xauth})
13526 The XAuth package to use.
13528 @item @code{shepherd} (default: @code{shepherd})
13529 The Shepherd package used when invoking @command{halt} and
13532 @item @code{sessreg} (default: @code{sessreg})
13533 The sessreg package used in order to register the session.
13535 @item @code{slim} (default: @code{slim})
13536 The SLiM package to use.
13540 @defvr {Scheme Variable} %default-theme
13541 @defvrx {Scheme Variable} %default-theme-name
13542 The default SLiM theme and its name.
13546 @deftp {Data Type} sddm-configuration
13547 This is the data type representing the sddm service configuration.
13550 @item @code{display-server} (default: "x11")
13551 Select display server to use for the greeter. Valid values are "x11"
13554 @item @code{numlock} (default: "on")
13555 Valid values are "on", "off" or "none".
13557 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13558 Command to run when halting.
13560 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13561 Command to run when rebooting.
13563 @item @code{theme} (default "maldives")
13564 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13566 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13567 Directory to look for themes.
13569 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13570 Directory to look for faces.
13572 @item @code{default-path} (default "/run/current-system/profile/bin")
13573 Default PATH to use.
13575 @item @code{minimum-uid} (default 1000)
13576 Minimum UID to display in SDDM.
13578 @item @code{maximum-uid} (default 2000)
13579 Maximum UID to display in SDDM
13581 @item @code{remember-last-user?} (default #t)
13582 Remember last user.
13584 @item @code{remember-last-session?} (default #t)
13585 Remember last session.
13587 @item @code{hide-users} (default "")
13588 Usernames to hide from SDDM greeter.
13590 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13591 Users with shells listed will be hidden from the SDDM greeter.
13593 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13594 Script to run before starting a wayland session.
13596 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13597 Directory to look for desktop files starting wayland sessions.
13599 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13600 Configuration of the Xorg graphical server.
13602 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13605 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13608 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13609 Script to run after starting xorg-server.
13611 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13612 Script to run before stopping xorg-server.
13614 @item @code{xsession-command} (default: @code{xinitrc})
13615 Script to run before starting a X session.
13617 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13618 Directory to look for desktop files starting X sessions.
13620 @item @code{minimum-vt} (default: 7)
13623 @item @code{auto-login-user} (default "")
13624 User to use for auto-login.
13626 @item @code{auto-login-session} (default "")
13627 Desktop file to use for auto-login.
13629 @item @code{relogin?} (default #f)
13630 Relogin after logout.
13635 @cindex login manager
13637 @deffn {Scheme Procedure} sddm-service config
13638 Return a service that spawns the SDDM graphical login manager for config of
13639 type @code{<sddm-configuration>}.
13642 (sddm-service (sddm-configuration
13643 (auto-login-user "Alice")
13644 (auto-login-session "xfce.desktop")))
13648 @cindex Xorg, configuration
13649 @deftp {Data Type} xorg-configuration
13650 This data type represents the configuration of the Xorg graphical display
13651 server. Note that there is not Xorg service; instead, the X server is started
13652 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13653 of these display managers aggregates an @code{xorg-configuration} record.
13656 @item @code{modules} (default: @code{%default-xorg-modules})
13657 This is a list of @dfn{module packages} loaded by the Xorg
13658 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13660 @item @code{fonts} (default: @code{%default-xorg-fonts})
13661 This is a list of font directories to add to the server's @dfn{font path}.
13663 @item @code{drivers} (default: @code{'()})
13664 This must be either the empty list, in which case Xorg chooses a graphics
13665 driver automatically, or a list of driver names that will be tried in this
13666 order---e.g., @code{("modesetting" "vesa")}.
13668 @item @code{resolutions} (default: @code{'()})
13669 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13670 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13673 @cindex keyboard layout, for Xorg
13674 @cindex keymap, for Xorg
13675 @item @code{keyboard-layout} (default: @code{#f})
13676 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13677 English (``qwerty'') for a 105-key PC keyboard.
13679 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13680 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13681 information on how to specify the keyboard layout.
13683 @item @code{extra-config} (default: @code{'()})
13684 This is a list of strings or objects appended to the configuration file. It
13685 is used to pass extra text to be added verbatim to the configuration file.
13687 @item @code{server} (default: @code{xorg-server})
13688 This is the package providing the Xorg server.
13690 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13691 This is the list of command-line arguments to pass to the X server. The
13692 default is @code{-nolisten tcp}.
13696 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13697 [@var{login-manager-service-type}]
13698 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13699 @var{config}, an <xorg-configuration> record.
13701 Since the Xorg configuration is embedded in the log-in manager's
13702 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13703 shorthand to set the Xorg configuration.
13706 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13707 Return a @code{startx} script in which the modules, fonts, etc. specified
13708 in @var{config}, are available. The result should be used in place of
13711 Usually the X server is started by a login manager.
13715 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13716 Add @var{package}, a package for a screen locker or screen saver whose
13717 command is @var{program}, to the set of setuid programs and add a PAM entry
13718 for it. For example:
13721 (screen-locker-service xlockmore "xlock")
13724 makes the good ol' XlockMore usable.
13728 @node Printing Services
13729 @subsection Printing Services
13731 @cindex printer support with CUPS
13732 The @code{(gnu services cups)} module provides a Guix service definition
13733 for the CUPS printing service. To add printer support to a Guix
13734 system, add a @code{cups-service} to the operating system definition:
13736 @deffn {Scheme Variable} cups-service-type
13737 The service type for the CUPS print server. Its value should be a valid
13738 CUPS configuration (see below). To use the default settings, simply
13741 (service cups-service-type)
13745 The CUPS configuration controls the basic things about your CUPS
13746 installation: what interfaces it listens on, what to do if a print job
13747 fails, how much logging to do, and so on. To actually add a printer,
13748 you have to visit the @url{http://localhost:631} URL, or use a tool such
13749 as GNOME's printer configuration services. By default, configuring a
13750 CUPS service will generate a self-signed certificate if needed, for
13751 secure connections to the print server.
13753 Suppose you want to enable the Web interface of CUPS and also add
13754 support for Epson printers @i{via} the @code{escpr} package and for HP
13755 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13756 like this (you need to use the @code{(gnu packages cups)} module):
13759 (service cups-service-type
13760 (cups-configuration
13761 (web-interface? #t)
13763 (list cups-filters escpr hplip-minimal))))
13766 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13767 package then it is suggested that you install the @code{hplip} package,
13768 either in your OS configuration file or as your user.
13770 The available configuration parameters follow. Each parameter
13771 definition is preceded by its type; for example, @samp{string-list foo}
13772 indicates that the @code{foo} parameter should be specified as a list of
13773 strings. There is also a way to specify the configuration as a string,
13774 if you have an old @code{cupsd.conf} file that you want to port over
13775 from some other system; see the end for more details.
13777 @c The following documentation was initially generated by
13778 @c (generate-documentation) in (gnu services cups). Manually maintained
13779 @c documentation is better, so we shouldn't hesitate to edit below as
13780 @c needed. However if the change you want to make to this documentation
13781 @c can be done in an automated way, it's probably easier to change
13782 @c (generate-documentation) than to make it below and have to deal with
13783 @c the churn as CUPS updates.
13786 Available @code{cups-configuration} fields are:
13788 @deftypevr {@code{cups-configuration} parameter} package cups
13792 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13793 Drivers and other extensions to the CUPS package.
13796 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13797 Configuration of where to write logs, what directories to use for print
13798 spools, and related privileged configuration parameters.
13800 Available @code{files-configuration} fields are:
13802 @deftypevr {@code{files-configuration} parameter} log-location access-log
13803 Defines the access log filename. Specifying a blank filename disables
13804 access log generation. The value @code{stderr} causes log entries to be
13805 sent to the standard error file when the scheduler is running in the
13806 foreground, or to the system log daemon when run in the background. The
13807 value @code{syslog} causes log entries to be sent to the system log
13808 daemon. The server name may be included in filenames using the string
13809 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13811 Defaults to @samp{"/var/log/cups/access_log"}.
13814 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13815 Where CUPS should cache data.
13817 Defaults to @samp{"/var/cache/cups"}.
13820 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13821 Specifies the permissions for all configuration files that the scheduler
13824 Note that the permissions for the printers.conf file are currently
13825 masked to only allow access from the scheduler user (typically root).
13826 This is done because printer device URIs sometimes contain sensitive
13827 authentication information that should not be generally known on the
13828 system. There is no way to disable this security feature.
13830 Defaults to @samp{"0640"}.
13833 @deftypevr {@code{files-configuration} parameter} log-location error-log
13834 Defines the error log filename. Specifying a blank filename disables
13835 access log generation. The value @code{stderr} causes log entries to be
13836 sent to the standard error file when the scheduler is running in the
13837 foreground, or to the system log daemon when run in the background. The
13838 value @code{syslog} causes log entries to be sent to the system log
13839 daemon. The server name may be included in filenames using the string
13840 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13842 Defaults to @samp{"/var/log/cups/error_log"}.
13845 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13846 Specifies which errors are fatal, causing the scheduler to exit. The
13851 No errors are fatal.
13854 All of the errors below are fatal.
13857 Browsing initialization errors are fatal, for example failed connections
13858 to the DNS-SD daemon.
13861 Configuration file syntax errors are fatal.
13864 Listen or Port errors are fatal, except for IPv6 failures on the
13865 loopback or @code{any} addresses.
13868 Log file creation or write errors are fatal.
13871 Bad startup file permissions are fatal, for example shared TLS
13872 certificate and key files with world-read permissions.
13875 Defaults to @samp{"all -browse"}.
13878 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13879 Specifies whether the file pseudo-device can be used for new printer
13880 queues. The URI @uref{file:///dev/null} is always allowed.
13882 Defaults to @samp{#f}.
13885 @deftypevr {@code{files-configuration} parameter} string group
13886 Specifies the group name or ID that will be used when executing external
13889 Defaults to @samp{"lp"}.
13892 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13893 Specifies the permissions for all log files that the scheduler writes.
13895 Defaults to @samp{"0644"}.
13898 @deftypevr {@code{files-configuration} parameter} log-location page-log
13899 Defines the page log filename. Specifying a blank filename disables
13900 access log generation. The value @code{stderr} causes log entries to be
13901 sent to the standard error file when the scheduler is running in the
13902 foreground, or to the system log daemon when run in the background. The
13903 value @code{syslog} causes log entries to be sent to the system log
13904 daemon. The server name may be included in filenames using the string
13905 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13907 Defaults to @samp{"/var/log/cups/page_log"}.
13910 @deftypevr {@code{files-configuration} parameter} string remote-root
13911 Specifies the username that is associated with unauthenticated accesses
13912 by clients claiming to be the root user. The default is @code{remroot}.
13914 Defaults to @samp{"remroot"}.
13917 @deftypevr {@code{files-configuration} parameter} file-name request-root
13918 Specifies the directory that contains print jobs and other HTTP request
13921 Defaults to @samp{"/var/spool/cups"}.
13924 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13925 Specifies the level of security sandboxing that is applied to print
13926 filters, backends, and other child processes of the scheduler; either
13927 @code{relaxed} or @code{strict}. This directive is currently only
13928 used/supported on macOS.
13930 Defaults to @samp{strict}.
13933 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13934 Specifies the location of TLS certificates and private keys. CUPS will
13935 look for public and private keys in this directory: a @code{.crt} files
13936 for PEM-encoded certificates and corresponding @code{.key} files for
13937 PEM-encoded private keys.
13939 Defaults to @samp{"/etc/cups/ssl"}.
13942 @deftypevr {@code{files-configuration} parameter} file-name server-root
13943 Specifies the directory containing the server configuration files.
13945 Defaults to @samp{"/etc/cups"}.
13948 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13949 Specifies whether the scheduler calls fsync(2) after writing
13950 configuration or state files.
13952 Defaults to @samp{#f}.
13955 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13956 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13959 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13960 Specifies the directory where temporary files are stored.
13962 Defaults to @samp{"/var/spool/cups/tmp"}.
13965 @deftypevr {@code{files-configuration} parameter} string user
13966 Specifies the user name or ID that is used when running external
13969 Defaults to @samp{"lp"}.
13973 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13974 Specifies the logging level for the AccessLog file. The @code{config}
13975 level logs when printers and classes are added, deleted, or modified and
13976 when configuration files are accessed or updated. The @code{actions}
13977 level logs when print jobs are submitted, held, released, modified, or
13978 canceled, and any of the conditions for @code{config}. The @code{all}
13979 level logs all requests.
13981 Defaults to @samp{actions}.
13984 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13985 Specifies whether to purge job history data automatically when it is no
13986 longer required for quotas.
13988 Defaults to @samp{#f}.
13991 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13992 Specifies which protocols to use for local printer sharing.
13994 Defaults to @samp{dnssd}.
13997 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13998 Specifies whether the CUPS web interface is advertised.
14000 Defaults to @samp{#f}.
14003 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14004 Specifies whether shared printers are advertised.
14006 Defaults to @samp{#f}.
14009 @deftypevr {@code{cups-configuration} parameter} string classification
14010 Specifies the security classification of the server. Any valid banner
14011 name can be used, including "classified", "confidential", "secret",
14012 "topsecret", and "unclassified", or the banner can be omitted to disable
14013 secure printing functions.
14015 Defaults to @samp{""}.
14018 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14019 Specifies whether users may override the classification (cover page) of
14020 individual print jobs using the @code{job-sheets} option.
14022 Defaults to @samp{#f}.
14025 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14026 Specifies the default type of authentication to use.
14028 Defaults to @samp{Basic}.
14031 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14032 Specifies whether encryption will be used for authenticated requests.
14034 Defaults to @samp{Required}.
14037 @deftypevr {@code{cups-configuration} parameter} string default-language
14038 Specifies the default language to use for text and web content.
14040 Defaults to @samp{"en"}.
14043 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14044 Specifies the default paper size for new print queues. @samp{"Auto"}
14045 uses a locale-specific default, while @samp{"None"} specifies there is
14046 no default paper size. Specific size names are typically
14047 @samp{"Letter"} or @samp{"A4"}.
14049 Defaults to @samp{"Auto"}.
14052 @deftypevr {@code{cups-configuration} parameter} string default-policy
14053 Specifies the default access policy to use.
14055 Defaults to @samp{"default"}.
14058 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14059 Specifies whether local printers are shared by default.
14061 Defaults to @samp{#t}.
14064 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14065 Specifies the delay for updating of configuration and state files, in
14066 seconds. A value of 0 causes the update to happen as soon as possible,
14067 typically within a few milliseconds.
14069 Defaults to @samp{30}.
14072 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14073 Specifies what to do when an error occurs. Possible values are
14074 @code{abort-job}, which will discard the failed print job;
14075 @code{retry-job}, which will retry the job at a later time;
14076 @code{retry-this-job}, which retries the failed job immediately; and
14077 @code{stop-printer}, which stops the printer.
14079 Defaults to @samp{stop-printer}.
14082 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14083 Specifies the maximum cost of filters that are run concurrently, which
14084 can be used to minimize disk, memory, and CPU resource problems. A
14085 limit of 0 disables filter limiting. An average print to a
14086 non-PostScript printer needs a filter limit of about 200. A PostScript
14087 printer needs about half that (100). Setting the limit below these
14088 thresholds will effectively limit the scheduler to printing a single job
14091 Defaults to @samp{0}.
14094 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14095 Specifies the scheduling priority of filters that are run to print a
14096 job. The nice value ranges from 0, the highest priority, to 19, the
14099 Defaults to @samp{0}.
14102 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14103 Specifies whether to do reverse lookups on connecting clients. The
14104 @code{double} setting causes @code{cupsd} to verify that the hostname
14105 resolved from the address matches one of the addresses returned for that
14106 hostname. Double lookups also prevent clients with unregistered
14107 addresses from connecting to your server. Only set this option to
14108 @code{#t} or @code{double} if absolutely required.
14110 Defaults to @samp{#f}.
14113 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14114 Specifies the number of seconds to wait before killing the filters and
14115 backend associated with a canceled or held job.
14117 Defaults to @samp{30}.
14120 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14121 Specifies the interval between retries of jobs in seconds. This is
14122 typically used for fax queues but can also be used with normal print
14123 queues whose error policy is @code{retry-job} or
14124 @code{retry-current-job}.
14126 Defaults to @samp{30}.
14129 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14130 Specifies the number of retries that are done for jobs. This is
14131 typically used for fax queues but can also be used with normal print
14132 queues whose error policy is @code{retry-job} or
14133 @code{retry-current-job}.
14135 Defaults to @samp{5}.
14138 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14139 Specifies whether to support HTTP keep-alive connections.
14141 Defaults to @samp{#t}.
14144 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14145 Specifies how long an idle client connection remains open, in seconds.
14147 Defaults to @samp{30}.
14150 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14151 Specifies the maximum size of print files, IPP requests, and HTML form
14152 data. A limit of 0 disables the limit check.
14154 Defaults to @samp{0}.
14157 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14158 Listens on the specified interfaces for connections. Valid values are
14159 of the form @var{address}:@var{port}, where @var{address} is either an
14160 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14161 indicate all addresses. Values can also be file names of local UNIX
14162 domain sockets. The Listen directive is similar to the Port directive
14163 but allows you to restrict access to specific interfaces or networks.
14166 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14167 Specifies the number of pending connections that will be allowed. This
14168 normally only affects very busy servers that have reached the MaxClients
14169 limit, but can also be triggered by large numbers of simultaneous
14170 connections. When the limit is reached, the operating system will
14171 refuse additional connections until the scheduler can accept the pending
14174 Defaults to @samp{128}.
14177 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14178 Specifies a set of additional access controls.
14180 Available @code{location-access-controls} fields are:
14182 @deftypevr {@code{location-access-controls} parameter} file-name path
14183 Specifies the URI path to which the access control applies.
14186 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14187 Access controls for all access to this path, in the same format as the
14188 @code{access-controls} of @code{operation-access-control}.
14190 Defaults to @samp{()}.
14193 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14194 Access controls for method-specific access to this path.
14196 Defaults to @samp{()}.
14198 Available @code{method-access-controls} fields are:
14200 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14201 If @code{#t}, apply access controls to all methods except the listed
14202 methods. Otherwise apply to only the listed methods.
14204 Defaults to @samp{#f}.
14207 @deftypevr {@code{method-access-controls} parameter} method-list methods
14208 Methods to which this access control applies.
14210 Defaults to @samp{()}.
14213 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14214 Access control directives, as a list of strings. Each string should be
14215 one directive, such as "Order allow,deny".
14217 Defaults to @samp{()}.
14222 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14223 Specifies the number of debugging messages that are retained for logging
14224 if an error occurs in a print job. Debug messages are logged regardless
14225 of the LogLevel setting.
14227 Defaults to @samp{100}.
14230 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14231 Specifies the level of logging for the ErrorLog file. The value
14232 @code{none} stops all logging while @code{debug2} logs everything.
14234 Defaults to @samp{info}.
14237 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14238 Specifies the format of the date and time in the log files. The value
14239 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14241 Defaults to @samp{standard}.
14244 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14245 Specifies the maximum number of simultaneous clients that are allowed by
14248 Defaults to @samp{100}.
14251 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14252 Specifies the maximum number of simultaneous clients that are allowed
14253 from a single address.
14255 Defaults to @samp{100}.
14258 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14259 Specifies the maximum number of copies that a user can print of each
14262 Defaults to @samp{9999}.
14265 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14266 Specifies the maximum time a job may remain in the @code{indefinite}
14267 hold state before it is canceled. A value of 0 disables cancellation of
14270 Defaults to @samp{0}.
14273 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14274 Specifies the maximum number of simultaneous jobs that are allowed. Set
14275 to 0 to allow an unlimited number of jobs.
14277 Defaults to @samp{500}.
14280 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14281 Specifies the maximum number of simultaneous jobs that are allowed per
14282 printer. A value of 0 allows up to MaxJobs jobs per printer.
14284 Defaults to @samp{0}.
14287 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14288 Specifies the maximum number of simultaneous jobs that are allowed per
14289 user. A value of 0 allows up to MaxJobs jobs per user.
14291 Defaults to @samp{0}.
14294 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14295 Specifies the maximum time a job may take to print before it is
14296 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14298 Defaults to @samp{10800}.
14301 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14302 Specifies the maximum size of the log files before they are rotated, in
14303 bytes. The value 0 disables log rotation.
14305 Defaults to @samp{1048576}.
14308 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14309 Specifies the maximum amount of time to allow between files in a
14310 multiple file print job, in seconds.
14312 Defaults to @samp{300}.
14315 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14316 Specifies the format of PageLog lines. Sequences beginning with percent
14317 (@samp{%}) characters are replaced with the corresponding information,
14318 while all other characters are copied literally. The following percent
14319 sequences are recognized:
14323 insert a single percent character
14326 insert the value of the specified IPP attribute
14329 insert the number of copies for the current page
14332 insert the current page number
14335 insert the current date and time in common log format
14341 insert the printer name
14344 insert the username
14347 A value of the empty string disables page logging. The string @code{%p
14348 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14349 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14352 Defaults to @samp{""}.
14355 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14356 Passes the specified environment variable(s) to child processes; a list
14359 Defaults to @samp{()}.
14362 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14363 Specifies named access control policies.
14365 Available @code{policy-configuration} fields are:
14367 @deftypevr {@code{policy-configuration} parameter} string name
14368 Name of the policy.
14371 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14372 Specifies an access list for a job's private values. @code{@@ACL} maps
14373 to the printer's requesting-user-name-allowed or
14374 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14375 owner. @code{@@SYSTEM} maps to the groups listed for the
14376 @code{system-group} field of the @code{files-config} configuration,
14377 which is reified into the @code{cups-files.conf(5)} file. Other
14378 possible elements of the access list include specific user names, and
14379 @code{@@@var{group}} to indicate members of a specific group. The
14380 access list may also be simply @code{all} or @code{default}.
14382 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14385 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14386 Specifies the list of job values to make private, or @code{all},
14387 @code{default}, or @code{none}.
14389 Defaults to @samp{"job-name job-originating-host-name
14390 job-originating-user-name phone"}.
14393 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14394 Specifies an access list for a subscription's private values.
14395 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14396 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14397 owner. @code{@@SYSTEM} maps to the groups listed for the
14398 @code{system-group} field of the @code{files-config} configuration,
14399 which is reified into the @code{cups-files.conf(5)} file. Other
14400 possible elements of the access list include specific user names, and
14401 @code{@@@var{group}} to indicate members of a specific group. The
14402 access list may also be simply @code{all} or @code{default}.
14404 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14407 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14408 Specifies the list of job values to make private, or @code{all},
14409 @code{default}, or @code{none}.
14411 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14412 notify-subscriber-user-name notify-user-data"}.
14415 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14416 Access control by IPP operation.
14418 Defaults to @samp{()}.
14422 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14423 Specifies whether job files (documents) are preserved after a job is
14424 printed. If a numeric value is specified, job files are preserved for
14425 the indicated number of seconds after printing. Otherwise a boolean
14426 value applies indefinitely.
14428 Defaults to @samp{86400}.
14431 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14432 Specifies whether the job history is preserved after a job is printed.
14433 If a numeric value is specified, the job history is preserved for the
14434 indicated number of seconds after printing. If @code{#t}, the job
14435 history is preserved until the MaxJobs limit is reached.
14437 Defaults to @samp{#t}.
14440 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14441 Specifies the amount of time to wait for job completion before
14442 restarting the scheduler.
14444 Defaults to @samp{30}.
14447 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14448 Specifies the maximum amount of memory to use when converting documents
14449 into bitmaps for a printer.
14451 Defaults to @samp{"128m"}.
14454 @deftypevr {@code{cups-configuration} parameter} string server-admin
14455 Specifies the email address of the server administrator.
14457 Defaults to @samp{"root@@localhost.localdomain"}.
14460 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14461 The ServerAlias directive is used for HTTP Host header validation when
14462 clients connect to the scheduler from external interfaces. Using the
14463 special name @code{*} can expose your system to known browser-based DNS
14464 rebinding attacks, even when accessing sites through a firewall. If the
14465 auto-discovery of alternate names does not work, we recommend listing
14466 each alternate name with a ServerAlias directive instead of using
14469 Defaults to @samp{*}.
14472 @deftypevr {@code{cups-configuration} parameter} string server-name
14473 Specifies the fully-qualified host name of the server.
14475 Defaults to @samp{"localhost"}.
14478 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14479 Specifies what information is included in the Server header of HTTP
14480 responses. @code{None} disables the Server header. @code{ProductOnly}
14481 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14482 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14483 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14484 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14485 2.0.0 (@var{uname}) IPP/2.0}.
14487 Defaults to @samp{Minimal}.
14490 @deftypevr {@code{cups-configuration} parameter} string set-env
14491 Set the specified environment variable to be passed to child processes.
14493 Defaults to @samp{"variable value"}.
14496 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14497 Listens on the specified interfaces for encrypted connections. Valid
14498 values are of the form @var{address}:@var{port}, where @var{address} is
14499 either an IPv6 address enclosed in brackets, an IPv4 address, or
14500 @code{*} to indicate all addresses.
14502 Defaults to @samp{()}.
14505 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14506 Sets encryption options. By default, CUPS only supports encryption
14507 using TLS v1.0 or higher using known secure cipher suites. The
14508 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14509 required for some older clients that do not implement newer ones. The
14510 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14511 older clients that do not support TLS v1.0.
14513 Defaults to @samp{()}.
14516 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14517 Specifies whether the scheduler requires clients to strictly adhere to
14518 the IPP specifications.
14520 Defaults to @samp{#f}.
14523 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14524 Specifies the HTTP request timeout, in seconds.
14526 Defaults to @samp{300}.
14530 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14531 Specifies whether the web interface is enabled.
14533 Defaults to @samp{#f}.
14536 At this point you're probably thinking ``oh dear, Guix manual, I like
14537 you but you can stop already with the configuration options''. Indeed.
14538 However, one more point: it could be that you have an existing
14539 @code{cupsd.conf} that you want to use. In that case, you can pass an
14540 @code{opaque-cups-configuration} as the configuration of a
14541 @code{cups-service-type}.
14543 Available @code{opaque-cups-configuration} fields are:
14545 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14549 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14550 The contents of the @code{cupsd.conf}, as a string.
14553 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14554 The contents of the @code{cups-files.conf} file, as a string.
14557 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14558 strings of the same name, you could instantiate a CUPS service like
14562 (service cups-service-type
14563 (opaque-cups-configuration
14564 (cupsd.conf cupsd.conf)
14565 (cups-files.conf cups-files.conf)))
14569 @node Desktop Services
14570 @subsection Desktop Services
14572 The @code{(gnu services desktop)} module provides services that are
14573 usually useful in the context of a ``desktop'' setup---that is, on a
14574 machine running a graphical display server, possibly with graphical user
14575 interfaces, etc. It also defines services that provide specific desktop
14576 environments like GNOME, Xfce or MATE.
14578 To simplify things, the module defines a variable containing the set of
14579 services that users typically expect on a machine with a graphical
14580 environment and networking:
14582 @defvr {Scheme Variable} %desktop-services
14583 This is a list of services that builds upon @var{%base-services} and
14584 adds or adjusts services for a typical ``desktop'' setup.
14586 In particular, it adds a graphical login manager (@pxref{X Window,
14587 @code{gdm-service-type}}), screen lockers, a network management tool
14588 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
14589 management services, the @code{elogind} login and seat manager, the
14590 Polkit privilege service, the GeoClue location service, the
14591 AccountsService daemon that allows authorized users change system
14592 passwords, an NTP client (@pxref{Networking Services}), the Avahi
14593 daemon, and has the name service switch service configured to be able to
14594 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
14597 The @var{%desktop-services} variable can be used as the @code{services}
14598 field of an @code{operating-system} declaration (@pxref{operating-system
14599 Reference, @code{services}}).
14601 Additionally, the @code{gnome-desktop-service-type},
14602 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14603 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14604 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14605 services like the backlight adjustment helpers and the power management
14606 utilities are added to the system, extending @code{polkit} and @code{dbus}
14607 appropriately, allowing GNOME to operate with elevated privileges on a
14608 limited number of special-purpose system interfaces. Additionally,
14609 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14610 metapackage to the system profile. Likewise, adding the Xfce service
14611 not only adds the @code{xfce} metapackage to the system profile, but it
14612 also gives the Thunar file manager the ability to open a ``root-mode''
14613 file management window, if the user authenticates using the
14614 administrator's password via the standard polkit graphical interface.
14615 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14616 appropriately, allowing MATE to operate with elevated privileges on a
14617 limited number of special-purpose system interfaces. Additionally,
14618 adding a service of type @code{mate-desktop-service-type} adds the MATE
14619 metapackage to the system profile. ``Adding Enlightenment'' means that
14620 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14621 are set as setuid, allowing Enlightenment's screen locker and other
14622 functionality to work as expetected.
14624 The desktop environments in Guix use the Xorg display server by
14625 default. If you'd like to use the newer display server protocol
14626 called Wayland, you need to use the @code{sddm-service} instead of
14627 GDM as the graphical login manager. You should then
14628 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14629 also try starting GNOME on Wayland manually from a TTY with the
14630 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14631 gnome-session``. Currently only GNOME has support for Wayland.
14633 @defvr {Scheme Variable} gnome-desktop-service-type
14634 This is the type of the service that adds the @uref{https://www.gnome.org,
14635 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14636 object (see below.)
14638 This service adds the @code{gnome} package to the system profile, and extends
14639 polkit with the actions from @code{gnome-settings-daemon}.
14642 @deftp {Data Type} gnome-desktop-configuration
14643 Configuration record for the GNOME desktop environment.
14646 @item @code{gnome} (default @code{gnome})
14647 The GNOME package to use.
14651 @defvr {Scheme Variable} xfce-desktop-service-type
14652 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14653 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14656 This service that adds the @code{xfce} package to the system profile, and
14657 extends polkit with the ability for @code{thunar} to manipulate the file
14658 system as root from within a user session, after the user has authenticated
14659 with the administrator's password.
14662 @deftp {Data Type} xfce-desktop-configuration
14663 Configuration record for the Xfce desktop environment.
14666 @item @code{xfce} (default @code{xfce})
14667 The Xfce package to use.
14671 @deffn {Scheme Variable} mate-desktop-service-type
14672 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14673 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14674 object (see below.)
14676 This service adds the @code{mate} package to the system
14677 profile, and extends polkit with the actions from
14678 @code{mate-settings-daemon}.
14681 @deftp {Data Type} mate-desktop-configuration
14682 Configuration record for the MATE desktop environment.
14685 @item @code{mate} (default @code{mate})
14686 The MATE package to use.
14690 @deffn {Scheme Variable} enlightenment-desktop-service-type
14691 Return a service that adds the @code{enlightenment} package to the system
14692 profile, and extends dbus with actions from @code{efl}.
14695 @deftp {Data Type} enlightenment-desktop-service-configuration
14697 @item @code{enlightenment} (default @code{enlightenment})
14698 The enlightenment package to use.
14702 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14703 the default @code{%desktop-services} variable doesn't include any of
14704 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14705 @code{%desktop-services} in the @code{services} field of your
14706 @code{operating-system}:
14709 (use-modules (gnu))
14710 (use-service-modules desktop)
14713 ;; cons* adds items to the list given as its last argument.
14714 (services (cons* (service gnome-desktop-service-type)
14715 (service xfce-desktop-service)
14716 %desktop-services))
14720 These desktop environments will then be available as options in the
14721 graphical login window.
14723 The actual service definitions included in @code{%desktop-services} and
14724 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14725 are described below.
14727 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14728 Return a service that runs the ``system bus'', using @var{dbus}, with
14729 support for @var{services}.
14731 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14732 facility. Its system bus is used to allow system services to communicate
14733 and to be notified of system-wide events.
14735 @var{services} must be a list of packages that provide an
14736 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14737 and policy files. For example, to allow avahi-daemon to use the system bus,
14738 @var{services} must be equal to @code{(list avahi)}.
14741 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14742 Return a service that runs the @code{elogind} login and
14743 seat management daemon. @uref{https://github.com/elogind/elogind,
14744 Elogind} exposes a D-Bus interface that can be used to know which users
14745 are logged in, know what kind of sessions they have open, suspend the
14746 system, inhibit system suspend, reboot the system, and other tasks.
14748 Elogind handles most system-level power events for a computer, for
14749 example suspending the system when a lid is closed, or shutting it down
14750 when the power button is pressed.
14752 The @var{config} keyword argument specifies the configuration for
14753 elogind, and should be the result of an @code{(elogind-configuration
14754 (@var{parameter} @var{value})...)} invocation. Available parameters and
14755 their default values are:
14758 @item kill-user-processes?
14760 @item kill-only-users
14762 @item kill-exclude-users
14764 @item inhibit-delay-max-seconds
14766 @item handle-power-key
14768 @item handle-suspend-key
14770 @item handle-hibernate-key
14772 @item handle-lid-switch
14774 @item handle-lid-switch-docked
14776 @item power-key-ignore-inhibited?
14778 @item suspend-key-ignore-inhibited?
14780 @item hibernate-key-ignore-inhibited?
14782 @item lid-switch-ignore-inhibited?
14784 @item holdoff-timeout-seconds
14788 @item idle-action-seconds
14790 @item runtime-directory-size-percent
14792 @item runtime-directory-size
14796 @item suspend-state
14797 @code{("mem" "standby" "freeze")}
14800 @item hibernate-state
14802 @item hibernate-mode
14803 @code{("platform" "shutdown")}
14804 @item hybrid-sleep-state
14806 @item hybrid-sleep-mode
14807 @code{("suspend" "platform" "shutdown")}
14811 @deffn {Scheme Procedure} accountsservice-service @
14812 [#:accountsservice @var{accountsservice}]
14813 Return a service that runs AccountsService, a system service that can
14814 list available accounts, change their passwords, and so on.
14815 AccountsService integrates with PolicyKit to enable unprivileged users
14816 to acquire the capability to modify their system configuration.
14817 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14818 accountsservice web site} for more information.
14820 The @var{accountsservice} keyword argument is the @code{accountsservice}
14821 package to expose as a service.
14824 @deffn {Scheme Procedure} polkit-service @
14825 [#:polkit @var{polkit}]
14826 Return a service that runs the
14827 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14828 management service}, which allows system administrators to grant access to
14829 privileged operations in a structured way. By querying the Polkit service, a
14830 privileged system component can know when it should grant additional
14831 capabilities to ordinary users. For example, an ordinary user can be granted
14832 the capability to suspend the system if the user is logged in locally.
14835 @defvr {Scheme Variable} upower-service-type
14836 Service that runs @uref{http://upower.freedesktop.org/, @command{upowerd}}, a
14837 system-wide monitor for power consumption and battery levels, with the given
14838 configuration settings.
14840 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14841 notably used by GNOME.
14844 @deftp {Data Type} upower-configuration
14845 Data type representation the configuration for UPower.
14849 @item @code{upower} (default: @var{upower})
14850 Package to use for @code{upower}.
14852 @item @code{watts-up-pro?} (default: @code{#f})
14853 Enable the Watts Up Pro device.
14855 @item @code{poll-batteries?} (default: @code{#t})
14856 Enable polling the kernel for battery level changes.
14858 @item @code{ignore-lid?} (default: @code{#f})
14859 Ignore the lid state, this can be useful if it's incorrect on a device.
14861 @item @code{use-percentage-for-policy?} (default: @code{#f})
14862 Whether battery percentage based policy should be used. The default is to use
14863 the time left, change to @code{#t} to use the percentage.
14865 @item @code{percentage-low} (default: @code{10})
14866 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14867 at which the battery is considered low.
14869 @item @code{percentage-critical} (default: @code{3})
14870 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14871 at which the battery is considered critical.
14873 @item @code{percentage-action} (default: @code{2})
14874 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
14875 at which action will be taken.
14877 @item @code{time-low} (default: @code{1200})
14878 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14879 seconds at which the battery is considered low.
14881 @item @code{time-critical} (default: @code{300})
14882 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14883 seconds at which the battery is considered critical.
14885 @item @code{time-action} (default: @code{120})
14886 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
14887 seconds at which action will be taken.
14889 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
14890 The action taken when @code{percentage-action} or @code{time-action} is
14891 reached (depending on the configuration of @code{use-percentage-for-policy?}).
14893 Possible values are:
14903 @code{'hybrid-sleep}.
14909 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14910 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14911 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14912 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14913 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14916 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14917 Return a service that runs @command{colord}, a system service with a D-Bus
14918 interface to manage the color profiles of input and output devices such as
14919 screens and scanners. It is notably used by the GNOME Color Manager graphical
14920 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14921 site} for more information.
14924 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14925 Return a configuration allowing an application to access GeoClue
14926 location data. @var{name} is the Desktop ID of the application, without
14927 the @code{.desktop} part. If @var{allowed?} is true, the application
14928 will have access to location information by default. The boolean
14929 @var{system?} value indicates whether an application is a system component
14930 or not. Finally @var{users} is a list of UIDs of all users for which
14931 this application is allowed location info access. An empty users list
14932 means that all users are allowed.
14935 @defvr {Scheme Variable} %standard-geoclue-applications
14936 The standard list of well-known GeoClue application configurations,
14937 granting authority to the GNOME date-and-time utility to ask for the
14938 current location in order to set the time zone, and allowing the
14939 IceCat and Epiphany web browsers to request location information.
14940 IceCat and Epiphany both query the user before allowing a web page to
14941 know the user's location.
14944 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14945 [#:whitelist '()] @
14946 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14947 [#:submit-data? #f]
14948 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14949 [#:submission-nick "geoclue"] @
14950 [#:applications %standard-geoclue-applications]
14951 Return a service that runs the GeoClue location service. This service
14952 provides a D-Bus interface to allow applications to request access to a
14953 user's physical location, and optionally to add information to online
14954 location databases. See
14955 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14956 web site} for more information.
14959 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14960 [@w{#:auto-enable? #f}]
14961 Return a service that runs the @command{bluetoothd} daemon, which
14962 manages all the Bluetooth devices and provides a number of D-Bus
14963 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14964 powered automatically at boot, which can be useful when using a
14965 bluetooth keyboard or mouse.
14967 Users need to be in the @code{lp} group to access the D-Bus service.
14970 @node Sound Services
14971 @subsection Sound Services
14973 @cindex sound support
14975 @cindex PulseAudio, sound support
14977 The @code{(gnu services sound)} module provides a service to configure the
14978 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14979 preferred ALSA output driver.
14981 @deffn {Scheme Variable} alsa-service-type
14982 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14983 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14984 configuration file. The value for this type is a @command{alsa-configuration}
14985 record as in this example:
14988 (service alsa-service-type)
14991 See below for details about @code{alsa-configuration}.
14994 @deftp {Data Type} alsa-configuration
14995 Data type representing the configuration for @code{alsa-service}.
14998 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14999 @code{alsa-plugins} package to use.
15001 @item @code{pulseaudio?} (default: @var{#t})
15002 Whether ALSA applications should transparently be made to use the
15003 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15005 Using PulseAudio allows you to run several sound-producing applications
15006 at the same time and to individual control them @i{via}
15007 @command{pavucontrol}, among other things.
15009 @item @code{extra-options} (default: @var{""})
15010 String to append to the @file{/etc/asound.conf} file.
15015 Individual users who want to override the system configuration of ALSA can do
15016 it with the @file{~/.asoundrc} file:
15019 # In guix, we have to specify the absolute path for plugins.
15021 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15024 # Routing ALSA to jack:
15025 # <http://jackaudio.org/faq/routing_alsa.html>.
15029 0 system:playback_1
15030 1 system:playback_2
15047 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15051 @node Database Services
15052 @subsection Database Services
15056 The @code{(gnu services databases)} module provides the following services.
15058 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15059 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15060 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15061 Return a service that runs @var{postgresql}, the PostgreSQL database
15064 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15065 creates a database cluster with @var{locale} as the default
15066 locale, stored in @var{data-directory}. It then listens on @var{port}.
15068 @cindex postgresql extension-packages
15069 Additional extensions are loaded from packages listed in
15070 @var{extension-packages}. Extensions are available at runtime. For instance,
15071 to create a geographic database using the @code{postgis} extension, a user can
15072 configure the postgresql-service as in this example:
15076 (use-package-modules databases geo)
15080 ;; postgresql is required to run `psql' but postgis is not required for
15081 ;; proper operation.
15082 (packages (cons* postgresql %base-packages))
15085 (postgresql-service #:extension-packages (list postgis))
15089 Then the extension becomes visible and you can initialise an empty geographic
15090 database in this way:
15094 > create database postgistest;
15095 > \connect postgistest;
15096 > create extension postgis;
15097 > create extension postgis_topology;
15100 There is no need to add this field for contrib extensions such as hstore or
15101 dblink as they are already loadable by postgresql. This field is only
15102 required to add extensions provided by other packages.
15105 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15106 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15109 The optional @var{config} argument specifies the configuration for
15110 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15113 @deftp {Data Type} mysql-configuration
15114 Data type representing the configuration of @var{mysql-service}.
15117 @item @code{mysql} (default: @var{mariadb})
15118 Package object of the MySQL database server, can be either @var{mariadb}
15121 For MySQL, a temporary root password will be displayed at activation time.
15122 For MariaDB, the root password is empty.
15124 @item @code{port} (default: @code{3306})
15125 TCP port on which the database server listens for incoming connections.
15129 @defvr {Scheme Variable} memcached-service-type
15130 This is the service type for the @uref{https://memcached.org/,
15131 Memcached} service, which provides a distributed in memory cache. The
15132 value for the service type is a @code{memcached-configuration} object.
15136 (service memcached-service-type)
15139 @deftp {Data Type} memcached-configuration
15140 Data type representing the configuration of memcached.
15143 @item @code{memcached} (default: @code{memcached})
15144 The Memcached package to use.
15146 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15147 Network interfaces on which to listen.
15149 @item @code{tcp-port} (default: @code{11211})
15150 Port on which to accept connections on,
15152 @item @code{udp-port} (default: @code{11211})
15153 Port on which to accept UDP connections on, a value of 0 will disable
15154 listening on a UDP socket.
15156 @item @code{additional-options} (default: @code{'()})
15157 Additional command line options to pass to @code{memcached}.
15161 @defvr {Scheme Variable} mongodb-service-type
15162 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15163 The value for the service type is a @code{mongodb-configuration} object.
15167 (service mongodb-service-type)
15170 @deftp {Data Type} mongodb-configuration
15171 Data type representing the configuration of mongodb.
15174 @item @code{mongodb} (default: @code{mongodb})
15175 The MongoDB package to use.
15177 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15178 The configuration file for MongoDB.
15180 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15181 This value is used to create the directory, so that it exists and is
15182 owned by the mongodb user. It should match the data-directory which
15183 MongoDB is configured to use through the configuration file.
15187 @defvr {Scheme Variable} redis-service-type
15188 This is the service type for the @uref{https://redis.io/, Redis}
15189 key/value store, whose value is a @code{redis-configuration} object.
15192 @deftp {Data Type} redis-configuration
15193 Data type representing the configuration of redis.
15196 @item @code{redis} (default: @code{redis})
15197 The Redis package to use.
15199 @item @code{bind} (default: @code{"127.0.0.1"})
15200 Network interface on which to listen.
15202 @item @code{port} (default: @code{6379})
15203 Port on which to accept connections on, a value of 0 will disable
15204 listening on a TCP socket.
15206 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15207 Directory in which to store the database and related files.
15211 @node Mail Services
15212 @subsection Mail Services
15216 The @code{(gnu services mail)} module provides Guix service definitions
15217 for email services: IMAP, POP3, and LMTP servers, as well as mail
15218 transport agents (MTAs). Lots of acronyms! These services are detailed
15219 in the subsections below.
15221 @subsubheading Dovecot Service
15223 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15224 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15227 By default, Dovecot does not need much configuration; the default
15228 configuration object created by @code{(dovecot-configuration)} will
15229 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15230 certificate will be generated for TLS-protected connections, though
15231 Dovecot will also listen on cleartext ports by default. There are a
15232 number of options, though, which mail administrators might need to change,
15233 and as is the case with other services, Guix allows the system
15234 administrator to specify these parameters via a uniform Scheme interface.
15236 For example, to specify that mail is located at @code{maildir~/.mail},
15237 one would instantiate the Dovecot service like this:
15240 (dovecot-service #:config
15241 (dovecot-configuration
15242 (mail-location "maildir:~/.mail")))
15245 The available configuration parameters follow. Each parameter
15246 definition is preceded by its type; for example, @samp{string-list foo}
15247 indicates that the @code{foo} parameter should be specified as a list of
15248 strings. There is also a way to specify the configuration as a string,
15249 if you have an old @code{dovecot.conf} file that you want to port over
15250 from some other system; see the end for more details.
15252 @c The following documentation was initially generated by
15253 @c (generate-documentation) in (gnu services mail). Manually maintained
15254 @c documentation is better, so we shouldn't hesitate to edit below as
15255 @c needed. However if the change you want to make to this documentation
15256 @c can be done in an automated way, it's probably easier to change
15257 @c (generate-documentation) than to make it below and have to deal with
15258 @c the churn as dovecot updates.
15260 Available @code{dovecot-configuration} fields are:
15262 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15263 The dovecot package.
15266 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15267 A list of IPs or hosts where to listen for connections. @samp{*}
15268 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15269 interfaces. If you want to specify non-default ports or anything more
15270 complex, customize the address and port fields of the
15271 @samp{inet-listener} of the specific services you are interested in.
15274 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15275 List of protocols we want to serve. Available protocols include
15276 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15278 Available @code{protocol-configuration} fields are:
15280 @deftypevr {@code{protocol-configuration} parameter} string name
15281 The name of the protocol.
15284 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15285 UNIX socket path to the master authentication server to find users.
15286 This is used by imap (for shared users) and lda.
15287 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15290 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15291 Space separated list of plugins to load.
15294 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15295 Maximum number of IMAP connections allowed for a user from each IP
15296 address. NOTE: The username is compared case-sensitively.
15297 Defaults to @samp{10}.
15302 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15303 List of services to enable. Available services include @samp{imap},
15304 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15307 Available @code{service-configuration} fields are:
15309 @deftypevr {@code{service-configuration} parameter} string kind
15310 The service kind. Valid values include @code{director},
15311 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15312 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15313 @code{tcpwrap}, @code{quota-warning}, or anything else.
15316 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15317 Listeners for the service. A listener is either a
15318 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15319 an @code{inet-listener-configuration}.
15320 Defaults to @samp{()}.
15322 Available @code{unix-listener-configuration} fields are:
15324 @deftypevr {@code{unix-listener-configuration} parameter} string path
15325 Path to the file, relative to @code{base-dir} field. This is also used as
15329 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15330 The access mode for the socket.
15331 Defaults to @samp{"0600"}.
15334 @deftypevr {@code{unix-listener-configuration} parameter} string user
15335 The user to own the socket.
15336 Defaults to @samp{""}.
15339 @deftypevr {@code{unix-listener-configuration} parameter} string group
15340 The group to own the socket.
15341 Defaults to @samp{""}.
15345 Available @code{fifo-listener-configuration} fields are:
15347 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15348 Path to the file, relative to @code{base-dir} field. This is also used as
15352 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15353 The access mode for the socket.
15354 Defaults to @samp{"0600"}.
15357 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15358 The user to own the socket.
15359 Defaults to @samp{""}.
15362 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15363 The group to own the socket.
15364 Defaults to @samp{""}.
15368 Available @code{inet-listener-configuration} fields are:
15370 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15371 The protocol to listen for.
15374 @deftypevr {@code{inet-listener-configuration} parameter} string address
15375 The address on which to listen, or empty for all addresses.
15376 Defaults to @samp{""}.
15379 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15380 The port on which to listen.
15383 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15384 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15386 Defaults to @samp{#t}.
15391 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15392 Maximum number of simultaneous client connections per process. Once
15393 this number of connections is received, the next incoming connection
15394 will prompt Dovecot to spawn another process. If set to 0,
15395 @code{default-client-limit} is used instead.
15397 Defaults to @samp{0}.
15401 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15402 Number of connections to handle before starting a new process.
15403 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15404 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15405 Defaults to @samp{1}.
15409 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15410 Maximum number of processes that can exist for this service. If set to
15411 0, @code{default-process-limit} is used instead.
15413 Defaults to @samp{0}.
15417 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15418 Number of processes to always keep waiting for more connections.
15419 Defaults to @samp{0}.
15422 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15423 If you set @samp{service-count 0}, you probably need to grow
15425 Defaults to @samp{256000000}.
15430 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15431 Dict configuration, as created by the @code{dict-configuration}
15434 Available @code{dict-configuration} fields are:
15436 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15437 A list of key-value pairs that this dict should hold.
15438 Defaults to @samp{()}.
15443 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15444 A list of passdb configurations, each one created by the
15445 @code{passdb-configuration} constructor.
15447 Available @code{passdb-configuration} fields are:
15449 @deftypevr {@code{passdb-configuration} parameter} string driver
15450 The driver that the passdb should use. Valid values include
15451 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15453 Defaults to @samp{"pam"}.
15456 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15457 Space separated list of arguments to the passdb driver.
15458 Defaults to @samp{""}.
15463 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15464 List of userdb configurations, each one created by the
15465 @code{userdb-configuration} constructor.
15467 Available @code{userdb-configuration} fields are:
15469 @deftypevr {@code{userdb-configuration} parameter} string driver
15470 The driver that the userdb should use. Valid values include
15471 @samp{passwd} and @samp{static}.
15472 Defaults to @samp{"passwd"}.
15475 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15476 Space separated list of arguments to the userdb driver.
15477 Defaults to @samp{""}.
15480 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15481 Override fields from passwd.
15482 Defaults to @samp{()}.
15487 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15488 Plug-in configuration, created by the @code{plugin-configuration}
15492 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15493 List of namespaces. Each item in the list is created by the
15494 @code{namespace-configuration} constructor.
15496 Available @code{namespace-configuration} fields are:
15498 @deftypevr {@code{namespace-configuration} parameter} string name
15499 Name for this namespace.
15502 @deftypevr {@code{namespace-configuration} parameter} string type
15503 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15504 Defaults to @samp{"private"}.
15507 @deftypevr {@code{namespace-configuration} parameter} string separator
15508 Hierarchy separator to use. You should use the same separator for
15509 all namespaces or some clients get confused. @samp{/} is usually a good
15510 one. The default however depends on the underlying mail storage
15512 Defaults to @samp{""}.
15515 @deftypevr {@code{namespace-configuration} parameter} string prefix
15516 Prefix required to access this namespace. This needs to be
15517 different for all namespaces. For example @samp{Public/}.
15518 Defaults to @samp{""}.
15521 @deftypevr {@code{namespace-configuration} parameter} string location
15522 Physical location of the mailbox. This is in the same format as
15523 mail_location, which is also the default for it.
15524 Defaults to @samp{""}.
15527 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15528 There can be only one INBOX, and this setting defines which
15530 Defaults to @samp{#f}.
15533 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15534 If namespace is hidden, it's not advertised to clients via NAMESPACE
15535 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15536 useful when converting from another server with different namespaces
15537 which you want to deprecate but still keep working. For example you can
15538 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15540 Defaults to @samp{#f}.
15543 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15544 Show the mailboxes under this namespace with the LIST command. This
15545 makes the namespace visible for clients that do not support the NAMESPACE
15546 extension. The special @code{children} value lists child mailboxes, but
15547 hides the namespace prefix.
15548 Defaults to @samp{#t}.
15551 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15552 Namespace handles its own subscriptions. If set to @code{#f}, the
15553 parent namespace handles them. The empty prefix should always have this
15555 Defaults to @samp{#t}.
15558 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15559 List of predefined mailboxes in this namespace.
15560 Defaults to @samp{()}.
15562 Available @code{mailbox-configuration} fields are:
15564 @deftypevr {@code{mailbox-configuration} parameter} string name
15565 Name for this mailbox.
15568 @deftypevr {@code{mailbox-configuration} parameter} string auto
15569 @samp{create} will automatically create this mailbox.
15570 @samp{subscribe} will both create and subscribe to the mailbox.
15571 Defaults to @samp{"no"}.
15574 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15575 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15576 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15577 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15578 Defaults to @samp{()}.
15585 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15586 Base directory where to store runtime data.
15587 Defaults to @samp{"/var/run/dovecot/"}.
15590 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15591 Greeting message for clients.
15592 Defaults to @samp{"Dovecot ready."}.
15595 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15596 List of trusted network ranges. Connections from these IPs are
15597 allowed to override their IP addresses and ports (for logging and for
15598 authentication checks). @samp{disable-plaintext-auth} is also ignored
15599 for these networks. Typically you would specify your IMAP proxy servers
15601 Defaults to @samp{()}.
15604 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15605 List of login access check sockets (e.g.@: tcpwrap).
15606 Defaults to @samp{()}.
15609 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15610 Show more verbose process titles (in ps). Currently shows user name
15611 and IP address. Useful for seeing who is actually using the IMAP
15612 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15614 Defaults to @samp{#f}.
15617 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15618 Should all processes be killed when Dovecot master process shuts down.
15619 Setting this to @code{#f} means that Dovecot can be upgraded without
15620 forcing existing client connections to close (although that could also
15621 be a problem if the upgrade is e.g.@: due to a security fix).
15622 Defaults to @samp{#t}.
15625 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15626 If non-zero, run mail commands via this many connections to doveadm
15627 server, instead of running them directly in the same process.
15628 Defaults to @samp{0}.
15631 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15632 UNIX socket or host:port used for connecting to doveadm server.
15633 Defaults to @samp{"doveadm-server"}.
15636 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15637 List of environment variables that are preserved on Dovecot startup
15638 and passed down to all of its child processes. You can also give
15639 key=value pairs to always set specific settings.
15642 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15643 Disable LOGIN command and all other plaintext authentications unless
15644 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15645 matches the local IP (i.e.@: you're connecting from the same computer),
15646 the connection is considered secure and plaintext authentication is
15647 allowed. See also ssl=required setting.
15648 Defaults to @samp{#t}.
15651 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15652 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15653 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15654 for caching to be used.
15655 Defaults to @samp{0}.
15658 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15659 Time to live for cached data. After TTL expires the cached record
15660 is no longer used, *except* if the main database lookup returns internal
15661 failure. We also try to handle password changes automatically: If
15662 user's previous authentication was successful, but this one wasn't, the
15663 cache isn't used. For now this works only with plaintext
15665 Defaults to @samp{"1 hour"}.
15668 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15669 TTL for negative hits (user not found, password mismatch).
15670 0 disables caching them completely.
15671 Defaults to @samp{"1 hour"}.
15674 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15675 List of realms for SASL authentication mechanisms that need them.
15676 You can leave it empty if you don't want to support multiple realms.
15677 Many clients simply use the first one listed here, so keep the default
15679 Defaults to @samp{()}.
15682 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15683 Default realm/domain to use if none was specified. This is used for
15684 both SASL realms and appending @@domain to username in plaintext
15686 Defaults to @samp{""}.
15689 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15690 List of allowed characters in username. If the user-given username
15691 contains a character not listed in here, the login automatically fails.
15692 This is just an extra check to make sure user can't exploit any
15693 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15694 you want to allow all characters, set this value to empty.
15695 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15698 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15699 Username character translations before it's looked up from
15700 databases. The value contains series of from -> to characters. For
15701 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15702 translated to @samp{@@}.
15703 Defaults to @samp{""}.
15706 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15707 Username formatting before it's looked up from databases. You can
15708 use the standard variables here, e.g.@: %Lu would lowercase the username,
15709 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15710 change the @samp{@@} into @samp{-AT-}. This translation is done after
15711 @samp{auth-username-translation} changes.
15712 Defaults to @samp{"%Lu"}.
15715 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15716 If you want to allow master users to log in by specifying the master
15717 username within the normal username string (i.e.@: not using SASL
15718 mechanism's support for it), you can specify the separator character
15719 here. The format is then <username><separator><master username>.
15720 UW-IMAP uses @samp{*} as the separator, so that could be a good
15722 Defaults to @samp{""}.
15725 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15726 Username to use for users logging in with ANONYMOUS SASL
15728 Defaults to @samp{"anonymous"}.
15731 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15732 Maximum number of dovecot-auth worker processes. They're used to
15733 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15734 They're automatically created and destroyed as needed.
15735 Defaults to @samp{30}.
15738 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15739 Host name to use in GSSAPI principal names. The default is to use
15740 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15741 allow all keytab entries.
15742 Defaults to @samp{""}.
15745 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15746 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15747 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15748 need to change the auth service to run as root to be able to read this
15750 Defaults to @samp{""}.
15753 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15754 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15755 and @samp{ntlm-auth} helper.
15756 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15757 Defaults to @samp{#f}.
15760 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15761 Path for Samba's @samp{ntlm-auth} helper binary.
15762 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15765 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15766 Time to delay before replying to failed authentications.
15767 Defaults to @samp{"2 secs"}.
15770 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15771 Require a valid SSL client certificate or the authentication
15773 Defaults to @samp{#f}.
15776 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15777 Take the username from client's SSL certificate, using
15778 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15780 Defaults to @samp{#f}.
15783 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15784 List of wanted authentication mechanisms. Supported mechanisms are:
15785 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15786 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15787 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15788 @samp{disable-plaintext-auth} setting.
15791 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15792 List of IPs or hostnames to all director servers, including ourself.
15793 Ports can be specified as ip:port. The default port is the same as what
15794 director service's @samp{inet-listener} is using.
15795 Defaults to @samp{()}.
15798 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15799 List of IPs or hostnames to all backend mail servers. Ranges are
15800 allowed too, like 10.0.0.10-10.0.0.30.
15801 Defaults to @samp{()}.
15804 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15805 How long to redirect users to a specific server after it no longer
15806 has any connections.
15807 Defaults to @samp{"15 min"}.
15810 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15811 How the username is translated before being hashed. Useful values
15812 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15813 are shared within domain.
15814 Defaults to @samp{"%Lu"}.
15817 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15818 Log file to use for error messages. @samp{syslog} logs to syslog,
15819 @samp{/dev/stderr} logs to stderr.
15820 Defaults to @samp{"syslog"}.
15823 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15824 Log file to use for informational messages. Defaults to
15826 Defaults to @samp{""}.
15829 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15830 Log file to use for debug messages. Defaults to
15831 @samp{info-log-path}.
15832 Defaults to @samp{""}.
15835 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15836 Syslog facility to use if you're logging to syslog. Usually if you
15837 don't want to use @samp{mail}, you'll use local0..local7. Also other
15838 standard facilities are supported.
15839 Defaults to @samp{"mail"}.
15842 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15843 Log unsuccessful authentication attempts and the reasons why they
15845 Defaults to @samp{#f}.
15848 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
15849 In case of password mismatches, log the attempted password. Valid
15850 values are no, plain and sha1. sha1 can be useful for detecting brute
15851 force password attempts vs. user simply trying the same password over
15852 and over again. You can also truncate the value to n chars by appending
15853 ":n" (e.g.@: sha1:6).
15854 Defaults to @samp{#f}.
15857 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
15858 Even more verbose logging for debugging purposes. Shows for example
15860 Defaults to @samp{#f}.
15863 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
15864 In case of password mismatches, log the passwords and used scheme so
15865 the problem can be debugged. Enabling this also enables
15867 Defaults to @samp{#f}.
15870 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
15871 Enable mail process debugging. This can help you figure out why
15872 Dovecot isn't finding your mails.
15873 Defaults to @samp{#f}.
15876 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
15877 Show protocol level SSL errors.
15878 Defaults to @samp{#f}.
15881 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
15882 Prefix for each line written to log file. % codes are in
15883 strftime(3) format.
15884 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
15887 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
15888 List of elements we want to log. The elements which have a
15889 non-empty variable value are joined together to form a comma-separated
15893 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
15894 Login log format. %s contains @samp{login-log-format-elements}
15895 string, %$ contains the data we want to log.
15896 Defaults to @samp{"%$: %s"}.
15899 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
15900 Log prefix for mail processes. See doc/wiki/Variables.txt for list
15901 of possible variables you can use.
15902 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
15905 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
15906 Format to use for logging mail deliveries. You can use variables:
15909 Delivery status message (e.g.@: @samp{saved to INBOX})
15921 Defaults to @samp{"msgid=%m: %$"}.
15924 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15925 Location for users' mailboxes. The default is empty, which means
15926 that Dovecot tries to find the mailboxes automatically. This won't work
15927 if the user doesn't yet have any mail, so you should explicitly tell
15928 Dovecot the full location.
15930 If you're using mbox, giving a path to the INBOX
15931 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15932 where the other mailboxes are kept. This is called the "root mail
15933 directory", and it must be the first path given in the
15934 @samp{mail-location} setting.
15936 There are a few special variables you can use, eg.:
15942 user part in user@@domain, same as %u if there's no domain
15944 domain part in user@@domain, empty if there's no domain
15949 See doc/wiki/Variables.txt for full list. Some examples:
15951 @item maildir:~/Maildir
15952 @item mbox:~/mail:INBOX=/var/mail/%u
15953 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15955 Defaults to @samp{""}.
15958 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15959 System user and group used to access mails. If you use multiple,
15960 userdb can override these by returning uid or gid fields. You can use
15961 either numbers or names. <doc/wiki/UserIds.txt>.
15962 Defaults to @samp{""}.
15965 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15967 Defaults to @samp{""}.
15970 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15971 Group to enable temporarily for privileged operations. Currently
15972 this is used only with INBOX when either its initial creation or
15973 dotlocking fails. Typically this is set to "mail" to give access to
15975 Defaults to @samp{""}.
15978 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15979 Grant access to these supplementary groups for mail processes.
15980 Typically these are used to set up access to shared mailboxes. Note
15981 that it may be dangerous to set these if users can create
15982 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15983 could allow a user to delete others' mailboxes, or ln -s
15984 /secret/shared/box ~/mail/mybox would allow reading it).
15985 Defaults to @samp{""}.
15988 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15989 Allow full file system access to clients. There's no access checks
15990 other than what the operating system does for the active UID/GID. It
15991 works with both maildir and mboxes, allowing you to prefix mailboxes
15992 names with e.g.@: /path/ or ~user/.
15993 Defaults to @samp{#f}.
15996 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15997 Don't use mmap() at all. This is required if you store indexes to
15998 shared file systems (NFS or clustered file system).
15999 Defaults to @samp{#f}.
16002 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16003 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16004 supports @samp{O_EXCL} since version 3, so this should be safe to use
16005 nowadays by default.
16006 Defaults to @samp{#t}.
16009 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16010 When to use fsync() or fdatasync() calls:
16013 Whenever necessary to avoid losing important data
16015 Useful with e.g.@: NFS when write()s are delayed
16017 Never use it (best performance, but crashes can lose data).
16019 Defaults to @samp{"optimized"}.
16022 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16023 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16024 NFS caches whenever needed. If you're using only a single mail server
16026 Defaults to @samp{#f}.
16029 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16030 Mail index files also exist in NFS. Setting this to yes requires
16031 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16032 Defaults to @samp{#f}.
16035 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16036 Locking method for index files. Alternatives are fcntl, flock and
16037 dotlock. Dotlocking uses some tricks which may create more disk I/O
16038 than other locking methods. NFS users: flock doesn't work, remember to
16039 change @samp{mmap-disable}.
16040 Defaults to @samp{"fcntl"}.
16043 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16044 Directory in which LDA/LMTP temporarily stores incoming mails >128
16046 Defaults to @samp{"/tmp"}.
16049 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16050 Valid UID range for users. This is mostly to make sure that users can't
16051 log in as daemons or other system users. Note that denying root logins is
16052 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16054 Defaults to @samp{500}.
16057 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16059 Defaults to @samp{0}.
16062 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16063 Valid GID range for users. Users having non-valid GID as primary group ID
16064 aren't allowed to log in. If user belongs to supplementary groups with
16065 non-valid GIDs, those groups are not set.
16066 Defaults to @samp{1}.
16069 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16071 Defaults to @samp{0}.
16074 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16075 Maximum allowed length for mail keyword name. It's only forced when
16076 trying to create new keywords.
16077 Defaults to @samp{50}.
16080 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16081 List of directories under which chrooting is allowed for mail
16082 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16083 too). This setting doesn't affect @samp{login-chroot}
16084 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16085 "/./" in home dirs are ignored. WARNING: Never add directories here
16086 which local users can modify, that may lead to root exploit. Usually
16087 this should be done only if you don't allow shell access for users.
16088 <doc/wiki/Chrooting.txt>.
16089 Defaults to @samp{()}.
16092 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16093 Default chroot directory for mail processes. This can be overridden
16094 for specific users in user database by giving /./ in user's home
16095 directory (e.g.@: /home/./user chroots into /home). Note that usually
16096 there is no real need to do chrooting, Dovecot doesn't allow users to
16097 access files outside their mail directory anyway. If your home
16098 directories are prefixed with the chroot directory, append "/."@: to
16099 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16100 Defaults to @samp{""}.
16103 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16104 UNIX socket path to master authentication server to find users.
16105 This is used by imap (for shared users) and lda.
16106 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16109 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16110 Directory where to look up mail plugins.
16111 Defaults to @samp{"/usr/lib/dovecot"}.
16114 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16115 List of plugins to load for all services. Plugins specific to IMAP,
16116 LDA, etc.@: are added to this list in their own .conf files.
16117 Defaults to @samp{()}.
16120 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16121 The minimum number of mails in a mailbox before updates are done to
16122 cache file. This allows optimizing Dovecot's behavior to do less disk
16123 writes at the cost of more disk reads.
16124 Defaults to @samp{0}.
16127 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16128 When IDLE command is running, mailbox is checked once in a while to
16129 see if there are any new mails or other changes. This setting defines
16130 the minimum time to wait between those checks. Dovecot can also use
16131 dnotify, inotify and kqueue to find out immediately when changes
16133 Defaults to @samp{"30 secs"}.
16136 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16137 Save mails with CR+LF instead of plain LF. This makes sending those
16138 mails take less CPU, especially with sendfile() syscall with Linux and
16139 FreeBSD. But it also creates a bit more disk I/O which may just make it
16140 slower. Also note that if other software reads the mboxes/maildirs,
16141 they may handle the extra CRs wrong and cause problems.
16142 Defaults to @samp{#f}.
16145 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16146 By default LIST command returns all entries in maildir beginning
16147 with a dot. Enabling this option makes Dovecot return only entries
16148 which are directories. This is done by stat()ing each entry, so it
16149 causes more disk I/O.
16150 (For systems setting struct @samp{dirent->d_type} this check is free
16151 and it's done always regardless of this setting).
16152 Defaults to @samp{#f}.
16155 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16156 When copying a message, do it with hard links whenever possible.
16157 This makes the performance much better, and it's unlikely to have any
16159 Defaults to @samp{#t}.
16162 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16163 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16164 directory only when its mtime changes unexpectedly or when we can't find
16165 the mail otherwise.
16166 Defaults to @samp{#f}.
16169 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16170 Which locking methods to use for locking mbox. There are four
16175 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16176 solution. If you want to use /var/mail/ like directory, the users will
16177 need write access to that directory.
16179 Same as dotlock, but if it fails because of permissions or because there
16180 isn't enough disk space, just skip it.
16182 Use this if possible. Works with NFS too if lockd is used.
16184 May not exist in all systems. Doesn't work with NFS.
16186 May not exist in all systems. Doesn't work with NFS.
16189 You can use multiple locking methods; if you do the order they're declared
16190 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16191 locking methods as well. Some operating systems don't allow using some of
16192 them simultaneously.
16195 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16199 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16200 Maximum time to wait for lock (all of them) before aborting.
16201 Defaults to @samp{"5 mins"}.
16204 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16205 If dotlock exists but the mailbox isn't modified in any way,
16206 override the lock file after this much time.
16207 Defaults to @samp{"2 mins"}.
16210 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16211 When mbox changes unexpectedly we have to fully read it to find out
16212 what changed. If the mbox is large this can take a long time. Since
16213 the change is usually just a newly appended mail, it'd be faster to
16214 simply read the new mails. If this setting is enabled, Dovecot does
16215 this but still safely fallbacks to re-reading the whole mbox file
16216 whenever something in mbox isn't how it's expected to be. The only real
16217 downside to this setting is that if some other MUA changes message
16218 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16219 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16220 Defaults to @samp{#t}.
16223 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16224 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16225 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16226 @samp{mbox-dirty-syncs} is ignored.
16227 Defaults to @samp{#f}.
16230 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16231 Delay writing mbox headers until doing a full write sync (EXPUNGE
16232 and CHECK commands and when closing the mailbox). This is especially
16233 useful for POP3 where clients often delete all mails. The downside is
16234 that our changes aren't immediately visible to other MUAs.
16235 Defaults to @samp{#t}.
16238 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16239 If mbox size is smaller than this (e.g.@: 100k), don't write index
16240 files. If an index file already exists it's still read, just not
16242 Defaults to @samp{0}.
16245 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16246 Maximum dbox file size until it's rotated.
16247 Defaults to @samp{10000000}.
16250 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16251 Maximum dbox file age until it's rotated. Typically in days. Day
16252 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16254 Defaults to @samp{"1d"}.
16257 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16258 When creating new mdbox files, immediately preallocate their size to
16259 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16260 with some file systems (ext4, xfs).
16261 Defaults to @samp{#f}.
16264 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16265 sdbox and mdbox support saving mail attachments to external files,
16266 which also allows single instance storage for them. Other backends
16267 don't support this for now.
16269 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16271 Directory root where to store mail attachments. Disabled, if empty.
16272 Defaults to @samp{""}.
16275 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16276 Attachments smaller than this aren't saved externally. It's also
16277 possible to write a plugin to disable saving specific attachments
16279 Defaults to @samp{128000}.
16282 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16283 File system backend to use for saving attachments:
16286 No SiS done by Dovecot (but this might help FS's own deduplication)
16288 SiS with immediate byte-by-byte comparison during saving
16289 @item sis-queue posix
16290 SiS with delayed comparison and deduplication.
16292 Defaults to @samp{"sis posix"}.
16295 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16296 Hash format to use in attachment filenames. You can add any text and
16297 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16298 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16299 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16300 Defaults to @samp{"%@{sha1@}"}.
16303 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16305 Defaults to @samp{100}.
16308 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16310 Defaults to @samp{1000}.
16313 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16314 Default VSZ (virtual memory size) limit for service processes.
16315 This is mainly intended to catch and kill processes that leak memory
16316 before they eat up everything.
16317 Defaults to @samp{256000000}.
16320 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16321 Login user is internally used by login processes. This is the most
16322 untrusted user in Dovecot system. It shouldn't have access to anything
16324 Defaults to @samp{"dovenull"}.
16327 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16328 Internal user is used by unprivileged processes. It should be
16329 separate from login user, so that login processes can't disturb other
16331 Defaults to @samp{"dovecot"}.
16334 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16335 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16336 Defaults to @samp{"required"}.
16339 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16340 PEM encoded X.509 SSL/TLS certificate (public key).
16341 Defaults to @samp{"</etc/dovecot/default.pem"}.
16344 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16345 PEM encoded SSL/TLS private key. The key is opened before
16346 dropping root privileges, so keep the key file unreadable by anyone but
16348 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16351 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16352 If key file is password protected, give the password here.
16353 Alternatively give it when starting dovecot with -p parameter. Since
16354 this file is often world-readable, you may want to place this setting
16355 instead to a different.
16356 Defaults to @samp{""}.
16359 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16360 PEM encoded trusted certificate authority. Set this only if you
16361 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16362 contain the CA certificate(s) followed by the matching
16363 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16364 Defaults to @samp{""}.
16367 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16368 Require that CRL check succeeds for client certificates.
16369 Defaults to @samp{#t}.
16372 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16373 Request client to send a certificate. If you also want to require
16374 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16375 Defaults to @samp{#f}.
16378 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16379 Which field from certificate to use for username. commonName and
16380 x500UniqueIdentifier are the usual choices. You'll also need to set
16381 @samp{auth-ssl-username-from-cert? #t}.
16382 Defaults to @samp{"commonName"}.
16385 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16386 Minimum SSL protocol version to accept.
16387 Defaults to @samp{"TLSv1"}.
16390 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16391 SSL ciphers to use.
16392 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16395 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16396 SSL crypto device to use, for valid values run "openssl engine".
16397 Defaults to @samp{""}.
16400 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16401 Address to use when sending rejection mails.
16402 %d expands to recipient domain.
16403 Defaults to @samp{"postmaster@@%d"}.
16406 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16407 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16408 and in LMTP replies. Default is the system's real hostname@@domain.
16409 Defaults to @samp{""}.
16412 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16413 If user is over quota, return with temporary failure instead of
16415 Defaults to @samp{#f}.
16418 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16419 Binary to use for sending mails.
16420 Defaults to @samp{"/usr/sbin/sendmail"}.
16423 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16424 If non-empty, send mails via this SMTP host[:port] instead of
16426 Defaults to @samp{""}.
16429 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16430 Subject: header to use for rejection mails. You can use the same
16431 variables as for @samp{rejection-reason} below.
16432 Defaults to @samp{"Rejected: %s"}.
16435 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16436 Human readable error message for rejection mails. You can use
16449 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16452 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16453 Delimiter character between local-part and detail in email
16455 Defaults to @samp{"+"}.
16458 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16459 Header where the original recipient address (SMTP's RCPT TO:
16460 address) is taken from if not available elsewhere. With dovecot-lda -a
16461 parameter overrides this. A commonly used header for this is
16463 Defaults to @samp{""}.
16466 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16467 Should saving a mail to a nonexistent mailbox automatically create
16469 Defaults to @samp{#f}.
16472 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16473 Should automatically created mailboxes be also automatically
16475 Defaults to @samp{#f}.
16478 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16479 Maximum IMAP command line length. Some clients generate very long
16480 command lines with huge mailboxes, so you may need to raise this if you
16481 get "Too long argument" or "IMAP command line too large" errors
16483 Defaults to @samp{64000}.
16486 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16487 IMAP logout format string:
16490 total number of bytes read from client
16492 total number of bytes sent to client.
16494 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16495 Defaults to @samp{"in=%i out=%o deleted=%@{deleted@} expunged=%@{expunged@} trashed=%@{trashed@} hdr_count=%@{fetch_hdr_count@} hdr_bytes=%@{fetch_hdr_bytes@} body_count=%@{fetch_body_count@} body_bytes=%@{fetch_body_bytes@}"}.
16498 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16499 Override the IMAP CAPABILITY response. If the value begins with '+',
16500 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16501 Defaults to @samp{""}.
16504 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16505 How long to wait between "OK Still here" notifications when client
16507 Defaults to @samp{"2 mins"}.
16510 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16511 ID field names and values to send to clients. Using * as the value
16512 makes Dovecot use the default value. The following fields have default
16513 values currently: name, version, os, os-version, support-url,
16515 Defaults to @samp{""}.
16518 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16519 ID fields sent by client to log. * means everything.
16520 Defaults to @samp{""}.
16523 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16524 Workarounds for various client bugs:
16527 @item delay-newmail
16528 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16529 CHECK commands. Some clients ignore them otherwise, for example OSX
16530 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16531 may show user "Message no longer in server" errors. Note that OE6
16532 still breaks even with this workaround if synchronization is set to
16535 @item tb-extra-mailbox-sep
16536 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16537 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16538 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16540 @item tb-lsub-flags
16541 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16542 This makes Thunderbird realize they aren't selectable and show them
16543 greyed out, instead of only later giving "not selectable" popup error.
16545 Defaults to @samp{()}.
16548 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16549 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16550 Defaults to @samp{""}.
16554 Whew! Lots of configuration options. The nice thing about it though is
16555 that Guix has a complete interface to Dovecot's configuration
16556 language. This allows not only a nice way to declare configurations,
16557 but also offers reflective capabilities as well: users can write code to
16558 inspect and transform configurations from within Scheme.
16560 However, it could be that you just want to get a @code{dovecot.conf} up
16561 and running. In that case, you can pass an
16562 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16563 @code{dovecot-service}. As its name indicates, an opaque configuration
16564 does not have easy reflective capabilities.
16566 Available @code{opaque-dovecot-configuration} fields are:
16568 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16569 The dovecot package.
16572 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16573 The contents of the @code{dovecot.conf}, as a string.
16576 For example, if your @code{dovecot.conf} is just the empty string, you
16577 could instantiate a dovecot service like this:
16580 (dovecot-service #:config
16581 (opaque-dovecot-configuration
16585 @subsubheading OpenSMTPD Service
16587 @deffn {Scheme Variable} opensmtpd-service-type
16588 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16589 service, whose value should be an @code{opensmtpd-configuration} object
16590 as in this example:
16593 (service opensmtpd-service-type
16594 (opensmtpd-configuration
16595 (config-file (local-file "./my-smtpd.conf"))))
16599 @deftp {Data Type} opensmtpd-configuration
16600 Data type representing the configuration of opensmtpd.
16603 @item @code{package} (default: @var{opensmtpd})
16604 Package object of the OpenSMTPD SMTP server.
16606 @item @code{config-file} (default: @var{%default-opensmtpd-file})
16607 File-like object of the OpenSMTPD configuration file to use. By default
16608 it listens on the loopback network interface, and allows for mail from
16609 users and daemons on the local machine, as well as permitting email to
16610 remote servers. Run @command{man smtpd.conf} for more information.
16615 @subsubheading Exim Service
16617 @cindex mail transfer agent (MTA)
16618 @cindex MTA (mail transfer agent)
16621 @deffn {Scheme Variable} exim-service-type
16622 This is the type of the @uref{https://exim.org, Exim} mail transfer
16623 agent (MTA), whose value should be an @code{exim-configuration} object
16624 as in this example:
16627 (service exim-service-type
16628 (exim-configuration
16629 (config-file (local-file "./my-exim.conf"))))
16633 In order to use an @code{exim-service-type} service you must also have a
16634 @code{mail-aliases-service-type} service present in your
16635 @code{operating-system} (even if it has no aliases).
16637 @deftp {Data Type} exim-configuration
16638 Data type representing the configuration of exim.
16641 @item @code{package} (default: @var{exim})
16642 Package object of the Exim server.
16644 @item @code{config-file} (default: @code{#f})
16645 File-like object of the Exim configuration file to use. If its value is
16646 @code{#f} then use the default configuration file from the package
16647 provided in @code{package}. The resulting configuration file is loaded
16648 after setting the @code{exim_user} and @code{exim_group} configuration
16654 @subsubheading Mail Aliases Service
16656 @cindex email aliases
16657 @cindex aliases, for email addresses
16659 @deffn {Scheme Variable} mail-aliases-service-type
16660 This is the type of the service which provides @code{/etc/aliases},
16661 specifying how to deliver mail to users on this system.
16664 (service mail-aliases-service-type
16665 '(("postmaster" "bob")
16666 ("bob" "bob@@example.com" "bob@@example2.com")))
16670 The configuration for a @code{mail-aliases-service-type} service is an
16671 association list denoting how to deliver mail that comes to this
16672 system. Each entry is of the form @code{(alias addresses ...)}, with
16673 @code{alias} specifying the local alias and @code{addresses} specifying
16674 where to deliver this user's mail.
16676 The aliases aren't required to exist as users on the local system. In
16677 the above example, there doesn't need to be a @code{postmaster} entry in
16678 the @code{operating-system}'s @code{user-accounts} in order to deliver
16679 the @code{postmaster} mail to @code{bob} (which subsequently would
16680 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
16682 @subsubheading GNU Mailutils IMAP4 Daemon
16683 @cindex GNU Mailutils IMAP4 Daemon
16685 @deffn {Scheme Variable} imap4d-service-type
16686 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
16687 mailutils, GNU Mailutils Manual}), whose value should be an
16688 @code{imap4d-configuration} object as in this example:
16691 (service imap4d-service-type
16692 (imap4d-configuration
16693 (config-file (local-file "imap4d.conf"))))
16697 @deftp {Data Type} imap4d-configuration
16698 Data type representing the configuration of @command{imap4d}.
16701 @item @code{package} (default: @code{mailutils})
16702 The package that provides @command{imap4d}.
16704 @item @code{config-file} (default: @code{%default-imap4d-config-file})
16705 File-like object of the configuration file to use, by default it will listen
16706 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
16707 Mailutils Manual}, for details.
16712 @node Messaging Services
16713 @subsection Messaging Services
16718 The @code{(gnu services messaging)} module provides Guix service
16719 definitions for messaging services: currently only Prosody is supported.
16721 @subsubheading Prosody Service
16723 @deffn {Scheme Variable} prosody-service-type
16724 This is the type for the @uref{https://prosody.im, Prosody XMPP
16725 communication server}. Its value must be a @code{prosody-configuration}
16726 record as in this example:
16729 (service prosody-service-type
16730 (prosody-configuration
16731 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
16734 (int-component-configuration
16735 (hostname "conference.example.net")
16737 (mod-muc (mod-muc-configuration)))))
16740 (virtualhost-configuration
16741 (domain "example.net"))))))
16744 See below for details about @code{prosody-configuration}.
16748 By default, Prosody does not need much configuration. Only one
16749 @code{virtualhosts} field is needed: it specifies the domain you wish
16752 You can perform various sanity checks on the generated configuration
16753 with the @code{prosodyctl check} command.
16755 Prosodyctl will also help you to import certificates from the
16756 @code{letsencrypt} directory so that the @code{prosody} user can access
16757 them. See @url{https://prosody.im/doc/letsencrypt}.
16760 prosodyctl --root cert import /etc/letsencrypt/live
16763 The available configuration parameters follow. Each parameter
16764 definition is preceded by its type; for example, @samp{string-list foo}
16765 indicates that the @code{foo} parameter should be specified as a list of
16766 strings. Types starting with @code{maybe-} denote parameters that won't
16767 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
16769 There is also a way to specify the configuration as a string, if you
16770 have an old @code{prosody.cfg.lua} file that you want to port over from
16771 some other system; see the end for more details.
16773 The @code{file-object} type designates either a file-like object
16774 (@pxref{G-Expressions, file-like objects}) or a file name.
16776 @c The following documentation was initially generated by
16777 @c (generate-documentation) in (gnu services messaging). Manually maintained
16778 @c documentation is better, so we shouldn't hesitate to edit below as
16779 @c needed. However if the change you want to make to this documentation
16780 @c can be done in an automated way, it's probably easier to change
16781 @c (generate-documentation) than to make it below and have to deal with
16782 @c the churn as Prosody updates.
16784 Available @code{prosody-configuration} fields are:
16786 @deftypevr {@code{prosody-configuration} parameter} package prosody
16787 The Prosody package.
16790 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
16791 Location of the Prosody data storage directory. See
16792 @url{https://prosody.im/doc/configure}.
16793 Defaults to @samp{"/var/lib/prosody"}.
16796 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
16797 Additional plugin directories. They are searched in all the specified
16798 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
16799 Defaults to @samp{()}.
16802 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
16803 Every virtual host and component needs a certificate so that clients and
16804 servers can securely verify its identity. Prosody will automatically load
16805 certificates/keys from the directory specified here.
16806 Defaults to @samp{"/etc/prosody/certs"}.
16809 @deftypevr {@code{prosody-configuration} parameter} string-list admins
16810 This is a list of accounts that are admins for the server. Note that you
16811 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
16812 @url{https://prosody.im/doc/creating_accounts}.
16813 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
16814 Defaults to @samp{()}.
16817 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
16818 Enable use of libevent for better performance under high load. See
16819 @url{https://prosody.im/doc/libevent}.
16820 Defaults to @samp{#f}.
16823 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
16824 This is the list of modules Prosody will load on startup. It looks for
16825 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
16826 Documentation on modules can be found at:
16827 @url{https://prosody.im/doc/modules}.
16828 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
16831 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
16832 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
16833 should you want to disable them then add them to this list.
16834 Defaults to @samp{()}.
16837 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
16838 Path to a text file where the shared groups are defined. If this path is
16839 empty then @samp{mod_groups} does nothing. See
16840 @url{https://prosody.im/doc/modules/mod_groups}.
16841 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
16844 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
16845 Disable account creation by default, for security. See
16846 @url{https://prosody.im/doc/creating_accounts}.
16847 Defaults to @samp{#f}.
16850 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
16851 These are the SSL/TLS-related settings. Most of them are disabled so to
16852 use Prosody's defaults. If you do not completely understand these options, do
16853 not add them to your config, it is easy to lower the security of your server
16854 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
16856 Available @code{ssl-configuration} fields are:
16858 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
16859 This determines what handshake to use.
16862 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
16863 Path to your private key file.
16866 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
16867 Path to your certificate file.
16870 @deftypevr {@code{ssl-configuration} parameter} file-object capath
16871 Path to directory containing root certificates that you wish Prosody to
16872 trust when verifying the certificates of remote servers.
16873 Defaults to @samp{"/etc/ssl/certs"}.
16876 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
16877 Path to a file containing root certificates that you wish Prosody to trust.
16878 Similar to @code{capath} but with all certificates concatenated together.
16881 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
16882 A list of verification options (these mostly map to OpenSSL's
16883 @code{set_verify()} flags).
16886 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
16887 A list of general options relating to SSL/TLS. These map to OpenSSL's
16888 @code{set_options()}. For a full list of options available in LuaSec, see the
16892 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
16893 How long a chain of certificate authorities to check when looking for a
16894 trusted root certificate.
16897 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
16898 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
16899 clients, and in what order.
16902 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
16903 A path to a file containing parameters for Diffie-Hellman key exchange. You
16904 can create such a file with:
16905 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
16908 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
16909 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
16910 @samp{"secp384r1"}.
16913 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
16914 A list of "extra" verification options.
16917 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
16918 Password for encrypted private keys.
16923 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
16924 Whether to force all client-to-server connections to be encrypted or not.
16925 See @url{https://prosody.im/doc/modules/mod_tls}.
16926 Defaults to @samp{#f}.
16929 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
16930 Set of mechanisms that will never be offered. See
16931 @url{https://prosody.im/doc/modules/mod_saslauth}.
16932 Defaults to @samp{("DIGEST-MD5")}.
16935 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
16936 Whether to force all server-to-server connections to be encrypted or not.
16937 See @url{https://prosody.im/doc/modules/mod_tls}.
16938 Defaults to @samp{#f}.
16941 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16942 Whether to require encryption and certificate authentication. This
16943 provides ideal security, but requires servers you communicate with to support
16944 encryption AND present valid, trusted certificates. See
16945 @url{https://prosody.im/doc/s2s#security}.
16946 Defaults to @samp{#f}.
16949 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16950 Many servers don't support encryption or have invalid or self-signed
16951 certificates. You can list domains here that will not be required to
16952 authenticate using certificates. They will be authenticated using DNS. See
16953 @url{https://prosody.im/doc/s2s#security}.
16954 Defaults to @samp{()}.
16957 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16958 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16959 valid certificates for some domains by specifying a list here. See
16960 @url{https://prosody.im/doc/s2s#security}.
16961 Defaults to @samp{()}.
16964 @deftypevr {@code{prosody-configuration} parameter} string authentication
16965 Select the authentication backend to use. The default provider stores
16966 passwords in plaintext and uses Prosody's configured data storage to store the
16967 authentication data. If you do not trust your server please see
16968 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16969 about using the hashed backend. See also
16970 @url{https://prosody.im/doc/authentication}
16971 Defaults to @samp{"internal_plain"}.
16974 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16975 Set logging options. Advanced logging configuration is not yet supported
16976 by the Prosody service. See @url{https://prosody.im/doc/logging}.
16977 Defaults to @samp{"*syslog"}.
16980 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16981 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16982 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16985 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16986 Maximum allowed size of the HTTP body (in bytes).
16989 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16990 Some modules expose their own URL in various ways. This URL is built
16991 from the protocol, host and port used. If Prosody sits behind a proxy, the
16992 public URL will be @code{http-external-url} instead. See
16993 @url{https://prosody.im/doc/http#external_url}.
16996 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16997 A host in Prosody is a domain on which user accounts can be created. For
16998 example if you want your users to have addresses like
16999 @samp{"john.smith@@example.com"} then you need to add a host
17000 @samp{"example.com"}. All options in this list will apply only to this host.
17002 Note: the name "virtual" host is used in configuration to avoid confusion with
17003 the actual physical host that Prosody is installed on. A single Prosody
17004 instance can serve many domains, each one defined as a VirtualHost entry in
17005 Prosody's configuration. Conversely a server that hosts a single domain would
17006 have just one VirtualHost entry.
17008 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17010 Available @code{virtualhost-configuration} fields are:
17012 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
17013 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17014 Domain you wish Prosody to serve.
17019 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17020 Components are extra services on a server which are available to clients,
17021 usually on a subdomain of the main server (such as
17022 @samp{"mycomponent.example.com"}). Example components might be chatroom
17023 servers, user directories, or gateways to other protocols.
17025 Internal components are implemented with Prosody-specific plugins. To add an
17026 internal component, you simply fill the hostname field, and the plugin you wish
17027 to use for the component.
17029 See @url{https://prosody.im/doc/components}.
17030 Defaults to @samp{()}.
17032 Available @code{int-component-configuration} fields are:
17034 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
17035 @deftypevr {@code{int-component-configuration} parameter} string hostname
17036 Hostname of the component.
17039 @deftypevr {@code{int-component-configuration} parameter} string plugin
17040 Plugin you wish to use for the component.
17043 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17044 Multi-user chat (MUC) is Prosody's module for allowing you to create
17045 hosted chatrooms/conferences for XMPP users.
17047 General information on setting up and using multi-user chatrooms can be found
17048 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17049 which you should read if you are new to XMPP chatrooms.
17051 See also @url{https://prosody.im/doc/modules/mod_muc}.
17053 Available @code{mod-muc-configuration} fields are:
17055 @deftypevr {@code{mod-muc-configuration} parameter} string name
17056 The name to return in service discovery responses.
17057 Defaults to @samp{"Prosody Chatrooms"}.
17060 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17061 If @samp{#t}, this will only allow admins to create new chatrooms.
17062 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17063 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17064 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17065 restricts to service administrators only.
17066 Defaults to @samp{#f}.
17069 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17070 Maximum number of history messages that will be sent to the member that has
17071 just joined the room.
17072 Defaults to @samp{20}.
17079 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17080 External components use XEP-0114, which most standalone components
17081 support. To add an external component, you simply fill the hostname field. See
17082 @url{https://prosody.im/doc/components}.
17083 Defaults to @samp{()}.
17085 Available @code{ext-component-configuration} fields are:
17087 all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
17088 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17089 Password which the component will use to log in.
17092 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17093 Hostname of the component.
17098 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17099 Port(s) Prosody listens on for component connections.
17100 Defaults to @samp{(5347)}.
17103 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17104 Interface Prosody listens on for component connections.
17105 Defaults to @samp{"127.0.0.1"}.
17108 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17109 Raw content that will be added to the configuration file.
17112 It could be that you just want to get a @code{prosody.cfg.lua}
17113 up and running. In that case, you can pass an
17114 @code{opaque-prosody-configuration} record as the value of
17115 @code{prosody-service-type}. As its name indicates, an opaque configuration
17116 does not have easy reflective capabilities.
17117 Available @code{opaque-prosody-configuration} fields are:
17119 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17120 The prosody package.
17123 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17124 The contents of the @code{prosody.cfg.lua} to use.
17127 For example, if your @code{prosody.cfg.lua} is just the empty
17128 string, you could instantiate a prosody service like this:
17131 (service prosody-service-type
17132 (opaque-prosody-configuration
17133 (prosody.cfg.lua "")))
17136 @c end of Prosody auto-generated documentation
17138 @subsubheading BitlBee Service
17140 @cindex IRC (Internet Relay Chat)
17141 @cindex IRC gateway
17142 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
17143 interface to a variety of messaging protocols such as XMPP.
17145 @defvr {Scheme Variable} bitlbee-service-type
17146 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
17147 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17150 To have BitlBee listen on port 6667 on localhost, add this line to your
17154 (service bitlbee-service-type)
17158 @deftp {Data Type} bitlbee-configuration
17159 This is the configuration for BitlBee, with the following fields:
17162 @item @code{interface} (default: @code{"127.0.0.1"})
17163 @itemx @code{port} (default: @code{6667})
17164 Listen on the network interface corresponding to the IP address
17165 specified in @var{interface}, on @var{port}.
17167 When @var{interface} is @code{127.0.0.1}, only local clients can
17168 connect; when it is @code{0.0.0.0}, connections can come from any
17169 networking interface.
17171 @item @code{package} (default: @code{bitlbee})
17172 The BitlBee package to use.
17174 @item @code{plugins} (default: @code{'()})
17175 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17177 @item @code{extra-settings} (default: @code{""})
17178 Configuration snippet added as-is to the BitlBee configuration file.
17182 @subsubheading Quassel Service
17184 @cindex IRC (Internet Relay Chat)
17185 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17186 meaning that one or more clients can attach to and detach from the
17189 @defvr {Scheme Variable} quassel-service-type
17190 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17191 IRC backend daemon. Its value is a @code{quassel-configuration}
17195 @deftp {Data Type} quassel-configuration
17196 This is the configuration for Quassel, with the following fields:
17199 @item @code{quassel} (default: @code{quassel})
17200 The Quassel package to use.
17202 @item @code{interface} (default: @code{"::,0.0.0.0"})
17203 @item @code{port} (default: @code{4242})
17204 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17205 interfaces specified in the comma delimited @var{interface}, on
17208 @item @code{loglevel} (default: @code{"Info"})
17209 The level of logging desired. Accepted values are Debug, Info, Warning
17214 @node Telephony Services
17215 @subsection Telephony Services
17217 @cindex Murmur (VoIP server)
17218 @cindex VoIP server
17219 This section describes how to set up and run a Murmur server. Murmur is
17220 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17223 @deftp {Data Type} murmur-configuration
17224 The service type for the Murmur server. An example configuration can
17228 (service murmur-service-type
17229 (murmur-configuration
17231 "Welcome to this Mumble server running on Guix!")
17232 (cert-required? #t) ;disallow text password logins
17233 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17234 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17237 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17238 password with the command that is printed during the activation phase.
17240 It is recommended to register a normal Mumble user account
17241 and grant it admin or moderator rights.
17242 You can use the @code{mumble} client to
17243 login as new normal user, register yourself, and log out.
17244 For the next step login with the name @code{SuperUser} use
17245 the @code{SuperUser} password that you set previously,
17246 and grant your newly registered mumble user administrator or moderator
17247 rights and create some channels.
17249 Available @code{murmur-configuration} fields are:
17252 @item @code{package} (default: @code{mumble})
17253 Package that contains @code{bin/murmurd}.
17255 @item @code{user} (default: @code{"murmur"})
17256 User who will run the Murmur server.
17258 @item @code{group} (default: @code{"murmur"})
17259 Group of the user who will run the murmur server.
17261 @item @code{port} (default: @code{64738})
17262 Port on which the server will listen.
17264 @item @code{welcome-text} (default: @code{""})
17265 Welcome text sent to clients when they connect.
17267 @item @code{server-password} (default: @code{""})
17268 Password the clients have to enter in order to connect.
17270 @item @code{max-users} (default: @code{100})
17271 Maximum of users that can be connected to the server at once.
17273 @item @code{max-user-bandwidth} (default: @code{#f})
17274 Maximum voice traffic a user can send per second.
17276 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17277 File name of the sqlite database.
17278 The service's user will become the owner of the directory.
17280 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17281 File name of the log file.
17282 The service's user will become the owner of the directory.
17284 @item @code{autoban-attempts} (default: @code{10})
17285 Maximum number of logins a user can make in @code{autoban-timeframe}
17286 without getting auto banned for @code{autoban-time}.
17288 @item @code{autoban-timeframe} (default: @code{120})
17289 Timeframe for autoban in seconds.
17291 @item @code{autoban-time} (default: @code{300})
17292 Amount of time in seconds for which a client gets banned
17293 when violating the autoban limits.
17295 @item @code{opus-threshold} (default: @code{100})
17296 Percentage of clients that need to support opus
17297 before switching over to opus audio codec.
17299 @item @code{channel-nesting-limit} (default: @code{10})
17300 How deep channels can be nested at maximum.
17302 @item @code{channelname-regex} (default: @code{#f})
17303 A string in form of a Qt regular expression that channel names must conform to.
17305 @item @code{username-regex} (default: @code{#f})
17306 A string in form of a Qt regular expression that user names must conform to.
17308 @item @code{text-message-length} (default: @code{5000})
17309 Maximum size in bytes that a user can send in one text chat message.
17311 @item @code{image-message-length} (default: @code{(* 128 1024)})
17312 Maximum size in bytes that a user can send in one image message.
17314 @item @code{cert-required?} (default: @code{#f})
17315 If it is set to @code{#t} clients that use weak password authentification
17316 will not be accepted. Users must have completed the certificate wizard to join.
17318 @item @code{remember-channel?} (default: @code{#f})
17319 Should murmur remember the last channel each user was in when they disconnected
17320 and put them into the remembered channel when they rejoin.
17322 @item @code{allow-html?} (default: @code{#f})
17323 Should html be allowed in text messages, user comments, and channel descriptions.
17325 @item @code{allow-ping?} (default: @code{#f})
17326 Setting to true exposes the current user count, the maximum user count, and
17327 the server's maximum bandwidth per client to unauthenticated users. In the
17328 Mumble client, this information is shown in the Connect dialog.
17330 Disabling this setting will prevent public listing of the server.
17332 @item @code{bonjour?} (default: @code{#f})
17333 Should the server advertise itself in the local network through the bonjour protocol.
17335 @item @code{send-version?} (default: @code{#f})
17336 Should the murmur server version be exposed in ping requests.
17338 @item @code{log-days} (default: @code{31})
17339 Murmur also stores logs in the database, which are accessible via RPC.
17340 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17341 or -1 to disable logging to the database.
17343 @item @code{obfuscate-ips?} (default: @code{#t})
17344 Should logged ips be obfuscated to protect the privacy of users.
17346 @item @code{ssl-cert} (default: @code{#f})
17347 File name of the SSL/TLS certificate used for encrypted connections.
17350 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17352 @item @code{ssl-key} (default: @code{#f})
17353 Filepath to the ssl private key used for encrypted connections.
17355 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17358 @item @code{ssl-dh-params} (default: @code{#f})
17359 File name of a PEM-encoded file with Diffie-Hellman parameters
17360 for the SSL/TLS encryption. Alternatively you set it to
17361 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17362 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17364 @item @code{ssl-ciphers} (default: @code{#f})
17365 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17368 This option is specified using
17369 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17370 OpenSSL cipher list notation}.
17372 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17373 before setting it here, to get a feel for which cipher suites you will get.
17374 After setting this option, it is recommend that you inspect your Murmur log
17375 to ensure that Murmur is using the cipher suites that you expected it to.
17377 Note: Changing this option may impact the backwards compatibility of your
17378 Murmur server, and can remove the ability for older Mumble clients to be able
17381 @item @code{public-registration} (default: @code{#f})
17382 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17384 You can optionally register your server in the public server list that the
17385 @code{mumble} client shows on startup.
17386 You cannot register your server if you have set a @code{server-password},
17387 or set @code{allow-ping} to @code{#f}.
17389 It might take a few hours until it shows up in the public list.
17391 @item @code{file} (default: @code{#f})
17392 Optional alternative override for this configuration.
17396 @deftp {Data Type} murmur-public-registration-configuration
17397 Configuration for public registration of a murmur service.
17401 This is a display name for your server. Not to be confused with the hostname.
17403 @item @code{password}
17404 A password to identify your registration.
17405 Subsequent updates will need the same password. Don't lose your password.
17408 This should be a @code{http://} or @code{https://} link to your web
17411 @item @code{hostname} (default: @code{#f})
17412 By default your server will be listed by its IP address.
17413 If it is set your server will be linked by this host name instead.
17419 @node Monitoring Services
17420 @subsection Monitoring Services
17422 @subsubheading Tailon Service
17424 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17425 viewing and searching log files.
17427 The following example will configure the service with default values.
17428 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17431 (service tailon-service-type)
17434 The following example customises more of the Tailon configuration,
17435 adding @command{sed} to the list of allowed commands.
17438 (service tailon-service-type
17439 (tailon-configuration
17441 (tailon-configuration-file
17442 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17446 @deftp {Data Type} tailon-configuration
17447 Data type representing the configuration of Tailon.
17448 This type has the following parameters:
17451 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17452 The configuration file to use for Tailon. This can be set to a
17453 @dfn{tailon-configuration-file} record value, or any gexp
17454 (@pxref{G-Expressions}).
17456 For example, to instead use a local file, the @code{local-file} function
17460 (service tailon-service-type
17461 (tailon-configuration
17462 (config-file (local-file "./my-tailon.conf"))))
17465 @item @code{package} (default: @code{tailon})
17466 The tailon package to use.
17471 @deftp {Data Type} tailon-configuration-file
17472 Data type representing the configuration options for Tailon.
17473 This type has the following parameters:
17476 @item @code{files} (default: @code{(list "/var/log")})
17477 List of files to display. The list can include strings for a single file
17478 or directory, or a list, where the first item is the name of a
17479 subsection, and the remaining items are the files or directories in that
17482 @item @code{bind} (default: @code{"localhost:8080"})
17483 Address and port to which Tailon should bind on.
17485 @item @code{relative-root} (default: @code{#f})
17486 URL path to use for Tailon, set to @code{#f} to not use a path.
17488 @item @code{allow-transfers?} (default: @code{#t})
17489 Allow downloading the log files in the web interface.
17491 @item @code{follow-names?} (default: @code{#t})
17492 Allow tailing of not-yet existent files.
17494 @item @code{tail-lines} (default: @code{200})
17495 Number of lines to read initially from each file.
17497 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17498 Commands to allow running. By default, @code{sed} is disabled.
17500 @item @code{debug?} (default: @code{#f})
17501 Set @code{debug?} to @code{#t} to show debug messages.
17503 @item @code{wrap-lines} (default: @code{#t})
17504 Initial line wrapping state in the web interface. Set to @code{#t} to
17505 initially wrap lines (the default), or to @code{#f} to initially not
17508 @item @code{http-auth} (default: @code{#f})
17509 HTTP authentication type to use. Set to @code{#f} to disable
17510 authentication (the default). Supported values are @code{"digest"} or
17513 @item @code{users} (default: @code{#f})
17514 If HTTP authentication is enabled (see @code{http-auth}), access will be
17515 restricted to the credentials provided here. To configure users, use a
17516 list of pairs, where the first element of the pair is the username, and
17517 the 2nd element of the pair is the password.
17520 (tailon-configuration-file
17521 (http-auth "basic")
17522 (users '(("user1" . "password1")
17523 ("user2" . "password2"))))
17530 @subsubheading Darkstat Service
17532 Darkstat is a packet sniffer that captures network traffic, calculates
17533 statistics about usage, and serves reports over HTTP.
17535 @defvar {Scheme Variable} darkstat-service-type
17536 This is the service type for the
17537 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17538 service, its value must be a @code{darkstat-configuration} record as in
17542 (service darkstat-service-type
17543 (darkstat-configuration
17544 (interface "eno1")))
17548 @deftp {Data Type} darkstat-configuration
17549 Data type representing the configuration of @command{darkstat}.
17552 @item @code{package} (default: @code{darkstat})
17553 The darkstat package to use.
17555 @item @code{interface}
17556 Capture traffic on the specified network interface.
17558 @item @code{port} (default: @code{"667"})
17559 Bind the web interface to the specified port.
17561 @item @code{bind-address} (default: @code{"127.0.0.1"})
17562 Bind the web interface to the specified address.
17564 @item @code{base} (default: @code{"/"})
17565 Specify the path of the base URL. This can be useful if
17566 @command{darkstat} is accessed via a reverse proxy.
17571 @subsubheading Prometheus Node Exporter Service
17573 @cindex prometheus-node-exporter
17574 The Prometheus ``node exporter'' makes hardware and operating system statistics
17575 provided by the Linux kernel available for the Prometheus monitoring system.
17576 This service should be deployed on all physical nodes and virtual machines,
17577 where monitoring these statistics is desirable.
17579 @defvar {Scheme variable} prometheus-node-exporter-service-type
17580 This is the service type for the
17581 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
17582 service, its value must be a @code{prometheus-node-exporter-configuration}
17583 record as in this example:
17586 (service prometheus-node-exporter-service-type
17587 (prometheus-node-exporter-configuration
17588 (web-listen-address ":9100")))
17592 @deftp {Data Type} prometheus-node-exporter-configuration
17593 Data type representing the configuration of @command{node_exporter}.
17596 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
17597 The prometheus-node-exporter package to use.
17599 @item @code{web-listen-address} (default: @code{":9100"})
17600 Bind the web interface to the specified address.
17605 @subsubheading Zabbix server
17606 @cindex zabbix zabbix-server
17607 Zabbix provides monitoring metrics, among others network utilization, CPU load
17608 and disk space consumption:
17611 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
17612 @item Auto-discovery of servers and network devices and interfaces.
17613 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
17614 @item Distributed monitoring with centralized web administration.
17615 @item Native high performance agents.
17616 @item SLA, and ITIL KPI metrics on reporting.
17617 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
17618 @item Remote command execution through Zabbix proxies.
17621 @c %start of fragment
17623 Available @code{zabbix-server-configuration} fields are:
17625 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
17626 The zabbix-server package.
17630 @deftypevr {@code{zabbix-server-configuration} parameter} string user
17631 User who will run the Zabbix server.
17633 Defaults to @samp{"zabbix"}.
17637 @deftypevr {@code{zabbix-server-configuration} parameter} group group
17638 Group who will run the Zabbix server.
17640 Defaults to @samp{"zabbix"}.
17644 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
17645 Database host name.
17647 Defaults to @samp{"127.0.0.1"}.
17651 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
17654 Defaults to @samp{"zabbix"}.
17658 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
17661 Defaults to @samp{"zabbix"}.
17665 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
17666 Database password. Please, use @code{include-files} with
17667 @code{DBPassword=SECRET} inside a specified file instead.
17669 Defaults to @samp{""}.
17673 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
17676 Defaults to @samp{5432}.
17680 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
17681 Specifies where log messages are written to:
17685 @code{system} - syslog.
17688 @code{file} - file specified with @code{log-file} parameter.
17691 @code{console} - standard output.
17695 Defaults to @samp{""}.
17699 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
17700 Log file name for @code{log-type} @code{file} parameter.
17702 Defaults to @samp{"/var/log/zabbix/server.log"}.
17706 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
17709 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
17713 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
17714 The location of certificate authority (CA) files for SSL server
17715 certificate verification.
17717 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
17721 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
17722 Location of SSL client certificates.
17724 Defaults to @samp{"/etc/ssl/certs"}.
17728 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
17729 Extra options will be appended to Zabbix server configuration file.
17731 Defaults to @samp{""}.
17735 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
17736 You may include individual files or all files in a directory in the
17737 configuration file.
17739 Defaults to @samp{()}.
17743 @c %end of fragment
17745 @subsubheading Zabbix agent
17746 @cindex zabbix zabbix-agent
17748 Zabbix agent gathers information for Zabbix server.
17750 @c %start of fragment
17752 Available @code{zabbix-agent-configuration} fields are:
17754 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
17755 The zabbix-agent package.
17759 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
17760 User who will run the Zabbix agent.
17762 Defaults to @samp{"zabbix"}.
17766 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
17767 Group who will run the Zabbix agent.
17769 Defaults to @samp{"zabbix"}.
17773 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
17774 Unique, case sensitive hostname which is required for active checks and
17775 must match hostname as configured on the server.
17777 Defaults to @samp{"Zabbix server"}.
17781 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
17782 Specifies where log messages are written to:
17786 @code{system} - syslog.
17789 @code{file} - file specified with @code{log-file} parameter.
17792 @code{console} - standard output.
17796 Defaults to @samp{""}.
17800 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
17801 Log file name for @code{log-type} @code{file} parameter.
17803 Defaults to @samp{"/var/log/zabbix/agent.log"}.
17807 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
17810 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
17814 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
17815 List of IP addresses, optionally in CIDR notation, or hostnames of
17816 Zabbix servers and Zabbix proxies. Incoming connections will be
17817 accepted only from the hosts listed here.
17819 Defaults to @samp{("127.0.0.1")}.
17823 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
17824 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
17825 proxies for active checks. If port is not specified, default port is
17826 used. If this parameter is not specified, active checks are disabled.
17828 Defaults to @samp{("127.0.0.1")}.
17832 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
17833 Extra options will be appended to Zabbix server configuration file.
17835 Defaults to @samp{""}.
17839 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
17840 You may include individual files or all files in a directory in the
17841 configuration file.
17843 Defaults to @samp{()}.
17847 @c %end of fragment
17849 @subsubheading Zabbix front-end
17850 @cindex zabbix zabbix-front-end
17852 This service provides a WEB interface to Zabbix server.
17854 @c %start of fragment
17856 Available @code{zabbix-front-end-configuration} fields are:
17858 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
17859 NGINX configuration.
17863 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
17864 Database host name.
17866 Defaults to @samp{"localhost"}.
17870 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
17873 Defaults to @samp{5432}.
17877 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
17880 Defaults to @samp{"zabbix"}.
17884 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
17887 Defaults to @samp{"zabbix"}.
17891 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
17892 Database password. Please, use @code{db-secret-file} instead.
17894 Defaults to @samp{""}.
17898 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
17899 Secret file which will be appended to @file{zabbix.conf.php} file. This
17900 file contains credentials for use by Zabbix front-end. You are expected
17901 to create it manually.
17903 Defaults to @samp{""}.
17907 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
17908 Zabbix server hostname.
17910 Defaults to @samp{"localhost"}.
17914 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
17915 Zabbix server port.
17917 Defaults to @samp{10051}.
17922 @c %end of fragment
17924 @node Kerberos Services
17925 @subsection Kerberos Services
17928 The @code{(gnu services kerberos)} module provides services relating to
17929 the authentication protocol @dfn{Kerberos}.
17931 @subsubheading Krb5 Service
17933 Programs using a Kerberos client library normally
17934 expect a configuration file in @file{/etc/krb5.conf}.
17935 This service generates such a file from a definition provided in the
17936 operating system declaration.
17937 It does not cause any daemon to be started.
17939 No ``keytab'' files are provided by this service---you must explicitly create them.
17940 This service is known to work with the MIT client library, @code{mit-krb5}.
17941 Other implementations have not been tested.
17943 @defvr {Scheme Variable} krb5-service-type
17944 A service type for Kerberos 5 clients.
17948 Here is an example of its use:
17950 (service krb5-service-type
17951 (krb5-configuration
17952 (default-realm "EXAMPLE.COM")
17953 (allow-weak-crypto? #t)
17956 (name "EXAMPLE.COM")
17957 (admin-server "groucho.example.com")
17958 (kdc "karl.example.com"))
17961 (admin-server "kerb-admin.argrx.edu")
17962 (kdc "keys.argrx.edu"))))))
17966 This example provides a Kerberos@tie{}5 client configuration which:
17968 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
17969 of which have distinct administration servers and key distribution centers;
17970 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
17971 specified by clients;
17972 @item Accepts services which only support encryption types known to be weak.
17975 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
17976 Only the most commonly used ones are described here.
17977 For a full list, and more detailed explanation of each, see the MIT
17978 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
17982 @deftp {Data Type} krb5-realm
17983 @cindex realm, kerberos
17986 This field is a string identifying the name of the realm.
17987 A common convention is to use the fully qualified DNS name of your organization,
17988 converted to upper case.
17990 @item @code{admin-server}
17991 This field is a string identifying the host where the administration server is
17995 This field is a string identifying the key distribution center
18000 @deftp {Data Type} krb5-configuration
18003 @item @code{allow-weak-crypto?} (default: @code{#f})
18004 If this flag is @code{#t} then services which only offer encryption algorithms
18005 known to be weak will be accepted.
18007 @item @code{default-realm} (default: @code{#f})
18008 This field should be a string identifying the default Kerberos
18009 realm for the client.
18010 You should set this field to the name of your Kerberos realm.
18011 If this value is @code{#f}
18012 then a realm must be specified with every Kerberos principal when invoking programs
18013 such as @command{kinit}.
18015 @item @code{realms}
18016 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18018 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18024 @subsubheading PAM krb5 Service
18027 The @code{pam-krb5} service allows for login authentication and password
18028 management via Kerberos.
18029 You will need this service if you want PAM enabled applications to authenticate
18030 users using Kerberos.
18032 @defvr {Scheme Variable} pam-krb5-service-type
18033 A service type for the Kerberos 5 PAM module.
18036 @deftp {Data Type} pam-krb5-configuration
18037 Data type representing the configuration of the Kerberos 5 PAM module
18038 This type has the following parameters:
18040 @item @code{pam-krb5} (default: @code{pam-krb5})
18041 The pam-krb5 package to use.
18043 @item @code{minimum-uid} (default: @code{1000})
18044 The smallest user ID for which Kerberos authentications should be attempted.
18045 Local accounts with lower values will silently fail to authenticate.
18050 @node LDAP Services
18051 @subsection LDAP Services
18053 @cindex nslcd, LDAP service
18055 The @code{(gnu services authentication)} module provides the
18056 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18057 server. In addition to configuring the service itself, you may want to add
18058 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18059 Switch} for detailed information.
18061 Here is a simple operating system declaration with a default configuration of
18062 the @code{nslcd-service-type} and a Name Service Switch configuration that
18063 consults the @code{ldap} name service last:
18066 (use-service-modules authentication)
18067 (use-modules (gnu system nss))
18073 (service nslcd-service-type)
18074 (service dhcp-client-service-type)
18076 (name-service-switch
18077 (let ((services (list (name-service (name "db"))
18078 (name-service (name "files"))
18079 (name-service (name "ldap")))))
18080 (name-service-switch
18081 (inherit %mdns-host-lookup-nss)
18082 (password services)
18085 (netgroup services)
18086 (gshadow services)))))
18089 @c %start of generated documentation for nslcd-configuration
18091 Available @code{nslcd-configuration} fields are:
18093 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18094 The @code{nss-pam-ldapd} package to use.
18098 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18099 The number of threads to start that can handle requests and perform LDAP
18100 queries. Each thread opens a separate connection to the LDAP server.
18101 The default is to start 5 threads.
18103 Defaults to @samp{disabled}.
18107 @deftypevr {@code{nslcd-configuration} parameter} string uid
18108 This specifies the user id with which the daemon should be run.
18110 Defaults to @samp{"nslcd"}.
18114 @deftypevr {@code{nslcd-configuration} parameter} string gid
18115 This specifies the group id with which the daemon should be run.
18117 Defaults to @samp{"nslcd"}.
18121 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18122 This option controls the way logging is done via a list containing
18123 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18124 or "syslog", or an absolute file name. The LEVEL argument is optional
18125 and specifies the log level. The log level may be one of the following
18126 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18127 messages with the specified log level or higher are logged.
18129 Defaults to @samp{("/var/log/nslcd" info)}.
18133 @deftypevr {@code{nslcd-configuration} parameter} list uri
18134 The list of LDAP server URIs. Normally, only the first server will be
18135 used with the following servers as fall-back.
18137 Defaults to @samp{("ldap://localhost:389/")}.
18141 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18142 The version of the LDAP protocol to use. The default is to use the
18143 maximum version supported by the LDAP library.
18145 Defaults to @samp{disabled}.
18149 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18150 Specifies the distinguished name with which to bind to the directory
18151 server for lookups. The default is to bind anonymously.
18153 Defaults to @samp{disabled}.
18157 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18158 Specifies the credentials with which to bind. This option is only
18159 applicable when used with binddn.
18161 Defaults to @samp{disabled}.
18165 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18166 Specifies the distinguished name to use when the root user tries to
18167 modify a user's password using the PAM module.
18169 Defaults to @samp{disabled}.
18173 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18174 Specifies the credentials with which to bind if the root user tries to
18175 change a user's password. This option is only applicable when used with
18178 Defaults to @samp{disabled}.
18182 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18183 Specifies the SASL mechanism to be used when performing SASL
18186 Defaults to @samp{disabled}.
18190 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18191 Specifies the SASL realm to be used when performing SASL authentication.
18193 Defaults to @samp{disabled}.
18197 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18198 Specifies the authentication identity to be used when performing SASL
18201 Defaults to @samp{disabled}.
18205 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18206 Specifies the authorization identity to be used when performing SASL
18209 Defaults to @samp{disabled}.
18213 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18214 Determines whether the LDAP server host name should be canonicalised. If
18215 this is enabled the LDAP library will do a reverse host name lookup. By
18216 default, it is left up to the LDAP library whether this check is
18219 Defaults to @samp{disabled}.
18223 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18224 Set the name for the GSS-API Kerberos credentials cache.
18226 Defaults to @samp{disabled}.
18230 @deftypevr {@code{nslcd-configuration} parameter} string base
18231 The directory search base.
18233 Defaults to @samp{"dc=example,dc=com"}.
18237 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18238 Specifies the search scope (subtree, onelevel, base or children). The
18239 default scope is subtree; base scope is almost never useful for name
18240 service lookups; children scope is not supported on all servers.
18242 Defaults to @samp{(subtree)}.
18246 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18247 Specifies the policy for dereferencing aliases. The default policy is
18248 to never dereference aliases.
18250 Defaults to @samp{disabled}.
18254 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18255 Specifies whether automatic referral chasing should be enabled. The
18256 default behaviour is to chase referrals.
18258 Defaults to @samp{disabled}.
18262 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18263 This option allows for custom attributes to be looked up instead of the
18264 default RFC 2307 attributes. It is a list of maps, each consisting of
18265 the name of a map, the RFC 2307 attribute to match and the query
18266 expression for the attribute as it is available in the directory.
18268 Defaults to @samp{()}.
18272 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18273 A list of filters consisting of the name of a map to which the filter
18274 applies and an LDAP search filter expression.
18276 Defaults to @samp{()}.
18280 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18281 Specifies the time limit in seconds to use when connecting to the
18282 directory server. The default value is 10 seconds.
18284 Defaults to @samp{disabled}.
18288 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18289 Specifies the time limit (in seconds) to wait for a response from the
18290 LDAP server. A value of zero, which is the default, is to wait
18291 indefinitely for searches to be completed.
18293 Defaults to @samp{disabled}.
18297 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18298 Specifies the period if inactivity (in seconds) after which the con‐
18299 nection to the LDAP server will be closed. The default is not to time
18302 Defaults to @samp{disabled}.
18306 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18307 Specifies the number of seconds to sleep when connecting to all LDAP
18308 servers fails. By default one second is waited between the first
18309 failure and the first retry.
18311 Defaults to @samp{disabled}.
18315 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18316 Specifies the time after which the LDAP server is considered to be
18317 permanently unavailable. Once this time is reached retries will be done
18318 only once per this time period. The default value is 10 seconds.
18320 Defaults to @samp{disabled}.
18324 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18325 Specifies whether to use SSL/TLS or not (the default is not to). If
18326 'start-tls is specified then StartTLS is used rather than raw LDAP over
18329 Defaults to @samp{disabled}.
18333 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18334 Specifies what checks to perform on a server-supplied certificate. The
18335 meaning of the values is described in the ldap.conf(5) manual page.
18337 Defaults to @samp{disabled}.
18341 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18342 Specifies the directory containing X.509 certificates for peer authen‐
18343 tication. This parameter is ignored when using GnuTLS.
18345 Defaults to @samp{disabled}.
18349 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18350 Specifies the path to the X.509 certificate for peer authentication.
18352 Defaults to @samp{disabled}.
18356 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18357 Specifies the path to an entropy source. This parameter is ignored when
18360 Defaults to @samp{disabled}.
18364 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18365 Specifies the ciphers to use for TLS as a string.
18367 Defaults to @samp{disabled}.
18371 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18372 Specifies the path to the file containing the local certificate for
18373 client TLS authentication.
18375 Defaults to @samp{disabled}.
18379 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18380 Specifies the path to the file containing the private key for client TLS
18383 Defaults to @samp{disabled}.
18387 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18388 Set this to a number greater than 0 to request paged results from the
18389 LDAP server in accordance with RFC2696. The default (0) is to not
18390 request paged results.
18392 Defaults to @samp{disabled}.
18396 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18397 This option prevents group membership lookups through LDAP for the
18398 specified users. Alternatively, the value 'all-local may be used. With
18399 that value nslcd builds a full list of non-LDAP users on startup.
18401 Defaults to @samp{disabled}.
18405 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18406 This option ensures that LDAP users with a numeric user id lower than
18407 the specified value are ignored.
18409 Defaults to @samp{disabled}.
18413 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18414 This option specifies an offset that is added to all LDAP numeric user
18415 ids. This can be used to avoid user id collisions with local users.
18417 Defaults to @samp{disabled}.
18421 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18422 This option specifies an offset that is added to all LDAP numeric group
18423 ids. This can be used to avoid user id collisions with local groups.
18425 Defaults to @samp{disabled}.
18429 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18430 If this option is set, the member attribute of a group may point to
18431 another group. Members of nested groups are also returned in the higher
18432 level group and parent groups are returned when finding groups for a
18433 specific user. The default is not to perform extra searches for nested
18436 Defaults to @samp{disabled}.
18440 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18441 If this option is set, the group member list is not retrieved when
18442 looking up groups. Lookups for finding which groups a user belongs to
18443 will remain functional so the user will likely still get the correct
18444 groups assigned on login.
18446 Defaults to @samp{disabled}.
18450 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18451 If this option is set, functions which cause all user/group entries to
18452 be loaded from the directory will not succeed in doing so. This can
18453 dramatically reduce LDAP server load in situations where there are a
18454 great number of users and/or groups. This option is not recommended for
18455 most configurations.
18457 Defaults to @samp{disabled}.
18461 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18462 This option can be used to specify how user and group names are verified
18463 within the system. This pattern is used to check all user and group
18464 names that are requested and returned from LDAP.
18466 Defaults to @samp{disabled}.
18470 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18471 This specifies whether or not to perform searches using case-insensitive
18472 matching. Enabling this could open up the system to authorization
18473 bypass vulnerabilities and introduce nscd cache poisoning
18474 vulnerabilities which allow denial of service.
18476 Defaults to @samp{disabled}.
18480 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18481 This option specifies whether password policy controls are requested and
18482 handled from the LDAP server when performing user authentication.
18484 Defaults to @samp{disabled}.
18488 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18489 By default nslcd performs an LDAP search with the user's credentials
18490 after BIND (authentication) to ensure that the BIND operation was
18491 successful. The default search is a simple check to see if the user's
18492 DN exists. A search filter can be specified that will be used instead.
18493 It should return at least one entry.
18495 Defaults to @samp{disabled}.
18499 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18500 This option allows flexible fine tuning of the authorisation check that
18501 should be performed. The search filter specified is executed and if any
18502 entries match, access is granted, otherwise access is denied.
18504 Defaults to @samp{disabled}.
18508 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18509 If this option is set password modification using pam_ldap will be
18510 denied and the specified message will be presented to the user instead.
18511 The message can be used to direct the user to an alternative means of
18512 changing their password.
18514 Defaults to @samp{disabled}.
18518 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18519 List of pam service names for which LDAP authentication should suffice.
18521 Defaults to @samp{()}.
18525 @c %end of generated documentation for nslcd-configuration
18529 @subsection Web Services
18534 The @code{(gnu services web)} module provides the Apache HTTP Server,
18535 the nginx web server, and also a fastcgi wrapper daemon.
18537 @subsubheading Apache HTTP Server
18539 @deffn {Scheme Variable} httpd-service-type
18540 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18541 (@dfn{httpd}). The value for this service type is a
18542 @code{httpd-configuration} record.
18544 A simple example configuration is given below.
18547 (service httpd-service-type
18548 (httpd-configuration
18551 (server-name "www.example.com")
18552 (document-root "/srv/http/www.example.com")))))
18555 Other services can also extend the @code{httpd-service-type} to add to
18559 (simple-service 'my-extra-server httpd-service-type
18563 (list (string-append
18564 "ServerName "www.example.com
18565 DocumentRoot \"/srv/http/www.example.com\"")))))
18569 The details for the @code{httpd-configuration}, @code{httpd-module},
18570 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
18573 @deffn {Data Type} httpd-configuration
18574 This data type represents the configuration for the httpd service.
18577 @item @code{package} (default: @code{httpd})
18578 The httpd package to use.
18580 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18581 The pid file used by the shepherd-service.
18583 @item @code{config} (default: @code{(httpd-config-file)})
18584 The configuration file to use with the httpd service. The default value
18585 is a @code{httpd-config-file} record, but this can also be a different
18586 G-expression that generates a file, for example a @code{plain-file}. A
18587 file outside of the store can also be specified through a string.
18592 @deffn {Data Type} httpd-module
18593 This data type represents a module for the httpd service.
18597 The name of the module.
18600 The file for the module. This can be relative to the httpd package being
18601 used, the absolute location of a file, or a G-expression for a file
18602 within the store, for example @code{(file-append mod-wsgi
18603 "/modules/mod_wsgi.so")}.
18608 @defvr {Scheme Variable} %default-httpd-modules
18609 A default list of @code{httpd-module} objects.
18612 @deffn {Data Type} httpd-config-file
18613 This data type represents a configuration file for the httpd service.
18616 @item @code{modules} (default: @code{%default-httpd-modules})
18617 The modules to load. Additional modules can be added here, or loaded by
18618 additional configuration.
18620 For example, in order to handle requests for PHP files, you can use Apache’s
18621 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
18624 (service httpd-service-type
18625 (httpd-configuration
18630 (name "proxy_module")
18631 (file "modules/mod_proxy.so"))
18633 (name "proxy_fcgi_module")
18634 (file "modules/mod_proxy_fcgi.so"))
18635 %default-httpd-modules))
18636 (extra-config (list "\
18637 <FilesMatch \\.php$>
18638 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
18639 </FilesMatch>"))))))
18640 (service php-fpm-service-type
18641 (php-fpm-configuration
18642 (socket "/var/run/php-fpm.sock")
18643 (socket-group "httpd")))
18646 @item @code{server-root} (default: @code{httpd})
18647 The @code{ServerRoot} in the configuration file, defaults to the httpd
18648 package. Directives including @code{Include} and @code{LoadModule} are
18649 taken as relative to the server root.
18651 @item @code{server-name} (default: @code{#f})
18652 The @code{ServerName} in the configuration file, used to specify the
18653 request scheme, hostname and port that the server uses to identify
18656 This doesn't need to be set in the server config, and can be specifyed
18657 in virtual hosts. The default is @code{#f} to not specify a
18660 @item @code{document-root} (default: @code{"/srv/http"})
18661 The @code{DocumentRoot} from which files will be served.
18663 @item @code{listen} (default: @code{'("80")})
18664 The list of values for the @code{Listen} directives in the config
18665 file. The value should be a list of strings, when each string can
18666 specify the port number to listen on, and optionally the IP address and
18669 @item @code{pid-file} (default: @code{"/var/run/httpd"})
18670 The @code{PidFile} to use. This should match the @code{pid-file} set in
18671 the @code{httpd-configuration} so that the Shepherd service is
18672 configured correctly.
18674 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
18675 The @code{ErrorLog} to which the server will log errors.
18677 @item @code{user} (default: @code{"httpd"})
18678 The @code{User} which the server will answer requests as.
18680 @item @code{group} (default: @code{"httpd"})
18681 The @code{Group} which the server will answer requests as.
18683 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
18684 A flat list of strings and G-expressions which will be added to the end
18685 of the configuration file.
18687 Any values which the service is extended with will be appended to this
18693 @deffn {Data Type} httpd-virtualhost
18694 This data type represents a virtualhost configuration block for the httpd service.
18696 These should be added to the extra-config for the httpd-service.
18699 (simple-service 'my-extra-server httpd-service-type
18703 (list (string-append
18704 "ServerName "www.example.com
18705 DocumentRoot \"/srv/http/www.example.com\"")))))
18709 @item @code{addresses-and-ports}
18710 The addresses and ports for the @code{VirtualHost} directive.
18712 @item @code{contents}
18713 The contents of the @code{VirtualHost} directive, this should be a list
18714 of strings and G-expressions.
18719 @subsubheading NGINX
18721 @deffn {Scheme Variable} nginx-service-type
18722 Service type for the @uref{https://nginx.org/,NGinx} web server. The
18723 value for this service type is a @code{<nginx-configuration>} record.
18725 A simple example configuration is given below.
18728 (service nginx-service-type
18729 (nginx-configuration
18731 (list (nginx-server-configuration
18732 (server-name '("www.example.com"))
18733 (root "/srv/http/www.example.com"))))))
18736 In addition to adding server blocks to the service configuration
18737 directly, this service can be extended by other services to add server
18738 blocks, as in this example:
18741 (simple-service 'my-extra-server nginx-service-type
18742 (list (nginx-server-configuration
18743 (root "/srv/http/extra-website")
18744 (try-files (list "$uri" "$uri/index.html")))))
18748 At startup, @command{nginx} has not yet read its configuration file, so
18749 it uses a default file to log error messages. If it fails to load its
18750 configuration file, that is where error messages are logged. After the
18751 configuration file is loaded, the default error log file changes as per
18752 configuration. In our case, startup error messages can be found in
18753 @file{/var/run/nginx/logs/error.log}, and after configuration in
18754 @file{/var/log/nginx/error.log}. The second location can be changed
18755 with the @var{log-directory} configuration option.
18757 @deffn {Data Type} nginx-configuration
18758 This data type represents the configuration for NGinx. Some
18759 configuration can be done through this and the other provided record
18760 types, or alternatively, a config file can be provided.
18763 @item @code{nginx} (default: @code{nginx})
18764 The nginx package to use.
18766 @item @code{log-directory} (default: @code{"/var/log/nginx"})
18767 The directory to which NGinx will write log files.
18769 @item @code{run-directory} (default: @code{"/var/run/nginx"})
18770 The directory in which NGinx will create a pid file, and write temporary
18773 @item @code{server-blocks} (default: @code{'()})
18774 A list of @dfn{server blocks} to create in the generated configuration
18775 file, the elements should be of type
18776 @code{<nginx-server-configuration>}.
18778 The following example would setup NGinx to serve @code{www.example.com}
18779 from the @code{/srv/http/www.example.com} directory, without using
18782 (service nginx-service-type
18783 (nginx-configuration
18785 (list (nginx-server-configuration
18786 (server-name '("www.example.com"))
18787 (root "/srv/http/www.example.com"))))))
18790 @item @code{upstream-blocks} (default: @code{'()})
18791 A list of @dfn{upstream blocks} to create in the generated configuration
18792 file, the elements should be of type
18793 @code{<nginx-upstream-configuration>}.
18795 Configuring upstreams through the @code{upstream-blocks} can be useful
18796 when combined with @code{locations} in the
18797 @code{<nginx-server-configuration>} records. The following example
18798 creates a server configuration with one location configuration, that
18799 will proxy requests to a upstream configuration, which will handle
18800 requests with two servers.
18805 (nginx-configuration
18807 (list (nginx-server-configuration
18808 (server-name '("www.example.com"))
18809 (root "/srv/http/www.example.com")
18812 (nginx-location-configuration
18814 (body '("proxy_pass http://server-proxy;"))))))))
18816 (list (nginx-upstream-configuration
18817 (name "server-proxy")
18818 (servers (list "server1.example.com"
18819 "server2.example.com")))))))
18822 @item @code{file} (default: @code{#f})
18823 If a configuration @var{file} is provided, this will be used, rather than
18824 generating a configuration file from the provided @code{log-directory},
18825 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
18826 proper operation, these arguments should match what is in @var{file} to ensure
18827 that the directories are created when the service is activated.
18829 This can be useful if you have an existing configuration file, or it's
18830 not possible to do what is required through the other parts of the
18831 nginx-configuration record.
18833 @item @code{server-names-hash-bucket-size} (default: @code{#f})
18834 Bucket size for the server names hash tables, defaults to @code{#f} to
18835 use the size of the processors cache line.
18837 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
18838 Maximum bucket size for the server names hash tables.
18840 @item @code{extra-content} (default: @code{""})
18841 Extra content for the @code{http} block. Should be string or a string
18842 valued G-expression.
18847 @deftp {Data Type} nginx-server-configuration
18848 Data type representing the configuration of an nginx server block.
18849 This type has the following parameters:
18852 @item @code{listen} (default: @code{'("80" "443 ssl")})
18853 Each @code{listen} directive sets the address and port for IP, or the
18854 path for a UNIX-domain socket on which the server will accept requests.
18855 Both address and port, or only address or only port can be specified.
18856 An address may also be a hostname, for example:
18859 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
18862 @item @code{server-name} (default: @code{(list 'default)})
18863 A list of server names this server represents. @code{'default} represents the
18864 default server for connections matching no other server.
18866 @item @code{root} (default: @code{"/srv/http"})
18867 Root of the website nginx will serve.
18869 @item @code{locations} (default: @code{'()})
18870 A list of @dfn{nginx-location-configuration} or
18871 @dfn{nginx-named-location-configuration} records to use within this
18874 @item @code{index} (default: @code{(list "index.html")})
18875 Index files to look for when clients ask for a directory. If it cannot be found,
18876 Nginx will send the list of files in the directory.
18878 @item @code{try-files} (default: @code{'()})
18879 A list of files whose existence is checked in the specified order.
18880 @code{nginx} will use the first file it finds to process the request.
18882 @item @code{ssl-certificate} (default: @code{#f})
18883 Where to find the certificate for secure connections. Set it to @code{#f} if
18884 you don't have a certificate or you don't want to use HTTPS.
18886 @item @code{ssl-certificate-key} (default: @code{#f})
18887 Where to find the private key for secure connections. Set it to @code{#f} if
18888 you don't have a key or you don't want to use HTTPS.
18890 @item @code{server-tokens?} (default: @code{#f})
18891 Whether the server should add its configuration to response.
18893 @item @code{raw-content} (default: @code{'()})
18894 A list of raw lines added to the server block.
18899 @deftp {Data Type} nginx-upstream-configuration
18900 Data type representing the configuration of an nginx @code{upstream}
18901 block. This type has the following parameters:
18905 Name for this group of servers.
18907 @item @code{servers}
18908 Specify the addresses of the servers in the group. The address can be
18909 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
18910 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
18911 prefix @samp{unix:}. For addresses using an IP address or domain name,
18912 the default port is 80, and a different port can be specified
18918 @deftp {Data Type} nginx-location-configuration
18919 Data type representing the configuration of an nginx @code{location}
18920 block. This type has the following parameters:
18924 URI which this location block matches.
18926 @anchor{nginx-location-configuration body}
18928 Body of the location block, specified as a list of strings. This can contain
18930 configuration directives. For example, to pass requests to a upstream
18931 server group defined using an @code{nginx-upstream-configuration} block,
18932 the following directive would be specified in the body @samp{(list "proxy_pass
18933 http://upstream-name;")}.
18938 @deftp {Data Type} nginx-named-location-configuration
18939 Data type representing the configuration of an nginx named location
18940 block. Named location blocks are used for request redirection, and not
18941 used for regular request processing. This type has the following
18946 Name to identify this location block.
18949 @xref{nginx-location-configuration body}, as the body for named location
18950 blocks can be used in a similar way to the
18951 @code{nginx-location-configuration body}. One restriction is that the
18952 body of a named location block cannot contain location blocks.
18957 @subsubheading Varnish Cache
18959 Varnish is a fast cache server that sits in between web applications
18960 and end users. It proxies requests from clients and caches the
18961 accessed URLs such that multiple requests for the same resource only
18962 creates one request to the back-end.
18964 @defvr {Scheme Variable} varnish-service-type
18965 Service type for the Varnish daemon.
18968 @deftp {Data Type} varnish-configuration
18969 Data type representing the @code{varnish} service configuration.
18970 This type has the following parameters:
18973 @item @code{package} (default: @code{varnish})
18974 The Varnish package to use.
18976 @item @code{name} (default: @code{"default"})
18977 A name for this Varnish instance. Varnish will create a directory in
18978 @file{/var/varnish/} with this name and keep temporary files there. If
18979 the name starts with a forward slash, it is interpreted as an absolute
18982 Pass the @code{-n} argument to other Varnish programs to connect to the
18983 named instance, e.g.@: @command{varnishncsa -n default}.
18985 @item @code{backend} (default: @code{"localhost:8080"})
18986 The backend to use. This option has no effect if @code{vcl} is set.
18988 @item @code{vcl} (default: #f)
18989 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
18990 is @code{#f}, Varnish will proxy @code{backend} using the default
18991 configuration. Otherwise this must be a file-like object with valid
18994 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
18995 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
18996 can do something along these lines:
18999 (define %gnu-mirror
19003 backend gnu @{ .host = "www.gnu.org"; @}"))
19007 (services (cons (service varnish-service-type
19008 (varnish-configuration
19010 (vcl %gnu-mirror)))
19014 The configuration of an already running Varnish instance can be inspected
19015 and changed using the @command{varnishadm} program.
19017 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19018 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19019 comprehensive documentation on Varnish and its configuration language.
19021 @item @code{listen} (default: @code{'("localhost:80")})
19022 List of addresses Varnish will listen on.
19024 @item @code{storage} (default: @code{'("malloc,128m")})
19025 List of storage backends that will be available in VCL.
19027 @item @code{parameters} (default: @code{'()})
19028 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19030 @item @code{extra-options} (default: @code{'()})
19031 Additional arguments to pass to the @command{varnishd} process.
19036 @subsubheading FastCGI
19039 FastCGI is an interface between the front-end and the back-end of a web
19040 service. It is a somewhat legacy facility; new web services should
19041 generally just talk HTTP between the front-end and the back-end.
19042 However there are a number of back-end services such as PHP or the
19043 optimized HTTP Git repository access that use FastCGI, so we have
19044 support for it in Guix.
19046 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19047 dispatch some subset of its requests to the fastcgi backend, which
19048 listens on a local TCP or UNIX socket. There is an intermediary
19049 @code{fcgiwrap} program that sits between the actual backend process and
19050 the web server. The front-end indicates which backend program to run,
19051 passing that information to the @code{fcgiwrap} process.
19053 @defvr {Scheme Variable} fcgiwrap-service-type
19054 A service type for the @code{fcgiwrap} FastCGI proxy.
19057 @deftp {Data Type} fcgiwrap-configuration
19058 Data type representing the configuration of the @code{fcgiwrap} service.
19059 This type has the following parameters:
19061 @item @code{package} (default: @code{fcgiwrap})
19062 The fcgiwrap package to use.
19064 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19065 The socket on which the @code{fcgiwrap} process should listen, as a
19066 string. Valid @var{socket} values include
19067 @code{unix:@var{/path/to/unix/socket}},
19068 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19069 @code{tcp6:[@var{ipv6_addr}]:port}.
19071 @item @code{user} (default: @code{fcgiwrap})
19072 @itemx @code{group} (default: @code{fcgiwrap})
19073 The user and group names, as strings, under which to run the
19074 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19075 the user asks for the specific user or group names @code{fcgiwrap} that
19076 the corresponding user and/or group is present on the system.
19078 It is possible to configure a FastCGI-backed web service to pass HTTP
19079 authentication information from the front-end to the back-end, and to
19080 allow @code{fcgiwrap} to run the back-end process as a corresponding
19081 local user. To enable this capability on the back-end., run
19082 @code{fcgiwrap} as the @code{root} user and group. Note that this
19083 capability also has to be configured on the front-end as well.
19088 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19089 with some additional features useful for sites of any size.
19091 These features include:
19093 @item Adaptive process spawning
19094 @item Basic statistics (similar to Apache's mod_status)
19095 @item Advanced process management with graceful stop/start
19096 @item Ability to start workers with different uid/gid/chroot/environment
19097 and different php.ini (replaces safe_mode)
19098 @item Stdout & stderr logging
19099 @item Emergency restart in case of accidental opcode cache destruction
19100 @item Accelerated upload support
19101 @item Support for a "slowlog"
19102 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19103 a special function to finish request & flush all data while continuing to do
19104 something time-consuming (video converting, stats processing, etc.)
19106 ...@: and much more.
19108 @defvr {Scheme Variable} php-fpm-service-type
19109 A Service type for @code{php-fpm}.
19112 @deftp {Data Type} php-fpm-configuration
19113 Data Type for php-fpm service configuration.
19115 @item @code{php} (default: @code{php})
19116 The php package to use.
19117 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19118 The address on which to accept FastCGI requests. Valid syntaxes are:
19120 @item @code{"ip.add.re.ss:port"}
19121 Listen on a TCP socket to a specific address on a specific port.
19122 @item @code{"port"}
19123 Listen on a TCP socket to all addresses on a specific port.
19124 @item @code{"/path/to/unix/socket"}
19125 Listen on a unix socket.
19128 @item @code{user} (default: @code{php-fpm})
19129 User who will own the php worker processes.
19130 @item @code{group} (default: @code{php-fpm})
19131 Group of the worker processes.
19132 @item @code{socket-user} (default: @code{php-fpm})
19133 User who can speak to the php-fpm socket.
19134 @item @code{socket-group} (default: @code{php-fpm})
19135 Group that can speak to the php-fpm socket.
19136 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19137 The process id of the php-fpm process is written to this file
19138 once the service has started.
19139 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19140 Log for the php-fpm master process.
19141 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19142 Detailed settings for the php-fpm process manager.
19145 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19146 @item @code{<php-fpm-static-process-manager-configuration>}
19147 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19149 @item @code{display-errors} (default @code{#f})
19150 Determines whether php errors and warning should be sent to clients
19151 and displayed in their browsers.
19152 This is useful for local php development, but a security risk for public sites,
19153 as error messages can reveal passwords and personal data.
19154 @item @code{timezone} (default @code{#f})
19155 Specifies @code{php_admin_value[date.timezone]} parameter.
19156 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19157 This file will log the @code{stderr} outputs of php worker processes.
19158 Can be set to @code{#f} to disable logging.
19159 @item @code{file} (default @code{#f})
19160 An optional override of the whole configuration.
19161 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19165 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19166 Data Type for the @code{dynamic} php-fpm process manager. With the
19167 @code{dynamic} process manager, spare worker processes are kept around
19168 based on it's configured limits.
19170 @item @code{max-children} (default: @code{5})
19171 Maximum of worker processes.
19172 @item @code{start-servers} (default: @code{2})
19173 How many worker processes should be started on start-up.
19174 @item @code{min-spare-servers} (default: @code{1})
19175 How many spare worker processes should be kept around at minimum.
19176 @item @code{max-spare-servers} (default: @code{3})
19177 How many spare worker processes should be kept around at maximum.
19181 @deftp {Data type} php-fpm-static-process-manager-configuration
19182 Data Type for the @code{static} php-fpm process manager. With the
19183 @code{static} process manager, an unchanging number of worker processes
19186 @item @code{max-children} (default: @code{5})
19187 Maximum of worker processes.
19191 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19192 Data Type for the @code{on-demand} php-fpm process manager. With the
19193 @code{on-demand} process manager, worker processes are only created as
19196 @item @code{max-children} (default: @code{5})
19197 Maximum of worker processes.
19198 @item @code{process-idle-timeout} (default: @code{10})
19199 The time in seconds after which a process with no requests is killed.
19204 @deffn {Scheme Procedure} nginx-php-fpm-location @
19205 [#:nginx-package nginx] @
19206 [socket (string-append "/var/run/php" @
19207 (version-major (package-version php)) @
19209 A helper function to quickly add php to an @code{nginx-server-configuration}.
19212 A simple services setup for nginx with php can look like this:
19214 (services (cons* (service dhcp-client-service-type)
19215 (service php-fpm-service-type)
19216 (service nginx-service-type
19217 (nginx-server-configuration
19218 (server-name '("example.com"))
19219 (root "/srv/http/")
19221 (list (nginx-php-location)))
19223 (ssl-certificate #f)
19224 (ssl-certificate-key #f)))
19228 @cindex cat-avatar-generator
19229 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19230 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19231 the hash of a user's email address.
19233 @deffn {Scheme Procedure} cat-avatar-generator-service @
19234 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19235 [#:package cat-avatar-generator] @
19236 [#:configuration (nginx-server-configuration)]
19237 Returns an nginx-server-configuration that inherits @code{configuration}. It
19238 extends the nginx configuration to add a server block that serves @code{package},
19239 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19240 be able to use @code{cache-dir} as its cache directory.
19243 A simple setup for cat-avatar-generator can look like this:
19245 (services (cons* (cat-avatar-generator-service
19247 (nginx-server-configuration
19248 (server-name '("example.com"))))
19253 @subsubheading Hpcguix-web
19255 @cindex hpcguix-web
19256 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
19257 program is a customizable web interface to browse Guix packages,
19258 initially designed for users of high-performance computing (HPC)
19261 @defvr {Scheme Variable} hpcguix-web-service-type
19262 The service type for @code{hpcguix-web}.
19265 @deftp {Data Type} hpcguix-web-configuration
19266 Data type for the hpcguix-web service configuration.
19270 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19271 configuration. The main items available in this spec are:
19274 @item @code{title-prefix} (default: @code{"hpcguix | "})
19275 The page title prefix.
19277 @item @code{guix-command} (default: @code{"guix"})
19278 The @command{guix} command.
19280 @item @code{package-filter-proc} (default: @code{(const #t)})
19281 A procedure specifying how to filter packages that are displayed.
19283 @item @code{package-page-extension-proc} (default: @code{(const '())})
19284 Extension package for @code{hpcguix-web}.
19286 @item @code{menu} (default: @code{'()})
19287 Additional entry in page @code{menu}.
19289 @item @code{channels} (default: @code{%default-channels})
19290 List of channels from which the package list is built (@pxref{Channels}).
19292 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19293 The expiration time, in seconds, after which the package list is rebuilt from
19294 the latest instances of the given channels.
19297 See the hpcguix-web repository for a
19298 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19301 @item @code{package} (default: @code{hpcguix-web})
19302 The hpcguix-web package to use.
19306 A typical hpcguix-web service declaration looks like this:
19309 (service hpcguix-web-service-type
19310 (hpcguix-web-configuration
19312 #~(define site-config
19313 (hpcweb-configuration
19314 (title-prefix "Guix-HPC - ")
19315 (menu '(("/about" "ABOUT"))))))))
19319 The hpcguix-web service periodically updates the package list it publishes by
19320 pulling channels from Git. To that end, it needs to access X.509 certificates
19321 so that it can authenticate Git servers when communicating over HTTPS, and it
19322 assumes that @file{/etc/ssl/certs} contains those certificates.
19324 Thus, make sure to add @code{nss-certs} or another certificate package to the
19325 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19326 more information on X.509 certificates.
19329 @node Certificate Services
19330 @subsection Certificate Services
19333 @cindex HTTP, HTTPS
19334 @cindex Let's Encrypt
19335 @cindex TLS certificates
19336 The @code{(gnu services certbot)} module provides a service to
19337 automatically obtain a valid TLS certificate from the Let's Encrypt
19338 certificate authority. These certificates can then be used to serve
19339 content securely over HTTPS or other TLS-based protocols, with the
19340 knowledge that the client will be able to verify the server's
19343 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19344 @code{certbot} tool to automate the certification process. This tool
19345 first securely generates a key on the server. It then makes a request
19346 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19347 checks that the request originates from the host in question by using a
19348 challenge-response protocol, requiring the server to provide its
19349 response over HTTP. If that protocol completes successfully, the CA
19350 signs the key, resulting in a certificate. That certificate is valid
19351 for a limited period of time, and therefore to continue to provide TLS
19352 services, the server needs to periodically ask the CA to renew its
19355 The certbot service automates this process: the initial key
19356 generation, the initial certification request to the Let's Encrypt
19357 service, the web server challenge/response integration, writing the
19358 certificate to disk, the automated periodic renewals, and the deployment
19359 tasks associated with the renewal (e.g.@: reloading services, copying keys
19360 with different permissions).
19362 Certbot is run twice a day, at a random minute within the hour. It
19363 won't do anything until your certificates are due for renewal or
19364 revoked, but running it regularly would give your service a chance of
19365 staying online in case a Let's Encrypt-initiated revocation happened for
19368 By using this service, you agree to the ACME Subscriber Agreement, which
19369 can be found there:
19370 @url{https://acme-v01.api.letsencrypt.org/directory}.
19372 @defvr {Scheme Variable} certbot-service-type
19373 A service type for the @code{certbot} Let's Encrypt client. Its value
19374 must be a @code{certbot-configuration} record as in this example:
19377 (define %nginx-deploy-hook
19379 "nginx-deploy-hook"
19380 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19381 (kill pid SIGHUP))))
19383 (service certbot-service-type
19384 (certbot-configuration
19385 (email "foo@@example.net")
19388 (certificate-configuration
19389 (domains '("example.net" "www.example.net"))
19390 (deploy-hook %nginx-deploy-hook))
19391 (certificate-configuration
19392 (domains '("bar.example.net")))))))
19395 See below for details about @code{certbot-configuration}.
19398 @deftp {Data Type} certbot-configuration
19399 Data type representing the configuration of the @code{certbot} service.
19400 This type has the following parameters:
19403 @item @code{package} (default: @code{certbot})
19404 The certbot package to use.
19406 @item @code{webroot} (default: @code{/var/www})
19407 The directory from which to serve the Let's Encrypt challenge/response
19410 @item @code{certificates} (default: @code{()})
19411 A list of @code{certificates-configuration}s for which to generate
19412 certificates and request signatures. Each certificate has a @code{name}
19413 and several @code{domains}.
19416 Mandatory email used for registration, recovery contact, and important
19417 account notifications.
19419 @item @code{rsa-key-size} (default: @code{2048})
19420 Size of the RSA key.
19422 @item @code{default-location} (default: @i{see below})
19423 The default @code{nginx-location-configuration}. Because @code{certbot}
19424 needs to be able to serve challenges and responses, it needs to be able
19425 to run a web server. It does so by extending the @code{nginx} web
19426 service with an @code{nginx-server-configuration} listening on the
19427 @var{domains} on port 80, and which has a
19428 @code{nginx-location-configuration} for the @code{/.well-known/} URI
19429 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
19430 these nginx configuration data types.
19432 Requests to other URL paths will be matched by the
19433 @code{default-location}, which if present is added to all
19434 @code{nginx-server-configuration}s.
19436 By default, the @code{default-location} will issue a redirect from
19437 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
19438 you to define what to serve on your site via @code{https}.
19440 Pass @code{#f} to not issue a default location.
19444 @deftp {Data Type} certificate-configuration
19445 Data type representing the configuration of a certificate.
19446 This type has the following parameters:
19449 @item @code{name} (default: @i{see below})
19450 This name is used by Certbot for housekeeping and in file paths; it
19451 doesn't affect the content of the certificate itself. To see
19452 certificate names, run @code{certbot certificates}.
19454 Its default is the first provided domain.
19456 @item @code{domains} (default: @code{()})
19457 The first domain provided will be the subject CN of the certificate, and
19458 all domains will be Subject Alternative Names on the certificate.
19460 @item @code{challenge} (default: @code{#f})
19461 The challenge type that has to be run by certbot. If @code{#f} is specified,
19462 default to the HTTP challenge. If a value is specified, defaults to the
19463 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
19464 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
19466 @item @code{authentication-hook} (default: @code{#f})
19467 Command to be run in a shell once for each certificate challenge to be
19468 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
19469 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
19470 contains the validation string and @code{$CERTBOT_TOKEN} contains the
19471 file name of the resource requested when performing an HTTP-01 challenge.
19473 @item @code{cleanup-hook} (default: @code{#f})
19474 Command to be run in a shell once for each certificate challenge that
19475 have been answered by the @code{auth-hook}. For this command, the shell
19476 variables available in the @code{auth-hook} script are still available, and
19477 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
19478 of the @code{auth-hook} script.
19480 @item @code{deploy-hook} (default: @code{#f})
19481 Command to be run in a shell once for each successfully issued
19482 certificate. For this command, the shell variable
19483 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
19484 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
19485 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
19486 contain a space-delimited list of renewed certificate domains (for
19487 example, @samp{"example.com www.example.com"}.
19492 For each @code{certificate-configuration}, the certificate is saved to
19493 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
19494 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
19496 @subsection DNS Services
19497 @cindex DNS (domain name system)
19498 @cindex domain name system (DNS)
19500 The @code{(gnu services dns)} module provides services related to the
19501 @dfn{domain name system} (DNS). It provides a server service for hosting
19502 an @emph{authoritative} DNS server for multiple zones, slave or master.
19503 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
19504 caching and forwarding DNS server for the LAN, which uses
19505 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
19507 @subsubheading Knot Service
19509 An example configuration of an authoritative server for two zones, one master
19513 (define-zone-entries example.org.zone
19514 ;; Name TTL Class Type Data
19515 ("@@" "" "IN" "A" "127.0.0.1")
19516 ("@@" "" "IN" "NS" "ns")
19517 ("ns" "" "IN" "A" "127.0.0.1"))
19519 (define master-zone
19520 (knot-zone-configuration
19521 (domain "example.org")
19523 (origin "example.org")
19524 (entries example.org.zone)))))
19527 (knot-zone-configuration
19528 (domain "plop.org")
19529 (dnssec-policy "default")
19530 (master (list "plop-master"))))
19532 (define plop-master
19533 (knot-remote-configuration
19535 (address (list "208.76.58.171"))))
19539 (services (cons* (service knot-service-type
19540 (knot-configuration
19541 (remotes (list plop-master))
19542 (zones (list master-zone slave-zone))))
19547 @deffn {Scheme Variable} knot-service-type
19548 This is the type for the Knot DNS server.
19550 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
19551 zones, that is to say domain names you would buy from a registrar. This server
19552 is not a resolver, meaning that it can only resolve names for which it is
19553 authoritative. This server can be configured to serve zones as a master server
19554 or a slave server as a per-zone basis. Slave zones will get their data from
19555 masters, and will serve it as an authoritative server. From the point of view
19556 of a resolver, there is no difference between master and slave.
19558 The following data types are used to configure the Knot DNS server:
19561 @deftp {Data Type} knot-key-configuration
19562 Data type representing a key.
19563 This type has the following parameters:
19566 @item @code{id} (default: @code{""})
19567 An identifier for other configuration fields to refer to this key. IDs must
19568 be unique and must not be empty.
19570 @item @code{algorithm} (default: @code{#f})
19571 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
19572 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
19573 and @code{'hmac-sha512}.
19575 @item @code{secret} (default: @code{""})
19576 The secret key itself.
19581 @deftp {Data Type} knot-acl-configuration
19582 Data type representing an Access Control List (ACL) configuration.
19583 This type has the following parameters:
19586 @item @code{id} (default: @code{""})
19587 An identifier for ether configuration fields to refer to this key. IDs must be
19588 unique and must not be empty.
19590 @item @code{address} (default: @code{'()})
19591 An ordered list of IP addresses, network subnets, or network ranges represented
19592 with strings. The query must match one of them. Empty value means that
19593 address match is not required.
19595 @item @code{key} (default: @code{'()})
19596 An ordered list of references to keys represented with strings. The string
19597 must match a key ID defined in a @code{knot-key-configuration}. No key means
19598 that a key is not require to match that ACL.
19600 @item @code{action} (default: @code{'()})
19601 An ordered list of actions that are permitted or forbidden by this ACL. Possible
19602 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
19603 and @code{'update}.
19605 @item @code{deny?} (default: @code{#f})
19606 When true, the ACL defines restrictions. Listed actions are forbidden. When
19607 false, listed actions are allowed.
19612 @deftp {Data Type} zone-entry
19613 Data type represnting a record entry in a zone file.
19614 This type has the following parameters:
19617 @item @code{name} (default: @code{"@@"})
19618 The name of the record. @code{"@@"} refers to the origin of the zone. Names
19619 are relative to the origin of the zone. For example, in the @code{example.org}
19620 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
19621 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
19622 refers to @code{ns.example.org}.
19624 @item @code{ttl} (default: @code{""})
19625 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
19627 @item @code{class} (default: @code{"IN"})
19628 The class of the record. Knot currently supports only @code{"IN"} and
19629 partially @code{"CH"}.
19631 @item @code{type} (default: @code{"A"})
19632 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
19633 address), NS (Name Server) and MX (Mail eXchange). Many other types are
19636 @item @code{data} (default: @code{""})
19637 The data contained in the record. For instance an IP address associated with
19638 an A record, or a domain name associated with an NS record. Remember that
19639 domain names are relative to the origin unless they end with a dot.
19644 @deftp {Data Type} zone-file
19645 Data type representing the content of a zone file.
19646 This type has the following parameters:
19649 @item @code{entries} (default: @code{'()})
19650 The list of entries. The SOA record is taken care of, so you don't need to
19651 put it in the list of entries. This list should probably contain an entry
19652 for your primary authoritative DNS server. Other than using a list of entries
19653 directly, you can use @code{define-zone-entries} to define a object containing
19654 the list of entries more easily, that you can later pass to the @code{entries}
19655 field of the @code{zone-file}.
19657 @item @code{origin} (default: @code{""})
19658 The name of your zone. This parameter cannot be empty.
19660 @item @code{ns} (default: @code{"ns"})
19661 The domain of your primary authoritative DNS server. The name is relative to
19662 the origin, unless it ends with a dot. It is mandatory that this primary
19663 DNS server corresponds to an NS record in the zone and that it is associated
19664 to an IP address in the list of entries.
19666 @item @code{mail} (default: @code{"hostmaster"})
19667 An email address people can contact you at, as the owner of the zone. This
19668 is translated as @code{<mail>@@<origin>}.
19670 @item @code{serial} (default: @code{1})
19671 The serial number of the zone. As this is used to keep track of changes by
19672 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
19673 Always increment it when you make a change in your zone.
19675 @item @code{refresh} (default: @code{(* 2 24 3600)})
19676 The frequency at which slaves will do a zone transfer. This value is a number
19677 of seconds. It can be computed by multiplications or with
19678 @code{(string->duration)}.
19680 @item @code{retry} (default: @code{(* 15 60)})
19681 The period after which a slave will retry to contact its master when it fails
19682 to do so a first time.
19684 @item @code{expiry} (default: @code{(* 14 24 3600)})
19685 Default TTL of records. Existing records are considered correct for at most
19686 this amount of time. After this period, resolvers will invalidate their cache
19687 and check again that it still exists.
19689 @item @code{nx} (default: @code{3600})
19690 Default TTL of inexistant records. This delay is usually short because you want
19691 your new domains to reach everyone quickly.
19696 @deftp {Data Type} knot-remote-configuration
19697 Data type representing a remote configuration.
19698 This type has the following parameters:
19701 @item @code{id} (default: @code{""})
19702 An identifier for other configuration fields to refer to this remote. IDs must
19703 be unique and must not be empty.
19705 @item @code{address} (default: @code{'()})
19706 An ordered list of destination IP addresses. Addresses are tried in sequence.
19707 An optional port can be given with the @@ separator. For instance:
19708 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
19710 @item @code{via} (default: @code{'()})
19711 An ordered list of source IP addresses. An empty list will have Knot choose
19712 an appropriate source IP. An optional port can be given with the @@ separator.
19713 The default is to choose at random.
19715 @item @code{key} (default: @code{#f})
19716 A reference to a key, that is a string containing the identifier of a key
19717 defined in a @code{knot-key-configuration} field.
19722 @deftp {Data Type} knot-keystore-configuration
19723 Data type representing a keystore to hold dnssec keys.
19724 This type has the following parameters:
19727 @item @code{id} (default: @code{""})
19728 The id of the keystore. It must not be empty.
19730 @item @code{backend} (default: @code{'pem})
19731 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
19733 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
19734 The configuration string of the backend. An example for the PKCS#11 is:
19735 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
19736 For the pem backend, the string reprensents a path in the file system.
19741 @deftp {Data Type} knot-policy-configuration
19742 Data type representing a dnssec policy. Knot DNS is able to automatically
19743 sign your zones. It can either generate and manage your keys automatically or
19744 use keys that you generate.
19746 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
19747 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
19748 zone. In order to be trusted, the KSK needs to be present in the parent zone
19749 (usually a top-level domain). If your registrar supports dnssec, you will
19750 have to send them your KSK's hash so they can add a DS record in their zone.
19751 This is not automated and need to be done each time you change your KSK.
19753 The policy also defines the lifetime of keys. Usually, ZSK can be changed
19754 easily and use weaker cryptographic functions (they use lower parameters) in
19755 order to sign records quickly, so they are changed often. The KSK however
19756 requires manual interaction with the registrar, so they are changed less often
19757 and use stronger parameters because they sign only one record.
19759 This type has the following parameters:
19762 @item @code{id} (default: @code{""})
19763 The id of the policy. It must not be empty.
19765 @item @code{keystore} (default: @code{"default"})
19766 A reference to a keystore, that is a string containing the identifier of a
19767 keystore defined in a @code{knot-keystore-configuration} field. The
19768 @code{"default"} identifier means the default keystore (a kasp database that
19769 was setup by this service).
19771 @item @code{manual?} (default: @code{#f})
19772 Whether the key management is manual or automatic.
19774 @item @code{single-type-signing?} (default: @code{#f})
19775 When @code{#t}, use the Single-Type Signing Scheme.
19777 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
19778 An algorithm of signing keys and issued signatures.
19780 @item @code{ksk-size} (default: @code{256})
19781 The length of the KSK. Note that this value is correct for the default
19782 algorithm, but would be unsecure for other algorithms.
19784 @item @code{zsk-size} (default: @code{256})
19785 The length of the ZSK. Note that this value is correct for the default
19786 algorithm, but would be unsecure for other algorithms.
19788 @item @code{dnskey-ttl} (default: @code{'default})
19789 The TTL value for DNSKEY records added into zone apex. The special
19790 @code{'default} value means same as the zone SOA TTL.
19792 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
19793 The period between ZSK publication and the next rollover initiation.
19795 @item @code{propagation-delay} (default: @code{(* 24 3600)})
19796 An extra delay added for each key rollover step. This value should be high
19797 enough to cover propagation of data from the master server to all slaves.
19799 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
19800 A validity period of newly issued signatures.
19802 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
19803 A period how long before a signature expiration the signature will be refreshed.
19805 @item @code{nsec3?} (default: @code{#f})
19806 When @code{#t}, NSEC3 will be used instead of NSEC.
19808 @item @code{nsec3-iterations} (default: @code{5})
19809 The number of additional times the hashing is performed.
19811 @item @code{nsec3-salt-length} (default: @code{8})
19812 The length of a salt field in octets, which is appended to the original owner
19813 name before hashing.
19815 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
19816 The validity period of newly issued salt field.
19821 @deftp {Data Type} knot-zone-configuration
19822 Data type representing a zone served by Knot.
19823 This type has the following parameters:
19826 @item @code{domain} (default: @code{""})
19827 The domain served by this configuration. It must not be empty.
19829 @item @code{file} (default: @code{""})
19830 The file where this zone is saved. This parameter is ignored by master zones.
19831 Empty means default location that depends on the domain name.
19833 @item @code{zone} (default: @code{(zone-file)})
19834 The content of the zone file. This parameter is ignored by slave zones. It
19835 must contain a zone-file record.
19837 @item @code{master} (default: @code{'()})
19838 A list of master remotes. When empty, this zone is a master. When set, this
19839 zone is a slave. This is a list of remotes identifiers.
19841 @item @code{ddns-master} (default: @code{#f})
19842 The main master. When empty, it defaults to the first master in the list of
19845 @item @code{notify} (default: @code{'()})
19846 A list of slave remote identifiers.
19848 @item @code{acl} (default: @code{'()})
19849 A list of acl identifiers.
19851 @item @code{semantic-checks?} (default: @code{#f})
19852 When set, this adds more semantic checks to the zone.
19854 @item @code{disable-any?} (default: @code{#f})
19855 When set, this forbids queries of the ANY type.
19857 @item @code{zonefile-sync} (default: @code{0})
19858 The delay between a modification in memory and on disk. 0 means immediate
19861 @item @code{zonefile-load} (default: @code{#f})
19862 The way the zone file contents are applied during zone load. Possible values
19866 @item @code{#f} for using the default value from Knot,
19867 @item @code{'none} for not using the zone file at all,
19868 @item @code{'difference} for computing the difference between already available
19869 contents and zone contents and applying it to the current zone contents,
19870 @item @code{'difference-no-serial} for the same as @code{'difference}, but
19871 ignoring the SOA serial in the zone file, while the server takes care of it
19873 @item @code{'whole} for loading zone contents from the zone file.
19876 @item @code{journal-content} (default: @code{#f})
19877 The way the journal is used to store zone and its changes. Possible values
19878 are @code{'none} to not use it at all, @code{'changes} to store changes and
19879 @code{'all} to store contents. @code{#f} does not set this option, so the
19880 default value from Knot is used.
19882 @item @code{max-journal-usage} (default: @code{#f})
19883 The maximum size for the journal on disk. @code{#f} does not set this option,
19884 so the default value from Knot is used.
19886 @item @code{max-journal-depth} (default: @code{#f})
19887 The maximum size of the history. @code{#f} does not set this option, so the
19888 default value from Knot is used.
19890 @item @code{max-zone-size} (default: @code{#f})
19891 The maximum size of the zone file. This limit is enforced for incoming
19892 transfer and updates. @code{#f} does not set this option, so the default
19893 value from Knot is used.
19895 @item @code{dnssec-policy} (default: @code{#f})
19896 A reference to a @code{knot-policy-configuration} record, or the special
19897 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
19900 @item @code{serial-policy} (default: @code{'increment})
19901 A policy between @code{'increment} and @code{'unixtime}.
19906 @deftp {Data Type} knot-configuration
19907 Data type representing the Knot configuration.
19908 This type has the following parameters:
19911 @item @code{knot} (default: @code{knot})
19914 @item @code{run-directory} (default: @code{"/var/run/knot"})
19915 The run directory. This directory will be used for pid file and sockets.
19917 @item @code{includes} (default: @code{'()})
19918 A list of strings or file-like objects denoting other files that must be
19919 included at the top of the configuration file.
19921 @cindex secrets, Knot service
19922 This can be used to manage secrets out-of-band. For example, secret
19923 keys may be stored in an out-of-band file not managed by Guix, and
19924 thus not visible in @file{/gnu/store}---e.g., you could store secret
19925 key configuration in @file{/etc/knot/secrets.conf} and add this file
19926 to the @code{includes} list.
19928 It can also be used to add configuration not supported by this interface.
19930 @item @code{listen-v4} (default: @code{"0.0.0.0"})
19931 An ip address on which to listen.
19933 @item @code{listen-v6} (default: @code{"::"})
19934 An ip address on which to listen.
19936 @item @code{listen-port} (default: @code{53})
19937 A port on which to listen.
19939 @item @code{keys} (default: @code{'()})
19940 The list of knot-key-configuration used by this configuration.
19942 @item @code{acls} (default: @code{'()})
19943 The list of knot-acl-configuration used by this configuration.
19945 @item @code{remotes} (default: @code{'()})
19946 The list of knot-remote-configuration used by this configuration.
19948 @item @code{zones} (default: @code{'()})
19949 The list of knot-zone-configuration used by this configuration.
19954 @subsubheading Dnsmasq Service
19956 @deffn {Scheme Variable} dnsmasq-service-type
19957 This is the type of the dnsmasq service, whose value should be an
19958 @code{dnsmasq-configuration} object as in this example:
19961 (service dnsmasq-service-type
19962 (dnsmasq-configuration
19964 (servers '("192.168.1.1"))))
19968 @deftp {Data Type} dnsmasq-configuration
19969 Data type representing the configuration of dnsmasq.
19972 @item @code{package} (default: @var{dnsmasq})
19973 Package object of the dnsmasq server.
19975 @item @code{no-hosts?} (default: @code{#f})
19976 When true, don't read the hostnames in /etc/hosts.
19978 @item @code{port} (default: @code{53})
19979 The port to listen on. Setting this to zero completely disables DNS
19980 responses, leaving only DHCP and/or TFTP functions.
19982 @item @code{local-service?} (default: @code{#t})
19983 Accept DNS queries only from hosts whose address is on a local subnet,
19984 ie a subnet for which an interface exists on the server.
19986 @item @code{listen-addresses} (default: @code{'()})
19987 Listen on the given IP addresses.
19989 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
19990 The file to read the IP address of the upstream nameservers from.
19992 @item @code{no-resolv?} (default: @code{#f})
19993 When true, don't read @var{resolv-file}.
19995 @item @code{servers} (default: @code{'()})
19996 Specify IP address of upstream servers directly.
19998 @item @code{cache-size} (default: @code{150})
19999 Set the size of dnsmasq's cache. Setting the cache size to zero
20002 @item @code{negative-cache?} (default: @code{#t})
20003 When false, disable negative caching.
20008 @subsubheading ddclient Service
20011 The ddclient service described below runs the ddclient daemon, which takes
20012 care of automatically updating DNS entries for service providers such as
20013 @uref{https://dyn.com/dns/, Dyn}.
20015 The following example show instantiates the service with its default
20019 (service ddclient-service-type)
20022 Note that ddclient needs to access credentials that are stored in a
20023 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20024 @code{secret-file} below.) You are expected to create this file manually, in
20025 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20026 service configuration, for instance by using @code{plain-file}, but it will be
20027 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20028 @file{share/ddclient} directory of the @code{ddclient} package.
20030 @c %start of fragment
20032 Available @code{ddclient-configuration} fields are:
20034 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20035 The ddclient package.
20039 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20040 The period after which ddclient will retry to check IP and domain name.
20042 Defaults to @samp{300}.
20046 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20047 Use syslog for the output.
20049 Defaults to @samp{#t}.
20053 @deftypevr {@code{ddclient-configuration} parameter} string mail
20056 Defaults to @samp{"root"}.
20060 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20061 Mail failed update to user.
20063 Defaults to @samp{"root"}.
20067 @deftypevr {@code{ddclient-configuration} parameter} string pid
20068 The ddclient PID file.
20070 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20074 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20075 Enable SSL support.
20077 Defaults to @samp{#t}.
20081 @deftypevr {@code{ddclient-configuration} parameter} string user
20082 Specifies the user name or ID that is used when running ddclient
20085 Defaults to @samp{"ddclient"}.
20089 @deftypevr {@code{ddclient-configuration} parameter} string group
20090 Group of the user who will run the ddclient program.
20092 Defaults to @samp{"ddclient"}.
20096 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20097 Secret file which will be appended to @file{ddclient.conf} file. This
20098 file contains credentials for use by ddclient. You are expected to
20099 create it manually.
20101 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20105 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20106 Extra options will be appended to @file{ddclient.conf} file.
20108 Defaults to @samp{()}.
20113 @c %end of fragment
20117 @subsection VPN Services
20118 @cindex VPN (virtual private network)
20119 @cindex virtual private network (VPN)
20121 The @code{(gnu services vpn)} module provides services related to
20122 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20123 your machine to connect to a VPN, and a @emph{servire} service for your machine
20124 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20126 @deffn {Scheme Procedure} openvpn-client-service @
20127 [#:config (openvpn-client-configuration)]
20129 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20132 @deffn {Scheme Procedure} openvpn-server-service @
20133 [#:config (openvpn-server-configuration)]
20135 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20137 Both can be run simultaneously.
20140 @c %automatically generated documentation
20142 Available @code{openvpn-client-configuration} fields are:
20144 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20145 The OpenVPN package.
20149 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20150 The OpenVPN pid file.
20152 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20156 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20157 The protocol (UDP or TCP) used to open a channel between clients and
20160 Defaults to @samp{udp}.
20164 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20165 The device type used to represent the VPN connection.
20167 Defaults to @samp{tun}.
20171 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20172 The certificate authority to check connections against.
20174 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20178 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20179 The certificate of the machine the daemon is running on. It should be
20180 signed by the authority given in @code{ca}.
20182 Defaults to @samp{"/etc/openvpn/client.crt"}.
20186 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20187 The key of the machine the daemon is running on. It must be the key whose
20188 certificate is @code{cert}.
20190 Defaults to @samp{"/etc/openvpn/client.key"}.
20194 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20195 Whether to use the lzo compression algorithm.
20197 Defaults to @samp{#t}.
20201 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20202 Don't re-read key files across SIGUSR1 or --ping-restart.
20204 Defaults to @samp{#t}.
20208 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20209 Don't close and reopen TUN/TAP device or run up/down scripts across
20210 SIGUSR1 or --ping-restart restarts.
20212 Defaults to @samp{#t}.
20216 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20219 Defaults to @samp{3}.
20223 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20224 Add an additional layer of HMAC authentication on top of the TLS control
20225 channel to protect against DoS attacks.
20227 Defaults to @samp{#f}.
20231 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20232 Whether to check the server certificate has server usage extension.
20234 Defaults to @samp{#t}.
20238 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20239 Bind to a specific local port number.
20241 Defaults to @samp{#f}.
20245 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20246 Retry resolving server address.
20248 Defaults to @samp{#t}.
20252 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20253 A list of remote servers to connect to.
20255 Defaults to @samp{()}.
20257 Available @code{openvpn-remote-configuration} fields are:
20259 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20262 Defaults to @samp{"my-server"}.
20266 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20267 Port number the server listens to.
20269 Defaults to @samp{1194}.
20274 @c %end of automatic openvpn-client documentation
20276 @c %automatically generated documentation
20278 Available @code{openvpn-server-configuration} fields are:
20280 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20281 The OpenVPN package.
20285 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20286 The OpenVPN pid file.
20288 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20292 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20293 The protocol (UDP or TCP) used to open a channel between clients and
20296 Defaults to @samp{udp}.
20300 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20301 The device type used to represent the VPN connection.
20303 Defaults to @samp{tun}.
20307 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20308 The certificate authority to check connections against.
20310 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20314 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20315 The certificate of the machine the daemon is running on. It should be
20316 signed by the authority given in @code{ca}.
20318 Defaults to @samp{"/etc/openvpn/client.crt"}.
20322 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20323 The key of the machine the daemon is running on. It must be the key whose
20324 certificate is @code{cert}.
20326 Defaults to @samp{"/etc/openvpn/client.key"}.
20330 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20331 Whether to use the lzo compression algorithm.
20333 Defaults to @samp{#t}.
20337 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20338 Don't re-read key files across SIGUSR1 or --ping-restart.
20340 Defaults to @samp{#t}.
20344 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20345 Don't close and reopen TUN/TAP device or run up/down scripts across
20346 SIGUSR1 or --ping-restart restarts.
20348 Defaults to @samp{#t}.
20352 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20355 Defaults to @samp{3}.
20359 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20360 Add an additional layer of HMAC authentication on top of the TLS control
20361 channel to protect against DoS attacks.
20363 Defaults to @samp{#f}.
20367 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20368 Specifies the port number on which the server listens.
20370 Defaults to @samp{1194}.
20374 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20375 An ip and mask specifying the subnet inside the virtual network.
20377 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20381 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
20382 A CIDR notation specifying the IPv6 subnet inside the virtual network.
20384 Defaults to @samp{#f}.
20388 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
20389 The Diffie-Hellman parameters file.
20391 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
20395 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
20396 The file that records client IPs.
20398 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
20402 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
20403 When true, the server will act as a gateway for its clients.
20405 Defaults to @samp{#f}.
20409 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
20410 When true, clients are allowed to talk to each other inside the VPN.
20412 Defaults to @samp{#f}.
20416 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
20417 Causes ping-like messages to be sent back and forth over the link so
20418 that each side knows when the other side has gone down. @code{keepalive}
20419 requires a pair. The first element is the period of the ping sending,
20420 and the second element is the timeout before considering the other side
20425 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
20426 The maximum number of clients.
20428 Defaults to @samp{100}.
20432 @deftypevr {@code{openvpn-server-configuration} parameter} string status
20433 The status file. This file shows a small report on current connection.
20434 It is truncated and rewritten every minute.
20436 Defaults to @samp{"/var/run/openvpn/status"}.
20440 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
20441 The list of configuration for some clients.
20443 Defaults to @samp{()}.
20445 Available @code{openvpn-ccd-configuration} fields are:
20447 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
20450 Defaults to @samp{"client"}.
20454 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
20457 Defaults to @samp{#f}.
20461 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
20464 Defaults to @samp{#f}.
20471 @c %end of automatic openvpn-server documentation
20474 @node Network File System
20475 @subsection Network File System
20478 The @code{(gnu services nfs)} module provides the following services,
20479 which are most commonly used in relation to mounting or exporting
20480 directory trees as @dfn{network file systems} (NFS).
20482 @subsubheading RPC Bind Service
20485 The RPC Bind service provides a facility to map program numbers into
20486 universal addresses.
20487 Many NFS related services use this facility. Hence it is automatically
20488 started when a dependent service starts.
20490 @defvr {Scheme Variable} rpcbind-service-type
20491 A service type for the RPC portmapper daemon.
20495 @deftp {Data Type} rpcbind-configuration
20496 Data type representing the configuration of the RPC Bind Service.
20497 This type has the following parameters:
20499 @item @code{rpcbind} (default: @code{rpcbind})
20500 The rpcbind package to use.
20502 @item @code{warm-start?} (default: @code{#t})
20503 If this parameter is @code{#t}, then the daemon will read a
20504 state file on startup thus reloading state information saved by a previous
20510 @subsubheading Pipefs Pseudo File System
20514 The pipefs file system is used to transfer NFS related data
20515 between the kernel and user space programs.
20517 @defvr {Scheme Variable} pipefs-service-type
20518 A service type for the pipefs pseudo file system.
20521 @deftp {Data Type} pipefs-configuration
20522 Data type representing the configuration of the pipefs pseudo file system service.
20523 This type has the following parameters:
20525 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20526 The directory to which the file system is to be attached.
20531 @subsubheading GSS Daemon Service
20534 @cindex global security system
20536 The @dfn{global security system} (GSS) daemon provides strong security for RPC
20538 Before exchanging RPC requests an RPC client must establish a security
20539 context. Typically this is done using the Kerberos command @command{kinit}
20540 or automatically at login time using PAM services (@pxref{Kerberos Services}).
20542 @defvr {Scheme Variable} gss-service-type
20543 A service type for the Global Security System (GSS) daemon.
20546 @deftp {Data Type} gss-configuration
20547 Data type representing the configuration of the GSS daemon service.
20548 This type has the following parameters:
20550 @item @code{nfs-utils} (default: @code{nfs-utils})
20551 The package in which the @command{rpc.gssd} command is to be found.
20553 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20554 The directory where the pipefs file system is mounted.
20560 @subsubheading IDMAP Daemon Service
20562 @cindex name mapper
20564 The idmap daemon service provides mapping between user IDs and user names.
20565 Typically it is required in order to access file systems mounted via NFSv4.
20567 @defvr {Scheme Variable} idmap-service-type
20568 A service type for the Identity Mapper (IDMAP) daemon.
20571 @deftp {Data Type} idmap-configuration
20572 Data type representing the configuration of the IDMAP daemon service.
20573 This type has the following parameters:
20575 @item @code{nfs-utils} (default: @code{nfs-utils})
20576 The package in which the @command{rpc.idmapd} command is to be found.
20578 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
20579 The directory where the pipefs file system is mounted.
20581 @item @code{domain} (default: @code{#f})
20582 The local NFSv4 domain name.
20583 This must be a string or @code{#f}.
20584 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
20589 @node Continuous Integration
20590 @subsection Continuous Integration
20592 @cindex continuous integration
20593 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
20594 continuous integration tool for Guix. It can be used both for development and
20595 for providing substitutes to others (@pxref{Substitutes}).
20597 The @code{(gnu services cuirass)} module provides the following service.
20599 @defvr {Scheme Procedure} cuirass-service-type
20600 The type of the Cuirass service. Its value must be a
20601 @code{cuirass-configuration} object, as described below.
20604 To add build jobs, you have to set the @code{specifications} field of the
20605 configuration. Here is an example of a service that polls the Guix repository
20606 and builds the packages from a manifest. Some of the packages are defined in
20607 the @code{"custom-packages"} input, which is the equivalent of
20608 @code{GUIX_PACKAGE_PATH}.
20611 (define %cuirass-specs
20613 '((#:name . "my-manifest")
20614 (#:load-path-inputs . ("guix"))
20615 (#:package-path-inputs . ("custom-packages"))
20616 (#:proc-input . "guix")
20617 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
20618 (#:proc . cuirass-jobs)
20619 (#:proc-args . ((subset . "manifests")
20620 (systems . ("x86_64-linux"))
20621 (manifests . (("config" . "guix/manifest.scm")))))
20622 (#:inputs . (((#:name . "guix")
20623 (#:url . "git://git.savannah.gnu.org/guix.git")
20624 (#:load-path . ".")
20625 (#:branch . "master")
20626 (#:no-compile? . #t))
20627 ((#:name . "config")
20628 (#:url . "git://git.example.org/config.git")
20629 (#:load-path . ".")
20630 (#:branch . "master")
20631 (#:no-compile? . #t))
20632 ((#:name . "custom-packages")
20633 (#:url . "git://git.example.org/custom-packages.git")
20634 (#:load-path . ".")
20635 (#:branch . "master")
20636 (#:no-compile? . #t)))))))
20638 (service cuirass-service-type
20639 (cuirass-configuration
20640 (specifications %cuirass-specs)))
20643 While information related to build jobs is located directly in the
20644 specifications, global settings for the @command{cuirass} process are
20645 accessible in other @code{cuirass-configuration} fields.
20647 @deftp {Data Type} cuirass-configuration
20648 Data type representing the configuration of Cuirass.
20651 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
20652 Location of the log file.
20654 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
20655 Location of the repository cache.
20657 @item @code{user} (default: @code{"cuirass"})
20658 Owner of the @code{cuirass} process.
20660 @item @code{group} (default: @code{"cuirass"})
20661 Owner's group of the @code{cuirass} process.
20663 @item @code{interval} (default: @code{60})
20664 Number of seconds between the poll of the repositories followed by the
20667 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
20668 Location of sqlite database which contains the build results and previously
20669 added specifications.
20671 @item @code{ttl} (default: @code{(* 30 24 3600)})
20672 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
20673 are registered for build results. This means that build results are protected
20674 from garbage collection for at least @var{ttl} seconds.
20676 @item @code{port} (default: @code{8081})
20677 Port number used by the HTTP server.
20679 @item --listen=@var{host}
20680 Listen on the network interface for @var{host}. The default is to
20681 accept connections from localhost.
20683 @item @code{specifications} (default: @code{#~'()})
20684 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
20685 where a specification is an association list
20686 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
20687 keys are keywords (@code{#:keyword-example}) as shown in the example
20690 @item @code{use-substitutes?} (default: @code{#f})
20691 This allows using substitutes to avoid building every dependencies of a job
20694 @item @code{one-shot?} (default: @code{#f})
20695 Only evaluate specifications and build derivations once.
20697 @item @code{fallback?} (default: @code{#f})
20698 When substituting a pre-built binary fails, fall back to building
20701 @item @code{cuirass} (default: @code{cuirass})
20702 The Cuirass package to use.
20706 @node Power Management Services
20707 @subsection Power Management Services
20710 @cindex power management with TLP
20711 @subsubheading TLP daemon
20713 The @code{(gnu services pm)} module provides a Guix service definition
20714 for the Linux power management tool TLP.
20716 TLP enables various powersaving modes in userspace and kernel.
20717 Contrary to @code{upower-service}, it is not a passive,
20718 monitoring tool, as it will apply custom settings each time a new power
20719 source is detected. More information can be found at
20720 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
20722 @deffn {Scheme Variable} tlp-service-type
20723 The service type for the TLP tool. Its value should be a valid
20724 TLP configuration (see below). To use the default settings, simply
20727 (service tlp-service-type)
20731 By default TLP does not need much configuration but most TLP parameters
20732 can be tweaked using @code{tlp-configuration}.
20734 Each parameter definition is preceded by its type; for example,
20735 @samp{boolean foo} indicates that the @code{foo} parameter
20736 should be specified as a boolean. Types starting with
20737 @code{maybe-} denote parameters that won't show up in TLP config file
20738 when their value is @code{'disabled}.
20740 @c The following documentation was initially generated by
20741 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
20742 @c documentation is better, so we shouldn't hesitate to edit below as
20743 @c needed. However if the change you want to make to this documentation
20744 @c can be done in an automated way, it's probably easier to change
20745 @c (generate-documentation) than to make it below and have to deal with
20746 @c the churn as TLP updates.
20748 Available @code{tlp-configuration} fields are:
20750 @deftypevr {@code{tlp-configuration} parameter} package tlp
20755 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
20756 Set to true if you wish to enable TLP.
20758 Defaults to @samp{#t}.
20762 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
20763 Default mode when no power supply can be detected. Alternatives are AC
20766 Defaults to @samp{"AC"}.
20770 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
20771 Number of seconds Linux kernel has to wait after the disk goes idle,
20772 before syncing on AC.
20774 Defaults to @samp{0}.
20778 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
20779 Same as @code{disk-idle-ac} but on BAT mode.
20781 Defaults to @samp{2}.
20785 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
20786 Dirty pages flushing periodicity, expressed in seconds.
20788 Defaults to @samp{15}.
20792 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
20793 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
20795 Defaults to @samp{60}.
20799 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
20800 CPU frequency scaling governor on AC mode. With intel_pstate driver,
20801 alternatives are powersave and performance. With acpi-cpufreq driver,
20802 alternatives are ondemand, powersave, performance and conservative.
20804 Defaults to @samp{disabled}.
20808 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
20809 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
20811 Defaults to @samp{disabled}.
20815 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
20816 Set the min available frequency for the scaling governor on AC.
20818 Defaults to @samp{disabled}.
20822 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
20823 Set the max available frequency for the scaling governor on AC.
20825 Defaults to @samp{disabled}.
20829 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
20830 Set the min available frequency for the scaling governor on BAT.
20832 Defaults to @samp{disabled}.
20836 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
20837 Set the max available frequency for the scaling governor on BAT.
20839 Defaults to @samp{disabled}.
20843 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
20844 Limit the min P-state to control the power dissipation of the CPU, in AC
20845 mode. Values are stated as a percentage of the available performance.
20847 Defaults to @samp{disabled}.
20851 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
20852 Limit the max P-state to control the power dissipation of the CPU, in AC
20853 mode. Values are stated as a percentage of the available performance.
20855 Defaults to @samp{disabled}.
20859 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
20860 Same as @code{cpu-min-perf-on-ac} on BAT mode.
20862 Defaults to @samp{disabled}.
20866 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
20867 Same as @code{cpu-max-perf-on-ac} on BAT mode.
20869 Defaults to @samp{disabled}.
20873 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
20874 Enable CPU turbo boost feature on AC mode.
20876 Defaults to @samp{disabled}.
20880 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
20881 Same as @code{cpu-boost-on-ac?} on BAT mode.
20883 Defaults to @samp{disabled}.
20887 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
20888 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
20889 used under light load conditions.
20891 Defaults to @samp{#f}.
20895 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
20896 Same as @code{sched-powersave-on-ac?} but on BAT mode.
20898 Defaults to @samp{#t}.
20902 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
20903 Enable Linux kernel NMI watchdog.
20905 Defaults to @samp{#f}.
20909 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
20910 For Linux kernels with PHC patch applied, change CPU voltages. An
20911 example value would be @samp{"F:V F:V F:V F:V"}.
20913 Defaults to @samp{disabled}.
20917 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
20918 Set CPU performance versus energy saving policy on AC. Alternatives are
20919 performance, normal, powersave.
20921 Defaults to @samp{"performance"}.
20925 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
20926 Same as @code{energy-perf-policy-ac} but on BAT mode.
20928 Defaults to @samp{"powersave"}.
20932 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
20937 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
20938 Hard disk advanced power management level.
20942 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
20943 Same as @code{disk-apm-bat} but on BAT mode.
20947 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
20948 Hard disk spin down timeout. One value has to be specified for each
20949 declared hard disk.
20951 Defaults to @samp{disabled}.
20955 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
20956 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
20958 Defaults to @samp{disabled}.
20962 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
20963 Select IO scheduler for disk devices. One value has to be specified for
20964 each declared hard disk. Example alternatives are cfq, deadline and
20967 Defaults to @samp{disabled}.
20971 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
20972 SATA aggressive link power management (ALPM) level. Alternatives are
20973 min_power, medium_power, max_performance.
20975 Defaults to @samp{"max_performance"}.
20979 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
20980 Same as @code{sata-linkpwr-ac} but on BAT mode.
20982 Defaults to @samp{"min_power"}.
20986 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
20987 Exclude specified SATA host devices for link power management.
20989 Defaults to @samp{disabled}.
20993 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
20994 Enable Runtime Power Management for AHCI controller and disks on AC
20997 Defaults to @samp{disabled}.
21001 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21002 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21004 Defaults to @samp{disabled}.
21008 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21009 Seconds of inactivity before disk is suspended.
21011 Defaults to @samp{15}.
21015 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21016 PCI Express Active State Power Management level. Alternatives are
21017 default, performance, powersave.
21019 Defaults to @samp{"performance"}.
21023 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21024 Same as @code{pcie-aspm-ac} but on BAT mode.
21026 Defaults to @samp{"powersave"}.
21030 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21031 Radeon graphics clock speed level. Alternatives are low, mid, high,
21034 Defaults to @samp{"high"}.
21038 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21039 Same as @code{radeon-power-ac} but on BAT mode.
21041 Defaults to @samp{"low"}.
21045 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21046 Radeon dynamic power management method (DPM). Alternatives are battery,
21049 Defaults to @samp{"performance"}.
21053 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21054 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21056 Defaults to @samp{"battery"}.
21060 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21061 Radeon DPM performance level. Alternatives are auto, low, high.
21063 Defaults to @samp{"auto"}.
21067 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21068 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21070 Defaults to @samp{"auto"}.
21074 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21075 Wifi power saving mode.
21077 Defaults to @samp{#f}.
21081 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21082 Same as @code{wifi-power-ac?} but on BAT mode.
21084 Defaults to @samp{#t}.
21088 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21089 Disable wake on LAN.
21091 Defaults to @samp{#t}.
21095 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21096 Timeout duration in seconds before activating audio power saving on
21097 Intel HDA and AC97 devices. A value of 0 disables power saving.
21099 Defaults to @samp{0}.
21103 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21104 Same as @code{sound-powersave-ac} but on BAT mode.
21106 Defaults to @samp{1}.
21110 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21111 Disable controller in powersaving mode on Intel HDA devices.
21113 Defaults to @samp{#t}.
21117 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21118 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21119 powered on again by releasing (and reinserting) the eject lever or by
21120 pressing the disc eject button on newer models.
21122 Defaults to @samp{#f}.
21126 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21127 Name of the optical drive device to power off.
21129 Defaults to @samp{"sr0"}.
21133 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21134 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21137 Defaults to @samp{"on"}.
21141 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21142 Same as @code{runtime-pm-ac} but on BAT mode.
21144 Defaults to @samp{"auto"}.
21148 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21149 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21152 Defaults to @samp{#t}.
21156 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21157 Exclude specified PCI(e) device addresses from Runtime Power Management.
21159 Defaults to @samp{disabled}.
21163 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21164 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21169 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21170 Enable USB autosuspend feature.
21172 Defaults to @samp{#t}.
21176 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21177 Exclude specified devices from USB autosuspend.
21179 Defaults to @samp{disabled}.
21183 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21184 Exclude WWAN devices from USB autosuspend.
21186 Defaults to @samp{#t}.
21190 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21191 Include specified devices into USB autosuspend, even if they are already
21192 excluded by the driver or via @code{usb-blacklist-wwan?}.
21194 Defaults to @samp{disabled}.
21198 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21199 Enable USB autosuspend before shutdown.
21201 Defaults to @samp{disabled}.
21205 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21206 Restore radio device state (bluetooth, wifi, wwan) from previous
21207 shutdown on system startup.
21209 Defaults to @samp{#f}.
21214 @cindex CPU frequency scaling with thermald
21215 @subsubheading Thermald daemon
21217 The @code{(gnu services pm)} module provides an interface to
21218 thermald, a CPU frequency scaling service which helps prevent overheating.
21220 @defvr {Scheme Variable} thermald-service-type
21221 This is the service type for
21222 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21223 Thermal Daemon, which is responsible for controlling the thermal state
21224 of processors and preventing overheating.
21227 @deftp {Data Type} thermald-configuration
21228 Data type representing the configuration of @code{thermald-service-type}.
21231 @item @code{ignore-cpuid-check?} (default: @code{#f})
21232 Ignore cpuid check for supported CPU models.
21234 @item @code{thermald} (default: @var{thermald})
21235 Package object of thermald.
21240 @node Audio Services
21241 @subsection Audio Services
21243 The @code{(gnu services audio)} module provides a service to start MPD
21244 (the Music Player Daemon).
21247 @subsubheading Music Player Daemon
21249 The Music Player Daemon (MPD) is a service that can play music while
21250 being controlled from the local machine or over the network by a variety
21253 The following example shows how one might run @code{mpd} as user
21254 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21257 (service mpd-service-type
21263 @defvr {Scheme Variable} mpd-service-type
21264 The service type for @command{mpd}
21267 @deftp {Data Type} mpd-configuration
21268 Data type representing the configuration of @command{mpd}.
21271 @item @code{user} (default: @code{"mpd"})
21272 The user to run mpd as.
21274 @item @code{music-dir} (default: @code{"~/Music"})
21275 The directory to scan for music files.
21277 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21278 The directory to store playlists.
21280 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21281 The location of the music database.
21283 @item @code{state-file} (default: @code{"~/.mpd/state"})
21284 The location of the file that stores current MPD's state.
21286 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21287 The location of the sticker database.
21289 @item @code{port} (default: @code{"6600"})
21290 The port to run mpd on.
21292 @item @code{address} (default: @code{"any"})
21293 The address that mpd will bind to. To use a Unix domain socket,
21294 an absolute path can be specified here.
21299 @node Virtualization Services
21300 @subsection Virtualization services
21302 The @code{(gnu services virtualization)} module provides services for
21303 the libvirt and virtlog daemons, as well as other virtualization-related
21306 @subsubheading Libvirt daemon
21307 @code{libvirtd} is the server side daemon component of the libvirt
21308 virtualization management system. This daemon runs on host servers
21309 and performs required management tasks for virtualized guests.
21311 @deffn {Scheme Variable} libvirt-service-type
21312 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21313 Its value must be a @code{libvirt-configuration}.
21316 (service libvirt-service-type
21317 (libvirt-configuration
21318 (unix-sock-group "libvirt")
21319 (tls-port "16555")))
21323 @c Auto-generated with (generate-libvirt-documentation)
21324 Available @code{libvirt-configuration} fields are:
21326 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21331 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21332 Flag listening for secure TLS connections on the public TCP/IP port.
21333 must set @code{listen} for this to have any effect.
21335 It is necessary to setup a CA and issue server certificates before using
21338 Defaults to @samp{#t}.
21342 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21343 Listen for unencrypted TCP connections on the public TCP/IP port. must
21344 set @code{listen} for this to have any effect.
21346 Using the TCP socket requires SASL authentication by default. Only SASL
21347 mechanisms which support data encryption are allowed. This is
21348 DIGEST_MD5 and GSSAPI (Kerberos5)
21350 Defaults to @samp{#f}.
21354 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21355 Port for accepting secure TLS connections This can be a port number, or
21358 Defaults to @samp{"16514"}.
21362 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21363 Port for accepting insecure TCP connections This can be a port number,
21366 Defaults to @samp{"16509"}.
21370 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21371 IP address or hostname used for client connections.
21373 Defaults to @samp{"0.0.0.0"}.
21377 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21378 Flag toggling mDNS advertisement of the libvirt service.
21380 Alternatively can disable for all services on a host by stopping the
21383 Defaults to @samp{#f}.
21387 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
21388 Default mDNS advertisement name. This must be unique on the immediate
21391 Defaults to @samp{"Virtualization Host <hostname>"}.
21395 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
21396 UNIX domain socket group ownership. This can be used to allow a
21397 'trusted' set of users access to management capabilities without
21400 Defaults to @samp{"root"}.
21404 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
21405 UNIX socket permissions for the R/O socket. This is used for monitoring
21408 Defaults to @samp{"0777"}.
21412 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
21413 UNIX socket permissions for the R/W socket. Default allows only root.
21414 If PolicyKit is enabled on the socket, the default will change to allow
21415 everyone (eg, 0777)
21417 Defaults to @samp{"0770"}.
21421 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
21422 UNIX socket permissions for the admin socket. Default allows only owner
21423 (root), do not change it unless you are sure to whom you are exposing
21426 Defaults to @samp{"0777"}.
21430 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
21431 The directory in which sockets will be found/created.
21433 Defaults to @samp{"/var/run/libvirt"}.
21437 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
21438 Authentication scheme for UNIX read-only sockets. By default socket
21439 permissions allow anyone to connect
21441 Defaults to @samp{"polkit"}.
21445 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
21446 Authentication scheme for UNIX read-write sockets. By default socket
21447 permissions only allow root. If PolicyKit support was compiled into
21448 libvirt, the default will be to use 'polkit' auth.
21450 Defaults to @samp{"polkit"}.
21454 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
21455 Authentication scheme for TCP sockets. If you don't enable SASL, then
21456 all TCP traffic is cleartext. Don't do this outside of a dev/test
21459 Defaults to @samp{"sasl"}.
21463 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
21464 Authentication scheme for TLS sockets. TLS sockets already have
21465 encryption provided by the TLS layer, and limited authentication is done
21468 It is possible to make use of any SASL authentication mechanism as well,
21469 by using 'sasl' for this option
21471 Defaults to @samp{"none"}.
21475 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
21476 API access control scheme.
21478 By default an authenticated user is allowed access to all APIs. Access
21479 drivers can place restrictions on this.
21481 Defaults to @samp{()}.
21485 @deftypevr {@code{libvirt-configuration} parameter} string key-file
21486 Server key file path. If set to an empty string, then no private key is
21489 Defaults to @samp{""}.
21493 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
21494 Server key file path. If set to an empty string, then no certificate is
21497 Defaults to @samp{""}.
21501 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
21502 Server key file path. If set to an empty string, then no CA certificate
21505 Defaults to @samp{""}.
21509 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
21510 Certificate revocation list path. If set to an empty string, then no
21513 Defaults to @samp{""}.
21517 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
21518 Disable verification of our own server certificates.
21520 When libvirtd starts it performs some sanity checks against its own
21523 Defaults to @samp{#f}.
21527 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
21528 Disable verification of client certificates.
21530 Client certificate verification is the primary authentication mechanism.
21531 Any client which does not present a certificate signed by the CA will be
21534 Defaults to @samp{#f}.
21538 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
21539 Whitelist of allowed x509 Distinguished Name.
21541 Defaults to @samp{()}.
21545 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
21546 Whitelist of allowed SASL usernames. The format for username depends on
21547 the SASL authentication mechanism.
21549 Defaults to @samp{()}.
21553 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
21554 Override the compile time default TLS priority string. The default is
21555 usually "NORMAL" unless overridden at build time. Only set this is it
21556 is desired for libvirt to deviate from the global default settings.
21558 Defaults to @samp{"NORMAL"}.
21562 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
21563 Maximum number of concurrent client connections to allow over all
21566 Defaults to @samp{5000}.
21570 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
21571 Maximum length of queue of connections waiting to be accepted by the
21572 daemon. Note, that some protocols supporting retransmission may obey
21573 this so that a later reattempt at connection succeeds.
21575 Defaults to @samp{1000}.
21579 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
21580 Maximum length of queue of accepted but not yet authenticated clients.
21581 Set this to zero to turn this feature off
21583 Defaults to @samp{20}.
21587 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
21588 Number of workers to start up initially.
21590 Defaults to @samp{5}.
21594 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
21595 Maximum number of worker threads.
21597 If the number of active clients exceeds @code{min-workers}, then more
21598 threads are spawned, up to max_workers limit. Typically you'd want
21599 max_workers to equal maximum number of clients allowed.
21601 Defaults to @samp{20}.
21605 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
21606 Number of priority workers. If all workers from above pool are stuck,
21607 some calls marked as high priority (notably domainDestroy) can be
21608 executed in this pool.
21610 Defaults to @samp{5}.
21614 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
21615 Total global limit on concurrent RPC calls.
21617 Defaults to @samp{20}.
21621 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
21622 Limit on concurrent requests from a single client connection. To avoid
21623 one client monopolizing the server this should be a small fraction of
21624 the global max_requests and max_workers parameter.
21626 Defaults to @samp{5}.
21630 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
21631 Same as @code{min-workers} but for the admin interface.
21633 Defaults to @samp{1}.
21637 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
21638 Same as @code{max-workers} but for the admin interface.
21640 Defaults to @samp{5}.
21644 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
21645 Same as @code{max-clients} but for the admin interface.
21647 Defaults to @samp{5}.
21651 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
21652 Same as @code{max-queued-clients} but for the admin interface.
21654 Defaults to @samp{5}.
21658 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
21659 Same as @code{max-client-requests} but for the admin interface.
21661 Defaults to @samp{5}.
21665 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
21666 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21668 Defaults to @samp{3}.
21672 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
21675 A filter allows to select a different logging level for a given category
21676 of logs The format for a filter is one of:
21687 where @code{name} is a string which is matched against the category
21688 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21689 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21690 be a substring of the full category name, in order to match multiple
21691 similar categories), the optional "+" prefix tells libvirt to log stack
21692 trace for each message matching name, and @code{x} is the minimal level
21693 where matching messages should be logged:
21710 Multiple filters can be defined in a single filters statement, they just
21711 need to be separated by spaces.
21713 Defaults to @samp{"3:remote 4:event"}.
21717 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
21720 An output is one of the places to save logging information The format
21721 for an output can be:
21725 output goes to stderr
21727 @item x:syslog:name
21728 use syslog for the output and use the given name as the ident
21730 @item x:file:file_path
21731 output to a file, with the given filepath
21734 output to journald logging system
21738 In all case the x prefix is the minimal level, acting as a filter
21755 Multiple outputs can be defined, they just need to be separated by
21758 Defaults to @samp{"3:stderr"}.
21762 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
21763 Allows usage of the auditing subsystem to be altered
21767 0: disable all auditing
21770 1: enable auditing, only if enabled on host
21773 2: enable auditing, and exit if disabled on host.
21777 Defaults to @samp{1}.
21781 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
21782 Send audit messages via libvirt logging infrastructure.
21784 Defaults to @samp{#f}.
21788 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
21789 Host UUID. UUID must not have all digits be the same.
21791 Defaults to @samp{""}.
21795 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
21796 Source to read host UUID.
21800 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
21803 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
21807 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
21810 Defaults to @samp{"smbios"}.
21814 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
21815 A keepalive message is sent to a client after @code{keepalive_interval}
21816 seconds of inactivity to check if the client is still responding. If
21817 set to -1, libvirtd will never send keepalive requests; however clients
21818 can still send them and the daemon will send responses.
21820 Defaults to @samp{5}.
21824 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
21825 Maximum number of keepalive messages that are allowed to be sent to the
21826 client without getting any response before the connection is considered
21829 In other words, the connection is automatically closed approximately
21830 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
21831 the last message received from the client. When @code{keepalive-count}
21832 is set to 0, connections will be automatically closed after
21833 @code{keepalive-interval} seconds of inactivity without sending any
21834 keepalive messages.
21836 Defaults to @samp{5}.
21840 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
21841 Same as above but for admin interface.
21843 Defaults to @samp{5}.
21847 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
21848 Same as above but for admin interface.
21850 Defaults to @samp{5}.
21854 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
21855 Timeout for Open vSwitch calls.
21857 The @code{ovs-vsctl} utility is used for the configuration and its
21858 timeout option is set by default to 5 seconds to avoid potential
21859 infinite waits blocking libvirt.
21861 Defaults to @samp{5}.
21865 @c %end of autogenerated docs
21867 @subsubheading Virtlog daemon
21868 The virtlogd service is a server side daemon component of libvirt that is
21869 used to manage logs from virtual machine consoles.
21871 This daemon is not used directly by libvirt client applications, rather it
21872 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
21873 standalone daemon, the main @code{libvirtd} daemon can be restarted without
21874 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
21875 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
21877 @deffn {Scheme Variable} virtlog-service-type
21878 This is the type of the virtlog daemon.
21879 Its value must be a @code{virtlog-configuration}.
21882 (service virtlog-service-type
21883 (virtlog-configuration
21884 (max-clients 1000)))
21888 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
21889 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
21891 Defaults to @samp{3}.
21895 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
21898 A filter allows to select a different logging level for a given category
21899 of logs The format for a filter is one of:
21910 where @code{name} is a string which is matched against the category
21911 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
21912 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
21913 be a substring of the full category name, in order to match multiple
21914 similar categories), the optional "+" prefix tells libvirt to log stack
21915 trace for each message matching name, and @code{x} is the minimal level
21916 where matching messages should be logged:
21933 Multiple filters can be defined in a single filters statement, they just
21934 need to be separated by spaces.
21936 Defaults to @samp{"3:remote 4:event"}.
21940 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
21943 An output is one of the places to save logging information The format
21944 for an output can be:
21948 output goes to stderr
21950 @item x:syslog:name
21951 use syslog for the output and use the given name as the ident
21953 @item x:file:file_path
21954 output to a file, with the given filepath
21957 output to journald logging system
21961 In all case the x prefix is the minimal level, acting as a filter
21978 Multiple outputs can be defined, they just need to be separated by
21981 Defaults to @samp{"3:stderr"}.
21985 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
21986 Maximum number of concurrent client connections to allow over all
21989 Defaults to @samp{1024}.
21993 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
21994 Maximum file size before rolling over.
21996 Defaults to @samp{2MB}
22000 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22001 Maximum number of backup files to keep.
22003 Defaults to @samp{3}
22007 @subsubheading Transparent Emulation with QEMU
22010 @cindex @code{binfmt_misc}
22011 @code{qemu-binfmt-service-type} provides support for transparent
22012 emulation of program binaries built for different architectures---e.g.,
22013 it allows you to transparently execute an ARMv7 program on an x86_64
22014 machine. It achieves this by combining the @uref{https://www.qemu.org,
22015 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22017 @defvr {Scheme Variable} qemu-binfmt-service-type
22018 This is the type of the QEMU/binfmt service for transparent emulation.
22019 Its value must be a @code{qemu-binfmt-configuration} object, which
22020 specifies the QEMU package to use as well as the architecture we want to
22024 (service qemu-binfmt-service-type
22025 (qemu-binfmt-configuration
22026 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22029 In this example, we enable transparent emulation for the ARM and aarch64
22030 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22031 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22032 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22035 @deftp {Data Type} qemu-binfmt-configuration
22036 This is the configuration for the @code{qemu-binfmt} service.
22039 @item @code{platforms} (default: @code{'()})
22040 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22041 object} as returned by @code{lookup-qemu-platforms} (see below).
22043 @item @code{guix-support?} (default: @code{#f})
22044 When it is true, QEMU and all its dependencies are added to the build
22045 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22046 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22047 handlers to be used within the build environment, which in turn means
22048 that you can transparently build programs for another architecture.
22050 For example, let's suppose you're on an x86_64 machine and you have this
22054 (service qemu-binfmt-service-type
22055 (qemu-binfmt-configuration
22056 (platforms (lookup-qemu-platforms "arm"))
22057 (guix-support? #t)))
22063 guix build -s armhf-linux inkscape
22067 and it will build Inkscape for ARMv7 @emph{as if it were a native
22068 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22069 if you'd like to test a package build for an architecture you don't have
22072 @item @code{qemu} (default: @code{qemu})
22073 The QEMU package to use.
22077 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22078 Return the list of QEMU platform objects corresponding to
22079 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22080 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22081 @code{"mips64el"}, and so on.
22084 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22085 Return true if @var{obj} is a platform object.
22088 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22089 Return the name of @var{platform}---a string such as @code{"arm"}.
22092 @node Version Control Services
22093 @subsection Version Control Services
22095 The @code{(gnu services version-control)} module provides a service to
22096 allow remote access to local Git repositories. There are three options:
22097 the @code{git-daemon-service}, which provides access to repositories via
22098 the @code{git://} unsecured TCP-based protocol, extending the
22099 @code{nginx} web server to proxy some requests to
22100 @code{git-http-backend}, or providing a web interface with
22101 @code{cgit-service-type}.
22103 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22105 Return a service that runs @command{git daemon}, a simple TCP server to
22106 expose repositories over the Git protocol for anonymous access.
22108 The optional @var{config} argument should be a
22109 @code{<git-daemon-configuration>} object, by default it allows read-only
22110 access to exported@footnote{By creating the magic file
22111 "git-daemon-export-ok" in the repository directory.} repositories under
22116 @deftp {Data Type} git-daemon-configuration
22117 Data type representing the configuration for @code{git-daemon-service}.
22120 @item @code{package} (default: @var{git})
22121 Package object of the Git distributed version control system.
22123 @item @code{export-all?} (default: @var{#f})
22124 Whether to allow access for all Git repositories, even if they do not
22125 have the @file{git-daemon-export-ok} file.
22127 @item @code{base-path} (default: @file{/srv/git})
22128 Whether to remap all the path requests as relative to the given path.
22129 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22130 then if you later try to pull @code{git://example.com/hello.git}, git
22131 daemon will interpret the path as @code{/srv/git/hello.git}.
22133 @item @code{user-path} (default: @var{#f})
22134 Whether to allow @code{~user} notation to be used in requests. When
22135 specified with empty string, requests to @code{git://host/~alice/foo} is
22136 taken as a request to access @code{foo} repository in the home directory
22137 of user @code{alice}. If @var{(user-path "path")} is specified, the
22138 same request is taken as a request to access @code{path/foo} repository
22139 in the home directory of user @code{alice}.
22141 @item @code{listen} (default: @var{'()})
22142 Whether to listen on specific IP addresses or hostnames, defaults to
22145 @item @code{port} (default: @var{#f})
22146 Whether to listen on an alternative port, which defaults to 9418.
22148 @item @code{whitelist} (default: @var{'()})
22149 If not empty, only allow access to this list of directories.
22151 @item @code{extra-options} (default: @var{'()})
22152 Extra options will be passed to @code{git daemon}, please run
22153 @command{man git-daemon} for more information.
22158 The @code{git://} protocol lacks authentication. When you pull from a
22159 repository fetched via @code{git://}, you don't know that the data you
22160 receive was modified is really coming from the specified host, and you
22161 have your connection is subject to eavesdropping. It's better to use an
22162 authenticated and encrypted transport, such as @code{https}. Although Git allows you
22163 to serve repositories using unsophisticated file-based web servers,
22164 there is a faster protocol implemented by the @code{git-http-backend}
22165 program. This program is the back-end of a proper Git web service. It
22166 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22167 on running the necessary @code{fcgiwrap} daemon.
22169 Guix has a separate configuration data type for serving Git repositories
22172 @deftp {Data Type} git-http-configuration
22173 Data type representing the configuration for @code{git-http-service}.
22176 @item @code{package} (default: @var{git})
22177 Package object of the Git distributed version control system.
22179 @item @code{git-root} (default: @file{/srv/git})
22180 Directory containing the Git repositories to expose to the world.
22182 @item @code{export-all?} (default: @var{#f})
22183 Whether to expose access for all Git repositories in @var{git-root},
22184 even if they do not have the @file{git-daemon-export-ok} file.
22186 @item @code{uri-path} (default: @file{/git/})
22187 Path prefix for Git access. With the default @code{/git/} prefix, this
22188 will map @code{http://@var{server}/git/@var{repo}.git} to
22189 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22190 with this prefix are not passed on to this Git instance.
22192 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22193 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22198 There is no @code{git-http-service-type}, currently; instead you can
22199 create an @code{nginx-location-configuration} from a
22200 @code{git-http-configuration} and then add that location to a web
22203 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22204 [config=(git-http-configuration)]
22205 Compute an @code{nginx-location-configuration} that corresponds to the
22206 given Git http configuration. An example nginx service definition to
22207 serve the default @file{/srv/git} over HTTPS might be:
22210 (service nginx-service-type
22211 (nginx-configuration
22214 (nginx-server-configuration
22215 (listen '("443 ssl"))
22216 (server-name "git.my-host.org")
22218 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22219 (ssl-certificate-key
22220 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22223 (git-http-nginx-location-configuration
22224 (git-http-configuration (uri-path "/"))))))))))
22227 This example assumes that you are using Let's Encrypt to get your TLS
22228 certificate. @xref{Certificate Services}. The default @code{certbot}
22229 service will redirect all HTTP traffic on @code{git.my-host.org} to
22230 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22231 system services. @xref{Web Services}.
22234 @subsubheading Cgit Service
22236 @cindex Cgit service
22237 @cindex Git, web interface
22238 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22239 repositories written in C.
22241 The following example will configure the service with default values.
22242 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22245 (service cgit-service-type)
22248 The @code{file-object} type designates either a file-like object
22249 (@pxref{G-Expressions, file-like objects}) or a string.
22251 @c %start of fragment
22253 Available @code{cgit-configuration} fields are:
22255 @deftypevr {@code{cgit-configuration} parameter} package package
22260 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22261 NGINX configuration.
22265 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22266 Specifies a command which will be invoked to format the content of about
22267 pages (both top-level and for each repository).
22269 Defaults to @samp{""}.
22273 @deftypevr {@code{cgit-configuration} parameter} string agefile
22274 Specifies a path, relative to each repository path, which can be used to
22275 specify the date and time of the youngest commit in the repository.
22277 Defaults to @samp{""}.
22281 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22282 Specifies a command that will be invoked for authenticating repository
22285 Defaults to @samp{""}.
22289 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22290 Flag which, when set to @samp{age}, enables date ordering in the branch
22291 ref list, and when set @samp{name} enables ordering by branch name.
22293 Defaults to @samp{"name"}.
22297 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22298 Path used to store the cgit cache entries.
22300 Defaults to @samp{"/var/cache/cgit"}.
22304 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22305 Number which specifies the time-to-live, in minutes, for the cached
22306 version of repository pages accessed with a fixed SHA1.
22308 Defaults to @samp{-1}.
22312 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22313 Number which specifies the time-to-live, in minutes, for the cached
22314 version of repository pages accessed without a fixed SHA1.
22316 Defaults to @samp{5}.
22320 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22321 Number which specifies the time-to-live, in minutes, for the cached
22322 version of the repository summary page.
22324 Defaults to @samp{5}.
22328 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22329 Number which specifies the time-to-live, in minutes, for the cached
22330 version of the repository index page.
22332 Defaults to @samp{5}.
22336 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22337 Number which specifies the time-to-live, in minutes, for the result of
22338 scanning a path for Git repositories.
22340 Defaults to @samp{15}.
22344 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22345 Number which specifies the time-to-live, in minutes, for the cached
22346 version of the repository about page.
22348 Defaults to @samp{15}.
22352 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22353 Number which specifies the time-to-live, in minutes, for the cached
22354 version of snapshots.
22356 Defaults to @samp{5}.
22360 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22361 The maximum number of entries in the cgit cache. When set to @samp{0},
22362 caching is disabled.
22364 Defaults to @samp{0}.
22368 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22369 Sort items in the repo list case sensitively.
22371 Defaults to @samp{#t}.
22375 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22376 List of common prefixes which, when combined with a repository URL,
22377 generates valid clone URLs for the repository.
22379 Defaults to @samp{()}.
22383 @deftypevr {@code{cgit-configuration} parameter} list clone-url
22384 List of @code{clone-url} templates.
22386 Defaults to @samp{()}.
22390 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
22391 Command which will be invoked to format commit messages.
22393 Defaults to @samp{""}.
22397 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
22398 Flag which, when set to @samp{date}, enables strict date ordering in the
22399 commit log, and when set to @samp{topo} enables strict topological
22402 Defaults to @samp{"git log"}.
22406 @deftypevr {@code{cgit-configuration} parameter} file-object css
22407 URL which specifies the css document to include in all cgit pages.
22409 Defaults to @samp{"/share/cgit/cgit.css"}.
22413 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
22414 Specifies a command which will be invoked to format names and email
22415 address of committers, authors, and taggers, as represented in various
22416 places throughout the cgit interface.
22418 Defaults to @samp{""}.
22422 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
22423 Flag which, when set to @samp{#t}, will make cgit generate a HTML
22424 fragment suitable for embedding in other HTML pages.
22426 Defaults to @samp{#f}.
22430 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
22431 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
22432 commit history graph to the left of the commit messages in the
22433 repository log page.
22435 Defaults to @samp{#f}.
22439 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
22440 Flag which, when set to @samp{#t}, allows all filter settings to be
22441 overridden in repository-specific cgitrc files.
22443 Defaults to @samp{#f}.
22447 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
22448 Flag which, when set to @samp{#t}, allows users to follow a file in the
22451 Defaults to @samp{#f}.
22455 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
22456 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
22459 Defaults to @samp{#t}.
22463 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
22464 Flag which, when set to @samp{#t}, will make cgit generate extra links
22465 "summary", "commit", "tree" for each repo in the repository index.
22467 Defaults to @samp{#f}.
22471 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
22472 Flag which, when set to @samp{#t}, will make cgit display the owner of
22473 each repo in the repository index.
22475 Defaults to @samp{#t}.
22479 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
22480 Flag which, when set to @samp{#t}, will make cgit print the number of
22481 modified files for each commit on the repository log page.
22483 Defaults to @samp{#f}.
22487 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
22488 Flag which, when set to @samp{#t}, will make cgit print the number of
22489 added and removed lines for each commit on the repository log page.
22491 Defaults to @samp{#f}.
22495 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
22496 Flag which, when set to @code{#t}, will make cgit display remote
22497 branches in the summary and refs views.
22499 Defaults to @samp{#f}.
22503 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
22504 Flag which, when set to @code{1}, will make cgit use the subject of the
22505 parent commit as link text when generating links to parent commits in
22508 Defaults to @samp{#f}.
22512 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
22513 Flag which, when set to @samp{#t}, will make cgit use the subject of the
22514 parent commit as link text when generating links to parent commits in
22517 Defaults to @samp{#f}.
22521 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
22522 Flag which, when set to @samp{#t}, will make cgit generate linenumber
22523 links for plaintext blobs printed in the tree view.
22525 Defaults to @samp{#t}.
22529 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
22530 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
22531 set any repo specific settings.
22533 Defaults to @samp{#f}.
22537 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
22538 URL used as link to a shortcut icon for cgit.
22540 Defaults to @samp{"/favicon.ico"}.
22544 @deftypevr {@code{cgit-configuration} parameter} string footer
22545 The content of the file specified with this option will be included
22546 verbatim at the bottom of all pages (i.e.@: it replaces the standard
22547 "generated by..."@: message).
22549 Defaults to @samp{""}.
22553 @deftypevr {@code{cgit-configuration} parameter} string head-include
22554 The content of the file specified with this option will be included
22555 verbatim in the HTML HEAD section on all pages.
22557 Defaults to @samp{""}.
22561 @deftypevr {@code{cgit-configuration} parameter} string header
22562 The content of the file specified with this option will be included
22563 verbatim at the top of all pages.
22565 Defaults to @samp{""}.
22569 @deftypevr {@code{cgit-configuration} parameter} file-object include
22570 Name of a configfile to include before the rest of the current config-
22573 Defaults to @samp{""}.
22577 @deftypevr {@code{cgit-configuration} parameter} string index-header
22578 The content of the file specified with this option will be included
22579 verbatim above the repository index.
22581 Defaults to @samp{""}.
22585 @deftypevr {@code{cgit-configuration} parameter} string index-info
22586 The content of the file specified with this option will be included
22587 verbatim below the heading on the repository index page.
22589 Defaults to @samp{""}.
22593 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
22594 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
22595 in the servers timezone.
22597 Defaults to @samp{#f}.
22601 @deftypevr {@code{cgit-configuration} parameter} file-object logo
22602 URL which specifies the source of an image which will be used as a logo
22605 Defaults to @samp{"/share/cgit/cgit.png"}.
22609 @deftypevr {@code{cgit-configuration} parameter} string logo-link
22610 URL loaded when clicking on the cgit logo image.
22612 Defaults to @samp{""}.
22616 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
22617 Command which will be invoked to format the Owner column of the main
22620 Defaults to @samp{""}.
22624 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
22625 Number of items to display in atom feeds view.
22627 Defaults to @samp{10}.
22631 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
22632 Number of entries to list per page in "log" view.
22634 Defaults to @samp{50}.
22638 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
22639 Number of commit message characters to display in "log" view.
22641 Defaults to @samp{80}.
22645 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
22646 Specifies the number of entries to list per page on the repository index
22649 Defaults to @samp{50}.
22653 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
22654 Specifies the maximum number of repo description characters to display
22655 on the repository index page.
22657 Defaults to @samp{80}.
22661 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
22662 Specifies the maximum size of a blob to display HTML for in KBytes.
22664 Defaults to @samp{0}.
22668 @deftypevr {@code{cgit-configuration} parameter} string max-stats
22669 Maximum statistics period. Valid values are @samp{week},@samp{month},
22670 @samp{quarter} and @samp{year}.
22672 Defaults to @samp{""}.
22676 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
22677 Mimetype for the specified filename extension.
22679 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
22680 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
22681 "image/png") (svg "image/svg+xml"))}.
22685 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
22686 Specifies the file to use for automatic mimetype lookup.
22688 Defaults to @samp{""}.
22692 @deftypevr {@code{cgit-configuration} parameter} string module-link
22693 Text which will be used as the formatstring for a hyperlink when a
22694 submodule is printed in a directory listing.
22696 Defaults to @samp{""}.
22700 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
22701 If set to the value @samp{#t} caching will be disabled.
22703 Defaults to @samp{#f}.
22707 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
22708 If set to @samp{#t} showing full author email addresses will be
22711 Defaults to @samp{#f}.
22715 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
22716 Flag which, when set to @samp{#t}, will make cgit omit the standard
22717 header on all pages.
22719 Defaults to @samp{#f}.
22723 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
22724 A list of subdirectories inside of @code{repository-directory}, relative
22725 to it, that should loaded as Git repositories. An empty list means that
22726 all subdirectories will be loaded.
22728 Defaults to @samp{()}.
22732 @deftypevr {@code{cgit-configuration} parameter} file-object readme
22733 Text which will be used as default value for @code{cgit-repo-readme}.
22735 Defaults to @samp{""}.
22739 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
22740 If set to @code{#t} and @code{repository-directory} is enabled, if any
22741 repositories are found with a suffix of @code{.git}, this suffix will be
22742 removed for the URL and name.
22744 Defaults to @samp{#f}.
22748 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
22749 Maximum number of files to consider when detecting renames.
22751 Defaults to @samp{-1}.
22755 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
22756 The way in which repositories in each section are sorted.
22758 Defaults to @samp{""}.
22762 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
22763 Text used as content for the @code{robots} meta-tag.
22765 Defaults to @samp{("noindex" "nofollow")}.
22769 @deftypevr {@code{cgit-configuration} parameter} string root-desc
22770 Text printed below the heading on the repository index page.
22772 Defaults to @samp{"a fast webinterface for the git dscm"}.
22776 @deftypevr {@code{cgit-configuration} parameter} string root-readme
22777 The content of the file specified with this option will be included
22778 verbatim below thef "about" link on the repository index page.
22780 Defaults to @samp{""}.
22784 @deftypevr {@code{cgit-configuration} parameter} string root-title
22785 Text printed as heading on the repository index page.
22787 Defaults to @samp{""}.
22791 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
22792 If set to @samp{#t} and repository-directory is enabled,
22793 repository-directory will recurse into directories whose name starts
22794 with a period. Otherwise, repository-directory will stay away from such
22795 directories, considered as "hidden". Note that this does not apply to
22796 the ".git" directory in non-bare repos.
22798 Defaults to @samp{#f}.
22802 @deftypevr {@code{cgit-configuration} parameter} list snapshots
22803 Text which specifies the default set of snapshot formats that cgit
22804 generates links for.
22806 Defaults to @samp{()}.
22810 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
22811 Name of the directory to scan for repositories (represents
22814 Defaults to @samp{"/srv/git"}.
22818 @deftypevr {@code{cgit-configuration} parameter} string section
22819 The name of the current repository section - all repositories defined
22820 after this option will inherit the current section name.
22822 Defaults to @samp{""}.
22826 @deftypevr {@code{cgit-configuration} parameter} string section-sort
22827 Flag which, when set to @samp{1}, will sort the sections on the
22828 repository listing by name.
22830 Defaults to @samp{""}.
22834 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
22835 A number which, if defined prior to repository-directory, specifies how
22836 many path elements from each repo path to use as a default section name.
22838 Defaults to @samp{0}.
22842 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
22843 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
22846 Defaults to @samp{#f}.
22850 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
22851 Specifies a command which will be invoked to format plaintext blobs in
22854 Defaults to @samp{""}.
22858 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
22859 Specifies the number of branches to display in the repository "summary"
22862 Defaults to @samp{10}.
22866 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
22867 Specifies the number of log entries to display in the repository
22870 Defaults to @samp{10}.
22874 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
22875 Specifies the number of tags to display in the repository "summary"
22878 Defaults to @samp{10}.
22882 @deftypevr {@code{cgit-configuration} parameter} string strict-export
22883 Filename which, if specified, needs to be present within the repository
22884 for cgit to allow access to that repository.
22886 Defaults to @samp{""}.
22890 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
22891 URL which, if specified, will be used as root for all cgit links.
22893 Defaults to @samp{"/"}.
22897 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
22898 A list of @dfn{cgit-repo} records to use with config.
22900 Defaults to @samp{()}.
22902 Available @code{repository-cgit-configuration} fields are:
22904 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
22905 A mask of snapshot formats for this repo that cgit generates links for,
22906 restricted by the global @code{snapshots} setting.
22908 Defaults to @samp{()}.
22912 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
22913 Override the default @code{source-filter}.
22915 Defaults to @samp{""}.
22919 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
22920 The relative URL used to access the repository.
22922 Defaults to @samp{""}.
22926 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
22927 Override the default @code{about-filter}.
22929 Defaults to @samp{""}.
22933 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
22934 Flag which, when set to @samp{age}, enables date ordering in the branch
22935 ref list, and when set to @samp{name} enables ordering by branch name.
22937 Defaults to @samp{""}.
22941 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
22942 A list of URLs which can be used to clone repo.
22944 Defaults to @samp{()}.
22948 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
22949 Override the default @code{commit-filter}.
22951 Defaults to @samp{""}.
22955 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
22956 Flag which, when set to @samp{date}, enables strict date ordering in the
22957 commit log, and when set to @samp{topo} enables strict topological
22960 Defaults to @samp{""}.
22964 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
22965 The name of the default branch for this repository. If no such branch
22966 exists in the repository, the first branch name (when sorted) is used as
22967 default instead. By default branch pointed to by HEAD, or "master" if
22968 there is no suitable HEAD.
22970 Defaults to @samp{""}.
22974 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
22975 The value to show as repository description.
22977 Defaults to @samp{""}.
22981 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
22982 The value to show as repository homepage.
22984 Defaults to @samp{""}.
22988 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
22989 Override the default @code{email-filter}.
22991 Defaults to @samp{""}.
22995 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
22996 A flag which can be used to disable the global setting
22997 @code{enable-commit-graph?}.
22999 Defaults to @samp{disabled}.
23003 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23004 A flag which can be used to disable the global setting
23005 @code{enable-log-filecount?}.
23007 Defaults to @samp{disabled}.
23011 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23012 A flag which can be used to disable the global setting
23013 @code{enable-log-linecount?}.
23015 Defaults to @samp{disabled}.
23019 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23020 Flag which, when set to @code{#t}, will make cgit display remote
23021 branches in the summary and refs views.
23023 Defaults to @samp{disabled}.
23027 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23028 A flag which can be used to override the global setting
23029 @code{enable-subject-links?}.
23031 Defaults to @samp{disabled}.
23035 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23036 A flag which can be used to override the global setting
23037 @code{enable-html-serving?}.
23039 Defaults to @samp{disabled}.
23043 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23044 Flag which, when set to @code{#t}, hides the repository from the
23047 Defaults to @samp{#f}.
23051 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23052 Flag which, when set to @samp{#t}, ignores the repository.
23054 Defaults to @samp{#f}.
23058 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23059 URL which specifies the source of an image which will be used as a logo
23060 on this repo’s pages.
23062 Defaults to @samp{""}.
23066 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23067 URL loaded when clicking on the cgit logo image.
23069 Defaults to @samp{""}.
23073 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23074 Override the default @code{owner-filter}.
23076 Defaults to @samp{""}.
23080 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23081 Text which will be used as the formatstring for a hyperlink when a
23082 submodule is printed in a directory listing. The arguments for the
23083 formatstring are the path and SHA1 of the submodule commit.
23085 Defaults to @samp{""}.
23089 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23090 Text which will be used as the formatstring for a hyperlink when a
23091 submodule with the specified subdirectory path is printed in a directory
23094 Defaults to @samp{()}.
23098 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23099 Override the default maximum statistics period.
23101 Defaults to @samp{""}.
23105 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23106 The value to show as repository name.
23108 Defaults to @samp{""}.
23112 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23113 A value used to identify the owner of the repository.
23115 Defaults to @samp{""}.
23119 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23120 An absolute path to the repository directory.
23122 Defaults to @samp{""}.
23126 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23127 A path (relative to repo) which specifies a file to include verbatim as
23128 the "About" page for this repo.
23130 Defaults to @samp{""}.
23134 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23135 The name of the current repository section - all repositories defined
23136 after this option will inherit the current section name.
23138 Defaults to @samp{""}.
23142 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23143 Extra options will be appended to cgitrc file.
23145 Defaults to @samp{()}.
23151 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23152 Extra options will be appended to cgitrc file.
23154 Defaults to @samp{()}.
23159 @c %end of fragment
23161 However, it could be that you just want to get a @code{cgitrc} up and
23162 running. In that case, you can pass an @code{opaque-cgit-configuration}
23163 as a record to @code{cgit-service-type}. As its name indicates, an
23164 opaque configuration does not have easy reflective capabilities.
23166 Available @code{opaque-cgit-configuration} fields are:
23168 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23172 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23173 The contents of the @code{cgitrc}, as a string.
23176 For example, if your @code{cgitrc} is just the empty string, you
23177 could instantiate a cgit service like this:
23180 (service cgit-service-type
23181 (opaque-cgit-configuration
23185 @subsubheading Gitolite Service
23187 @cindex Gitolite service
23188 @cindex Git, hosting
23189 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23190 repositories on a central server.
23192 Gitolite can handle multiple repositories and users, and supports flexible
23193 configuration of the permissions for the users on the repositories.
23195 The following example will configure Gitolite using the default @code{git}
23196 user, and the provided SSH public key.
23199 (service gitolite-service-type
23200 (gitolite-configuration
23201 (admin-pubkey (plain-file
23203 "ssh-rsa AAAA... guix@@example.com"))))
23206 Gitolite is configured through a special admin repository which you can clone,
23207 for example, if you setup Gitolite on @code{example.com}, you would run the
23208 following command to clone the admin repository.
23211 git clone git@@example.com:gitolite-admin
23214 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23215 be inserted in to the @file{keydir} directory in the gitolite-admin
23216 repository. If this results in a change in the repository, it will be
23217 committed using the message ``gitolite setup by GNU Guix''.
23219 @deftp {Data Type} gitolite-configuration
23220 Data type representing the configuration for @code{gitolite-service-type}.
23223 @item @code{package} (default: @var{gitolite})
23224 Gitolite package to use.
23226 @item @code{user} (default: @var{git})
23227 User to use for Gitolite. This will be user that you use when accessing
23230 @item @code{group} (default: @var{git})
23231 Group to use for Gitolite.
23233 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23234 Directory in which to store the Gitolite configuration and repositories.
23236 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23237 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23238 representing the configuration for Gitolite.
23240 @item @code{admin-pubkey} (default: @var{#f})
23241 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23242 setup Gitolite. This will be inserted in to the @file{keydir} directory
23243 within the gitolite-admin repository.
23245 To specify the SSH key as a string, use the @code{plain-file} function.
23248 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23254 @deftp {Data Type} gitolite-rc-file
23255 Data type representing the Gitolite RC file.
23258 @item @code{umask} (default: @code{#o0077})
23259 This controls the permissions Gitolite sets on the repositories and their
23262 A value like @code{#o0027} will give read access to the group used by Gitolite
23263 (by default: @code{git}). This is necessary when using Gitolite with software
23264 like cgit or gitweb.
23266 @item @code{git-config-keys} (default: @code{""})
23267 Gitolite allows you to set git config values using the "config" keyword. This
23268 setting allows control over the config keys to accept.
23270 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23271 Set the role names allowed to be used by users running the perms command.
23273 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23274 This setting controls the commands and features to enable within Gitolite.
23280 @node Game Services
23281 @subsection Game Services
23283 @subsubheading The Battle for Wesnoth Service
23285 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23286 based tactical strategy game, with several single player campaigns, and
23287 multiplayer games (both networked and local).
23289 @defvar {Scheme Variable} wesnothd-service-type
23290 Service type for the wesnothd service. Its value must be a
23291 @code{wesnothd-configuration} object. To run wesnothd in the default
23292 configuration, instantiate it as:
23295 (service wesnothd-service-type)
23299 @deftp {Data Type} wesnothd-configuration
23300 Data type representing the configuration of @command{wesnothd}.
23303 @item @code{package} (default: @code{wesnoth-server})
23304 The wesnoth server package to use.
23306 @item @code{port} (default: @code{15000})
23307 The port to bind the server to.
23311 @node Miscellaneous Services
23312 @subsection Miscellaneous Services
23314 @cindex fingerprint
23315 @subsubheading Fingerprint Service
23317 The @code{(gnu services authentication)} module provides a DBus service to
23318 read and identify fingerprints via a fingerprint sensor.
23320 @defvr {Scheme Variable} fprintd-service-type
23321 The service type for @command{fprintd}, which provides the fingerprint
23322 reading capability.
23325 (service fprintd-service-type)
23330 @subsubheading System Control Service
23332 The @code{(gnu services sysctl)} provides a service to configure kernel
23333 parameters at boot.
23335 @defvr {Scheme Variable} sysctl-service-type
23336 The service type for @command{sysctl}, which modifies kernel parameters
23337 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23341 (service sysctl-service-type
23342 (sysctl-configuration
23343 (settings '(("net.ipv4.ip_forward" . "1")))))
23347 @deftp {Data Type} sysctl-configuration
23348 The data type representing the configuration of @command{sysctl}.
23351 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23352 The @command{sysctl} executable to use.
23354 @item @code{settings} (default: @code{'()})
23355 An association list specifies kernel parameters and their values.
23360 @subsubheading PC/SC Smart Card Daemon Service
23362 The @code{(gnu services security-token)} module provides the following service
23363 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23364 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23365 manager that coordinates communications with smart card readers, smart cards
23366 and cryptographic tokens that are connected to the system.
23368 @defvr {Scheme Variable} pcscd-service-type
23369 Service type for the @command{pcscd} service. Its value must be a
23370 @code{pcscd-configuration} object. To run pcscd in the default
23371 configuration, instantiate it as:
23374 (service pcscd-service-type)
23378 @deftp {Data Type} pcscd-configuration
23379 The data type representing the configuration of @command{pcscd}.
23382 @item @code{pcsc-lite} (default: @code{pcsc-lite})
23383 The pcsc-lite package that provides pcscd.
23384 @item @code{usb-drivers} (default: @code{(list ccid)})
23385 List of packages that provide USB drivers to pcscd. Drivers are expected to be
23386 under @file{pcsc/drivers} in the store directory of the package.
23391 @subsubheading Lirc Service
23393 The @code{(gnu services lirc)} module provides the following service.
23395 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
23396 [#:device #f] [#:driver #f] [#:config-file #f] @
23397 [#:extra-options '()]
23398 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
23399 decodes infrared signals from remote controls.
23401 Optionally, @var{device}, @var{driver} and @var{config-file}
23402 (configuration file name) may be specified. See @command{lircd} manual
23405 Finally, @var{extra-options} is a list of additional command-line options
23406 passed to @command{lircd}.
23410 @subsubheading Spice Service
23412 The @code{(gnu services spice)} module provides the following service.
23414 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
23415 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
23416 that enables sharing the clipboard with a vm and setting the guest display
23417 resolution when the graphical console window resizes.
23420 @cindex inputattach
23421 @subsubheading inputattach Service
23423 @cindex tablet input, for Xorg
23424 @cindex touchscreen input, for Xorg
23425 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
23426 use input devices such as Wacom tablets, touchscreens, or joysticks with the
23427 Xorg display server.
23429 @deffn {Scheme Variable} inputattach-service-type
23430 Type of a service that runs @command{inputattach} on a device and
23431 dispatches events from it.
23434 @deftp {Data Type} inputattach-configuration
23436 @item @code{device-type} (default: @code{"wacom"})
23437 The type of device to connect to. Run @command{inputattach --help}, from the
23438 @code{inputattach} package, to see the list of supported device types.
23440 @item @code{device} (default: @code{"/dev/ttyS0"})
23441 The device file to connect to the device.
23443 @item @code{log-file} (default: @code{#f})
23444 If true, this must be the name of a file to log messages to.
23448 @subsection Dictionary Services
23450 The @code{(gnu services dict)} module provides the following service:
23452 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
23453 Return a service that runs the @command{dicod} daemon, an implementation
23454 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
23456 The optional @var{config} argument specifies the configuration for
23457 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
23458 default it serves the GNU Collaborative International Dictonary of English.
23460 You can add @command{open localhost} to your @file{~/.dico} file to make
23461 @code{localhost} the default server for @command{dico} client
23462 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
23465 @deftp {Data Type} dicod-configuration
23466 Data type representing the configuration of dicod.
23469 @item @code{dico} (default: @var{dico})
23470 Package object of the GNU Dico dictionary server.
23472 @item @code{interfaces} (default: @var{'("localhost")})
23473 This is the list of IP addresses and ports and possibly socket file
23474 names to listen to (@pxref{Server Settings, @code{listen} directive,,
23475 dico, GNU Dico Manual}).
23477 @item @code{handlers} (default: @var{'()})
23478 List of @code{<dicod-handler>} objects denoting handlers (module instances).
23480 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
23481 List of @code{<dicod-database>} objects denoting dictionaries to be served.
23485 @deftp {Data Type} dicod-handler
23486 Data type representing a dictionary handler (module instance).
23490 Name of the handler (module instance).
23492 @item @code{module} (default: @var{#f})
23493 Name of the dicod module of the handler (instance). If it is @code{#f},
23494 the module has the same name as the handler.
23495 (@pxref{Modules,,, dico, GNU Dico Manual}).
23497 @item @code{options}
23498 List of strings or gexps representing the arguments for the module handler
23502 @deftp {Data Type} dicod-database
23503 Data type representing a dictionary database.
23507 Name of the database, will be used in DICT commands.
23509 @item @code{handler}
23510 Name of the dicod handler (module instance) used by this database
23511 (@pxref{Handlers,,, dico, GNU Dico Manual}).
23513 @item @code{complex?} (default: @var{#f})
23514 Whether the database configuration complex. The complex configuration
23515 will need a corresponding @code{<dicod-handler>} object, otherwise not.
23517 @item @code{options}
23518 List of strings or gexps representing the arguments for the database
23519 (@pxref{Databases,,, dico, GNU Dico Manual}).
23523 @defvr {Scheme Variable} %dicod-database:gcide
23524 A @code{<dicod-database>} object serving the GNU Collaborative International
23525 Dictionary of English using the @code{gcide} package.
23528 The following is an example @code{dicod-service} configuration.
23531 (dicod-service #:config
23532 (dicod-configuration
23533 (handlers (list (dicod-handler
23537 (list #~(string-append "dbdir=" #$wordnet))))))
23538 (databases (list (dicod-database
23541 (handler "wordnet")
23542 (options '("database=wn")))
23543 %dicod-database:gcide))))
23547 @subsubheading Docker Service
23549 The @code{(gnu services docker)} module provides the following service.
23551 @defvr {Scheme Variable} docker-service-type
23553 This is the type of the service that runs @url{http://www.docker.com,Docker},
23554 a daemon that can execute application bundles (sometimes referred to as
23555 ``containers'') in isolated environments.
23559 @deftp {Data Type} docker-configuration
23560 This is the data type representing the configuration of Docker and Containerd.
23564 @item @code{package} (default: @code{docker})
23565 The Docker package to use.
23567 @item @code{containerd} (default: @var{containerd})
23568 The Containerd package to use.
23573 @node Setuid Programs
23574 @section Setuid Programs
23576 @cindex setuid programs
23577 Some programs need to run with ``root'' privileges, even when they are
23578 launched by unprivileged users. A notorious example is the
23579 @command{passwd} program, which users can run to change their
23580 password, and which needs to access the @file{/etc/passwd} and
23581 @file{/etc/shadow} files---something normally restricted to root, for
23582 obvious security reasons. To address that, these executables are
23583 @dfn{setuid-root}, meaning that they always run with root privileges
23584 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
23585 for more info about the setuid mechanism.)
23587 The store itself @emph{cannot} contain setuid programs: that would be a
23588 security issue since any user on the system can write derivations that
23589 populate the store (@pxref{The Store}). Thus, a different mechanism is
23590 used: instead of changing the setuid bit directly on files that are in
23591 the store, we let the system administrator @emph{declare} which programs
23592 should be setuid root.
23594 The @code{setuid-programs} field of an @code{operating-system}
23595 declaration contains a list of G-expressions denoting the names of
23596 programs to be setuid-root (@pxref{Using the Configuration System}).
23597 For instance, the @command{passwd} program, which is part of the Shadow
23598 package, can be designated by this G-expression (@pxref{G-Expressions}):
23601 #~(string-append #$shadow "/bin/passwd")
23604 A default set of setuid programs is defined by the
23605 @code{%setuid-programs} variable of the @code{(gnu system)} module.
23607 @defvr {Scheme Variable} %setuid-programs
23608 A list of G-expressions denoting common programs that are setuid-root.
23610 The list includes commands such as @command{passwd}, @command{ping},
23611 @command{su}, and @command{sudo}.
23614 Under the hood, the actual setuid programs are created in the
23615 @file{/run/setuid-programs} directory at system activation time. The
23616 files in this directory refer to the ``real'' binaries, which are in the
23619 @node X.509 Certificates
23620 @section X.509 Certificates
23622 @cindex HTTPS, certificates
23623 @cindex X.509 certificates
23625 Web servers available over HTTPS (that is, HTTP over the transport-layer
23626 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
23627 that the client can then use to @emph{authenticate} the server. To do
23628 that, clients verify that the server's certificate is signed by a
23629 so-called @dfn{certificate authority} (CA). But to verify the CA's
23630 signature, clients must have first acquired the CA's certificate.
23632 Web browsers such as GNU@tie{}IceCat include their own set of CA
23633 certificates, such that they are able to verify CA signatures
23636 However, most other programs that can talk HTTPS---@command{wget},
23637 @command{git}, @command{w3m}, etc.---need to be told where CA
23638 certificates can be found.
23640 @cindex @code{nss-certs}
23641 In Guix, this is done by adding a package that provides certificates
23642 to the @code{packages} field of the @code{operating-system} declaration
23643 (@pxref{operating-system Reference}). Guix includes one such package,
23644 @code{nss-certs}, which is a set of CA certificates provided as part of
23645 Mozilla's Network Security Services.
23647 Note that it is @emph{not} part of @var{%base-packages}, so you need to
23648 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
23649 most applications and libraries look for certificates by default, points
23650 to the certificates installed globally.
23652 Unprivileged users, including users of Guix on a foreign distro,
23653 can also install their own certificate package in
23654 their profile. A number of environment variables need to be defined so
23655 that applications and libraries know where to find them. Namely, the
23656 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
23657 variables. Some applications add their own environment variables; for
23658 instance, the Git version control system honors the certificate bundle
23659 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
23660 would typically run something like:
23663 $ guix install nss-certs
23664 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
23665 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23666 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
23669 As another example, R requires the @code{CURL_CA_BUNDLE} environment
23670 variable to point to a certificate bundle, so you would have to run
23671 something like this:
23674 $ guix install nss-certs
23675 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
23678 For other applications you may want to look up the required environment
23679 variable in the relevant documentation.
23682 @node Name Service Switch
23683 @section Name Service Switch
23685 @cindex name service switch
23687 The @code{(gnu system nss)} module provides bindings to the
23688 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
23689 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
23690 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
23691 extended with new ``name'' lookup methods for system databases, which
23692 includes host names, service names, user accounts, and more (@pxref{Name
23693 Service Switch, System Databases and Name Service Switch,, libc, The GNU
23694 C Library Reference Manual}).
23696 The NSS configuration specifies, for each system database, which lookup
23697 method is to be used, and how the various methods are chained
23698 together---for instance, under which circumstances NSS should try the
23699 next method in the list. The NSS configuration is given in the
23700 @code{name-service-switch} field of @code{operating-system} declarations
23701 (@pxref{operating-system Reference, @code{name-service-switch}}).
23704 @cindex .local, host name lookup
23705 As an example, the declaration below configures the NSS to use the
23706 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
23707 back-end}, which supports host name lookups over multicast DNS (mDNS)
23708 for host names ending in @code{.local}:
23711 (name-service-switch
23712 (hosts (list %files ;first, check /etc/hosts
23714 ;; If the above did not succeed, try
23715 ;; with 'mdns_minimal'.
23717 (name "mdns_minimal")
23719 ;; 'mdns_minimal' is authoritative for
23720 ;; '.local'. When it returns "not found",
23721 ;; no need to try the next methods.
23722 (reaction (lookup-specification
23723 (not-found => return))))
23725 ;; Then fall back to DNS.
23729 ;; Finally, try with the "full" 'mdns'.
23734 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
23735 contains this configuration, so you will not have to type it if all you
23736 want is to have @code{.local} host lookup working.
23738 Note that, in this case, in addition to setting the
23739 @code{name-service-switch} of the @code{operating-system} declaration,
23740 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
23741 @code{avahi-service-type}}), or @var{%desktop-services}, which includes it
23742 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
23743 to the name service cache daemon (@pxref{Base Services,
23744 @code{nscd-service}}).
23746 For convenience, the following variables provide typical NSS
23749 @defvr {Scheme Variable} %default-nss
23750 This is the default name service switch configuration, a
23751 @code{name-service-switch} object.
23754 @defvr {Scheme Variable} %mdns-host-lookup-nss
23755 This is the name service switch configuration with support for host name
23756 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
23759 The reference for name service switch configuration is given below. It
23760 is a direct mapping of the configuration file format of the C library , so
23761 please refer to the C library manual for more information (@pxref{NSS
23762 Configuration File,,, libc, The GNU C Library Reference Manual}).
23763 Compared to the configuration file format of libc NSS, it has the advantage
23764 not only of adding this warm parenthetic feel that we like, but also
23765 static checks: you will know about syntax errors and typos as soon as you
23766 run @command{guix system}.
23768 @deftp {Data Type} name-service-switch
23770 This is the data type representation the configuration of libc's name
23771 service switch (NSS). Each field below represents one of the supported
23788 The system databases handled by the NSS. Each of these fields must be a
23789 list of @code{<name-service>} objects (see below).
23793 @deftp {Data Type} name-service
23795 This is the data type representing an actual name service and the
23796 associated lookup action.
23800 A string denoting the name service (@pxref{Services in the NSS
23801 configuration,,, libc, The GNU C Library Reference Manual}).
23803 Note that name services listed here must be visible to nscd. This is
23804 achieved by passing the @code{#:name-services} argument to
23805 @code{nscd-service} the list of packages providing the needed name
23806 services (@pxref{Base Services, @code{nscd-service}}).
23809 An action specified using the @code{lookup-specification} macro
23810 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
23811 Reference Manual}). For example:
23814 (lookup-specification (unavailable => continue)
23815 (success => return))
23820 @node Initial RAM Disk
23821 @section Initial RAM Disk
23824 @cindex initial RAM disk
23825 For bootstrapping purposes, the Linux-Libre kernel is passed an
23826 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
23827 root file system as well as an initialization script. The latter is
23828 responsible for mounting the real root file system, and for loading any
23829 kernel modules that may be needed to achieve that.
23831 The @code{initrd-modules} field of an @code{operating-system}
23832 declaration allows you to specify Linux-libre kernel modules that must
23833 be available in the initrd. In particular, this is where you would list
23834 modules needed to actually drive the hard disk where your root partition
23835 is---although the default value of @code{initrd-modules} should cover
23836 most use cases. For example, assuming you need the @code{megaraid_sas}
23837 module in addition to the default modules to be able to access your root
23838 file system, you would write:
23843 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
23846 @defvr {Scheme Variable} %base-initrd-modules
23847 This is the list of kernel modules included in the initrd by default.
23850 Furthermore, if you need lower-level customization, the @code{initrd}
23851 field of an @code{operating-system} declaration allows
23852 you to specify which initrd you would like to use. The @code{(gnu
23853 system linux-initrd)} module provides three ways to build an initrd: the
23854 high-level @code{base-initrd} procedure and the low-level
23855 @code{raw-initrd} and @code{expression->initrd} procedures.
23857 The @code{base-initrd} procedure is intended to cover most common uses.
23858 For example, if you want to add a bunch of kernel modules to be loaded
23859 at boot time, you can define the @code{initrd} field of the operating
23860 system declaration like this:
23863 (initrd (lambda (file-systems . rest)
23864 ;; Create a standard initrd but set up networking
23865 ;; with the parameters QEMU expects by default.
23866 (apply base-initrd file-systems
23867 #:qemu-networking? #t
23871 The @code{base-initrd} procedure also handles common use cases that
23872 involves using the system as a QEMU guest, or as a ``live'' system with
23873 volatile root file system.
23875 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
23876 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
23877 such as trying to guess which kernel modules and packages should be included
23878 to the initrd. An example use of @code{raw-initrd} is when a user has
23879 a custom Linux kernel configuration and default kernel modules included by
23880 @code{base-initrd} are not available.
23882 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
23883 honors several options passed on the Linux kernel command line
23884 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
23885 @code{-append} option of QEMU), notably:
23888 @item --load=@var{boot}
23889 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
23890 program, once it has mounted the root file system.
23892 Guix uses this option to yield control to a boot program that runs the
23893 service activation programs and then spawns the GNU@tie{}Shepherd, the
23894 initialization system.
23896 @item --root=@var{root}
23897 Mount @var{root} as the root file system. @var{root} can be a
23898 device name like @code{/dev/sda1}, a file system label, or a file system
23901 @item --system=@var{system}
23902 Have @file{/run/booted-system} and @file{/run/current-system} point to
23905 @item modprobe.blacklist=@var{modules}@dots{}
23906 @cindex module, black-listing
23907 @cindex black list, of kernel modules
23908 Instruct the initial RAM disk as well as the @command{modprobe} command
23909 (from the kmod package) to refuse to load @var{modules}. @var{modules}
23910 must be a comma-separated list of module names---e.g.,
23911 @code{usbkbd,9pnet}.
23914 Start a read-eval-print loop (REPL) from the initial RAM disk before it
23915 tries to load kernel modules and to mount the root file system. Our
23916 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
23917 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
23918 Manual}, for more information on Guile's REPL.
23922 Now that you know all the features that initial RAM disks produced by
23923 @code{base-initrd} and @code{raw-initrd} provide,
23924 here is how to use it and customize it further.
23927 @cindex initial RAM disk
23928 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
23929 [#:linux-modules '()] [#:mapped-devices '()] @
23930 [#:keyboard-layout #f] @
23931 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
23932 Return a derivation that builds a raw initrd. @var{file-systems} is
23933 a list of file systems to be mounted by the initrd, possibly in addition to
23934 the root file system specified on the kernel command line via @code{--root}.
23935 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
23936 @var{mapped-devices} is a list of device mappings to realize before
23937 @var{file-systems} are mounted (@pxref{Mapped Devices}).
23938 @var{helper-packages} is a list of packages to be copied in the initrd. It may
23939 include @code{e2fsck/static} or other packages needed by the initrd to check
23940 the root file system.
23942 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23943 the desired console keyboard layout. This is done before @var{mapped-devices}
23944 are set up and before @var{file-systems} are mounted such that, should the
23945 user need to enter a passphrase or use the REPL, this happens using the
23946 intended keyboard layout.
23948 When @var{qemu-networking?} is true, set up networking with the standard QEMU
23949 parameters. When @var{virtio?} is true, load additional modules so that the
23950 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
23952 When @var{volatile-root?} is true, the root file system is writable but any changes
23956 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
23957 [#:mapped-devices '()] [#:keyboard-layout #f] @
23958 [#:qemu-networking? #f] [#:volatile-root? #f] @
23959 [#:linux-modules '()]
23960 Return as a file-like object a generic initrd, with kernel
23961 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
23962 mounted by the initrd, possibly in addition to the root file system specified
23963 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
23964 mappings to realize before @var{file-systems} are mounted.
23966 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
23967 the desired console keyboard layout. This is done before @var{mapped-devices}
23968 are set up and before @var{file-systems} are mounted such that, should the
23969 user need to enter a passphrase or use the REPL, this happens using the
23970 intended keyboard layout.
23972 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
23974 The initrd is automatically populated with all the kernel modules necessary
23975 for @var{file-systems} and for the given options. Additional kernel
23976 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
23977 loaded at boot time in the order in which they appear.
23980 Needless to say, the initrds we produce and use embed a
23981 statically-linked Guile, and the initialization program is a Guile
23982 program. That gives a lot of flexibility. The
23983 @code{expression->initrd} procedure builds such an initrd, given the
23984 program to run in that initrd.
23986 @deffn {Scheme Procedure} expression->initrd @var{exp} @
23987 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
23988 Return as a file-like object a Linux initrd (a gzipped cpio archive)
23989 containing @var{guile} and that evaluates @var{exp}, a G-expression,
23990 upon booting. All the derivations referenced by @var{exp} are
23991 automatically copied to the initrd.
23994 @node Bootloader Configuration
23995 @section Bootloader Configuration
23998 @cindex boot loader
24000 The operating system supports multiple bootloaders. The bootloader is
24001 configured using @code{bootloader-configuration} declaration. All the
24002 fields of this structure are bootloader agnostic except for one field,
24003 @code{bootloader} that indicates the bootloader to be configured and
24006 Some of the bootloaders do not honor every field of
24007 @code{bootloader-configuration}. For instance, the extlinux
24008 bootloader does not support themes and thus ignores the @code{theme}
24011 @deftp {Data Type} bootloader-configuration
24012 The type of a bootloader configuration declaration.
24016 @item @code{bootloader}
24017 @cindex EFI, bootloader
24018 @cindex UEFI, bootloader
24019 @cindex BIOS, bootloader
24020 The bootloader to use, as a @code{bootloader} object. For now
24021 @code{grub-bootloader}, @code{grub-efi-bootloader},
24022 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24024 @vindex grub-efi-bootloader
24025 @code{grub-efi-bootloader} allows to boot on modern systems using the
24026 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24027 use if the installation image contains a @file{/sys/firmware/efi} directory
24028 when you boot it on your system.
24030 @vindex grub-bootloader
24031 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24032 in ``legacy'' BIOS mode.
24034 @cindex ARM, bootloaders
24035 @cindex AArch64, bootloaders
24036 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24037 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24038 of bootloaders for a wide range of ARM and AArch64 systems, using the
24039 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24041 @item @code{target}
24042 This is a string denoting the target onto which to install the
24045 The interpretation depends on the bootloader in question. For
24046 @code{grub-bootloader}, for example, it should be a device name understood by
24047 the bootloader @command{installer} command, such as @code{/dev/sda} or
24048 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24049 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24050 system, usually @file{/boot/efi}.
24052 @item @code{menu-entries} (default: @code{()})
24053 A possibly empty list of @code{menu-entry} objects (see below), denoting
24054 entries to appear in the bootloader menu, in addition to the current
24055 system entry and the entry pointing to previous system generations.
24057 @item @code{default-entry} (default: @code{0})
24058 The index of the default boot menu entry. Index 0 is for the entry of the
24061 @item @code{timeout} (default: @code{5})
24062 The number of seconds to wait for keyboard input before booting. Set to
24063 0 to boot immediately, and to -1 to wait indefinitely.
24065 @cindex keyboard layout, for the bootloader
24066 @item @code{keyboard-layout} (default: @code{#f})
24067 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24068 layout, usually US@tie{}English (``qwerty'').
24070 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24074 This option is currently ignored by bootloaders other than @code{grub} and
24078 @item @code{theme} (default: @var{#f})
24079 The bootloader theme object describing the theme to use. If no theme
24080 is provided, some bootloaders might use a default theme, that's true
24083 @item @code{terminal-outputs} (default: @code{'gfxterm})
24084 The output terminals used for the bootloader boot menu, as a list of
24085 symbols. GRUB accepts the values: @code{console}, @code{serial},
24086 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24087 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24088 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24089 configuration,,, grub,GNU GRUB manual}).
24091 @item @code{terminal-inputs} (default: @code{'()})
24092 The input terminals used for the bootloader boot menu, as a list of
24093 symbols. For GRUB, the default is the native platform terminal as
24094 determined at run-time. GRUB accepts the values: @code{console},
24095 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24096 @code{usb_keyboard}. This field corresponds to the GRUB variable
24097 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24100 @item @code{serial-unit} (default: @code{#f})
24101 The serial unit used by the bootloader, as an integer from 0 to 3.
24102 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24103 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24105 @item @code{serial-speed} (default: @code{#f})
24106 The speed of the serial interface, as an integer. For GRUB, the
24107 default value is chosen at run-time; currently GRUB chooses
24108 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24115 Should you want to list additional boot menu entries @i{via} the
24116 @code{menu-entries} field above, you will need to create them with the
24117 @code{menu-entry} form. For example, imagine you want to be able to
24118 boot another distro (hard to imagine!), you can define a menu entry
24123 (label "The Other Distro")
24124 (linux "/boot/old/vmlinux-2.6.32")
24125 (linux-arguments '("root=/dev/sda2"))
24126 (initrd "/boot/old/initrd"))
24131 @deftp {Data Type} menu-entry
24132 The type of an entry in the bootloader menu.
24137 The label to show in the menu---e.g., @code{"GNU"}.
24140 The Linux kernel image to boot, for example:
24143 (file-append linux-libre "/bzImage")
24146 For GRUB, it is also possible to specify a device explicitly in the
24147 file path using GRUB's device naming convention (@pxref{Naming
24148 convention,,, grub, GNU GRUB manual}), for example:
24151 "(hd0,msdos1)/boot/vmlinuz"
24154 If the device is specified explicitly as above, then the @code{device}
24155 field is ignored entirely.
24157 @item @code{linux-arguments} (default: @code{()})
24158 The list of extra Linux kernel command-line arguments---e.g.,
24159 @code{("console=ttyS0")}.
24161 @item @code{initrd}
24162 A G-Expression or string denoting the file name of the initial RAM disk
24163 to use (@pxref{G-Expressions}).
24164 @item @code{device} (default: @code{#f})
24165 The device where the kernel and initrd are to be found---i.e., for GRUB,
24166 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24168 This may be a file system label (a string), a file system UUID (a
24169 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24170 the bootloader will search the device containing the file specified by
24171 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24172 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24177 @c FIXME: Write documentation once it's stable.
24178 For now only GRUB has theme support. GRUB themes are created using
24179 the @code{grub-theme} form, which is not documented yet.
24181 @defvr {Scheme Variable} %default-theme
24182 This is the default GRUB theme used by the operating system if no
24183 @code{theme} field is specified in @code{bootloader-configuration}
24186 It comes with a fancy background image displaying the GNU and Guix
24191 @node Invoking guix system
24192 @section Invoking @code{guix system}
24194 Once you have written an operating system declaration as seen in the
24195 previous section, it can be @dfn{instantiated} using the @command{guix
24196 system} command. The synopsis is:
24199 guix system @var{options}@dots{} @var{action} @var{file}
24202 @var{file} must be the name of a file containing an
24203 @code{operating-system} declaration. @var{action} specifies how the
24204 operating system is instantiated. Currently the following values are
24209 Display available service type definitions that match the given regular
24210 expressions, sorted by relevance:
24213 $ guix system search console font
24214 name: console-fonts
24215 location: gnu/services/base.scm:729:2
24216 extends: shepherd-root
24217 description: Install the given fonts on the specified ttys (fonts are
24218 + per virtual console on GNU/Linux). The value of this service is a list
24219 + of tty/font pairs like:
24221 + '(("tty1" . "LatGrkCyr-8x16"))
24225 location: gnu/services/base.scm:1048:2
24226 extends: shepherd-root
24227 description: Provide console login using the `mingetty' program.
24231 location: gnu/services/base.scm:775:2
24233 description: Provide a console log-in service as specified by its
24234 + configuration value, a `login-configuration' object.
24240 As for @command{guix package --search}, the result is written in
24241 @code{recutils} format, which makes it easy to filter the output
24242 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24245 Build the operating system described in @var{file}, activate it, and
24246 switch to it@footnote{This action (and the related actions
24247 @code{switch-generation} and @code{roll-back}) are usable only on
24248 systems already running Guix System.}.
24250 This effects all the configuration specified in @var{file}: user
24251 accounts, system services, global package list, setuid programs, etc.
24252 The command starts system services specified in @var{file} that are not
24253 currently running; if a service is currently running this command will
24254 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24255 @code{herd stop X} or @code{herd restart X}).
24257 This command creates a new generation whose number is one greater than
24258 the current generation (as reported by @command{guix system
24259 list-generations}). If that generation already exists, it will be
24260 overwritten. This behavior mirrors that of @command{guix package}
24261 (@pxref{Invoking guix package}).
24263 It also adds a bootloader menu entry for the new OS configuration,
24264 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24265 entries for older configurations to a submenu, allowing you to choose
24266 an older system generation at boot time should you need it.
24269 @c The paragraph below refers to the problem discussed at
24270 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24271 It is highly recommended to run @command{guix pull} once before you run
24272 @command{guix system reconfigure} for the first time (@pxref{Invoking
24273 guix pull}). Failing to do that you would see an older version of Guix
24274 once @command{reconfigure} has completed.
24277 @item switch-generation
24278 @cindex generations
24279 Switch to an existing system generation. This action atomically
24280 switches the system profile to the specified system generation. It
24281 also rearranges the system's existing bootloader menu entries. It
24282 makes the menu entry for the specified system generation the default,
24283 and it moves the entries for the other generatiors to a submenu, if
24284 supported by the bootloader being used. The next time the system
24285 boots, it will use the specified system generation.
24287 The bootloader itself is not being reinstalled when using this
24288 command. Thus, the installed bootloader is used with an updated
24289 configuration file.
24291 The target generation can be specified explicitly by its generation
24292 number. For example, the following invocation would switch to system
24296 guix system switch-generation 7
24299 The target generation can also be specified relative to the current
24300 generation with the form @code{+N} or @code{-N}, where @code{+3} means
24301 ``3 generations ahead of the current generation,'' and @code{-1} means
24302 ``1 generation prior to the current generation.'' When specifying a
24303 negative value such as @code{-1}, you must precede it with @code{--} to
24304 prevent it from being parsed as an option. For example:
24307 guix system switch-generation -- -1
24310 Currently, the effect of invoking this action is @emph{only} to switch
24311 the system profile to an existing generation and rearrange the
24312 bootloader menu entries. To actually start using the target system
24313 generation, you must reboot after running this action. In the future,
24314 it will be updated to do the same things as @command{reconfigure},
24315 like activating and deactivating services.
24317 This action will fail if the specified generation does not exist.
24320 @cindex rolling back
24321 Switch to the preceding system generation. The next time the system
24322 boots, it will use the preceding system generation. This is the inverse
24323 of @command{reconfigure}, and it is exactly the same as invoking
24324 @command{switch-generation} with an argument of @code{-1}.
24326 Currently, as with @command{switch-generation}, you must reboot after
24327 running this action to actually start using the preceding system
24330 @item delete-generations
24331 @cindex deleting system generations
24332 @cindex saving space
24333 Delete system generations, making them candidates for garbage collection
24334 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
24337 This works in the same way as @command{guix package --delete-generations}
24338 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
24339 arguments, all system generations but the current one are deleted:
24342 guix system delete-generations
24345 You can also select the generations you want to delete. The example below
24346 deletes all the system generations that are more than two month old:
24349 guix system delete-generations 2m
24352 Running this command automatically reinstalls the bootloader with an updated
24353 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
24354 longer lists the generations that have been deleted.
24357 Build the derivation of the operating system, which includes all the
24358 configuration files and programs needed to boot and run the system.
24359 This action does not actually install anything.
24362 Populate the given directory with all the files necessary to run the
24363 operating system specified in @var{file}. This is useful for first-time
24364 installations of Guix System. For instance:
24367 guix system init my-os-config.scm /mnt
24370 copies to @file{/mnt} all the store items required by the configuration
24371 specified in @file{my-os-config.scm}. This includes configuration
24372 files, packages, and so on. It also creates other essential files
24373 needed for the system to operate correctly---e.g., the @file{/etc},
24374 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
24376 This command also installs bootloader on the target specified in
24377 @file{my-os-config}, unless the @option{--no-bootloader} option was
24381 @cindex virtual machine
24383 @anchor{guix system vm}
24384 Build a virtual machine that contains the operating system declared in
24385 @var{file}, and return a script to run that virtual machine (VM).
24388 The @code{vm} action and others below
24389 can use KVM support in the Linux-libre kernel. Specifically, if the
24390 machine has hardware virtualization support, the corresponding
24391 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
24392 must exist and be readable and writable by the user and by the
24393 build users of the daemon (@pxref{Build Environment Setup}).
24396 Arguments given to the script are passed to QEMU as in the example
24397 below, which enables networking and requests 1@tie{}GiB of RAM for the
24401 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
24404 The VM shares its store with the host system.
24406 Additional file systems can be shared between the host and the VM using
24407 the @code{--share} and @code{--expose} command-line options: the former
24408 specifies a directory to be shared with write access, while the latter
24409 provides read-only access to the shared directory.
24411 The example below creates a VM in which the user's home directory is
24412 accessible read-only, and where the @file{/exchange} directory is a
24413 read-write mapping of @file{$HOME/tmp} on the host:
24416 guix system vm my-config.scm \
24417 --expose=$HOME --share=$HOME/tmp=/exchange
24420 On GNU/Linux, the default is to boot directly to the kernel; this has
24421 the advantage of requiring only a very tiny root disk image since the
24422 store of the host can then be mounted.
24424 The @code{--full-boot} option forces a complete boot sequence, starting
24425 with the bootloader. This requires more disk space since a root image
24426 containing at least the kernel, initrd, and bootloader data files must
24427 be created. The @code{--image-size} option can be used to specify the
24430 @cindex System images, creation in various formats
24431 @cindex Creating system images in various formats
24434 @itemx docker-image
24435 Return a virtual machine, disk image, or Docker image of the operating
24436 system declared in @var{file} that stands alone. By default,
24437 @command{guix system} estimates the size of the image needed to store
24438 the system, but you can use the @option{--image-size} option to specify
24439 a value. Docker images are built to contain exactly what they need, so
24440 the @option{--image-size} option is ignored in the case of
24441 @code{docker-image}.
24443 You can specify the root file system type by using the
24444 @option{--file-system-type} option. It defaults to @code{ext4}.
24446 When using @code{vm-image}, the returned image is in qcow2 format, which
24447 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
24448 for more information on how to run the image in a virtual machine.
24450 When using @code{disk-image}, a raw disk image is produced; it can be
24451 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
24452 the device corresponding to a USB stick, one can copy the image to it
24453 using the following command:
24456 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
24459 When using @code{docker-image}, a Docker image is produced. Guix builds
24460 the image from scratch, not from a pre-existing Docker base image. As a
24461 result, it contains @emph{exactly} what you define in the operating
24462 system configuration file. You can then load the image and launch a
24463 Docker container using commands like the following:
24466 image_id="$(docker load < guix-system-docker-image.tar.gz)"
24467 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
24468 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
24469 $image_id /var/guix/profiles/system/boot
24472 This command starts a new Docker container from the specified image. It
24473 will boot the Guix system in the usual manner, which means it will
24474 start any services you have defined in the operating system
24475 configuration. Depending on what you run in the Docker container, it
24476 may be necessary to give the container additional permissions. For
24477 example, if you intend to build software using Guix inside of the Docker
24478 container, you may need to pass the @option{--privileged} option to
24482 Return a script to run the operating system declared in @var{file}
24483 within a container. Containers are a set of lightweight isolation
24484 mechanisms provided by the kernel Linux-libre. Containers are
24485 substantially less resource-demanding than full virtual machines since
24486 the kernel, shared objects, and other resources can be shared with the
24487 host system; this also means they provide thinner isolation.
24489 Currently, the script must be run as root in order to support more than
24490 a single user and group. The container shares its store with the host
24493 As with the @code{vm} action (@pxref{guix system vm}), additional file
24494 systems to be shared between the host and container can be specified
24495 using the @option{--share} and @option{--expose} options:
24498 guix system container my-config.scm \
24499 --expose=$HOME --share=$HOME/tmp=/exchange
24503 This option requires Linux-libre 3.19 or newer.
24508 @var{options} can contain any of the common build options (@pxref{Common
24509 Build Options}). In addition, @var{options} can contain one of the
24513 @item --expression=@var{expr}
24514 @itemx -e @var{expr}
24515 Consider the operating-system @var{expr} evaluates to.
24516 This is an alternative to specifying a file which evaluates to an
24518 This is used to generate the Guix system installer @pxref{Building the
24519 Installation Image}).
24521 @item --system=@var{system}
24522 @itemx -s @var{system}
24523 Attempt to build for @var{system} instead of the host system type.
24524 This works as per @command{guix build} (@pxref{Invoking guix build}).
24528 Return the derivation file name of the given operating system without
24531 @item --file-system-type=@var{type}
24532 @itemx -t @var{type}
24533 For the @code{disk-image} action, create a file system of the given
24534 @var{type} on the image.
24536 When this option is omitted, @command{guix system} uses @code{ext4}.
24538 @cindex ISO-9660 format
24539 @cindex CD image format
24540 @cindex DVD image format
24541 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
24542 for burning on CDs and DVDs.
24544 @item --image-size=@var{size}
24545 For the @code{vm-image} and @code{disk-image} actions, create an image
24546 of the given @var{size}. @var{size} may be a number of bytes, or it may
24547 include a unit as a suffix (@pxref{Block size, size specifications,,
24548 coreutils, GNU Coreutils}).
24550 When this option is omitted, @command{guix system} computes an estimate
24551 of the image size as a function of the size of the system declared in
24554 @item --root=@var{file}
24555 @itemx -r @var{file}
24556 Make @var{file} a symlink to the result, and register it as a garbage
24559 @item --skip-checks
24560 Skip pre-installation safety checks.
24562 By default, @command{guix system init} and @command{guix system
24563 reconfigure} perform safety checks: they make sure the file systems that
24564 appear in the @code{operating-system} declaration actually exist
24565 (@pxref{File Systems}), and that any Linux kernel modules that may be
24566 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
24567 RAM Disk}). Passing this option skips these tests altogether.
24570 @cindex on-error strategy
24571 @cindex error strategy
24572 @item --on-error=@var{strategy}
24573 Apply @var{strategy} when an error occurs when reading @var{file}.
24574 @var{strategy} may be one of the following:
24577 @item nothing-special
24578 Report the error concisely and exit. This is the default strategy.
24581 Likewise, but also display a backtrace.
24584 Report the error and enter Guile's debugger. From there, you can run
24585 commands such as @code{,bt} to get a backtrace, @code{,locals} to
24586 display local variable values, and more generally inspect the state of the
24587 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
24588 a list of available debugging commands.
24592 Once you have built, configured, re-configured, and re-re-configured
24593 your Guix installation, you may find it useful to list the operating
24594 system generations available on disk---and that you can choose from the
24595 bootloader boot menu:
24599 @item list-generations
24600 List a summary of each generation of the operating system available on
24601 disk, in a human-readable way. This is similar to the
24602 @option{--list-generations} option of @command{guix package}
24603 (@pxref{Invoking guix package}).
24605 Optionally, one can specify a pattern, with the same syntax that is used
24606 in @command{guix package --list-generations}, to restrict the list of
24607 generations displayed. For instance, the following command displays
24608 generations that are up to 10 days old:
24611 $ guix system list-generations 10d
24616 The @command{guix system} command has even more to offer! The following
24617 sub-commands allow you to visualize how your system services relate to
24620 @anchor{system-extension-graph}
24623 @item extension-graph
24624 Emit in Dot/Graphviz format to standard output the @dfn{service
24625 extension graph} of the operating system defined in @var{file}
24626 (@pxref{Service Composition}, for more information on service
24632 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
24635 produces a PDF file showing the extension relations among services.
24637 @anchor{system-shepherd-graph}
24638 @item shepherd-graph
24639 Emit in Dot/Graphviz format to standard output the @dfn{dependency
24640 graph} of shepherd services of the operating system defined in
24641 @var{file}. @xref{Shepherd Services}, for more information and for an
24646 @node Running Guix in a VM
24647 @section Running Guix in a Virtual Machine
24649 @cindex virtual machine
24650 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
24652 @indicateurl{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.@var{system}.xz}
24653 This image is a compressed image in QCOW format. You will first need to
24654 decompress with @command{xz -d}, and then you can pass it to an emulator such
24655 as QEMU (see below for details).
24657 This image boots the Xfce graphical environment and it contains some
24658 commonly-used tools. You can install more software in the image by running
24659 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
24660 also reconfigure the system based on its initial configuration file available
24661 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
24663 Instead of using this pre-built image, one can also build their own virtual
24664 machine image using @command{guix system vm-image} (@pxref{Invoking guix
24665 system}). The returned image is in qcow2 format, which the
24666 @uref{http://qemu.org/, QEMU emulator} can efficiently use.
24669 If you built your own image, you must copy it out of the store
24670 (@pxref{The Store}) and give yourself permission to write to the copy
24671 before you can use it. When invoking QEMU, you must choose a system
24672 emulator that is suitable for your hardware platform. Here is a minimal
24673 QEMU invocation that will boot the result of @command{guix system
24674 vm-image} on x86_64 hardware:
24677 $ qemu-system-x86_64 \
24678 -net user -net nic,model=virtio \
24679 -enable-kvm -m 512 \
24680 -device virtio-blk,drive=myhd \
24681 -drive if=none,file=/tmp/qemu-image,id=myhd
24684 Here is what each of these options means:
24687 @item qemu-system-x86_64
24688 This specifies the hardware platform to emulate. This should match the
24692 Enable the unprivileged user-mode network stack. The guest OS can
24693 access the host but not vice versa. This is the simplest way to get the
24696 @item -net nic,model=virtio
24697 You must create a network interface of a given model. If you do not
24698 create a NIC, the boot will fail. Assuming your hardware platform is
24699 x86_64, you can get a list of available NIC models by running
24700 @command{qemu-system-x86_64 -net nic,model=help}.
24703 If your system has hardware virtualization extensions, enabling the
24704 virtual machine support (KVM) of the Linux kernel will make things run
24707 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
24709 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
24710 which may be insufficient for some operations.
24712 @item -device virtio-blk,drive=myhd
24713 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
24714 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
24715 better performance than if it were emulating a complete disk drive. See the
24716 QEMU and KVM documentation for more info.
24718 @item -drive if=none,file=/tmp/qemu-image,id=myhd
24719 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
24720 the ``myhd'' drive.
24723 The default @command{run-vm.sh} script that is returned by an invocation of
24724 @command{guix system vm} does not add a @command{-net user} flag by default.
24725 To get network access from within the vm add the @code{(dhcp-client-service)}
24726 to your system definition and start the VM using
24727 @command{`guix system vm config.scm` -net user}. An important caveat of using
24728 @command{-net user} for networking is that @command{ping} will not work, because
24729 it uses the ICMP protocol. You'll have to use a different command to check for
24730 network connectivity, for example @command{guix download}.
24732 @subsection Connecting Through SSH
24736 To enable SSH inside a VM you need to add an SSH server like
24737 @code{openssh-service-type} to your VM (@pxref{Networking Services,
24738 @code{openssh-service-type}}). In addition you need to forward the SSH port,
24739 22 by default, to the host. You can do this with
24742 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
24745 To connect to the VM you can run
24748 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
24751 The @command{-p} tells @command{ssh} the port you want to connect to.
24752 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
24753 every time you modify your @command{config.scm} file and the
24754 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
24755 connection to an unknown host every time you connect.
24757 @subsection Using @command{virt-viewer} with Spice
24759 As an alternative to the default @command{qemu} graphical client you can
24760 use the @command{remote-viewer} from the @command{virt-viewer} package. To
24761 connect pass the @command{-spice port=5930,disable-ticketing} flag to
24762 @command{qemu}. See previous section for further information on how to do this.
24764 Spice also allows you to do some nice stuff like share your clipboard with your
24765 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
24768 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
24769 -chardev spicevmc,name=vdagent,id=vdagent
24770 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
24771 name=com.redhat.spice.0
24774 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
24776 @node Defining Services
24777 @section Defining Services
24779 The previous sections show the available services and how one can combine
24780 them in an @code{operating-system} declaration. But how do we define
24781 them in the first place? And what is a service anyway?
24784 * Service Composition:: The model for composing services.
24785 * Service Types and Services:: Types and services.
24786 * Service Reference:: API reference.
24787 * Shepherd Services:: A particular type of service.
24790 @node Service Composition
24791 @subsection Service Composition
24795 Here we define a @dfn{service} as, broadly, something that extends the
24796 functionality of the operating system. Often a service is a process---a
24797 @dfn{daemon}---started when the system boots: a secure shell server, a
24798 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
24799 whose execution can be triggered by another daemon---e.g., an FTP server
24800 started by @command{inetd} or a D-Bus service activated by
24801 @command{dbus-daemon}. Occasionally, a service does not map to a
24802 daemon. For instance, the ``account'' service collects user accounts
24803 and makes sure they exist when the system runs; the ``udev'' service
24804 collects device management rules and makes them available to the eudev
24805 daemon; the @file{/etc} service populates the @file{/etc} directory
24808 @cindex service extensions
24809 Guix system services are connected by @dfn{extensions}. For instance, the
24810 secure shell service @emph{extends} the Shepherd---the
24811 initialization system, running as PID@tie{}1---by giving it the command
24812 lines to start and stop the secure shell daemon (@pxref{Networking
24813 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
24814 service by passing it its @file{.service} specification, and extends the
24815 udev service by passing it device management rules (@pxref{Desktop
24816 Services, @code{upower-service}}); the Guix daemon service extends the
24817 Shepherd by passing it the command lines to start and stop the daemon,
24818 and extends the account service by passing it a list of required build
24819 user accounts (@pxref{Base Services}).
24821 All in all, services and their ``extends'' relations form a directed
24822 acyclic graph (DAG). If we represent services as boxes and extensions
24823 as arrows, a typical system might provide something like this:
24825 @image{images/service-graph,,5in,Typical service extension graph.}
24827 @cindex system service
24828 At the bottom, we see the @dfn{system service}, which produces the
24829 directory containing everything to run and boot the system, as returned
24830 by the @command{guix system build} command. @xref{Service Reference},
24831 to learn about the other service types shown here.
24832 @xref{system-extension-graph, the @command{guix system extension-graph}
24833 command}, for information on how to generate this representation for a
24834 particular operating system definition.
24836 @cindex service types
24837 Technically, developers can define @dfn{service types} to express these
24838 relations. There can be any number of services of a given type on the
24839 system---for instance, a system running two instances of the GNU secure
24840 shell server (lsh) has two instances of @code{lsh-service-type}, with
24841 different parameters.
24843 The following section describes the programming interface for service
24844 types and services.
24846 @node Service Types and Services
24847 @subsection Service Types and Services
24849 A @dfn{service type} is a node in the DAG described above. Let us start
24850 with a simple example, the service type for the Guix build daemon
24851 (@pxref{Invoking guix-daemon}):
24854 (define guix-service-type
24858 (list (service-extension shepherd-root-service-type guix-shepherd-service)
24859 (service-extension account-service-type guix-accounts)
24860 (service-extension activation-service-type guix-activation)))
24861 (default-value (guix-configuration))))
24865 It defines three things:
24869 A name, whose sole purpose is to make inspection and debugging easier.
24872 A list of @dfn{service extensions}, where each extension designates the
24873 target service type and a procedure that, given the parameters of the
24874 service, returns a list of objects to extend the service of that type.
24876 Every service type has at least one service extension. The only
24877 exception is the @dfn{boot service type}, which is the ultimate service.
24880 Optionally, a default value for instances of this type.
24883 In this example, @code{guix-service-type} extends three services:
24886 @item shepherd-root-service-type
24887 The @code{guix-shepherd-service} procedure defines how the Shepherd
24888 service is extended. Namely, it returns a @code{<shepherd-service>}
24889 object that defines how @command{guix-daemon} is started and stopped
24890 (@pxref{Shepherd Services}).
24892 @item account-service-type
24893 This extension for this service is computed by @code{guix-accounts},
24894 which returns a list of @code{user-group} and @code{user-account}
24895 objects representing the build user accounts (@pxref{Invoking
24898 @item activation-service-type
24899 Here @code{guix-activation} is a procedure that returns a gexp, which is
24900 a code snippet to run at ``activation time''---e.g., when the service is
24904 A service of this type is instantiated like this:
24907 (service guix-service-type
24908 (guix-configuration
24910 (use-substitutes? #f)))
24913 The second argument to the @code{service} form is a value representing
24914 the parameters of this specific service instance.
24915 @xref{guix-configuration-type, @code{guix-configuration}}, for
24916 information about the @code{guix-configuration} data type. When the
24917 value is omitted, the default value specified by
24918 @code{guix-service-type} is used:
24921 (service guix-service-type)
24924 @code{guix-service-type} is quite simple because it extends other
24925 services but is not extensible itself.
24927 @c @subsubsubsection Extensible Service Types
24929 The service type for an @emph{extensible} service looks like this:
24932 (define udev-service-type
24933 (service-type (name 'udev)
24935 (list (service-extension shepherd-root-service-type
24936 udev-shepherd-service)))
24938 (compose concatenate) ;concatenate the list of rules
24939 (extend (lambda (config rules)
24941 (($ <udev-configuration> udev initial-rules)
24942 (udev-configuration
24943 (udev udev) ;the udev package to use
24944 (rules (append initial-rules rules)))))))))
24947 This is the service type for the
24948 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
24949 management daemon}. Compared to the previous example, in addition to an
24950 extension of @code{shepherd-root-service-type}, we see two new fields:
24954 This is the procedure to @dfn{compose} the list of extensions to
24955 services of this type.
24957 Services can extend the udev service by passing it lists of rules; we
24958 compose those extensions simply by concatenating them.
24961 This procedure defines how the value of the service is @dfn{extended} with
24962 the composition of the extensions.
24964 Udev extensions are composed into a list of rules, but the udev service
24965 value is itself a @code{<udev-configuration>} record. So here, we
24966 extend that record by appending the list of rules it contains to the
24967 list of contributed rules.
24970 This is a string giving an overview of the service type. The string can
24971 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
24972 @command{guix system search} command searches these strings and displays
24973 them (@pxref{Invoking guix system}).
24976 There can be only one instance of an extensible service type such as
24977 @code{udev-service-type}. If there were more, the
24978 @code{service-extension} specifications would be ambiguous.
24980 Still here? The next section provides a reference of the programming
24981 interface for services.
24983 @node Service Reference
24984 @subsection Service Reference
24986 We have seen an overview of service types (@pxref{Service Types and
24987 Services}). This section provides a reference on how to manipulate
24988 services and service types. This interface is provided by the
24989 @code{(gnu services)} module.
24991 @deffn {Scheme Procedure} service @var{type} [@var{value}]
24992 Return a new service of @var{type}, a @code{<service-type>} object (see
24993 below.) @var{value} can be any object; it represents the parameters of
24994 this particular service instance.
24996 When @var{value} is omitted, the default value specified by @var{type}
24997 is used; if @var{type} does not specify a default value, an error is
25000 For instance, this:
25003 (service openssh-service-type)
25007 is equivalent to this:
25010 (service openssh-service-type
25011 (openssh-configuration))
25014 In both cases the result is an instance of @code{openssh-service-type}
25015 with the default configuration.
25018 @deffn {Scheme Procedure} service? @var{obj}
25019 Return true if @var{obj} is a service.
25022 @deffn {Scheme Procedure} service-kind @var{service}
25023 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25026 @deffn {Scheme Procedure} service-value @var{service}
25027 Return the value associated with @var{service}. It represents its
25031 Here is an example of how a service is created and manipulated:
25035 (service nginx-service-type
25036 (nginx-configuration
25038 (log-directory log-directory)
25039 (run-directory run-directory)
25040 (file config-file))))
25045 (eq? (service-kind s) nginx-service-type)
25049 The @code{modify-services} form provides a handy way to change the
25050 parameters of some of the services of a list such as
25051 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25052 evaluates to a list of services. Of course, you could always use
25053 standard list combinators such as @code{map} and @code{fold} to do that
25054 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25055 @code{modify-services} simply provides a more concise form for this
25058 @deffn {Scheme Syntax} modify-services @var{services} @
25059 (@var{type} @var{variable} => @var{body}) @dots{}
25061 Modify the services listed in @var{services} according to the given
25062 clauses. Each clause has the form:
25065 (@var{type} @var{variable} => @var{body})
25068 where @var{type} is a service type---e.g.,
25069 @code{guix-service-type}---and @var{variable} is an identifier that is
25070 bound within the @var{body} to the service parameters---e.g., a
25071 @code{guix-configuration} instance---of the original service of that
25074 The @var{body} should evaluate to the new service parameters, which will
25075 be used to configure the new service. This new service will replace the
25076 original in the resulting list. Because a service's service parameters
25077 are created using @code{define-record-type*}, you can write a succinct
25078 @var{body} that evaluates to the new service parameters by using the
25079 @code{inherit} feature that @code{define-record-type*} provides.
25081 @xref{Using the Configuration System}, for example usage.
25085 Next comes the programming interface for service types. This is
25086 something you want to know when writing new service definitions, but not
25087 necessarily when simply looking for ways to customize your
25088 @code{operating-system} declaration.
25090 @deftp {Data Type} service-type
25091 @cindex service type
25092 This is the representation of a @dfn{service type} (@pxref{Service Types
25097 This is a symbol, used only to simplify inspection and debugging.
25099 @item @code{extensions}
25100 A non-empty list of @code{<service-extension>} objects (see below).
25102 @item @code{compose} (default: @code{#f})
25103 If this is @code{#f}, then the service type denotes services that cannot
25104 be extended---i.e., services that do not receive ``values'' from other
25107 Otherwise, it must be a one-argument procedure. The procedure is called
25108 by @code{fold-services} and is passed a list of values collected from
25109 extensions. It may return any single value.
25111 @item @code{extend} (default: @code{#f})
25112 If this is @code{#f}, services of this type cannot be extended.
25114 Otherwise, it must be a two-argument procedure: @code{fold-services}
25115 calls it, passing it the initial value of the service as the first
25116 argument and the result of applying @code{compose} to the extension
25117 values as the second argument. It must return a value that is a valid
25118 parameter value for the service instance.
25121 @xref{Service Types and Services}, for examples.
25124 @deffn {Scheme Procedure} service-extension @var{target-type} @
25126 Return a new extension for services of type @var{target-type}.
25127 @var{compute} must be a one-argument procedure: @code{fold-services}
25128 calls it, passing it the value associated with the service that provides
25129 the extension; it must return a valid value for the target service.
25132 @deffn {Scheme Procedure} service-extension? @var{obj}
25133 Return true if @var{obj} is a service extension.
25136 Occasionally, you might want to simply extend an existing service. This
25137 involves creating a new service type and specifying the extension of
25138 interest, which can be verbose; the @code{simple-service} procedure
25139 provides a shorthand for this.
25141 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25142 Return a service that extends @var{target} with @var{value}. This works
25143 by creating a singleton service type @var{name}, of which the returned
25144 service is an instance.
25146 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25150 (simple-service 'my-mcron-job mcron-service-type
25151 #~(job '(next-hour (3)) "guix gc -F 2G"))
25155 At the core of the service abstraction lies the @code{fold-services}
25156 procedure, which is responsible for ``compiling'' a list of services
25157 down to a single directory that contains everything needed to boot and
25158 run the system---the directory shown by the @command{guix system build}
25159 command (@pxref{Invoking guix system}). In essence, it propagates
25160 service extensions down the service graph, updating each node parameters
25161 on the way, until it reaches the root node.
25163 @deffn {Scheme Procedure} fold-services @var{services} @
25164 [#:target-type @var{system-service-type}]
25165 Fold @var{services} by propagating their extensions down to the root of
25166 type @var{target-type}; return the root service adjusted accordingly.
25169 Lastly, the @code{(gnu services)} module also defines several essential
25170 service types, some of which are listed below.
25172 @defvr {Scheme Variable} system-service-type
25173 This is the root of the service graph. It produces the system directory
25174 as returned by the @command{guix system build} command.
25177 @defvr {Scheme Variable} boot-service-type
25178 The type of the ``boot service'', which produces the @dfn{boot script}.
25179 The boot script is what the initial RAM disk runs when booting.
25182 @defvr {Scheme Variable} etc-service-type
25183 The type of the @file{/etc} service. This service is used to create
25184 files under @file{/etc} and can be extended by
25185 passing it name/file tuples such as:
25188 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25191 In this example, the effect would be to add an @file{/etc/issue} file
25192 pointing to the given file.
25195 @defvr {Scheme Variable} setuid-program-service-type
25196 Type for the ``setuid-program service''. This service collects lists of
25197 executable file names, passed as gexps, and adds them to the set of
25198 setuid-root programs on the system (@pxref{Setuid Programs}).
25201 @defvr {Scheme Variable} profile-service-type
25202 Type of the service that populates the @dfn{system profile}---i.e., the
25203 programs under @file{/run/current-system/profile}. Other services can
25204 extend it by passing it lists of packages to add to the system profile.
25208 @node Shepherd Services
25209 @subsection Shepherd Services
25211 @cindex shepherd services
25213 @cindex init system
25214 The @code{(gnu services shepherd)} module provides a way to define
25215 services managed by the GNU@tie{}Shepherd, which is the
25216 initialization system---the first process that is started when the
25217 system boots, also known as PID@tie{}1
25218 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25220 Services in the Shepherd can depend on each other. For instance, the
25221 SSH daemon may need to be started after the syslog daemon has been
25222 started, which in turn can only happen once all the file systems have
25223 been mounted. The simple operating system defined earlier (@pxref{Using
25224 the Configuration System}) results in a service graph like this:
25226 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25228 You can actually generate such a graph for any operating system
25229 definition using the @command{guix system shepherd-graph} command
25230 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25232 The @code{%shepherd-root-service} is a service object representing
25233 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25234 by passing it lists of @code{<shepherd-service>} objects.
25236 @deftp {Data Type} shepherd-service
25237 The data type representing a service managed by the Shepherd.
25240 @item @code{provision}
25241 This is a list of symbols denoting what the service provides.
25243 These are the names that may be passed to @command{herd start},
25244 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25245 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25246 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25248 @item @code{requirements} (default: @code{'()})
25249 List of symbols denoting the Shepherd services this one depends on.
25251 @cindex one-shot services, for the Shepherd
25252 @item @code{one-shot?} (default: @code{#f})
25253 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25254 after their @code{start} action has completed. @xref{Slots of services,,,
25255 shepherd, The GNU Shepherd Manual}, for more info.
25257 @item @code{respawn?} (default: @code{#t})
25258 Whether to restart the service when it stops, for instance when the
25259 underlying process dies.
25262 @itemx @code{stop} (default: @code{#~(const #f)})
25263 The @code{start} and @code{stop} fields refer to the Shepherd's
25264 facilities to start and stop processes (@pxref{Service De- and
25265 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25266 G-expressions that get expanded in the Shepherd configuration file
25267 (@pxref{G-Expressions}).
25269 @item @code{actions} (default: @code{'()})
25270 @cindex actions, of Shepherd services
25271 This is a list of @code{shepherd-action} objects (see below) defining
25272 @dfn{actions} supported by the service, in addition to the standard
25273 @code{start} and @code{stop} actions. Actions listed here become available as
25274 @command{herd} sub-commands:
25277 herd @var{action} @var{service} [@var{arguments}@dots{}]
25280 @item @code{documentation}
25281 A documentation string, as shown when running:
25284 herd doc @var{service-name}
25287 where @var{service-name} is one of the symbols in @code{provision}
25288 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
25290 @item @code{modules} (default: @code{%default-modules})
25291 This is the list of modules that must be in scope when @code{start} and
25292 @code{stop} are evaluated.
25297 @deftp {Data Type} shepherd-action
25298 This is the data type that defines additional actions implemented by a
25299 Shepherd service (see above).
25303 Symbol naming the action.
25305 @item documentation
25306 This is a documentation string for the action. It can be viewed by running:
25309 herd doc @var{service} action @var{action}
25313 This should be a gexp that evaluates to a procedure of at least one argument,
25314 which is the ``running value'' of the service (@pxref{Slots of services,,,
25315 shepherd, The GNU Shepherd Manual}).
25318 The following example defines an action called @code{say-hello} that kindly
25324 (documentation "Say hi!")
25325 (procedure #~(lambda (running . args)
25326 (format #t "Hello, friend! arguments: ~s\n"
25331 Assuming this action is added to the @code{example} service, then you can do:
25334 # herd say-hello example
25335 Hello, friend! arguments: ()
25336 # herd say-hello example a b c
25337 Hello, friend! arguments: ("a" "b" "c")
25340 This, as you can see, is a fairly sophisticated way to say hello.
25341 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
25345 @defvr {Scheme Variable} shepherd-root-service-type
25346 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
25348 This is the service type that extensions target when they want to create
25349 shepherd services (@pxref{Service Types and Services}, for an example).
25350 Each extension must pass a list of @code{<shepherd-service>}.
25353 @defvr {Scheme Variable} %shepherd-root-service
25354 This service represents PID@tie{}1.
25358 @node Documentation
25359 @chapter Documentation
25361 @cindex documentation, searching for
25362 @cindex searching for documentation
25363 @cindex Info, documentation format
25365 @cindex manual pages
25366 In most cases packages installed with Guix come with documentation.
25367 There are two main documentation formats: ``Info'', a browseable
25368 hypertext format used for GNU software, and ``manual pages'' (or ``man
25369 pages''), the linear documentation format traditionally found on Unix.
25370 Info manuals are accessed with the @command{info} command or with Emacs,
25371 and man pages are accessed using @command{man}.
25373 You can look for documentation of software installed on your system by
25374 keyword. For example, the following command searches for information
25375 about ``TLS'' in Info manuals:
25379 "(emacs)Network Security" -- STARTTLS
25380 "(emacs)Network Security" -- TLS
25381 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
25382 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
25387 The command below searches for the same keyword in man pages:
25391 SSL (7) - OpenSSL SSL/TLS library
25392 certtool (1) - GnuTLS certificate tool
25396 These searches are purely local to your computer so you have the
25397 guarantee that documentation you find corresponds to what you have
25398 actually installed, you can access it off-line, and your privacy is
25401 Once you have these results, you can view the relevant documentation by
25405 $ info "(gnutls)Core TLS API"
25415 Info manuals contain sections and indices as well as hyperlinks like
25416 those found in Web pages. The @command{info} reader (@pxref{Top, Info
25417 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
25418 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
25419 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
25420 Introduction}, for an introduction to Info navigation.
25422 @node Installing Debugging Files
25423 @chapter Installing Debugging Files
25425 @cindex debugging files
25426 Program binaries, as produced by the GCC compilers for instance, are
25427 typically written in the ELF format, with a section containing
25428 @dfn{debugging information}. Debugging information is what allows the
25429 debugger, GDB, to map binary code to source code; it is required to
25430 debug a compiled program in good conditions.
25432 The problem with debugging information is that is takes up a fair amount
25433 of disk space. For example, debugging information for the GNU C Library
25434 weighs in at more than 60 MiB. Thus, as a user, keeping all the
25435 debugging info of all the installed programs is usually not an option.
25436 Yet, space savings should not come at the cost of an impediment to
25437 debugging---especially in the GNU system, which should make it easier
25438 for users to exert their computing freedom (@pxref{GNU Distribution}).
25440 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
25441 mechanism that allows users to get the best of both worlds: debugging
25442 information can be stripped from the binaries and stored in separate
25443 files. GDB is then able to load debugging information from those files,
25444 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
25447 The GNU distribution takes advantage of this by storing debugging
25448 information in the @code{lib/debug} sub-directory of a separate package
25449 output unimaginatively called @code{debug} (@pxref{Packages with
25450 Multiple Outputs}). Users can choose to install the @code{debug} output
25451 of a package when they need it. For instance, the following command
25452 installs the debugging information for the GNU C Library and for GNU
25456 guix install glibc:debug guile:debug
25459 GDB must then be told to look for debug files in the user's profile, by
25460 setting the @code{debug-file-directory} variable (consider setting it
25461 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
25465 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
25468 From there on, GDB will pick up debugging information from the
25469 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
25471 In addition, you will most likely want GDB to be able to show the source
25472 code being debugged. To do that, you will have to unpack the source
25473 code of the package of interest (obtained with @code{guix build
25474 --source}, @pxref{Invoking guix build}), and to point GDB to that source
25475 directory using the @code{directory} command (@pxref{Source Path,
25476 @code{directory},, gdb, Debugging with GDB}).
25478 @c XXX: keep me up-to-date
25479 The @code{debug} output mechanism in Guix is implemented by the
25480 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
25481 opt-in---debugging information is available only for the packages
25482 with definitions explicitly declaring a @code{debug} output. This may be
25483 changed to opt-out in the future if our build farm servers can handle
25484 the load. To check whether a package has a @code{debug} output, use
25485 @command{guix package --list-available} (@pxref{Invoking guix package}).
25488 @node Security Updates
25489 @chapter Security Updates
25491 @cindex security updates
25492 @cindex security vulnerabilities
25493 Occasionally, important security vulnerabilities are discovered in software
25494 packages and must be patched. Guix developers try hard to keep track of
25495 known vulnerabilities and to apply fixes as soon as possible in the
25496 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
25497 containing only security updates.) The @command{guix lint} tool helps
25498 developers find out about vulnerable versions of software packages in the
25503 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
25504 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
25505 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
25509 @xref{Invoking guix lint}, for more information.
25512 As of version @value{VERSION}, the feature described below is considered
25516 Guix follows a functional
25517 package management discipline (@pxref{Introduction}), which implies
25518 that, when a package is changed, @emph{every package that depends on it}
25519 must be rebuilt. This can significantly slow down the deployment of
25520 fixes in core packages such as libc or Bash, since basically the whole
25521 distribution would need to be rebuilt. Using pre-built binaries helps
25522 (@pxref{Substitutes}), but deployment may still take more time than
25526 To address this, Guix implements @dfn{grafts}, a mechanism that allows
25527 for fast deployment of critical updates without the costs associated
25528 with a whole-distribution rebuild. The idea is to rebuild only the
25529 package that needs to be patched, and then to ``graft'' it onto packages
25530 explicitly installed by the user and that were previously referring to
25531 the original package. The cost of grafting is typically very low, and
25532 order of magnitudes lower than a full rebuild of the dependency chain.
25534 @cindex replacements of packages, for grafts
25535 For instance, suppose a security update needs to be applied to Bash.
25536 Guix developers will provide a package definition for the ``fixed''
25537 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
25538 Packages}). Then, the original package definition is augmented with a
25539 @code{replacement} field pointing to the package containing the bug fix:
25546 (replacement bash-fixed)))
25549 From there on, any package depending directly or indirectly on Bash---as
25550 reported by @command{guix gc --requisites} (@pxref{Invoking guix
25551 gc})---that is installed is automatically ``rewritten'' to refer to
25552 @code{bash-fixed} instead of @code{bash}. This grafting process takes
25553 time proportional to the size of the package, usually less than a
25554 minute for an ``average'' package on a recent machine. Grafting is
25555 recursive: when an indirect dependency requires grafting, then grafting
25556 ``propagates'' up to the package that the user is installing.
25558 Currently, the length of the name and version of the graft and that of
25559 the package it replaces (@code{bash-fixed} and @code{bash} in the example
25560 above) must be equal. This restriction mostly comes from the fact that
25561 grafting works by patching files, including binary files, directly.
25562 Other restrictions may apply: for instance, when adding a graft to a
25563 package providing a shared library, the original shared library and its
25564 replacement must have the same @code{SONAME} and be binary-compatible.
25566 The @option{--no-grafts} command-line option allows you to forcefully
25567 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
25571 guix build bash --no-grafts
25575 returns the store file name of the original Bash, whereas:
25582 returns the store file name of the ``fixed'', replacement Bash. This
25583 allows you to distinguish between the two variants of Bash.
25585 To verify which Bash your whole profile refers to, you can run
25586 (@pxref{Invoking guix gc}):
25589 guix gc -R `readlink -f ~/.guix-profile` | grep bash
25593 @dots{} and compare the store file names that you get with those above.
25594 Likewise for a complete Guix system generation:
25597 guix gc -R `guix system build my-config.scm` | grep bash
25600 Lastly, to check which Bash running processes are using, you can use the
25601 @command{lsof} command:
25604 lsof | grep /gnu/store/.*bash
25608 @node Bootstrapping
25609 @chapter Bootstrapping
25611 @c Adapted from the ELS 2013 paper.
25613 @cindex bootstrapping
25615 Bootstrapping in our context refers to how the distribution gets built
25616 ``from nothing''. Remember that the build environment of a derivation
25617 contains nothing but its declared inputs (@pxref{Introduction}). So
25618 there's an obvious chicken-and-egg problem: how does the first package
25619 get built? How does the first compiler get compiled? Note that this is
25620 a question of interest only to the curious hacker, not to the regular
25621 user, so you can shamelessly skip this section if you consider yourself
25622 a ``regular user''.
25624 @cindex bootstrap binaries
25625 The GNU system is primarily made of C code, with libc at its core. The
25626 GNU build system itself assumes the availability of a Bourne shell and
25627 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
25628 `grep'. Furthermore, build programs---programs that run
25629 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
25630 (@pxref{Derivations}). Consequently, to be able to build anything at
25631 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
25632 Binutils, libc, and the other packages mentioned above---the
25633 @dfn{bootstrap binaries}.
25635 These bootstrap binaries are ``taken for granted'', though we can also
25636 re-create them if needed (more on that later).
25638 @unnumberedsec Preparing to Use the Bootstrap Binaries
25640 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
25641 @c large image, it's hard to scroll. Oh well.
25642 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
25644 The figure above shows the very beginning of the dependency graph of the
25645 distribution, corresponding to the package definitions of the @code{(gnu
25646 packages bootstrap)} module. A similar figure can be generated with
25647 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
25650 guix graph -t derivation \
25651 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
25655 At this level of detail, things are
25656 slightly complex. First, Guile itself consists of an ELF executable,
25657 along with many source and compiled Scheme files that are dynamically
25658 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
25659 tarball shown in this graph. This tarball is part of Guix's ``source''
25660 distribution, and gets inserted into the store with @code{add-to-store}
25661 (@pxref{The Store}).
25663 But how do we write a derivation that unpacks this tarball and adds it
25664 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
25665 derivation---the first one that gets built---uses @code{bash} as its
25666 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
25667 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
25668 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
25669 the Guix source distribution, whose sole purpose is to allow the Guile
25670 tarball to be unpacked.
25672 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
25673 Guile that can be used to run subsequent build programs. Its first task
25674 is to download tarballs containing the other pre-built binaries---this
25675 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
25676 @code{ftp-client.scm} are used for this purpose. The
25677 @code{module-import.drv} derivations import those modules in a directory
25678 in the store, using the original layout. The
25679 @code{module-import-compiled.drv} derivations compile those modules, and
25680 write them in an output directory with the right layout. This
25681 corresponds to the @code{#:modules} argument of
25682 @code{build-expression->derivation} (@pxref{Derivations}).
25684 Finally, the various tarballs are unpacked by the
25685 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
25686 etc., at which point we have a working C tool chain.
25689 @unnumberedsec Building the Build Tools
25691 Bootstrapping is complete when we have a full tool chain that does not
25692 depend on the pre-built bootstrap tools discussed above. This
25693 no-dependency requirement is verified by checking whether the files of
25694 the final tool chain contain references to the @file{/gnu/store}
25695 directories of the bootstrap inputs. The process that leads to this
25696 ``final'' tool chain is described by the package definitions found in
25697 the @code{(gnu packages commencement)} module.
25699 The @command{guix graph} command allows us to ``zoom out'' compared to
25700 the graph above, by looking at the level of package objects instead of
25701 individual derivations---remember that a package may translate to
25702 several derivations, typically one derivation to download its source,
25703 one to build the Guile modules it needs, and one to actually build the
25704 package from source. The command:
25707 guix graph -t bag \
25708 -e '(@@@@ (gnu packages commencement)
25709 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
25713 produces the dependency graph leading to the ``final'' C
25714 library@footnote{You may notice the @code{glibc-intermediate} label,
25715 suggesting that it is not @emph{quite} final, but as a good
25716 approximation, we will consider it final.}, depicted below.
25718 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
25720 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
25721 The first tool that gets built with the bootstrap binaries is
25722 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
25723 for all the following packages. From there Findutils and Diffutils get
25726 Then come the first-stage Binutils and GCC, built as pseudo cross
25727 tools---i.e., with @code{--target} equal to @code{--host}. They are
25728 used to build libc. Thanks to this cross-build trick, this libc is
25729 guaranteed not to hold any reference to the initial tool chain.
25731 From there the final Binutils and GCC (not shown above) are built.
25733 from the final Binutils, and links programs against the just-built libc.
25734 This tool chain is used to build the other packages used by Guix and by
25735 the GNU Build System: Guile, Bash, Coreutils, etc.
25737 And voilà! At this point we have the complete set of build tools that
25738 the GNU Build System expects. These are in the @code{%final-inputs}
25739 variable of the @code{(gnu packages commencement)} module, and are
25740 implicitly used by any package that uses @code{gnu-build-system}
25741 (@pxref{Build Systems, @code{gnu-build-system}}).
25744 @unnumberedsec Building the Bootstrap Binaries
25746 @cindex bootstrap binaries
25747 Because the final tool chain does not depend on the bootstrap binaries,
25748 those rarely need to be updated. Nevertheless, it is useful to have an
25749 automated way to produce them, should an update occur, and this is what
25750 the @code{(gnu packages make-bootstrap)} module provides.
25752 The following command builds the tarballs containing the bootstrap
25753 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
25754 of Coreutils and other basic command-line tools):
25757 guix build bootstrap-tarballs
25760 The generated tarballs are those that should be referred to in the
25761 @code{(gnu packages bootstrap)} module mentioned at the beginning of
25764 Still here? Then perhaps by now you've started to wonder: when do we
25765 reach a fixed point? That is an interesting question! The answer is
25766 unknown, but if you would like to investigate further (and have
25767 significant computational and storage resources to do so), then let us
25770 @unnumberedsec Reducing the Set of Bootstrap Binaries
25772 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
25773 of binary code! Why is that a problem? It's a problem because these
25774 big chunks of binary code are practically non-auditable, which makes it
25775 hard to establish what source code produced them. Every unauditable
25776 binary also leaves us vulnerable to compiler backdoors as described by
25777 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
25779 This is mitigated by the fact that our bootstrap binaries were generated
25780 from an earlier Guix revision. Nevertheless it lacks the level of
25781 transparency that we get in the rest of the package dependency graph,
25782 where Guix always gives us a source-to-binary mapping. Thus, our goal
25783 is to reduce the set of bootstrap binaries to the bare minimum.
25785 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
25786 on-going projects to do that. One of these is about replacing the
25787 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
25788 of increasing complexity, which could be built from source starting from
25789 a simple and auditable assembler. Your help is welcome!
25793 @chapter Porting to a New Platform
25795 As discussed above, the GNU distribution is self-contained, and
25796 self-containment is achieved by relying on pre-built ``bootstrap
25797 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
25798 operating system kernel, CPU architecture, and application binary
25799 interface (ABI). Thus, to port the distribution to a platform that is
25800 not yet supported, one must build those bootstrap binaries, and update
25801 the @code{(gnu packages bootstrap)} module to use them on that platform.
25803 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
25804 When everything goes well, and assuming the GNU tool chain supports the
25805 target platform, this can be as simple as running a command like this
25809 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
25812 For this to work, the @code{glibc-dynamic-linker} procedure in
25813 @code{(gnu packages bootstrap)} must be augmented to return the right
25814 file name for libc's dynamic linker on that platform; likewise,
25815 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
25816 taught about the new platform.
25818 Once these are built, the @code{(gnu packages bootstrap)} module needs
25819 to be updated to refer to these binaries on the target platform. That
25820 is, the hashes and URLs of the bootstrap tarballs for the new platform
25821 must be added alongside those of the currently supported platforms. The
25822 bootstrap Guile tarball is treated specially: it is expected to be
25823 available locally, and @file{gnu/local.mk} has rules to download it for
25824 the supported architectures; a rule for the new platform must be added
25827 In practice, there may be some complications. First, it may be that the
25828 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
25829 above) is not recognized by all the GNU tools. Typically, glibc
25830 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
25831 configure flag (see @code{gcc.scm} for examples of how to handle this).
25832 Second, some of the required packages could fail to build for that
25833 platform. Lastly, the generated binaries could be broken for some
25836 @c *********************************************************************
25837 @include contributing.texi
25839 @c *********************************************************************
25840 @node Acknowledgments
25841 @chapter Acknowledgments
25843 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
25844 which was designed and
25845 implemented by Eelco Dolstra, with contributions from other people (see
25846 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
25847 management, and promoted unprecedented features, such as transactional
25848 package upgrades and rollbacks, per-user profiles, and referentially
25849 transparent build processes. Without this work, Guix would not exist.
25851 The Nix-based software distributions, Nixpkgs and NixOS, have also been
25852 an inspiration for Guix.
25854 GNU@tie{}Guix itself is a collective work with contributions from a
25855 number of people. See the @file{AUTHORS} file in Guix for more
25856 information on these fine people. The @file{THANKS} file lists people
25857 who have helped by reporting bugs, taking care of the infrastructure,
25858 providing artwork and themes, making suggestions, and more---thank you!
25861 @c *********************************************************************
25862 @node GNU Free Documentation License
25863 @appendix GNU Free Documentation License
25864 @cindex license, GNU Free Documentation License
25865 @include fdl-1.3.texi
25867 @c *********************************************************************
25868 @node Concept Index
25869 @unnumbered Concept Index
25872 @node Programming Index
25873 @unnumbered Programming Index
25874 @syncodeindex tp fn
25875 @syncodeindex vr fn
25880 @c Local Variables:
25881 @c ispell-local-dictionary: "american";