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 The official substitute server used by default.
17 @set SUBSTITUTE-SERVER ci.guix.info
20 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès@*
21 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
22 Copyright @copyright{} 2013 Nikita Karetnikov@*
23 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
24 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
25 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
26 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
27 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
28 Copyright @copyright{} 2015, 2016, 2017, 2018 Ricardo Wurmus@*
29 Copyright @copyright{} 2016 Ben Woodcroft@*
30 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
31 Copyright @copyright{} 2016, 2017, 2018 Efraim Flashner@*
32 Copyright @copyright{} 2016 John Darrington@*
33 Copyright @copyright{} 2016, 2017 Nils Gillmann@*
34 Copyright @copyright{} 2016, 2017, 2018 Jan Nieuwenhuizen@*
35 Copyright @copyright{} 2016 Julien Lepiller@*
36 Copyright @copyright{} 2016 Alex ter Weele@*
37 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
38 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
39 Copyright @copyright{} 2017 Federico Beffa@*
40 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
41 Copyright @copyright{} 2017 Thomas Danckaert@*
42 Copyright @copyright{} 2017 humanitiesNerd@*
43 Copyright @copyright{} 2017 Christopher Allan Webber@*
44 Copyright @copyright{} 2017, 2018 Marius Bakke@*
45 Copyright @copyright{} 2017 Hartmut Goebel@*
46 Copyright @copyright{} 2017 Maxim Cournoyer@*
47 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
48 Copyright @copyright{} 2017 George Clemmer@*
49 Copyright @copyright{} 2017 Andy Wingo@*
50 Copyright @copyright{} 2017, 2018 Arun Isaac@*
51 Copyright @copyright{} 2017 nee@*
52 Copyright @copyright{} 2018 Rutger Helling@*
53 Copyright @copyright{} 2018 Oleg Pykhalov@*
54 Copyright @copyright{} 2018 Mike Gerwitz@*
55 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
56 Copyright @copyright{} 2018 Gábor Boskovits@*
57 Copyright @copyright{} 2018 Florian Pelz@*
58 Copyright @copyright{} 2018 Laura Lazzati@*
59 Copyright @copyright{} 2018 Alex Vong@*
61 Permission is granted to copy, distribute and/or modify this document
62 under the terms of the GNU Free Documentation License, Version 1.3 or
63 any later version published by the Free Software Foundation; with no
64 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
65 copy of the license is included in the section entitled ``GNU Free
66 Documentation License''.
69 @dircategory System administration
71 * Guix: (guix). Manage installed software and system configuration.
72 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
73 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
74 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
75 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
78 @dircategory Software development
80 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
81 * guix build: (guix)Invoking guix build. Building packages.
82 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
86 @title GNU Guix Reference Manual
87 @subtitle Using the GNU Guix Functional Package Manager
88 @author The GNU Guix Developers
91 @vskip 0pt plus 1filll
92 Edition @value{EDITION} @*
100 @c *********************************************************************
104 This document describes GNU Guix version @value{VERSION}, a functional
105 package management tool written for the GNU system.
107 @c TRANSLATORS: You can replace the following paragraph with information on
108 @c how to join your own translation team and how to report issues with the
110 This manual is also available in French (@pxref{Top,,, guix.fr, Manuel de
111 référence de GNU Guix}) and German (@pxref{Top,,, guix.de, Referenzhandbuch
112 zu GNU Guix}). If you would like to translate it in your native language,
114 @uref{https://translationproject.org/domain/guix-manual.html, Translation
118 * Introduction:: What is Guix about?
119 * Installation:: Installing Guix.
120 * Package Management:: Package installation, upgrade, etc.
121 * Programming Interface:: Using Guix in Scheme.
122 * Utilities:: Package management commands.
123 * GNU Distribution:: Software for your friendly GNU system.
124 * Contributing:: Your help needed!
126 * Acknowledgments:: Thanks!
127 * GNU Free Documentation License:: The license of this manual.
128 * Concept Index:: Concepts.
129 * Programming Index:: Data types, functions, and variables.
132 --- The Detailed Node Listing ---
136 * Binary Installation:: Getting Guix running in no time!
137 * Requirements:: Software needed to build and run Guix.
138 * Running the Test Suite:: Testing Guix.
139 * Setting Up the Daemon:: Preparing the build daemon's environment.
140 * Invoking guix-daemon:: Running the build daemon.
141 * Application Setup:: Application-specific setup.
143 Setting Up the Daemon
145 * Build Environment Setup:: Preparing the isolated build environment.
146 * Daemon Offload Setup:: Offloading builds to remote machines.
147 * SELinux Support:: Using an SELinux policy for the daemon.
151 * Features:: How Guix will make your life brighter.
152 * Invoking guix package:: Package installation, removal, etc.
153 * Substitutes:: Downloading pre-built binaries.
154 * Packages with Multiple Outputs:: Single source package, multiple outputs.
155 * Invoking guix gc:: Running the garbage collector.
156 * Invoking guix pull:: Fetching the latest Guix and distribution.
157 * Channels:: Customizing the package collection.
158 * Inferiors:: Interacting with another revision of Guix.
159 * Invoking guix describe:: Display information about your Guix revision.
160 * Invoking guix pack:: Creating software bundles.
161 * Invoking guix archive:: Exporting and importing store files.
165 * Official Substitute Server:: One particular source of substitutes.
166 * Substitute Server Authorization:: How to enable or disable substitutes.
167 * Substitute Authentication:: How Guix verifies substitutes.
168 * Proxy Settings:: How to get substitutes via proxy.
169 * Substitution Failure:: What happens when substitution fails.
170 * On Trusting Binaries:: How can you trust that binary blob?
172 Programming Interface
174 * Defining Packages:: Defining new packages.
175 * Build Systems:: Specifying how packages are built.
176 * The Store:: Manipulating the package store.
177 * Derivations:: Low-level interface to package derivations.
178 * The Store Monad:: Purely functional interface to the store.
179 * G-Expressions:: Manipulating build expressions.
180 * Invoking guix repl:: Fiddling with Guix interactively.
184 * package Reference:: The package data type.
185 * origin Reference:: The origin data type.
189 * Invoking guix build:: Building packages from the command line.
190 * Invoking guix edit:: Editing package definitions.
191 * Invoking guix download:: Downloading a file and printing its hash.
192 * Invoking guix hash:: Computing the cryptographic hash of a file.
193 * Invoking guix import:: Importing package definitions.
194 * Invoking guix refresh:: Updating package definitions.
195 * Invoking guix lint:: Finding errors in package definitions.
196 * Invoking guix size:: Profiling disk usage.
197 * Invoking guix graph:: Visualizing the graph of packages.
198 * Invoking guix environment:: Setting up development environments.
199 * Invoking guix publish:: Sharing substitutes.
200 * Invoking guix challenge:: Challenging substitute servers.
201 * Invoking guix copy:: Copying to and from a remote store.
202 * Invoking guix container:: Process isolation.
203 * Invoking guix weather:: Assessing substitute availability.
204 * Invoking guix processes:: Listing client processes.
206 Invoking @command{guix build}
208 * Common Build Options:: Build options for most commands.
209 * Package Transformation Options:: Creating variants of packages.
210 * Additional Build Options:: Options specific to 'guix build'.
211 * Debugging Build Failures:: Real life packaging experience.
215 * System Installation:: Installing the whole operating system.
216 * System Configuration:: Configuring the operating system.
217 * Documentation:: Browsing software user manuals.
218 * Installing Debugging Files:: Feeding the debugger.
219 * Security Updates:: Deploying security fixes quickly.
220 * Package Modules:: Packages from the programmer's viewpoint.
221 * Packaging Guidelines:: Growing the distribution.
222 * Bootstrapping:: GNU/Linux built from scratch.
223 * Porting:: Targeting another platform or kernel.
227 * Limitations:: What you can expect.
228 * Hardware Considerations:: Supported hardware.
229 * USB Stick and DVD Installation:: Preparing the installation medium.
230 * Preparing for Installation:: Networking, partitioning, etc.
231 * Proceeding with the Installation:: The real thing.
232 * Installing GuixSD in a VM:: GuixSD playground.
233 * Building the Installation Image:: How this comes to be.
237 * Using the Configuration System:: Customizing your GNU system.
238 * operating-system Reference:: Detail of operating-system declarations.
239 * File Systems:: Configuring file system mounts.
240 * Mapped Devices:: Block device extra processing.
241 * User Accounts:: Specifying user accounts.
242 * Locales:: Language and cultural convention settings.
243 * Services:: Specifying system services.
244 * Setuid Programs:: Programs running with root privileges.
245 * X.509 Certificates:: Authenticating HTTPS servers.
246 * Name Service Switch:: Configuring libc's name service switch.
247 * Initial RAM Disk:: Linux-Libre bootstrapping.
248 * Bootloader Configuration:: Configuring the boot loader.
249 * Invoking guix system:: Instantiating a system configuration.
250 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
251 * Defining Services:: Adding new service definitions.
255 * Base Services:: Essential system services.
256 * Scheduled Job Execution:: The mcron service.
257 * Log Rotation:: The rottlog service.
258 * Networking Services:: Network setup, SSH daemon, etc.
259 * X Window:: Graphical display.
260 * Printing Services:: Local and remote printer support.
261 * Desktop Services:: D-Bus and desktop services.
262 * Sound Services:: ALSA and Pulseaudio services.
263 * Database Services:: SQL databases, key-value stores, etc.
264 * Mail Services:: IMAP, POP3, SMTP, and all that.
265 * Messaging Services:: Messaging services.
266 * Telephony Services:: Telephony services.
267 * Monitoring Services:: Monitoring services.
268 * Kerberos Services:: Kerberos services.
269 * Web Services:: Web servers.
270 * Certificate Services:: TLS certificates via Let's Encrypt.
271 * DNS Services:: DNS daemons.
272 * VPN Services:: VPN daemons.
273 * Network File System:: NFS related services.
274 * Continuous Integration:: The Cuirass service.
275 * Power Management Services:: Extending battery life.
276 * Audio Services:: The MPD.
277 * Virtualization Services:: Virtualization services.
278 * Version Control Services:: Providing remote access to Git repositories.
279 * Game Services:: Game servers.
280 * Miscellaneous Services:: Other services.
284 * Service Composition:: The model for composing services.
285 * Service Types and Services:: Types and services.
286 * Service Reference:: API reference.
287 * Shepherd Services:: A particular type of service.
291 * Software Freedom:: What may go into the distribution.
292 * Package Naming:: What's in a name?
293 * Version Numbers:: When the name is not enough.
294 * Synopses and Descriptions:: Helping users find the right package.
295 * Python Modules:: A touch of British comedy.
296 * Perl Modules:: Little pearls.
297 * Java Packages:: Coffee break.
298 * Fonts:: Fond of fonts.
302 * Building from Git:: The latest and greatest.
303 * Running Guix Before It Is Installed:: Hacker tricks.
304 * The Perfect Setup:: The right tools.
305 * Coding Style:: Hygiene of the contributor.
306 * Submitting Patches:: Share your work.
310 * Programming Paradigm:: How to compose your elements.
311 * Modules:: Where to store your code?
312 * Data Types and Pattern Matching:: Implementing data structures.
313 * Formatting Code:: Writing conventions.
318 @c *********************************************************************
320 @chapter Introduction
323 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
324 using the international phonetic alphabet (IPA).} is a package
325 management tool for the GNU system. Guix makes it easy for unprivileged
326 users to install, upgrade, or remove packages, to roll back to a
327 previous package set, to build packages from source, and generally
328 assists with the creation and maintenance of software environments.
330 @cindex user interfaces
331 Guix provides a command-line package management interface
332 (@pxref{Invoking guix package}), a set of command-line utilities
333 (@pxref{Utilities}), as well as Scheme programming interfaces
334 (@pxref{Programming Interface}).
336 Its @dfn{build daemon} is responsible for building packages on behalf of
337 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
338 binaries from authorized sources (@pxref{Substitutes}).
340 @cindex extensibility of the distribution
341 @cindex customization, of packages
342 Guix includes package definitions for many GNU and non-GNU packages, all
343 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
344 user's computing freedom}. It is @emph{extensible}: users can write
345 their own package definitions (@pxref{Defining Packages}) and make them
346 available as independent package modules (@pxref{Package Modules}). It
347 is also @emph{customizable}: users can @emph{derive} specialized package
348 definitions from existing ones, including from the command line
349 (@pxref{Package Transformation Options}).
351 @cindex Guix System Distribution
353 You can install GNU@tie{}Guix on top of an existing GNU/Linux system
354 where it complements the available tools without interference
355 (@pxref{Installation}), or you can use it as part of the standalone
356 @dfn{Guix System Distribution} or GuixSD (@pxref{GNU Distribution}).
357 With GNU@tie{}GuixSD, you @emph{declare} all aspects of the operating
358 system configuration and Guix takes care of instantiating the
359 configuration in a transactional, reproducible, and stateless fashion
360 (@pxref{System Configuration}).
362 @cindex functional package management
364 Under the hood, Guix implements the @dfn{functional package management}
365 discipline pioneered by Nix (@pxref{Acknowledgments}).
366 In Guix, the package build and installation process is seen
367 as a @emph{function}, in the mathematical sense. That function takes inputs,
368 such as build scripts, a compiler, and libraries, and
369 returns an installed package. As a pure function, its result depends
370 solely on its inputs---for instance, it cannot refer to software or
371 scripts that were not explicitly passed as inputs. A build function
372 always produces the same result when passed a given set of inputs. It
373 cannot alter the environment of the running system in
374 any way; for instance, it cannot create, modify, or delete files outside
375 of its build and installation directories. This is achieved by running
376 build processes in isolated environments (or @dfn{containers}), where only their
377 explicit inputs are visible.
380 The result of package build functions is @dfn{cached} in the file
381 system, in a special directory called @dfn{the store} (@pxref{The
382 Store}). Each package is installed in a directory of its own in the
383 store---by default under @file{/gnu/store}. The directory name contains
384 a hash of all the inputs used to build that package; thus, changing an
385 input yields a different directory name.
387 This approach is the foundation for the salient features of Guix: support
388 for transactional package upgrade and rollback, per-user installation, and
389 garbage collection of packages (@pxref{Features}).
392 @c *********************************************************************
394 @chapter Installation
396 @cindex installing Guix
397 @cindex official website
398 GNU Guix is available for download from its website at
399 @url{http://www.gnu.org/software/guix/}. This section describes the
400 software requirements of Guix, as well as how to install it and get
403 Note that this section is concerned with the installation of the package
404 manager, which can be done on top of a running GNU/Linux system. If,
405 instead, you want to install the complete GNU operating system,
406 @pxref{System Installation}.
408 @cindex foreign distro
409 @cindex directories related to foreign distro
411 When installed on a running GNU/Linux system---thereafter called a
412 @dfn{foreign distro}---GNU@tie{}Guix complements the available tools
413 without interference. Its data lives exclusively in two directories,
414 usually @file{/gnu/store} and @file{/var/guix}; other files on your
415 system, such as @file{/etc}, are left untouched.
417 Once installed, Guix can be updated by running @command{guix pull}
418 (@pxref{Invoking guix pull}).
421 * Binary Installation:: Getting Guix running in no time!
422 * Requirements:: Software needed to build and run Guix.
423 * Running the Test Suite:: Testing Guix.
424 * Setting Up the Daemon:: Preparing the build daemon's environment.
425 * Invoking guix-daemon:: Running the build daemon.
426 * Application Setup:: Application-specific setup.
429 @node Binary Installation
430 @section Binary Installation
432 @cindex installing Guix from binaries
433 @cindex installer script
434 This section describes how to install Guix on an arbitrary system from a
435 self-contained tarball providing binaries for Guix and for all its
436 dependencies. This is often quicker than installing from source, which
437 is described in the next sections. The only requirement is to have
441 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
442 shell installer script}, which automates the download, installation, and
443 initial configuration of Guix. It should be run as the root user.
445 Installing goes along these lines:
449 @cindex downloading Guix binary
450 Download the binary tarball from
451 @indicateurl{https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
452 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
453 already running the kernel Linux, and so on.
455 @c The following is somewhat duplicated in ``System Installation''.
456 Make sure to download the associated @file{.sig} file and to verify the
457 authenticity of the tarball against it, along these lines:
460 $ wget https://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
461 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
464 If that command fails because you do not have the required public key,
465 then run this command to import it:
468 $ gpg --keyserver @value{KEY-SERVER} \
469 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
473 and rerun the @code{gpg --verify} command.
474 @c end authentication part
477 Now, you need to become the @code{root} user. Depending on your distribution,
478 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
482 # tar --warning=no-timestamp -xf \
483 guix-binary-@value{VERSION}.@var{system}.tar.xz
484 # mv var/guix /var/ && mv gnu /
487 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
488 The latter contains a ready-to-use profile for @code{root} (see next
491 Do @emph{not} unpack the tarball on a working Guix system since that
492 would overwrite its own essential files.
494 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
495 not emit warnings about ``implausibly old time stamps'' (such
496 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
498 They stem from the fact that all the
499 files in the archive have their modification time set to zero (which
500 means January 1st, 1970.) This is done on purpose to make sure the
501 archive content is independent of its creation time, thus making it
505 Make the profile available under @file{~root/.config/guix/current}, which is
506 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
509 # mkdir -p ~root/.config/guix
510 # ln -sf /var/guix/profiles/per-user/root/current-guix \
511 ~root/.config/guix/current
514 Source @file{etc/profile} to augment @code{PATH} and other relevant
515 environment variables:
518 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
519 source $GUIX_PROFILE/etc/profile
523 Create the group and user accounts for build users as explained below
524 (@pxref{Build Environment Setup}).
527 Run the daemon, and set it to automatically start on boot.
529 If your host distro uses the systemd init system, this can be achieved
532 @c Versions of systemd that supported symlinked service files are not
533 @c yet widely deployed, so we should suggest that users copy the service
536 @c See this thread for more information:
537 @c http://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
540 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
542 # systemctl start guix-daemon && systemctl enable guix-daemon
545 If your host distro uses the Upstart init system:
548 # initctl reload-configuration
549 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
554 Otherwise, you can still start the daemon manually with:
557 # ~root/.config/guix/current/bin/guix-daemon \
558 --build-users-group=guixbuild
562 Make the @command{guix} command available to other users on the machine,
566 # mkdir -p /usr/local/bin
568 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
571 It is also a good idea to make the Info version of this manual available
575 # mkdir -p /usr/local/share/info
576 # cd /usr/local/share/info
577 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
581 That way, assuming @file{/usr/local/share/info} is in the search path,
582 running @command{info guix} will open this manual (@pxref{Other Info
583 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
587 @cindex substitutes, authorization thereof
588 To use substitutes from @code{hydra.gnu.org} or one of its mirrors
589 (@pxref{Substitutes}), authorize them:
592 # guix archive --authorize < \
593 ~root/.config/guix/current/share/guix/hydra.gnu.org.pub
597 Each user may need to perform a few additional steps to make their Guix
598 environment ready for use, @pxref{Application Setup}.
601 Voilà, the installation is complete!
603 You can confirm that Guix is working by installing a sample package into
607 # guix package -i hello
610 The @code{guix} package must remain available in @code{root}'s profile,
611 or it would become subject to garbage collection---in which case you
612 would find yourself badly handicapped by the lack of the @command{guix}
613 command. In other words, do not remove @code{guix} by running
614 @code{guix package -r guix}.
616 The binary installation tarball can be (re)produced and verified simply
617 by running the following command in the Guix source tree:
620 make guix-binary.@var{system}.tar.xz
624 ...@: which, in turn, runs:
627 guix pack -s @var{system} --localstatedir \
628 --profile-name=current-guix guix
631 @xref{Invoking guix pack}, for more info on this handy tool.
634 @section Requirements
636 This section lists requirements when building Guix from source. The
637 build procedure for Guix is the same as for other GNU software, and is
638 not covered here. Please see the files @file{README} and @file{INSTALL}
639 in the Guix source tree for additional details.
641 GNU Guix depends on the following packages:
644 @item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.13 or
645 later, including 2.2.x;
646 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
649 @uref{http://gnutls.org/, GnuTLS}, specifically its Guile bindings
650 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
651 Guile,, gnutls-guile, GnuTLS-Guile});
653 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
656 @c FIXME: Specify a version number once a release has been made.
657 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
659 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
660 @item @url{http://zlib.net, zlib};
661 @item @url{http://www.gnu.org/software/make/, GNU Make}.
664 The following dependencies are optional:
668 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
669 Support for build offloading (@pxref{Daemon Offload Setup}) and
670 @command{guix copy} (@pxref{Invoking guix copy}) depends on
671 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
672 version 0.10.2 or later.
675 When @url{http://www.bzip.org, libbz2} is available,
676 @command{guix-daemon} can use it to compress build logs.
679 Unless @code{--disable-daemon} was passed to @command{configure}, the
680 following packages are also needed:
683 @item @url{http://gnupg.org/, GNU libgcrypt};
684 @item @url{http://sqlite.org, SQLite 3};
685 @item @url{http://gcc.gnu.org, GCC's g++}, with support for the
689 @cindex state directory
690 When configuring Guix on a system that already has a Guix installation,
691 be sure to specify the same state directory as the existing installation
692 using the @code{--localstatedir} option of the @command{configure}
693 script (@pxref{Directory Variables, @code{localstatedir},, standards,
694 GNU Coding Standards}). The @command{configure} script protects against
695 unintended misconfiguration of @var{localstatedir} so you do not
696 inadvertently corrupt your store (@pxref{The Store}).
698 @cindex Nix, compatibility
699 When a working installation of @url{http://nixos.org/nix/, the Nix package
700 manager} is available, you
701 can instead configure Guix with @code{--disable-daemon}. In that case,
702 Nix replaces the three dependencies above.
704 Guix is compatible with Nix, so it is possible to share the same store
705 between both. To do so, you must pass @command{configure} not only the
706 same @code{--with-store-dir} value, but also the same
707 @code{--localstatedir} value. The latter is essential because it
708 specifies where the database that stores metadata about the store is
709 located, among other things. The default values for Nix are
710 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
711 Note that @code{--disable-daemon} is not required if
712 your goal is to share the store with Nix.
714 @node Running the Test Suite
715 @section Running the Test Suite
718 After a successful @command{configure} and @code{make} run, it is a good
719 idea to run the test suite. It can help catch issues with the setup or
720 environment, or bugs in Guix itself---and really, reporting test
721 failures is a good way to help improve the software. To run the test
728 Test cases can run in parallel: you can use the @code{-j} option of
729 GNU@tie{}make to speed things up. The first run may take a few minutes
730 on a recent machine; subsequent runs will be faster because the store
731 that is created for test purposes will already have various things in
734 It is also possible to run a subset of the tests by defining the
735 @code{TESTS} makefile variable as in this example:
738 make check TESTS="tests/store.scm tests/cpio.scm"
741 By default, tests results are displayed at a file level. In order to
742 see the details of every individual test cases, it is possible to define
743 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
746 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
749 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
750 @file{test-suite.log} file. Please specify the Guix version being used
751 as well as version numbers of the dependencies (@pxref{Requirements}) in
754 Guix also comes with a whole-system test suite that tests complete
755 GuixSD operating system instances. It can only run on systems where
756 Guix is already installed, using:
763 or, again, by defining @code{TESTS} to select a subset of tests to run:
766 make check-system TESTS="basic mcron"
769 These system tests are defined in the @code{(gnu tests @dots{})}
770 modules. They work by running the operating systems under test with
771 lightweight instrumentation in a virtual machine (VM). They can be
772 computationally intensive or rather cheap, depending on whether
773 substitutes are available for their dependencies (@pxref{Substitutes}).
774 Some of them require a lot of storage space to hold VM images.
776 Again in case of test failures, please send @email{bug-guix@@gnu.org}
779 @node Setting Up the Daemon
780 @section Setting Up the Daemon
783 Operations such as building a package or running the garbage collector
784 are all performed by a specialized process, the @dfn{build daemon}, on
785 behalf of clients. Only the daemon may access the store and its
786 associated database. Thus, any operation that manipulates the store
787 goes through the daemon. For instance, command-line tools such as
788 @command{guix package} and @command{guix build} communicate with the
789 daemon (@i{via} remote procedure calls) to instruct it what to do.
791 The following sections explain how to prepare the build daemon's
792 environment. See also @ref{Substitutes}, for information on how to allow
793 the daemon to download pre-built binaries.
796 * Build Environment Setup:: Preparing the isolated build environment.
797 * Daemon Offload Setup:: Offloading builds to remote machines.
798 * SELinux Support:: Using an SELinux policy for the daemon.
801 @node Build Environment Setup
802 @subsection Build Environment Setup
804 @cindex build environment
805 In a standard multi-user setup, Guix and its daemon---the
806 @command{guix-daemon} program---are installed by the system
807 administrator; @file{/gnu/store} is owned by @code{root} and
808 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
809 Guix tools to build packages or otherwise access the store, and the
810 daemon will do it on their behalf, ensuring that the store is kept in a
811 consistent state, and allowing built packages to be shared among users.
814 When @command{guix-daemon} runs as @code{root}, you may not want package
815 build processes themselves to run as @code{root} too, for obvious
816 security reasons. To avoid that, a special pool of @dfn{build users}
817 should be created for use by build processes started by the daemon.
818 These build users need not have a shell and a home directory: they will
819 just be used when the daemon drops @code{root} privileges in build
820 processes. Having several such users allows the daemon to launch
821 distinct build processes under separate UIDs, which guarantees that they
822 do not interfere with each other---an essential feature since builds are
823 regarded as pure functions (@pxref{Introduction}).
825 On a GNU/Linux system, a build user pool may be created like this (using
826 Bash syntax and the @code{shadow} commands):
828 @c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
829 @c for why `-G' is needed.
831 # groupadd --system guixbuild
832 # for i in `seq -w 1 10`;
834 useradd -g guixbuild -G guixbuild \
835 -d /var/empty -s `which nologin` \
836 -c "Guix build user $i" --system \
842 The number of build users determines how many build jobs may run in
843 parallel, as specified by the @option{--max-jobs} option
844 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
845 @command{guix system vm} and related commands, you may need to add the
846 build users to the @code{kvm} group so they can access @file{/dev/kvm},
847 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
848 (@pxref{Invoking guix system}).
850 The @code{guix-daemon} program may then be run as @code{root} with the
851 following command@footnote{If your machine uses the systemd init system,
852 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
853 file in @file{/etc/systemd/system} will ensure that
854 @command{guix-daemon} is automatically started. Similarly, if your
855 machine uses the Upstart init system, drop the
856 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
857 file in @file{/etc/init}.}:
860 # guix-daemon --build-users-group=guixbuild
865 This way, the daemon starts build processes in a chroot, under one of
866 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
867 environment contains nothing but:
869 @c Keep this list in sync with libstore/build.cc! -----------------------
872 a minimal @code{/dev} directory, created mostly independently from the
873 host @code{/dev}@footnote{``Mostly'', because while the set of files
874 that appear in the chroot's @code{/dev} is fixed, most of these files
875 can only be created if the host has them.};
878 the @code{/proc} directory; it only shows the processes of the container
879 since a separate PID name space is used;
882 @file{/etc/passwd} with an entry for the current user and an entry for
886 @file{/etc/group} with an entry for the user's group;
889 @file{/etc/hosts} with an entry that maps @code{localhost} to
893 a writable @file{/tmp} directory.
896 You can influence the directory where the daemon stores build trees
897 @i{via} the @code{TMPDIR} environment variable. However, the build tree
898 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
899 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
900 This way, the value of @code{TMPDIR} does not leak inside build
901 environments, which avoids discrepancies in cases where build processes
902 capture the name of their build tree.
905 The daemon also honors the @code{http_proxy} environment variable for
906 HTTP downloads it performs, be it for fixed-output derivations
907 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
909 If you are installing Guix as an unprivileged user, it is still possible
910 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
911 However, build processes will not be isolated from one another, and not
912 from the rest of the system. Thus, build processes may interfere with
913 each other, and may access programs, libraries, and other files
914 available on the system---making it much harder to view them as
915 @emph{pure} functions.
918 @node Daemon Offload Setup
919 @subsection Using the Offload Facility
923 When desired, the build daemon can @dfn{offload} derivation builds to
924 other machines running Guix, using the @code{offload} @dfn{build
925 hook}@footnote{This feature is available only when
926 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
928 feature is enabled, a list of user-specified build machines is read from
929 @file{/etc/guix/machines.scm}; every time a build is requested, for
930 instance via @code{guix build}, the daemon attempts to offload it to one
931 of the machines that satisfy the constraints of the derivation, in
932 particular its system type---e.g., @file{x86_64-linux}. Missing
933 prerequisites for the build are copied over SSH to the target machine,
934 which then proceeds with the build; upon success the output(s) of the
935 build are copied back to the initial machine.
937 The @file{/etc/guix/machines.scm} file typically looks like this:
941 (name "eightysix.example.org")
942 (system "x86_64-linux")
943 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
945 (speed 2.)) ;incredibly fast!
948 (name "meeps.example.org")
949 (system "mips64el-linux")
950 (host-key "ssh-rsa AAAAB3Nza@dots{}")
953 (string-append (getenv "HOME")
954 "/.ssh/identity-for-guix"))))
958 In the example above we specify a list of two build machines, one for
959 the @code{x86_64} architecture and one for the @code{mips64el}
962 In fact, this file is---not surprisingly!---a Scheme file that is
963 evaluated when the @code{offload} hook is started. Its return value
964 must be a list of @code{build-machine} objects. While this example
965 shows a fixed list of build machines, one could imagine, say, using
966 DNS-SD to return a list of potential build machines discovered in the
967 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
968 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
971 @deftp {Data Type} build-machine
972 This data type represents build machines to which the daemon may offload
973 builds. The important fields are:
978 The host name of the remote machine.
981 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
984 The user account to use when connecting to the remote machine over SSH.
985 Note that the SSH key pair must @emph{not} be passphrase-protected, to
986 allow non-interactive logins.
989 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
990 This is used to authenticate the machine when we connect to it. It is a
991 long string that looks like this:
994 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
997 If the machine is running the OpenSSH daemon, @command{sshd}, the host
998 key can be found in a file such as
999 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1001 If the machine is running the SSH daemon of GNU@tie{}lsh,
1002 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1003 similar file. It can be converted to the OpenSSH format using
1004 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1007 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1008 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1013 A number of optional fields may be specified:
1017 @item @code{port} (default: @code{22})
1018 Port number of SSH server on the machine.
1020 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1021 The SSH private key file to use when connecting to the machine, in
1022 OpenSSH format. This key must not be protected with a passphrase.
1024 Note that the default value is the private key @emph{of the root
1025 account}. Make sure it exists if you use the default.
1027 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1028 @itemx @code{compression-level} (default: @code{3})
1029 The SSH-level compression methods and compression level requested.
1031 Note that offloading relies on SSH compression to reduce bandwidth usage
1032 when transferring files to and from build machines.
1034 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1035 File name of the Unix-domain socket @command{guix-daemon} is listening
1038 @item @code{parallel-builds} (default: @code{1})
1039 The number of builds that may run in parallel on the machine.
1041 @item @code{speed} (default: @code{1.0})
1042 A ``relative speed factor''. The offload scheduler will tend to prefer
1043 machines with a higher speed factor.
1045 @item @code{features} (default: @code{'()})
1046 A list of strings denoting specific features supported by the machine.
1047 An example is @code{"kvm"} for machines that have the KVM Linux modules
1048 and corresponding hardware support. Derivations can request features by
1049 name, and they will be scheduled on matching build machines.
1054 The @code{guile} command must be in the search path on the build
1055 machines. In addition, the Guix modules must be in
1056 @code{$GUILE_LOAD_PATH} on the build machine---you can check whether
1057 this is the case by running:
1060 ssh build-machine guile -c "'(use-modules (guix config))'"
1063 There is one last thing to do once @file{machines.scm} is in place. As
1064 explained above, when offloading, files are transferred back and forth
1065 between the machine stores. For this to work, you first need to
1066 generate a key pair on each machine to allow the daemon to export signed
1067 archives of files from the store (@pxref{Invoking guix archive}):
1070 # guix archive --generate-key
1074 Each build machine must authorize the key of the master machine so that
1075 it accepts store items it receives from the master:
1078 # guix archive --authorize < master-public-key.txt
1082 Likewise, the master machine must authorize the key of each build machine.
1084 All the fuss with keys is here to express pairwise mutual trust
1085 relations between the master and the build machines. Concretely, when
1086 the master receives files from a build machine (and @i{vice versa}), its
1087 build daemon can make sure they are genuine, have not been tampered
1088 with, and that they are signed by an authorized key.
1090 @cindex offload test
1091 To test whether your setup is operational, run this command on the
1098 This will attempt to connect to each of the build machines specified in
1099 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1100 available on each machine, attempt to export to the machine and import
1101 from it, and report any error in the process.
1103 If you want to test a different machine file, just specify it on the
1107 # guix offload test machines-qualif.scm
1110 Last, you can test the subset of the machines whose name matches a
1111 regular expression like this:
1114 # guix offload test machines.scm '\.gnu\.org$'
1117 @cindex offload status
1118 To display the current load of all build hosts, run this command on the
1122 # guix offload status
1126 @node SELinux Support
1127 @subsection SELinux Support
1129 @cindex SELinux, daemon policy
1130 @cindex mandatory access control, SELinux
1131 @cindex security, guix-daemon
1132 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1133 can be installed on a system where SELinux is enabled, in order to label
1134 Guix files and to specify the expected behavior of the daemon. Since
1135 GuixSD does not provide an SELinux base policy, the daemon policy cannot
1138 @subsubsection Installing the SELinux policy
1139 @cindex SELinux, policy installation
1140 To install the policy run this command as root:
1143 semodule -i etc/guix-daemon.cil
1146 Then relabel the file system with @code{restorecon} or by a different
1147 mechanism provided by your system.
1149 Once the policy is installed, the file system has been relabeled, and
1150 the daemon has been restarted, it should be running in the
1151 @code{guix_daemon_t} context. You can confirm this with the following
1155 ps -Zax | grep guix-daemon
1158 Monitor the SELinux log files as you run a command like @code{guix build
1159 hello} to convince yourself that SELinux permits all necessary
1162 @subsubsection Limitations
1163 @cindex SELinux, limitations
1165 This policy is not perfect. Here is a list of limitations or quirks
1166 that should be considered when deploying the provided SELinux policy for
1171 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1172 operations involve contexts that have anything to do with
1173 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1174 but it would be preferrable to define socket rules for only this label.
1177 @code{guix gc} cannot access arbitrary links to profiles. By design,
1178 the file label of the destination of a symlink is independent of the
1179 file label of the link itself. Although all profiles under
1180 $localstatedir are labelled, the links to these profiles inherit the
1181 label of the directory they are in. For links in the user’s home
1182 directory this will be @code{user_home_t}. But for links from the root
1183 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1184 directory, etc, this won’t work. @code{guix gc} would be prevented from
1185 reading and following these links.
1188 The daemon’s feature to listen for TCP connections might no longer work.
1189 This might require extra rules, because SELinux treats network sockets
1190 differently from files.
1193 Currently all files with a name matching the regular expression
1194 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1195 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1196 that name in any profile would be permitted to run in the
1197 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1198 build a package that provides this executable and convince a user to
1199 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1200 At that point SELinux could not prevent it from accessing files that are
1201 allowed for processes in that domain.
1203 We could generate a much more restrictive policy at installation time,
1204 so that only the @emph{exact} file name of the currently installed
1205 @code{guix-daemon} executable would be labelled with
1206 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1207 The downside is that root would have to install or upgrade the policy at
1208 installation time whenever the Guix package that provides the
1209 effectively running @code{guix-daemon} executable is upgraded.
1212 @node Invoking guix-daemon
1213 @section Invoking @command{guix-daemon}
1215 The @command{guix-daemon} program implements all the functionality to
1216 access the store. This includes launching build processes, running the
1217 garbage collector, querying the availability of a build result, etc. It
1218 is normally run as @code{root} like this:
1221 # guix-daemon --build-users-group=guixbuild
1225 For details on how to set it up, @pxref{Setting Up the Daemon}.
1228 @cindex container, build environment
1229 @cindex build environment
1230 @cindex reproducible builds
1231 By default, @command{guix-daemon} launches build processes under
1232 different UIDs, taken from the build group specified with
1233 @code{--build-users-group}. In addition, each build process is run in a
1234 chroot environment that only contains the subset of the store that the
1235 build process depends on, as specified by its derivation
1236 (@pxref{Programming Interface, derivation}), plus a set of specific
1237 system directories. By default, the latter contains @file{/dev} and
1238 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1239 @dfn{container}: in addition to having its own file system tree, it has
1240 a separate mount name space, its own PID name space, network name space,
1241 etc. This helps achieve reproducible builds (@pxref{Features}).
1243 When the daemon performs a build on behalf of the user, it creates a
1244 build directory under @file{/tmp} or under the directory specified by
1245 its @code{TMPDIR} environment variable. This directory is shared with
1246 the container for the duration of the build, though within the container,
1247 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1249 The build directory is automatically deleted upon completion, unless the
1250 build failed and the client specified @option{--keep-failed}
1251 (@pxref{Invoking guix build, @option{--keep-failed}}).
1253 The daemon listens for connections and spawns one sub-process for each session
1254 started by a client (one of the @command{guix} sub-commands.) The
1255 @command{guix processes} command allows you to get an overview of the activity
1256 on your system by viewing each of the active sessions and clients.
1257 @xref{Invoking guix processes}, for more information.
1259 The following command-line options are supported:
1262 @item --build-users-group=@var{group}
1263 Take users from @var{group} to run build processes (@pxref{Setting Up
1264 the Daemon, build users}).
1266 @item --no-substitutes
1268 Do not use substitutes for build products. That is, always build things
1269 locally instead of allowing downloads of pre-built binaries
1270 (@pxref{Substitutes}).
1272 When the daemon runs with @code{--no-substitutes}, clients can still
1273 explicitly enable substitution @i{via} the @code{set-build-options}
1274 remote procedure call (@pxref{The Store}).
1276 @item --substitute-urls=@var{urls}
1277 @anchor{daemon-substitute-urls}
1278 Consider @var{urls} the default whitespace-separated list of substitute
1279 source URLs. When this option is omitted,
1280 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1282 This means that substitutes may be downloaded from @var{urls}, as long
1283 as they are signed by a trusted signature (@pxref{Substitutes}).
1286 @item --no-build-hook
1287 Do not use the @dfn{build hook}.
1289 The build hook is a helper program that the daemon can start and to
1290 which it submits build requests. This mechanism is used to offload
1291 builds to other machines (@pxref{Daemon Offload Setup}).
1293 @item --cache-failures
1294 Cache build failures. By default, only successful builds are cached.
1296 When this option is used, @command{guix gc --list-failures} can be used
1297 to query the set of store items marked as failed; @command{guix gc
1298 --clear-failures} removes store items from the set of cached failures.
1299 @xref{Invoking guix gc}.
1301 @item --cores=@var{n}
1303 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1306 The default value is @code{0}, but it may be overridden by clients, such
1307 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1310 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1311 in the build process, which can then use it to exploit internal
1312 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1314 @item --max-jobs=@var{n}
1316 Allow at most @var{n} build jobs in parallel. The default value is
1317 @code{1}. Setting it to @code{0} means that no builds will be performed
1318 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1319 Setup}), or simply fail.
1321 @item --max-silent-time=@var{seconds}
1322 When the build or substitution process remains silent for more than
1323 @var{seconds}, terminate it and report a build failure.
1325 The default value is @code{0}, which disables the timeout.
1327 The value specified here can be overridden by clients (@pxref{Common
1328 Build Options, @code{--max-silent-time}}).
1330 @item --timeout=@var{seconds}
1331 Likewise, when the build or substitution process lasts for more than
1332 @var{seconds}, terminate it and report a build failure.
1334 The default value is @code{0}, which disables the timeout.
1336 The value specified here can be overridden by clients (@pxref{Common
1337 Build Options, @code{--timeout}}).
1339 @item --rounds=@var{N}
1340 Build each derivation @var{n} times in a row, and raise an error if
1341 consecutive build results are not bit-for-bit identical. Note that this
1342 setting can be overridden by clients such as @command{guix build}
1343 (@pxref{Invoking guix build}).
1345 When used in conjunction with @option{--keep-failed}, the differing
1346 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1347 This makes it easy to look for differences between the two results.
1350 Produce debugging output.
1352 This is useful to debug daemon start-up issues, but then it may be
1353 overridden by clients, for example the @code{--verbosity} option of
1354 @command{guix build} (@pxref{Invoking guix build}).
1356 @item --chroot-directory=@var{dir}
1357 Add @var{dir} to the build chroot.
1359 Doing this may change the result of build processes---for instance if
1360 they use optional dependencies found in @var{dir} when it is available,
1361 and not otherwise. For that reason, it is not recommended to do so.
1362 Instead, make sure that each derivation declares all the inputs that it
1365 @item --disable-chroot
1366 Disable chroot builds.
1368 Using this option is not recommended since, again, it would allow build
1369 processes to gain access to undeclared dependencies. It is necessary,
1370 though, when @command{guix-daemon} is running under an unprivileged user
1373 @item --log-compression=@var{type}
1374 Compress build logs according to @var{type}, one of @code{gzip},
1375 @code{bzip2}, or @code{none}.
1377 Unless @code{--lose-logs} is used, all the build logs are kept in the
1378 @var{localstatedir}. To save space, the daemon automatically compresses
1379 them with bzip2 by default.
1381 @item --disable-deduplication
1382 @cindex deduplication
1383 Disable automatic file ``deduplication'' in the store.
1385 By default, files added to the store are automatically ``deduplicated'':
1386 if a newly added file is identical to another one found in the store,
1387 the daemon makes the new file a hard link to the other file. This can
1388 noticeably reduce disk usage, at the expense of slightly increased
1389 input/output load at the end of a build process. This option disables
1392 @item --gc-keep-outputs[=yes|no]
1393 Tell whether the garbage collector (GC) must keep outputs of live
1397 @cindex garbage collector roots
1398 When set to ``yes'', the GC will keep the outputs of any live derivation
1399 available in the store---the @code{.drv} files. The default is ``no'',
1400 meaning that derivation outputs are kept only if they are reachable from a GC
1401 root. @xref{Invoking guix gc}, for more on GC roots.
1403 @item --gc-keep-derivations[=yes|no]
1404 Tell whether the garbage collector (GC) must keep derivations
1405 corresponding to live outputs.
1407 When set to ``yes'', as is the case by default, the GC keeps
1408 derivations---i.e., @code{.drv} files---as long as at least one of their
1409 outputs is live. This allows users to keep track of the origins of
1410 items in their store. Setting it to ``no'' saves a bit of disk space.
1412 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1413 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1414 ``yes'' causes liveness to flow from derivations to outputs. When both are
1415 set to ``yes'', the effect is to keep all the build prerequisites (the
1416 sources, compiler, libraries, and other build-time tools) of live objects in
1417 the store, regardless of whether these prerequisites are reachable from a GC
1418 root. This is convenient for developers since it saves rebuilds or downloads.
1420 @item --impersonate-linux-2.6
1421 On Linux-based systems, impersonate Linux 2.6. This means that the
1422 kernel's @code{uname} system call will report 2.6 as the release number.
1424 This might be helpful to build programs that (usually wrongfully) depend
1425 on the kernel version number.
1428 Do not keep build logs. By default they are kept under
1429 @code{@var{localstatedir}/guix/log}.
1431 @item --system=@var{system}
1432 Assume @var{system} as the current system type. By default it is the
1433 architecture/kernel pair found at configure time, such as
1434 @code{x86_64-linux}.
1436 @item --listen=@var{endpoint}
1437 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1438 as the file name of a Unix-domain socket if it starts with
1439 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1440 host name or host name and port to listen to. Here are a few examples:
1443 @item --listen=/gnu/var/daemon
1444 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1445 creating it if needed.
1447 @item --listen=localhost
1448 @cindex daemon, remote access
1449 @cindex remote access to the daemon
1450 @cindex daemon, cluster setup
1451 @cindex clusters, daemon setup
1452 Listen for TCP connections on the network interface corresponding to
1453 @code{localhost}, on port 44146.
1455 @item --listen=128.0.0.42:1234
1456 Listen for TCP connections on the network interface corresponding to
1457 @code{128.0.0.42}, on port 1234.
1460 This option can be repeated multiple times, in which case
1461 @command{guix-daemon} accepts connections on all the specified
1462 endpoints. Users can tell client commands what endpoint to connect to
1463 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1464 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1467 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1468 @code{--listen=@var{host}} is suitable on local networks, such as
1469 clusters, where only trusted nodes may connect to the build daemon. In
1470 other cases where remote access to the daemon is needed, we recommend
1471 using Unix-domain sockets along with SSH.
1474 When @code{--listen} is omitted, @command{guix-daemon} listens for
1475 connections on the Unix-domain socket located at
1476 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1480 @node Application Setup
1481 @section Application Setup
1483 @cindex foreign distro
1484 When using Guix on top of GNU/Linux distribution other than GuixSD---a
1485 so-called @dfn{foreign distro}---a few additional steps are needed to
1486 get everything in place. Here are some of them.
1490 @anchor{locales-and-locpath}
1491 @cindex locales, when not on GuixSD
1493 @vindex GUIX_LOCPATH
1494 Packages installed @i{via} Guix will not use the locale data of the
1495 host system. Instead, you must first install one of the locale packages
1496 available with Guix and then define the @code{GUIX_LOCPATH} environment
1500 $ guix package -i glibc-locales
1501 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1504 Note that the @code{glibc-locales} package contains data for all the
1505 locales supported by the GNU@tie{}libc and weighs in at around
1506 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1507 limited to a few UTF-8 locales.
1509 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1510 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1511 Manual}). There are two important differences though:
1515 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1516 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1517 to make sure the programs of the foreign distro will not end up loading
1518 incompatible locale data.
1521 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1522 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1523 should your Guix profile contain a mixture of programs linked against
1524 different libc version, each libc version will only try to load locale
1525 data in the right format.
1528 This is important because the locale data format used by different libc
1529 versions may be incompatible.
1531 @subsection Name Service Switch
1533 @cindex name service switch, glibc
1534 @cindex NSS (name service switch), glibc
1535 @cindex nscd (name service caching daemon)
1536 @cindex name service caching daemon (nscd)
1537 When using Guix on a foreign distro, we @emph{strongly recommend} that
1538 the system run the GNU C library's @dfn{name service cache daemon},
1539 @command{nscd}, which should be listening on the
1540 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1541 installed with Guix may fail to look up host names or user accounts, or
1542 may even crash. The next paragraphs explain why.
1544 @cindex @file{nsswitch.conf}
1545 The GNU C library implements a @dfn{name service switch} (NSS), which is
1546 an extensible mechanism for ``name lookups'' in general: host name
1547 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1548 The GNU C Library Reference Manual}).
1550 @cindex Network information service (NIS)
1551 @cindex NIS (Network information service)
1552 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1553 lookup implementations: for example, the @code{nss-mdns} plugin allow
1554 resolution of @code{.local} host names, the @code{nis} plugin allows
1555 user account lookup using the Network information service (NIS), and so
1556 on. These extra ``lookup services'' are configured system-wide in
1557 @file{/etc/nsswitch.conf}, and all the programs running on the system
1558 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1561 When they perform a name lookup---for instance by calling the
1562 @code{getaddrinfo} function in C---applications first try to connect to
1563 the nscd; on success, nscd performs name lookups on their behalf. If
1564 the nscd is not running, then they perform the name lookup by
1565 themselves, by loading the name lookup services into their own address
1566 space and running it. These name lookup services---the
1567 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1568 the host system's C library, rather than from the C library the
1569 application is linked against (the C library coming from Guix).
1571 And this is where the problem is: if your application is linked against
1572 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1573 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1574 likely crash or have its name lookups fail unexpectedly.
1576 Running @command{nscd} on the system, among other advantages, eliminates
1577 this binary incompatibility problem because those @code{libnss_*.so}
1578 files are loaded in the @command{nscd} process, not in applications
1581 @subsection X11 Fonts
1584 The majority of graphical applications use Fontconfig to locate and
1585 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1586 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1587 by default. Thus, to allow graphical applications installed with Guix
1588 to display fonts, you have to install fonts with Guix as well.
1589 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1590 @code{font-gnu-freefont-ttf}.
1592 To display text written in Chinese languages, Japanese, or Korean in
1593 graphical applications, consider installing
1594 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1595 has multiple outputs, one per language family (@pxref{Packages with
1596 Multiple Outputs}). For instance, the following command installs fonts
1597 for Chinese languages:
1600 guix package -i font-adobe-source-han-sans:cn
1603 @cindex @code{xterm}
1604 Older programs such as @command{xterm} do not use Fontconfig and instead
1605 rely on server-side font rendering. Such programs require to specify a
1606 full name of a font using XLFD (X Logical Font Description), like this:
1609 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1612 To be able to use such full names for the TrueType fonts installed in
1613 your Guix profile, you need to extend the font path of the X server:
1615 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1616 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1618 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1621 @cindex @code{xlsfonts}
1622 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1623 to make sure your TrueType fonts are listed there.
1625 @cindex @code{fc-cache}
1627 After installing fonts you may have to refresh the font cache to use
1628 them in applications. The same applies when applications installed via
1629 Guix do not seem to find fonts. To force rebuilding of the font cache
1630 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1631 @code{fontconfig} package.
1633 @subsection X.509 Certificates
1635 @cindex @code{nss-certs}
1636 The @code{nss-certs} package provides X.509 certificates, which allow
1637 programs to authenticate Web servers accessed over HTTPS.
1639 When using Guix on a foreign distro, you can install this package and
1640 define the relevant environment variables so that packages know where to
1641 look for certificates. @xref{X.509 Certificates}, for detailed
1644 @subsection Emacs Packages
1646 @cindex @code{emacs}
1647 When you install Emacs packages with Guix, the elisp files may be placed
1648 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1650 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1651 directory exists because potentially there may exist thousands of Emacs
1652 packages and storing all their files in a single directory may not be
1653 reliable (because of name conflicts). So we think using a separate
1654 directory for each package is a good idea. It is very similar to how
1655 the Emacs package system organizes the file structure (@pxref{Package
1656 Files,,, emacs, The GNU Emacs Manual}).
1658 By default, Emacs (installed with Guix) ``knows'' where these packages
1659 are placed, so you do not need to perform any configuration. If, for
1660 some reason, you want to avoid auto-loading Emacs packages installed
1661 with Guix, you can do so by running Emacs with @code{--no-site-file}
1662 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1664 @subsection The GCC toolchain
1669 Guix offers individual compiler packages such as @code{gcc} but if you
1670 are in need of a complete toolchain for compiling and linking source
1671 code what you really want is the @code{gcc-toolchain} package. This
1672 package provides a complete GCC toolchain for C/C++ development,
1673 including GCC itself, the GNU C Library (headers and binaries, plus
1674 debugging symbols in the @code{debug} output), Binutils, and a linker
1677 @cindex attempt to use impure library, error message
1679 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1680 passed to the linker, add corresponding @code{-rpath} arguments, and
1681 invoke the actual linker with this new set of arguments. By default,
1682 the linker wrapper refuses to link to libraries outside the store to
1683 ensure ``purity''. This can be annoying when using the toolchain to
1684 link with local libraries. To allow references to libraries outside the
1685 store you need to define the environment variable
1686 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES}.
1690 @c *********************************************************************
1691 @node Package Management
1692 @chapter Package Management
1695 The purpose of GNU Guix is to allow users to easily install, upgrade, and
1696 remove software packages, without having to know about their build
1697 procedures or dependencies. Guix also goes beyond this obvious set of
1700 This chapter describes the main features of Guix, as well as the
1701 package management tools it provides. Along with the command-line
1702 interface described below (@pxref{Invoking guix package, @code{guix
1703 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
1704 emacs-guix, The Emacs-Guix Reference Manual}), after installing
1705 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
1709 guix package -i emacs-guix
1713 * Features:: How Guix will make your life brighter.
1714 * Invoking guix package:: Package installation, removal, etc.
1715 * Substitutes:: Downloading pre-built binaries.
1716 * Packages with Multiple Outputs:: Single source package, multiple outputs.
1717 * Invoking guix gc:: Running the garbage collector.
1718 * Invoking guix pull:: Fetching the latest Guix and distribution.
1719 * Channels:: Customizing the package collection.
1720 * Inferiors:: Interacting with another revision of Guix.
1721 * Invoking guix describe:: Display information about your Guix revision.
1722 * Invoking guix pack:: Creating software bundles.
1723 * Invoking guix archive:: Exporting and importing store files.
1729 When using Guix, each package ends up in the @dfn{package store}, in its
1730 own directory---something that resembles
1731 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
1733 Instead of referring to these directories, users have their own
1734 @dfn{profile}, which points to the packages that they actually want to
1735 use. These profiles are stored within each user's home directory, at
1736 @code{$HOME/.guix-profile}.
1738 For example, @code{alice} installs GCC 4.7.2. As a result,
1739 @file{/home/alice/.guix-profile/bin/gcc} points to
1740 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
1741 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
1742 simply continues to point to
1743 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
1744 coexist on the same system without any interference.
1746 The @command{guix package} command is the central tool to manage
1747 packages (@pxref{Invoking guix package}). It operates on the per-user
1748 profiles, and can be used @emph{with normal user privileges}.
1750 @cindex transactions
1751 The command provides the obvious install, remove, and upgrade
1752 operations. Each invocation is actually a @emph{transaction}: either
1753 the specified operation succeeds, or nothing happens. Thus, if the
1754 @command{guix package} process is terminated during the transaction,
1755 or if a power outage occurs during the transaction, then the user's
1756 profile remains in its previous state, and remains usable.
1758 In addition, any package transaction may be @emph{rolled back}. So, if,
1759 for example, an upgrade installs a new version of a package that turns
1760 out to have a serious bug, users may roll back to the previous instance
1761 of their profile, which was known to work well. Similarly, the global
1762 system configuration on GuixSD is subject to
1763 transactional upgrades and roll-back
1764 (@pxref{Using the Configuration System}).
1766 All packages in the package store may be @emph{garbage-collected}.
1767 Guix can determine which packages are still referenced by user
1768 profiles, and remove those that are provably no longer referenced
1769 (@pxref{Invoking guix gc}). Users may also explicitly remove old
1770 generations of their profile so that the packages they refer to can be
1773 @cindex reproducibility
1774 @cindex reproducible builds
1775 Guix takes a @dfn{purely functional} approach to package
1776 management, as described in the introduction (@pxref{Introduction}).
1777 Each @file{/gnu/store} package directory name contains a hash of all the
1778 inputs that were used to build that package---compiler, libraries, build
1779 scripts, etc. This direct correspondence allows users to make sure a
1780 given package installation matches the current state of their
1781 distribution. It also helps maximize @dfn{build reproducibility}:
1782 thanks to the isolated build environments that are used, a given build
1783 is likely to yield bit-identical files when performed on different
1784 machines (@pxref{Invoking guix-daemon, container}).
1787 This foundation allows Guix to support @dfn{transparent binary/source
1788 deployment}. When a pre-built binary for a @file{/gnu/store} item is
1789 available from an external source---a @dfn{substitute}, Guix just
1790 downloads it and unpacks it;
1791 otherwise, it builds the package from source, locally
1792 (@pxref{Substitutes}). Because build results are usually bit-for-bit
1793 reproducible, users do not have to trust servers that provide
1794 substitutes: they can force a local build and @emph{challenge} providers
1795 (@pxref{Invoking guix challenge}).
1797 Control over the build environment is a feature that is also useful for
1798 developers. The @command{guix environment} command allows developers of
1799 a package to quickly set up the right development environment for their
1800 package, without having to manually install the dependencies of the
1801 package into their profile (@pxref{Invoking guix environment}).
1803 @cindex replication, of software environments
1804 @cindex provenance tracking, of software artifacts
1805 All of Guix and its package definitions is version-controlled, and
1806 @command{guix pull} allows you to ``travel in time'' on the history of Guix
1807 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
1808 Guix instance on a different machine or at a later point in time, which in
1809 turn allows you to @emph{replicate complete software environments}, while
1810 retaining precise @dfn{provenance tracking} of the software.
1812 @node Invoking guix package
1813 @section Invoking @command{guix package}
1815 @cindex installing packages
1816 @cindex removing packages
1817 @cindex package installation
1818 @cindex package removal
1819 The @command{guix package} command is the tool that allows users to
1820 install, upgrade, and remove packages, as well as rolling back to
1821 previous configurations. It operates only on the user's own profile,
1822 and works with normal user privileges (@pxref{Features}). Its syntax
1826 guix package @var{options}
1828 @cindex transactions
1829 Primarily, @var{options} specifies the operations to be performed during
1830 the transaction. Upon completion, a new profile is created, but
1831 previous @dfn{generations} of the profile remain available, should the user
1834 For example, to remove @code{lua} and install @code{guile} and
1835 @code{guile-cairo} in a single transaction:
1838 guix package -r lua -i guile guile-cairo
1841 @command{guix package} also supports a @dfn{declarative approach}
1842 whereby the user specifies the exact set of packages to be available and
1843 passes it @i{via} the @option{--manifest} option
1844 (@pxref{profile-manifest, @option{--manifest}}).
1847 For each user, a symlink to the user's default profile is automatically
1848 created in @file{$HOME/.guix-profile}. This symlink always points to the
1849 current generation of the user's default profile. Thus, users can add
1850 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
1851 variable, and so on.
1852 @cindex search paths
1853 If you are not using the Guix System Distribution, consider adding the
1854 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
1855 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
1856 shells get all the right environment variable definitions:
1859 GUIX_PROFILE="$HOME/.guix-profile" ; \
1860 source "$HOME/.guix-profile/etc/profile"
1863 In a multi-user setup, user profiles are stored in a place registered as
1864 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
1865 to (@pxref{Invoking guix gc}). That directory is normally
1866 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
1867 @var{localstatedir} is the value passed to @code{configure} as
1868 @code{--localstatedir}, and @var{user} is the user name. The
1869 @file{per-user} directory is created when @command{guix-daemon} is
1870 started, and the @var{user} sub-directory is created by @command{guix
1873 The @var{options} can be among the following:
1877 @item --install=@var{package} @dots{}
1878 @itemx -i @var{package} @dots{}
1879 Install the specified @var{package}s.
1881 Each @var{package} may specify either a simple package name, such as
1882 @code{guile}, or a package name followed by an at-sign and version number,
1883 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
1884 case, the newest version prefixed by @code{1.8} is selected.)
1886 If no version number is specified, the
1887 newest available version will be selected. In addition, @var{package}
1888 may contain a colon, followed by the name of one of the outputs of the
1889 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
1890 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
1891 name (and optionally version) are searched for among the GNU
1892 distribution modules (@pxref{Package Modules}).
1894 @cindex propagated inputs
1895 Sometimes packages have @dfn{propagated inputs}: these are dependencies
1896 that automatically get installed along with the required package
1897 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
1898 @code{package} objects}, for information about propagated inputs in
1899 package definitions).
1901 @anchor{package-cmd-propagated-inputs}
1902 An example is the GNU MPC library: its C header files refer to those of
1903 the GNU MPFR library, which in turn refer to those of the GMP library.
1904 Thus, when installing MPC, the MPFR and GMP libraries also get installed
1905 in the profile; removing MPC also removes MPFR and GMP---unless they had
1906 also been explicitly installed by the user.
1908 Besides, packages sometimes rely on the definition of environment
1909 variables for their search paths (see explanation of
1910 @code{--search-paths} below). Any missing or possibly incorrect
1911 environment variable definitions are reported here.
1913 @item --install-from-expression=@var{exp}
1915 Install the package @var{exp} evaluates to.
1917 @var{exp} must be a Scheme expression that evaluates to a
1918 @code{<package>} object. This option is notably useful to disambiguate
1919 between same-named variants of a package, with expressions such as
1920 @code{(@@ (gnu packages base) guile-final)}.
1922 Note that this option installs the first output of the specified
1923 package, which may be insufficient when needing a specific output of a
1924 multiple-output package.
1926 @item --install-from-file=@var{file}
1927 @itemx -f @var{file}
1928 Install the package that the code within @var{file} evaluates to.
1930 As an example, @var{file} might contain a definition like this
1931 (@pxref{Defining Packages}):
1934 @verbatiminclude package-hello.scm
1937 Developers may find it useful to include such a @file{guix.scm} file
1938 in the root of their project source tree that can be used to test
1939 development snapshots and create reproducible development environments
1940 (@pxref{Invoking guix environment}).
1942 @item --remove=@var{package} @dots{}
1943 @itemx -r @var{package} @dots{}
1944 Remove the specified @var{package}s.
1946 As for @code{--install}, each @var{package} may specify a version number
1947 and/or output name in addition to the package name. For instance,
1948 @code{-r glibc:debug} would remove the @code{debug} output of
1951 @item --upgrade[=@var{regexp} @dots{}]
1952 @itemx -u [@var{regexp} @dots{}]
1953 @cindex upgrading packages
1954 Upgrade all the installed packages. If one or more @var{regexp}s are
1955 specified, upgrade only installed packages whose name matches a
1956 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
1958 Note that this upgrades package to the latest version of packages found
1959 in the distribution currently installed. To update your distribution,
1960 you should regularly run @command{guix pull} (@pxref{Invoking guix
1963 @item --do-not-upgrade[=@var{regexp} @dots{}]
1964 When used together with the @code{--upgrade} option, do @emph{not}
1965 upgrade any packages whose name matches a @var{regexp}. For example, to
1966 upgrade all packages in the current profile except those containing the
1967 substring ``emacs'':
1970 $ guix package --upgrade . --do-not-upgrade emacs
1973 @item @anchor{profile-manifest}--manifest=@var{file}
1974 @itemx -m @var{file}
1975 @cindex profile declaration
1976 @cindex profile manifest
1977 Create a new generation of the profile from the manifest object
1978 returned by the Scheme code in @var{file}.
1980 This allows you to @emph{declare} the profile's contents rather than
1981 constructing it through a sequence of @code{--install} and similar
1982 commands. The advantage is that @var{file} can be put under version
1983 control, copied to different machines to reproduce the same profile, and
1986 @c FIXME: Add reference to (guix profile) documentation when available.
1987 @var{file} must return a @dfn{manifest} object, which is roughly a list
1990 @findex packages->manifest
1992 (use-package-modules guile emacs)
1997 ;; Use a specific package output.
1998 (list guile-2.0 "debug")))
2001 @findex specifications->manifest
2002 In this example we have to know which modules define the @code{emacs}
2003 and @code{guile-2.0} variables to provide the right
2004 @code{use-package-modules} line, which can be cumbersome. We can
2005 instead provide regular package specifications and let
2006 @code{specifications->manifest} look up the corresponding package
2010 (specifications->manifest
2011 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2015 @cindex rolling back
2016 @cindex undoing transactions
2017 @cindex transactions, undoing
2018 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2019 the last transaction.
2021 When combined with options such as @code{--install}, roll back occurs
2022 before any other actions.
2024 When rolling back from the first generation that actually contains
2025 installed packages, the profile is made to point to the @dfn{zeroth
2026 generation}, which contains no files apart from its own metadata.
2028 After having rolled back, installing, removing, or upgrading packages
2029 overwrites previous future generations. Thus, the history of the
2030 generations in a profile is always linear.
2032 @item --switch-generation=@var{pattern}
2033 @itemx -S @var{pattern}
2035 Switch to a particular generation defined by @var{pattern}.
2037 @var{pattern} may be either a generation number or a number prefixed
2038 with ``+'' or ``-''. The latter means: move forward/backward by a
2039 specified number of generations. For example, if you want to return to
2040 the latest generation after @code{--roll-back}, use
2041 @code{--switch-generation=+1}.
2043 The difference between @code{--roll-back} and
2044 @code{--switch-generation=-1} is that @code{--switch-generation} will
2045 not make a zeroth generation, so if a specified generation does not
2046 exist, the current generation will not be changed.
2048 @item --search-paths[=@var{kind}]
2049 @cindex search paths
2050 Report environment variable definitions, in Bash syntax, that may be
2051 needed in order to use the set of installed packages. These environment
2052 variables are used to specify @dfn{search paths} for files used by some
2053 of the installed packages.
2055 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2056 environment variables to be defined so it can look for headers and
2057 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2058 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2059 library are installed in the profile, then @code{--search-paths} will
2060 suggest setting these variables to @code{@var{profile}/include} and
2061 @code{@var{profile}/lib}, respectively.
2063 The typical use case is to define these environment variables in the
2067 $ eval `guix package --search-paths`
2070 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2071 meaning that the returned environment variable definitions will either
2072 be exact settings, or prefixes or suffixes of the current value of these
2073 variables. When omitted, @var{kind} defaults to @code{exact}.
2075 This option can also be used to compute the @emph{combined} search paths
2076 of several profiles. Consider this example:
2079 $ guix package -p foo -i guile
2080 $ guix package -p bar -i guile-json
2081 $ guix package -p foo -p bar --search-paths
2084 The last command above reports about the @code{GUILE_LOAD_PATH}
2085 variable, even though, taken individually, neither @file{foo} nor
2086 @file{bar} would lead to that recommendation.
2089 @item --profile=@var{profile}
2090 @itemx -p @var{profile}
2091 Use @var{profile} instead of the user's default profile.
2093 @cindex collisions, in a profile
2094 @cindex colliding packages in profiles
2095 @cindex profile collisions
2096 @item --allow-collisions
2097 Allow colliding packages in the new profile. Use at your own risk!
2099 By default, @command{guix package} reports as an error @dfn{collisions}
2100 in the profile. Collisions happen when two or more different versions
2101 or variants of a given package end up in the profile.
2104 Produce verbose output. In particular, emit the build log of the
2105 environment on the standard error port.
2108 Use the bootstrap Guile to build the profile. This option is only
2109 useful to distribution developers.
2113 In addition to these actions, @command{guix package} supports the
2114 following options to query the current state of a profile, or the
2115 availability of packages:
2119 @item --search=@var{regexp}
2120 @itemx -s @var{regexp}
2121 @cindex searching for packages
2122 List the available packages whose name, synopsis, or description matches
2123 @var{regexp}, sorted by relevance. Print all the metadata of matching packages in
2124 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2125 GNU recutils manual}).
2127 This allows specific fields to be extracted using the @command{recsel}
2128 command, for instance:
2131 $ guix package -s malloc | recsel -p name,version,relevance
2145 Similarly, to show the name of all the packages available under the
2146 terms of the GNU@tie{}LGPL version 3:
2149 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2156 It is also possible to refine search results using several @code{-s}
2157 flags. For example, the following command returns a list of board
2161 $ guix package -s '\<board\>' -s game | recsel -p name
2166 If we were to omit @code{-s game}, we would also get software packages
2167 that deal with printed circuit boards; removing the angle brackets
2168 around @code{board} would further add packages that have to do with
2171 And now for a more elaborate example. The following command searches
2172 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2173 libraries, and prints the name and synopsis of the matching packages:
2176 $ guix package -s crypto -s library | \
2177 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2181 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2182 information on @dfn{selection expressions} for @code{recsel -e}.
2184 @item --show=@var{package}
2185 Show details about @var{package}, taken from the list of available packages, in
2186 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
2190 $ guix package --show=python | recsel -p name,version
2198 You may also specify the full name of a package to only get details about a
2199 specific version of it:
2201 $ guix package --show=python@@3.4 | recsel -p name,version
2208 @item --list-installed[=@var{regexp}]
2209 @itemx -I [@var{regexp}]
2210 List the currently installed packages in the specified profile, with the
2211 most recently installed packages shown last. When @var{regexp} is
2212 specified, list only installed packages whose name matches @var{regexp}.
2214 For each installed package, print the following items, separated by
2215 tabs: the package name, its version string, the part of the package that
2216 is installed (for instance, @code{out} for the default output,
2217 @code{include} for its headers, etc.), and the path of this package in
2220 @item --list-available[=@var{regexp}]
2221 @itemx -A [@var{regexp}]
2222 List packages currently available in the distribution for this system
2223 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
2224 installed packages whose name matches @var{regexp}.
2226 For each package, print the following items separated by tabs: its name,
2227 its version string, the parts of the package (@pxref{Packages with
2228 Multiple Outputs}), and the source location of its definition.
2230 @item --list-generations[=@var{pattern}]
2231 @itemx -l [@var{pattern}]
2233 Return a list of generations along with their creation dates; for each
2234 generation, show the installed packages, with the most recently
2235 installed packages shown last. Note that the zeroth generation is never
2238 For each installed package, print the following items, separated by
2239 tabs: the name of a package, its version string, the part of the package
2240 that is installed (@pxref{Packages with Multiple Outputs}), and the
2241 location of this package in the store.
2243 When @var{pattern} is used, the command returns only matching
2244 generations. Valid patterns include:
2247 @item @emph{Integers and comma-separated integers}. Both patterns denote
2248 generation numbers. For instance, @code{--list-generations=1} returns
2251 And @code{--list-generations=1,8,2} outputs three generations in the
2252 specified order. Neither spaces nor trailing commas are allowed.
2254 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
2255 specified generations and everything in between. Note that the start of
2256 a range must be smaller than its end.
2258 It is also possible to omit the endpoint. For example,
2259 @code{--list-generations=2..}, returns all generations starting from the
2262 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
2263 or months by passing an integer along with the first letter of the
2264 duration. For example, @code{--list-generations=20d} lists generations
2265 that are up to 20 days old.
2268 @item --delete-generations[=@var{pattern}]
2269 @itemx -d [@var{pattern}]
2270 When @var{pattern} is omitted, delete all generations except the current
2273 This command accepts the same patterns as @option{--list-generations}.
2274 When @var{pattern} is specified, delete the matching generations. When
2275 @var{pattern} specifies a duration, generations @emph{older} than the
2276 specified duration match. For instance, @code{--delete-generations=1m}
2277 deletes generations that are more than one month old.
2279 If the current generation matches, it is @emph{not} deleted. Also, the
2280 zeroth generation is never deleted.
2282 Note that deleting generations prevents rolling back to them.
2283 Consequently, this command must be used with care.
2287 Finally, since @command{guix package} may actually start build
2288 processes, it supports all the common build options (@pxref{Common Build
2289 Options}). It also supports package transformation options, such as
2290 @option{--with-source} (@pxref{Package Transformation Options}).
2291 However, note that package transformations are lost when upgrading; to
2292 preserve transformations across upgrades, you should define your own
2293 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
2294 (@pxref{Defining Packages}).
2297 @section Substitutes
2300 @cindex pre-built binaries
2301 Guix supports transparent source/binary deployment, which means that it
2302 can either build things locally, or download pre-built items from a
2303 server, or both. We call these pre-built items @dfn{substitutes}---they
2304 are substitutes for local build results. In many cases, downloading a
2305 substitute is much faster than building things locally.
2307 Substitutes can be anything resulting from a derivation build
2308 (@pxref{Derivations}). Of course, in the common case, they are
2309 pre-built package binaries, but source tarballs, for instance, which
2310 also result from derivation builds, can be available as substitutes.
2313 * Official Substitute Server:: One particular source of substitutes.
2314 * Substitute Server Authorization:: How to enable or disable substitutes.
2315 * Substitute Authentication:: How Guix verifies substitutes.
2316 * Proxy Settings:: How to get substitutes via proxy.
2317 * Substitution Failure:: What happens when substitution fails.
2318 * On Trusting Binaries:: How can you trust that binary blob?
2321 @node Official Substitute Server
2322 @subsection Official Substitute Server
2326 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
2327 that builds packages from Guix continuously for some
2328 architectures, and makes them available as substitutes. This is the
2329 default source of substitutes; it can be overridden by passing the
2330 @option{--substitute-urls} option either to @command{guix-daemon}
2331 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
2332 or to client tools such as @command{guix package}
2333 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
2336 Substitute URLs can be either HTTP or HTTPS.
2337 HTTPS is recommended because communications are encrypted; conversely,
2338 using HTTP makes all communications visible to an eavesdropper, who
2339 could use the information gathered to determine, for instance, whether
2340 your system has unpatched security vulnerabilities.
2342 Substitutes from the official build farm are enabled by default when
2343 using the Guix System Distribution (@pxref{GNU Distribution}). However,
2344 they are disabled by default when using Guix on a foreign distribution,
2345 unless you have explicitly enabled them via one of the recommended
2346 installation steps (@pxref{Installation}). The following paragraphs
2347 describe how to enable or disable substitutes for the official build
2348 farm; the same procedure can also be used to enable substitutes for any
2349 other substitute server.
2351 @node Substitute Server Authorization
2352 @subsection Substitute Server Authorization
2355 @cindex substitutes, authorization thereof
2356 @cindex access control list (ACL), for substitutes
2357 @cindex ACL (access control list), for substitutes
2358 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
2360 must add its public key to the access control list (ACL) of archive
2361 imports, using the @command{guix archive} command (@pxref{Invoking guix
2362 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
2363 be compromised and to serve genuine substitutes.
2365 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
2366 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
2367 the installation prefix of Guix. If you installed Guix from source,
2368 make sure you checked the GPG signature of
2369 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
2370 Then, you can run something like this:
2373 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
2377 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
2378 of an independent build farm also run by the project, reachable at
2379 @indicateurl{https://mirror.hydra.gnu.org}.
2382 Once this is in place, the output of a command like @code{guix build}
2383 should change from something like:
2386 $ guix build emacs --dry-run
2387 The following derivations would be built:
2388 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
2389 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
2390 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
2391 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
2399 $ guix build emacs --dry-run
2400 112.3 MB would be downloaded:
2401 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
2402 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
2403 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
2404 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
2409 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
2410 will be downloaded, when possible, for future builds.
2412 @cindex substitutes, how to disable
2413 The substitute mechanism can be disabled globally by running
2414 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
2415 guix-daemon}). It can also be disabled temporarily by passing the
2416 @code{--no-substitutes} option to @command{guix package}, @command{guix
2417 build}, and other command-line tools.
2419 @node Substitute Authentication
2420 @subsection Substitute Authentication
2422 @cindex digital signatures
2423 Guix detects and raises an error when attempting to use a substitute
2424 that has been tampered with. Likewise, it ignores substitutes that are
2425 not signed, or that are not signed by one of the keys listed in the ACL.
2427 There is one exception though: if an unauthorized server provides
2428 substitutes that are @emph{bit-for-bit identical} to those provided by
2429 an authorized server, then the unauthorized server becomes eligible for
2430 downloads. For example, assume we have chosen two substitute servers
2434 --substitute-urls="https://a.example.org https://b.example.org"
2438 @cindex reproducible builds
2439 If the ACL contains only the key for @code{b.example.org}, and if
2440 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
2441 then Guix will download substitutes from @code{a.example.org} because it
2442 comes first in the list and can be considered a mirror of
2443 @code{b.example.org}. In practice, independent build machines usually
2444 produce the same binaries, thanks to bit-reproducible builds (see
2447 When using HTTPS, the server's X.509 certificate is @emph{not} validated
2448 (in other words, the server is not authenticated), contrary to what
2449 HTTPS clients such as Web browsers usually do. This is because Guix
2450 authenticates substitute information itself, as explained above, which
2451 is what we care about (whereas X.509 certificates are about
2452 authenticating bindings between domain names and public keys.)
2454 @node Proxy Settings
2455 @subsection Proxy Settings
2458 Substitutes are downloaded over HTTP or HTTPS.
2459 The @code{http_proxy} environment
2460 variable can be set in the environment of @command{guix-daemon} and is
2461 honored for downloads of substitutes. Note that the value of
2462 @code{http_proxy} in the environment where @command{guix build},
2463 @command{guix package}, and other client commands are run has
2464 @emph{absolutely no effect}.
2466 @node Substitution Failure
2467 @subsection Substitution Failure
2469 Even when a substitute for a derivation is available, sometimes the
2470 substitution attempt will fail. This can happen for a variety of
2471 reasons: the substitute server might be offline, the substitute may
2472 recently have been deleted, the connection might have been interrupted,
2475 When substitutes are enabled and a substitute for a derivation is
2476 available, but the substitution attempt fails, Guix will attempt to
2477 build the derivation locally depending on whether or not
2478 @code{--fallback} was given (@pxref{fallback-option,, common build
2479 option @code{--fallback}}). Specifically, if @code{--fallback} was
2480 omitted, then no local build will be performed, and the derivation is
2481 considered to have failed. However, if @code{--fallback} was given,
2482 then Guix will attempt to build the derivation locally, and the success
2483 or failure of the derivation depends on the success or failure of the
2484 local build. Note that when substitutes are disabled or no substitute
2485 is available for the derivation in question, a local build will
2486 @emph{always} be performed, regardless of whether or not
2487 @code{--fallback} was given.
2489 To get an idea of how many substitutes are available right now, you can
2490 try running the @command{guix weather} command (@pxref{Invoking guix
2491 weather}). This command provides statistics on the substitutes provided
2494 @node On Trusting Binaries
2495 @subsection On Trusting Binaries
2497 @cindex trust, of pre-built binaries
2498 Today, each individual's control over their own computing is at the
2499 mercy of institutions, corporations, and groups with enough power and
2500 determination to subvert the computing infrastructure and exploit its
2501 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
2502 convenient, we encourage users to also build on their own, or even run
2503 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
2504 interesting target. One way to help is by publishing the software you
2505 build using @command{guix publish} so that others have one more choice
2506 of server to download substitutes from (@pxref{Invoking guix publish}).
2508 Guix has the foundations to maximize build reproducibility
2509 (@pxref{Features}). In most cases, independent builds of a given
2510 package or derivation should yield bit-identical results. Thus, through
2511 a diverse set of independent package builds, we can strengthen the
2512 integrity of our systems. The @command{guix challenge} command aims to
2513 help users assess substitute servers, and to assist developers in
2514 finding out about non-deterministic package builds (@pxref{Invoking guix
2515 challenge}). Similarly, the @option{--check} option of @command{guix
2516 build} allows users to check whether previously-installed substitutes
2517 are genuine by rebuilding them locally (@pxref{build-check,
2518 @command{guix build --check}}).
2520 In the future, we want Guix to have support to publish and retrieve
2521 binaries to/from other users, in a peer-to-peer fashion. If you would
2522 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
2524 @node Packages with Multiple Outputs
2525 @section Packages with Multiple Outputs
2527 @cindex multiple-output packages
2528 @cindex package outputs
2531 Often, packages defined in Guix have a single @dfn{output}---i.e., the
2532 source package leads to exactly one directory in the store. When running
2533 @command{guix package -i glibc}, one installs the default output of the
2534 GNU libc package; the default output is called @code{out}, but its name
2535 can be omitted as shown in this command. In this particular case, the
2536 default output of @code{glibc} contains all the C header files, shared
2537 libraries, static libraries, Info documentation, and other supporting
2540 Sometimes it is more appropriate to separate the various types of files
2541 produced from a single source package into separate outputs. For
2542 instance, the GLib C library (used by GTK+ and related packages)
2543 installs more than 20 MiB of reference documentation as HTML pages.
2544 To save space for users who do not need it, the documentation goes to a
2545 separate output, called @code{doc}. To install the main GLib output,
2546 which contains everything but the documentation, one would run:
2549 guix package -i glib
2552 @cindex documentation
2553 The command to install its documentation is:
2556 guix package -i glib:doc
2559 Some packages install programs with different ``dependency footprints''.
2560 For instance, the WordNet package installs both command-line tools and
2561 graphical user interfaces (GUIs). The former depend solely on the C
2562 library, whereas the latter depend on Tcl/Tk and the underlying X
2563 libraries. In this case, we leave the command-line tools in the default
2564 output, whereas the GUIs are in a separate output. This allows users
2565 who do not need the GUIs to save space. The @command{guix size} command
2566 can help find out about such situations (@pxref{Invoking guix size}).
2567 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
2569 There are several such multiple-output packages in the GNU distribution.
2570 Other conventional output names include @code{lib} for libraries and
2571 possibly header files, @code{bin} for stand-alone programs, and
2572 @code{debug} for debugging information (@pxref{Installing Debugging
2573 Files}). The outputs of a packages are listed in the third column of
2574 the output of @command{guix package --list-available} (@pxref{Invoking
2578 @node Invoking guix gc
2579 @section Invoking @command{guix gc}
2581 @cindex garbage collector
2583 Packages that are installed, but not used, may be @dfn{garbage-collected}.
2584 The @command{guix gc} command allows users to explicitly run the garbage
2585 collector to reclaim space from the @file{/gnu/store} directory. It is
2586 the @emph{only} way to remove files from @file{/gnu/store}---removing
2587 files or directories manually may break it beyond repair!
2590 @cindex garbage collector roots
2591 The garbage collector has a set of known @dfn{roots}: any file under
2592 @file{/gnu/store} reachable from a root is considered @dfn{live} and
2593 cannot be deleted; any other file is considered @dfn{dead} and may be
2594 deleted. The set of garbage collector roots (``GC roots'' for short)
2595 includes default user profiles; by default, the symlinks under
2596 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
2597 added with @command{guix build --root}, for example (@pxref{Invoking
2600 Prior to running @code{guix gc --collect-garbage} to make space, it is
2601 often useful to remove old generations from user profiles; that way, old
2602 package builds referenced by those generations can be reclaimed. This
2603 is achieved by running @code{guix package --delete-generations}
2604 (@pxref{Invoking guix package}).
2606 Our recommendation is to run a garbage collection periodically, or when
2607 you are short on disk space. For instance, to guarantee that at least
2608 5@tie{}GB are available on your disk, simply run:
2614 It is perfectly safe to run as a non-interactive periodic job
2615 (@pxref{Scheduled Job Execution}, for how to set up such a job on
2616 GuixSD). Running @command{guix gc} with no arguments will collect as
2617 much garbage as it can, but that is often inconvenient: you may find
2618 yourself having to rebuild or re-download software that is ``dead'' from
2619 the GC viewpoint but that is necessary to build other pieces of
2620 software---e.g., the compiler tool chain.
2622 The @command{guix gc} command has three modes of operation: it can be
2623 used to garbage-collect any dead files (the default), to delete specific
2624 files (the @code{--delete} option), to print garbage-collector
2625 information, or for more advanced queries. The garbage collection
2626 options are as follows:
2629 @item --collect-garbage[=@var{min}]
2630 @itemx -C [@var{min}]
2631 Collect garbage---i.e., unreachable @file{/gnu/store} files and
2632 sub-directories. This is the default operation when no option is
2635 When @var{min} is given, stop once @var{min} bytes have been collected.
2636 @var{min} may be a number of bytes, or it may include a unit as a
2637 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
2638 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
2640 When @var{min} is omitted, collect all the garbage.
2642 @item --free-space=@var{free}
2643 @itemx -F @var{free}
2644 Collect garbage until @var{free} space is available under
2645 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
2646 as @code{500MiB}, as described above.
2648 When @var{free} or more is already available in @file{/gnu/store}, do
2649 nothing and exit immediately.
2653 Attempt to delete all the store files and directories specified as
2654 arguments. This fails if some of the files are not in the store, or if
2655 they are still live.
2657 @item --list-failures
2658 List store items corresponding to cached build failures.
2660 This prints nothing unless the daemon was started with
2661 @option{--cache-failures} (@pxref{Invoking guix-daemon,
2662 @option{--cache-failures}}).
2664 @item --clear-failures
2665 Remove the specified store items from the failed-build cache.
2667 Again, this option only makes sense when the daemon is started with
2668 @option{--cache-failures}. Otherwise, it does nothing.
2671 Show the list of dead files and directories still present in the
2672 store---i.e., files and directories no longer reachable from any root.
2675 Show the list of live store files and directories.
2679 In addition, the references among existing store files can be queried:
2685 @cindex package dependencies
2686 List the references (respectively, the referrers) of store files given
2692 List the requisites of the store files passed as arguments. Requisites
2693 include the store files themselves, their references, and the references
2694 of these, recursively. In other words, the returned list is the
2695 @dfn{transitive closure} of the store files.
2697 @xref{Invoking guix size}, for a tool to profile the size of the closure
2698 of an element. @xref{Invoking guix graph}, for a tool to visualize
2699 the graph of references.
2703 Return the derivation(s) leading to the given store items
2704 (@pxref{Derivations}).
2706 For example, this command:
2709 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
2713 returns the @file{.drv} file(s) leading to the @code{emacs} package
2714 installed in your profile.
2716 Note that there may be zero matching @file{.drv} files, for instance
2717 because these files have been garbage-collected. There can also be more
2718 than one matching @file{.drv} due to fixed-output derivations.
2721 Lastly, the following options allow you to check the integrity of the
2722 store and to control disk usage.
2726 @item --verify[=@var{options}]
2727 @cindex integrity, of the store
2728 @cindex integrity checking
2729 Verify the integrity of the store.
2731 By default, make sure that all the store items marked as valid in the
2732 database of the daemon actually exist in @file{/gnu/store}.
2734 When provided, @var{options} must be a comma-separated list containing one
2735 or more of @code{contents} and @code{repair}.
2737 When passing @option{--verify=contents}, the daemon computes the
2738 content hash of each store item and compares it against its hash in the
2739 database. Hash mismatches are reported as data corruptions. Because it
2740 traverses @emph{all the files in the store}, this command can take a
2741 long time, especially on systems with a slow disk drive.
2743 @cindex repairing the store
2744 @cindex corruption, recovering from
2745 Using @option{--verify=repair} or @option{--verify=contents,repair}
2746 causes the daemon to try to repair corrupt store items by fetching
2747 substitutes for them (@pxref{Substitutes}). Because repairing is not
2748 atomic, and thus potentially dangerous, it is available only to the
2749 system administrator. A lightweight alternative, when you know exactly
2750 which items in the store are corrupt, is @command{guix build --repair}
2751 (@pxref{Invoking guix build}).
2754 @cindex deduplication
2755 Optimize the store by hard-linking identical files---this is
2756 @dfn{deduplication}.
2758 The daemon performs deduplication after each successful build or archive
2759 import, unless it was started with @code{--disable-deduplication}
2760 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
2761 this option is primarily useful when the daemon was running with
2762 @code{--disable-deduplication}.
2766 @node Invoking guix pull
2767 @section Invoking @command{guix pull}
2769 @cindex upgrading Guix
2770 @cindex updating Guix
2771 @cindex @command{guix pull}
2773 Packages are installed or upgraded to the latest version available in
2774 the distribution currently available on your local machine. To update
2775 that distribution, along with the Guix tools, you must run @command{guix
2776 pull}: the command downloads the latest Guix source code and package
2777 descriptions, and deploys it. Source code is downloaded from a
2778 @uref{https://git-scm.com, Git} repository, by default the official
2779 GNU@tie{}Guix repository, though this can be customized.
2781 On completion, @command{guix package} will use packages and package
2782 versions from this just-retrieved copy of Guix. Not only that, but all
2783 the Guix commands and Scheme modules will also be taken from that latest
2784 version. New @command{guix} sub-commands added by the update also
2787 Any user can update their Guix copy using @command{guix pull}, and the
2788 effect is limited to the user who run @command{guix pull}. For
2789 instance, when user @code{root} runs @command{guix pull}, this has no
2790 effect on the version of Guix that user @code{alice} sees, and vice
2793 The result of running @command{guix pull} is a @dfn{profile} available
2794 under @file{~/.config/guix/current} containing the latest Guix. Thus,
2795 make sure to add it to the beginning of your search path so that you use
2796 the latest version, and similarly for the Info manual
2797 (@pxref{Documentation}):
2800 export PATH="$HOME/.config/guix/current/bin:$PATH"
2801 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
2804 The @code{--list-generations} or @code{-l} option lists past generations
2805 produced by @command{guix pull}, along with details about their provenance:
2809 Generation 1 Jun 10 2018 00:18:18
2811 repository URL: https://git.savannah.gnu.org/git/guix.git
2812 branch: origin/master
2813 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
2815 Generation 2 Jun 11 2018 11:02:49
2817 repository URL: https://git.savannah.gnu.org/git/guix.git
2818 branch: origin/master
2819 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
2820 2 new packages: keepalived, libnfnetlink
2821 6 packages upgraded: emacs-nix-mode@@2.0.4,
2822 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
2823 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
2825 Generation 3 Jun 13 2018 23:31:07 (current)
2827 repository URL: https://git.savannah.gnu.org/git/guix.git
2828 branch: origin/master
2829 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
2830 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
2831 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
2834 @ref{Invoking guix describe, @command{guix describe}}, for other ways to
2835 describe the current status of Guix.
2837 This @code{~/.config/guix/current} profile works like any other profile
2838 created by @command{guix package} (@pxref{Invoking guix package}). That
2839 is, you can list generations, roll back to the previous
2840 generation---i.e., the previous Guix---and so on:
2843 $ guix package -p ~/.config/guix/current --roll-back
2844 switched from generation 3 to 2
2845 $ guix package -p ~/.config/guix/current --delete-generations=1
2846 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
2849 The @command{guix pull} command is usually invoked with no arguments,
2850 but it supports the following options:
2853 @item --url=@var{url}
2854 @itemx --commit=@var{commit}
2855 @itemx --branch=@var{branch}
2856 Download code from the specified @var{url}, at the given @var{commit} (a valid
2857 Git commit ID represented as a hexadecimal string), or @var{branch}.
2859 @cindex @file{channels.scm}, configuration file
2860 @cindex configuration file for channels
2861 These options are provided for convenience, but you can also specify your
2862 configuration in the @file{~/.config/guix/channels.scm} file or using the
2863 @option{--channels} option (see below).
2865 @item --channels=@var{file}
2866 @itemx -C @var{file}
2867 Read the list of channels from @var{file} instead of
2868 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
2869 evaluates to a list of channel objects. @xref{Channels}, for more
2872 @item --list-generations[=@var{pattern}]
2873 @itemx -l [@var{pattern}]
2874 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
2875 is provided, the subset of generations that match @var{pattern}.
2876 The syntax of @var{pattern} is the same as with @code{guix package
2877 --list-generations} (@pxref{Invoking guix package}).
2879 @ref{Invoking guix describe}, for a way to display information about the
2880 current generation only.
2882 @item --profile=@var{profile}
2883 @itemx -p @var{profile}
2884 Use @var{profile} instead of @file{~/.config/guix/current}.
2888 Show which channel commit(s) would be used and what would be built or
2889 substituted but do not actually do it.
2892 Produce verbose output, writing build logs to the standard error output.
2895 Use the bootstrap Guile to build the latest Guix. This option is only
2896 useful to Guix developers.
2899 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
2900 repository and branch to pull from, as well as @emph{additional} repositories
2901 containing package modules that should be deployed. @xref{Channels}, for more
2904 In addition, @command{guix pull} supports all the common build options
2905 (@pxref{Common Build Options}).
2911 @cindex @file{channels.scm}, configuration file
2912 @cindex configuration file for channels
2913 @cindex @command{guix pull}, configuration file
2914 @cindex configuration of @command{guix pull}
2915 Guix and its package collection are updated by running @command{guix pull}
2916 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
2917 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
2918 customized by defining @dfn{channels} in the
2919 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
2920 of a Git repository to be deployed, and @command{guix pull} can be instructed
2921 to pull from one or more channels. In other words, channels can be used to
2922 @emph{customize} and to @emph{extend} Guix, as we will see below.
2924 @subsection Using a Custom Guix Channel
2926 The channel called @code{guix} specifies where Guix itself---its command-line
2927 tools as well as its package collection---should be downloaded. For instance,
2928 suppose you want to update from your own copy of the Guix repository at
2929 @code{example.org}, and specifically the @code{super-hacks} branch, you can
2930 write in @code{~/.config/guix/channels.scm} this specification:
2933 ;; Tell 'guix pull' to use my own repo.
2936 (url "https://example.org/my-guix.git")
2937 (branch "super-hacks")))
2941 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
2942 branch of the repository at @code{example.org}.
2944 @subsection Specifying Additional Channels
2946 @cindex extending the package collection (channels)
2947 @cindex personal packages (channels)
2948 @cindex channels, for personal packages
2949 You can also specify @emph{additional channels} to pull from. Let's say you
2950 have a bunch of custom package variants or personal packages that you think
2951 would make little sense to contribute to the Guix project, but would like to
2952 have these packages transparently available to you at the command line. You
2953 would first write modules containing those package definitions (@pxref{Package
2954 Modules}), maintain them in a Git repository, and then you and anyone else can
2955 use it as an additional channel to get packages from. Neat, no?
2957 @c What follows stems from discussions at
2958 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
2959 @c earlier discussions on guix-devel@gnu.org.
2961 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
2962 publish your personal channel to the world, we would like to share a few words
2967 Before publishing a channel, please consider contributing your package
2968 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
2969 to free software of all sorts, and packages in Guix proper are readily
2970 available to all Guix users and benefit from the project's quality assurance
2974 When you maintain package definitions outside Guix, we, Guix developers,
2975 consider that @emph{the compatibility burden is on you}. Remember that
2976 package modules and package definitions are just Scheme code that uses various
2977 programming interfaces (APIs). We want to remain free to change these APIs to
2978 keep improving Guix, possibly in ways that break your channel. We never
2979 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
2983 Corollary: if you're using an external channel and that channel breaks, please
2984 @emph{report the issue to the channel authors}, not to the Guix project.
2987 You've been warned! Having said this, we believe external channels are a
2988 practical way to exert your freedom to augment Guix' package collection and to
2989 share your improvements, which are basic tenets of
2990 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
2991 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
2994 Once you have a Git repository containing your own package modules, you can
2995 write @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to
2996 pull from your personal channel @emph{in addition} to the default Guix
2999 @vindex %default-channels
3001 ;; Add my personal packages to those Guix provides.
3003 (name 'my-personal-packages)
3004 (url "https://example.org/personal-packages.git"))
3009 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3010 add a channel the list of channels that the variable @code{%default-channels}
3011 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3012 Manual}). With this file in place, @command{guix pull} builds not only Guix
3013 but also the package modules from your own repository. The result in
3014 @file{~/.config/guix/current} is the union of Guix with your own package
3018 $ guix pull --list-generations
3020 Generation 19 Aug 27 2018 16:20:48
3022 repository URL: https://git.savannah.gnu.org/git/guix.git
3024 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3025 my-personal-packages dd3df5e
3026 repository URL: https://example.org/personal-packages.git
3028 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3029 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3030 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3034 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3035 both Guix and packages from the @code{my-personal-packages} channel. Among
3036 the new and upgraded packages that are listed, some like @code{my-gimp} and
3037 @code{my-emacs-with-cool-features} might come from
3038 @code{my-personal-packages}, while others come from the Guix default channel.
3040 @subsection Replicating Guix
3042 @cindex pinning, channels
3043 @cindex replicating Guix
3044 @cindex reproducibility, of Guix
3045 The @command{guix pull --list-generations} output above shows precisely which
3046 commits were used to build this instance of Guix. We can thus replicate it,
3047 say, on another machine, by providing a channel specification in
3048 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3051 ;; Deploy specific commits of my channels of interest.
3054 (url "https://git.savannah.gnu.org/git/guix.git")
3055 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3057 (name 'my-personal-packages)
3058 (url "https://example.org/personal-packages.git")
3059 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3062 The @command{guix describe --format=channels} command can even generate this
3063 list of channels directly (@pxref{Invoking guix describe}).
3065 At this point the two machines run the @emph{exact same Guix}, with access to
3066 the @emph{exact same packages}. The output of @command{guix build gimp} on
3067 one machine will be exactly the same, bit for bit, as the output of the same
3068 command on the other machine. It also means both machines have access to all
3069 the source code of Guix and, transitively, to all the source code of every
3072 This gives you super powers, allowing you to track the provenance of binary
3073 artifacts with very fine grain, and to reproduce software environments at
3074 will---some sort of ``meta reproducibility'' capabilities, if you will.
3075 @xref{Inferiors}, for another way to take advantage of these super powers.
3080 @c TODO: Remove this once we're more confident about API stability.
3082 The functionality described here is a ``technology preview'' as of version
3083 @value{VERSION}. As such, the interface is subject to change.
3087 @cindex composition of Guix revisions
3088 Sometimes you might need to mix packages from the revision of Guix you're
3089 currently running with packages available in a different revision of Guix.
3090 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3091 revisions in arbitrary ways.
3093 @cindex inferior packages
3094 Technically, an ``inferior'' is essentially a separate Guix process connected
3095 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3096 @code{(guix inferior)} module allows you to create inferiors and to
3097 communicate with them. It also provides a high-level interface to browse and
3098 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3100 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3101 to interact with a separate revision of Guix. For example, let's assume you
3102 want to install in your profile the current @code{guile} package, along with
3103 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3104 because the newer @code{guile-json} has an incompatible API and you want to
3105 run your code against the old API@. To do that, you could write a manifest for
3106 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3107 manifest, you would create an inferior for that old Guix revision you care
3108 about, and you would look up the @code{guile-json} package in the inferior:
3111 (use-modules (guix inferior) (guix channels)
3112 (srfi srfi-1)) ;for 'first'
3115 ;; This is the old revision from which we want to
3116 ;; extract guile-json.
3119 (url "https://git.savannah.gnu.org/git/guix.git")
3121 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
3124 ;; An inferior representing the above revision.
3125 (inferior-for-channels channels))
3127 ;; Now create a manifest with the current "guile" package
3128 ;; and the old "guile-json" package.
3130 (list (first (lookup-inferior-packages inferior "guile-json"))
3131 (specification->package "guile")))
3134 On its first run, @command{guix package --manifest} might have to build the
3135 channel you specified before it can create the inferior; subsequent runs will
3136 be much faster because the Guix revision will be cached.
3138 The @code{(guix inferior)} module provides the following procedures to open an
3141 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
3142 [#:cache-directory] [#:ttl]
3143 Return an inferior for @var{channels}, a list of channels. Use the cache at
3144 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
3145 This procedure opens a new connection to the build daemon.
3147 As a side effect, this procedure may build or substitute binaries for
3148 @var{channels}, which can take time.
3151 @deffn {Scheme Procedure} open-inferior @var{directory} @
3152 [#:command "bin/guix"]
3153 Open the inferior Guix in @var{directory}, running
3154 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
3155 the inferior could not be launched.
3158 @cindex inferior packages
3159 The procedures listed below allow you to obtain and manipulate inferior
3162 @deffn {Scheme Procedure} inferior-packages @var{inferior}
3163 Return the list of packages known to @var{inferior}.
3166 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
3168 Return the sorted list of inferior packages matching @var{name} in
3169 @var{inferior}, with highest version numbers first. If @var{version} is true,
3170 return only packages with a version number prefixed by @var{version}.
3173 @deffn {Scheme Procedure} inferior-package? @var{obj}
3174 Return true if @var{obj} is an inferior package.
3177 @deffn {Scheme Procedure} inferior-package-name @var{package}
3178 @deffnx {Scheme Procedure} inferior-package-version @var{package}
3179 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
3180 @deffnx {Scheme Procedure} inferior-package-description @var{package}
3181 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
3182 @deffnx {Scheme Procedure} inferior-package-location @var{package}
3183 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
3184 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
3185 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
3186 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
3187 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
3188 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
3189 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
3190 These procedures are the counterpart of package record accessors
3191 (@pxref{package Reference}). Most of them work by querying the inferior
3192 @var{package} comes from, so the inferior must still be live when you call
3196 Inferior packages can be used transparently like any other package or
3197 file-like object in G-expressions (@pxref{G-Expressions}). They are also
3198 transparently handled by the @code{packages->manifest} procedure, which is
3199 commonly use in manifests (@pxref{Invoking guix package, the
3200 @option{--manifest} option of @command{guix package}}). Thus you can insert
3201 an inferior package pretty much anywhere you would insert a regular package:
3202 in manifests, in the @code{packages} field of your @code{operating-system}
3203 declaration, and so on.
3205 @node Invoking guix describe
3206 @section Invoking @command{guix describe}
3208 @cindex reproducibility
3209 @cindex replicating Guix
3210 Often you may want to answer questions like: ``Which revision of Guix am I
3211 using?'' or ``Which channels am I using?'' This is useful information in many
3212 situations: if you want to @emph{replicate} an environment on a different
3213 machine or user account, if you want to report a bug or to determine what
3214 change in the channels you are using caused it, or if you want to record your
3215 system state for reproducibility purposes. The @command{guix describe}
3216 command answers these questions.
3218 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
3219 displays the channel(s) that it was built from, including their repository URL
3220 and commit IDs (@pxref{Channels}):
3224 Generation 10 Sep 03 2018 17:32:44 (current)
3226 repository URL: https://git.savannah.gnu.org/git/guix.git
3228 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
3231 If you're familiar with the Git version control system, this is similar in
3232 spirit to @command{git describe}; the output is also similar to that of
3233 @command{guix pull --list-generations}, but limited to the current generation
3234 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
3235 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
3236 information is all it takes to describe the revision of Guix you're using, and
3237 also to replicate it.
3239 To make it easier to replicate Guix, @command{guix describe} can also be asked
3240 to return a list of channels instead of the human-readable description above:
3243 $ guix describe -f channels
3246 (url "https://git.savannah.gnu.org/git/guix.git")
3248 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
3252 You can save this to a file and feed it to @command{guix pull -C} on some
3253 other machine or at a later point in time, which will instantiate @emph{this
3254 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
3255 From there on, since you're able to deploy the same revision of Guix, you can
3256 just as well @emph{replicate a complete software environment}. We humbly
3257 think that this is @emph{awesome}, and we hope you'll like it too!
3259 The details of the options supported by @command{guix describe} are as
3263 @item --format=@var{format}
3264 @itemx -f @var{format}
3265 Produce output in the specified @var{format}, one of:
3269 produce human-readable output;
3271 produce a list of channel specifications that can be passed to @command{guix
3272 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
3276 produce a list of channel specifications in JSON format;
3278 produce a list of channel specifications in Recutils format.
3281 @item --profile=@var{profile}
3282 @itemx -p @var{profile}
3283 Display information about @var{profile}.
3286 @node Invoking guix pack
3287 @section Invoking @command{guix pack}
3289 Occasionally you want to pass software to people who are not (yet!)
3290 lucky enough to be using Guix. You'd tell them to run @command{guix
3291 package -i @var{something}}, but that's not possible in this case. This
3292 is where @command{guix pack} comes in.
3295 If you are looking for ways to exchange binaries among machines that
3296 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
3297 publish}, and @ref{Invoking guix archive}.
3302 @cindex application bundle
3303 @cindex software bundle
3304 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
3305 @dfn{software bundle}: it creates a tarball or some other archive
3306 containing the binaries of the software you're interested in, and all
3307 its dependencies. The resulting archive can be used on any machine that
3308 does not have Guix, and people can run the exact same binaries as those
3309 you have with Guix. The pack itself is created in a bit-reproducible
3310 fashion, so anyone can verify that it really contains the build results
3311 that you pretend to be shipping.
3313 For example, to create a bundle containing Guile, Emacs, Geiser, and all
3314 their dependencies, you can run:
3317 $ guix pack guile emacs geiser
3319 /gnu/store/@dots{}-pack.tar.gz
3322 The result here is a tarball containing a @file{/gnu/store} directory
3323 with all the relevant packages. The resulting tarball contains a
3324 @dfn{profile} with the three packages of interest; the profile is the
3325 same as would be created by @command{guix package -i}. It is this
3326 mechanism that is used to create Guix's own standalone binary tarball
3327 (@pxref{Binary Installation}).
3329 Users of this pack would have to run
3330 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
3331 find inconvenient. To work around it, you can create, say, a
3332 @file{/opt/gnu/bin} symlink to the profile:
3335 guix pack -S /opt/gnu/bin=bin guile emacs geiser
3339 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
3341 @cindex relocatable binaries, with @command{guix pack}
3342 What if the recipient of your pack does not have root privileges on
3343 their machine, and thus cannot unpack it in the root file system? In
3344 that case, you will want to use the @code{--relocatable} option (see
3345 below). This option produces @dfn{relocatable binaries}, meaning they
3346 they can be placed anywhere in the file system hierarchy: in the example
3347 above, users can unpack your tarball in their home directory and
3348 directly run @file{./opt/gnu/bin/guile}.
3350 @cindex Docker, build an image with guix pack
3351 Alternatively, you can produce a pack in the Docker image format using
3352 the following command:
3355 guix pack -f docker guile emacs geiser
3359 The result is a tarball that can be passed to the @command{docker load}
3361 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
3362 documentation} for more information.
3364 @cindex Singularity, build an image with guix pack
3365 @cindex SquashFS, build an image with guix pack
3366 Yet another option is to produce a SquashFS image with the following
3370 guix pack -f squashfs guile emacs geiser
3374 The result is a SquashFS file system image that can either be mounted or
3375 directly be used as a file system container image with the
3376 @uref{http://singularity.lbl.gov, Singularity container execution
3377 environment}, using commands like @command{singularity shell} or
3378 @command{singularity exec}.
3380 Several command-line options allow you to customize your pack:
3383 @item --format=@var{format}
3384 @itemx -f @var{format}
3385 Produce a pack in the given @var{format}.
3387 The available formats are:
3391 This is the default format. It produces a tarball containing all the
3392 specified binaries and symlinks.
3395 This produces a tarball that follows the
3396 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
3397 Docker Image Specification}.
3400 This produces a SquashFS image containing all the specified binaries and
3401 symlinks, as well as empty mount points for virtual file systems like
3407 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
3408 anywhere in the file system hierarchy and run from there. For example,
3409 if you create a pack containing Bash with:
3412 guix pack -R -S /mybin=bin bash
3416 ...@: you can copy that pack to a machine that lacks Guix, and from your
3417 home directory as a normal user, run:
3425 In that shell, if you type @code{ls /gnu/store}, you'll notice that
3426 @file{/gnu/store} shows up and contains all the dependencies of
3427 @code{bash}, even though the machine actually lacks @file{/gnu/store}
3428 altogether! That is probably the simplest way to deploy Guix-built
3429 software on a non-Guix machine.
3431 There's a gotcha though: this technique relies on the @dfn{user
3432 namespace} feature of the kernel Linux, which allows unprivileged users
3433 to mount or change root. Old versions of Linux did not support it, and
3434 some GNU/Linux distributions turn it off; on these systems, programs
3435 from the pack @emph{will fail to run}, unless they are unpacked in the
3438 @item --expression=@var{expr}
3439 @itemx -e @var{expr}
3440 Consider the package @var{expr} evaluates to.
3442 This has the same purpose as the same-named option in @command{guix
3443 build} (@pxref{Additional Build Options, @code{--expression} in
3444 @command{guix build}}).
3446 @item --manifest=@var{file}
3447 @itemx -m @var{file}
3448 Use the packages contained in the manifest object returned by the Scheme
3451 This has a similar purpose as the same-named option in @command{guix
3452 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
3453 same manifest files. It allows you to define a collection of packages
3454 once and use it both for creating profiles and for creating archives
3455 for use on machines that do not have Guix installed. Note that you can
3456 specify @emph{either} a manifest file @emph{or} a list of packages,
3459 @item --system=@var{system}
3460 @itemx -s @var{system}
3461 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3462 the system type of the build host.
3464 @item --target=@var{triplet}
3465 @cindex cross-compilation
3466 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
3467 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
3468 configuration triplets,, autoconf, Autoconf}).
3470 @item --compression=@var{tool}
3471 @itemx -C @var{tool}
3472 Compress the resulting tarball using @var{tool}---one of @code{gzip},
3473 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
3475 @item --symlink=@var{spec}
3476 @itemx -S @var{spec}
3477 Add the symlinks specified by @var{spec} to the pack. This option can
3478 appear several times.
3480 @var{spec} has the form @code{@var{source}=@var{target}}, where
3481 @var{source} is the symlink that will be created and @var{target} is the
3484 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
3485 symlink pointing to the @file{bin} sub-directory of the profile.
3487 @item --localstatedir
3488 @itemx --profile-name=@var{name}
3489 Include the ``local state directory'', @file{/var/guix}, in the resulting
3490 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
3491 profile---by default @var{name} is @code{guix-profile}, which corresponds to
3492 @file{~root/.guix-profile}.
3494 @file{/var/guix} contains the store database (@pxref{The Store}) as well
3495 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
3496 the pack means that the store is ``complete'' and manageable by Guix;
3497 not providing it pack means that the store is ``dead'': items cannot be
3498 added to it or removed from it after extraction of the pack.
3500 One use case for this is the Guix self-contained binary tarball
3501 (@pxref{Binary Installation}).
3504 Use the bootstrap binaries to build the pack. This option is only
3505 useful to Guix developers.
3508 In addition, @command{guix pack} supports all the common build options
3509 (@pxref{Common Build Options}) and all the package transformation
3510 options (@pxref{Package Transformation Options}).
3513 @node Invoking guix archive
3514 @section Invoking @command{guix archive}
3516 @cindex @command{guix archive}
3518 The @command{guix archive} command allows users to @dfn{export} files
3519 from the store into a single archive, and to later @dfn{import} them on
3520 a machine that runs Guix.
3521 In particular, it allows store files to be transferred from one machine
3522 to the store on another machine.
3525 If you're looking for a way to produce archives in a format suitable for
3526 tools other than Guix, @pxref{Invoking guix pack}.
3529 @cindex exporting store items
3530 To export store files as an archive to standard output, run:
3533 guix archive --export @var{options} @var{specifications}...
3536 @var{specifications} may be either store file names or package
3537 specifications, as for @command{guix package} (@pxref{Invoking guix
3538 package}). For instance, the following command creates an archive
3539 containing the @code{gui} output of the @code{git} package and the main
3540 output of @code{emacs}:
3543 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
3546 If the specified packages are not built yet, @command{guix archive}
3547 automatically builds them. The build process may be controlled with the
3548 common build options (@pxref{Common Build Options}).
3550 To transfer the @code{emacs} package to a machine connected over SSH,
3554 guix archive --export -r emacs | ssh the-machine guix archive --import
3558 Similarly, a complete user profile may be transferred from one machine
3559 to another like this:
3562 guix archive --export -r $(readlink -f ~/.guix-profile) | \
3563 ssh the-machine guix-archive --import
3567 However, note that, in both examples, all of @code{emacs} and the
3568 profile as well as all of their dependencies are transferred (due to
3569 @code{-r}), regardless of what is already available in the store on the
3570 target machine. The @code{--missing} option can help figure out which
3571 items are missing from the target store. The @command{guix copy}
3572 command simplifies and optimizes this whole process, so this is probably
3573 what you should use in this case (@pxref{Invoking guix copy}).
3575 @cindex nar, archive format
3576 @cindex normalized archive (nar)
3577 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
3578 comparable in spirit to `tar', but with differences
3579 that make it more appropriate for our purposes. First, rather than
3580 recording all Unix metadata for each file, the nar format only mentions
3581 the file type (regular, directory, or symbolic link); Unix permissions
3582 and owner/group are dismissed. Second, the order in which directory
3583 entries are stored always follows the order of file names according to
3584 the C locale collation order. This makes archive production fully
3587 When exporting, the daemon digitally signs the contents of the archive,
3588 and that digital signature is appended. When importing, the daemon
3589 verifies the signature and rejects the import in case of an invalid
3590 signature or if the signing key is not authorized.
3591 @c FIXME: Add xref to daemon doc about signatures.
3593 The main options are:
3597 Export the specified store files or packages (see below.) Write the
3598 resulting archive to the standard output.
3600 Dependencies are @emph{not} included in the output, unless
3601 @code{--recursive} is passed.
3605 When combined with @code{--export}, this instructs @command{guix
3606 archive} to include dependencies of the given items in the archive.
3607 Thus, the resulting archive is self-contained: it contains the closure
3608 of the exported store items.
3611 Read an archive from the standard input, and import the files listed
3612 therein into the store. Abort if the archive has an invalid digital
3613 signature, or if it is signed by a public key not among the authorized
3614 keys (see @code{--authorize} below.)
3617 Read a list of store file names from the standard input, one per line,
3618 and write on the standard output the subset of these files missing from
3621 @item --generate-key[=@var{parameters}]
3622 @cindex signing, archives
3623 Generate a new key pair for the daemon. This is a prerequisite before
3624 archives can be exported with @code{--export}. Note that this operation
3625 usually takes time, because it needs to gather enough entropy to
3626 generate the key pair.
3628 The generated key pair is typically stored under @file{/etc/guix}, in
3629 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
3630 key, which must be kept secret.) When @var{parameters} is omitted,
3631 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
3632 versions before 1.6.0, it is a 4096-bit RSA key.
3633 Alternatively, @var{parameters} can specify
3634 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
3635 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
3636 Libgcrypt Reference Manual}).
3639 @cindex authorizing, archives
3640 Authorize imports signed by the public key passed on standard input.
3641 The public key must be in ``s-expression advanced format''---i.e., the
3642 same format as the @file{signing-key.pub} file.
3644 The list of authorized keys is kept in the human-editable file
3645 @file{/etc/guix/acl}. The file contains
3646 @url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
3647 s-expressions''} and is structured as an access-control list in the
3648 @url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
3651 @item --extract=@var{directory}
3652 @itemx -x @var{directory}
3653 Read a single-item archive as served by substitute servers
3654 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
3655 low-level operation needed in only very narrow use cases; see below.
3657 For example, the following command extracts the substitute for Emacs
3658 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
3662 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
3663 | bunzip2 | guix archive -x /tmp/emacs
3666 Single-item archives are different from multiple-item archives produced
3667 by @command{guix archive --export}; they contain a single store item,
3668 and they do @emph{not} embed a signature. Thus this operation does
3669 @emph{no} signature verification and its output should be considered
3672 The primary purpose of this operation is to facilitate inspection of
3673 archive contents coming from possibly untrusted substitute servers.
3677 @c *********************************************************************
3678 @node Programming Interface
3679 @chapter Programming Interface
3681 GNU Guix provides several Scheme programming interfaces (APIs) to
3682 define, build, and query packages. The first interface allows users to
3683 write high-level package definitions. These definitions refer to
3684 familiar packaging concepts, such as the name and version of a package,
3685 its build system, and its dependencies. These definitions can then be
3686 turned into concrete build actions.
3688 Build actions are performed by the Guix daemon, on behalf of users. In a
3689 standard setup, the daemon has write access to the store---the
3690 @file{/gnu/store} directory---whereas users do not. The recommended
3691 setup also has the daemon perform builds in chroots, under a specific
3692 build users, to minimize interference with the rest of the system.
3695 Lower-level APIs are available to interact with the daemon and the
3696 store. To instruct the daemon to perform a build action, users actually
3697 provide it with a @dfn{derivation}. A derivation is a low-level
3698 representation of the build actions to be taken, and the environment in
3699 which they should occur---derivations are to package definitions what
3700 assembly is to C programs. The term ``derivation'' comes from the fact
3701 that build results @emph{derive} from them.
3703 This chapter describes all these APIs in turn, starting from high-level
3704 package definitions.
3707 * Defining Packages:: Defining new packages.
3708 * Build Systems:: Specifying how packages are built.
3709 * The Store:: Manipulating the package store.
3710 * Derivations:: Low-level interface to package derivations.
3711 * The Store Monad:: Purely functional interface to the store.
3712 * G-Expressions:: Manipulating build expressions.
3713 * Invoking guix repl:: Fiddling with Guix interactively.
3716 @node Defining Packages
3717 @section Defining Packages
3719 The high-level interface to package definitions is implemented in the
3720 @code{(guix packages)} and @code{(guix build-system)} modules. As an
3721 example, the package definition, or @dfn{recipe}, for the GNU Hello
3722 package looks like this:
3725 (define-module (gnu packages hello)
3726 #:use-module (guix packages)
3727 #:use-module (guix download)
3728 #:use-module (guix build-system gnu)
3729 #:use-module (guix licenses)
3730 #:use-module (gnu packages gawk))
3732 (define-public hello
3738 (uri (string-append "mirror://gnu/hello/hello-" version
3742 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
3743 (build-system gnu-build-system)
3744 (arguments '(#:configure-flags '("--enable-silent-rules")))
3745 (inputs `(("gawk" ,gawk)))
3746 (synopsis "Hello, GNU world: An example GNU package")
3747 (description "Guess what GNU Hello prints!")
3748 (home-page "http://www.gnu.org/software/hello/")
3753 Without being a Scheme expert, the reader may have guessed the meaning
3754 of the various fields here. This expression binds the variable
3755 @code{hello} to a @code{<package>} object, which is essentially a record
3756 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
3757 This package object can be inspected using procedures found in the
3758 @code{(guix packages)} module; for instance, @code{(package-name hello)}
3759 returns---surprise!---@code{"hello"}.
3761 With luck, you may be able to import part or all of the definition of
3762 the package you are interested in from another repository, using the
3763 @code{guix import} command (@pxref{Invoking guix import}).
3765 In the example above, @var{hello} is defined in a module of its own,
3766 @code{(gnu packages hello)}. Technically, this is not strictly
3767 necessary, but it is convenient to do so: all the packages defined in
3768 modules under @code{(gnu packages @dots{})} are automatically known to
3769 the command-line tools (@pxref{Package Modules}).
3771 There are a few points worth noting in the above package definition:
3775 The @code{source} field of the package is an @code{<origin>} object
3776 (@pxref{origin Reference}, for the complete reference).
3777 Here, the @code{url-fetch} method from @code{(guix download)} is used,
3778 meaning that the source is a file to be downloaded over FTP or HTTP.
3780 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
3781 the GNU mirrors defined in @code{(guix download)}.
3783 The @code{sha256} field specifies the expected SHA256 hash of the file
3784 being downloaded. It is mandatory, and allows Guix to check the
3785 integrity of the file. The @code{(base32 @dots{})} form introduces the
3786 base32 representation of the hash. You can obtain this information with
3787 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
3788 hash} (@pxref{Invoking guix hash}).
3791 When needed, the @code{origin} form can also have a @code{patches} field
3792 listing patches to be applied, and a @code{snippet} field giving a
3793 Scheme expression to modify the source code.
3796 @cindex GNU Build System
3797 The @code{build-system} field specifies the procedure to build the
3798 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
3799 represents the familiar GNU Build System, where packages may be
3800 configured, built, and installed with the usual @code{./configure &&
3801 make && make check && make install} command sequence.
3804 The @code{arguments} field specifies options for the build system
3805 (@pxref{Build Systems}). Here it is interpreted by
3806 @var{gnu-build-system} as a request run @file{configure} with the
3807 @code{--enable-silent-rules} flag.
3813 What about these quote (@code{'}) characters? They are Scheme syntax to
3814 introduce a literal list; @code{'} is synonymous with @code{quote}.
3815 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
3816 for details. Here the value of the @code{arguments} field is a list of
3817 arguments passed to the build system down the road, as with @code{apply}
3818 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
3821 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
3822 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
3823 @code{#:configure-flags} is a keyword used to pass a keyword argument
3824 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
3828 The @code{inputs} field specifies inputs to the build process---i.e.,
3829 build-time or run-time dependencies of the package. Here, we define an
3830 input called @code{"gawk"} whose value is that of the @var{gawk}
3831 variable; @var{gawk} is itself bound to a @code{<package>} object.
3833 @cindex backquote (quasiquote)
3836 @cindex comma (unquote)
3840 @findex unquote-splicing
3841 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
3842 us to introduce a literal list in the @code{inputs} field, while
3843 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
3844 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
3847 Note that GCC, Coreutils, Bash, and other essential tools do not need to
3848 be specified as inputs here. Instead, @var{gnu-build-system} takes care
3849 of ensuring that they are present (@pxref{Build Systems}).
3851 However, any other dependencies need to be specified in the
3852 @code{inputs} field. Any dependency not specified here will simply be
3853 unavailable to the build process, possibly leading to a build failure.
3856 @xref{package Reference}, for a full description of possible fields.
3858 Once a package definition is in place, the
3859 package may actually be built using the @code{guix build} command-line
3860 tool (@pxref{Invoking guix build}), troubleshooting any build failures
3861 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
3862 package definition using the @command{guix edit} command
3863 (@pxref{Invoking guix edit}).
3864 @xref{Packaging Guidelines}, for
3865 more information on how to test package definitions, and
3866 @ref{Invoking guix lint}, for information on how to check a definition
3867 for style conformance.
3868 @vindex GUIX_PACKAGE_PATH
3869 Lastly, @pxref{Channels}, for information
3870 on how to extend the distribution by adding your own package definitions
3873 Finally, updating the package definition to a new upstream version
3874 can be partly automated by the @command{guix refresh} command
3875 (@pxref{Invoking guix refresh}).
3877 Behind the scenes, a derivation corresponding to the @code{<package>}
3878 object is first computed by the @code{package-derivation} procedure.
3879 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
3880 The build actions it prescribes may then be realized by using the
3881 @code{build-derivations} procedure (@pxref{The Store}).
3883 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
3884 Return the @code{<derivation>} object of @var{package} for @var{system}
3885 (@pxref{Derivations}).
3887 @var{package} must be a valid @code{<package>} object, and @var{system}
3888 must be a string denoting the target system type---e.g.,
3889 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
3890 must be a connection to the daemon, which operates on the store
3891 (@pxref{The Store}).
3895 @cindex cross-compilation
3896 Similarly, it is possible to compute a derivation that cross-builds a
3897 package for some other system:
3899 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
3900 @var{package} @var{target} [@var{system}]
3901 Return the @code{<derivation>} object of @var{package} cross-built from
3902 @var{system} to @var{target}.
3904 @var{target} must be a valid GNU triplet denoting the target hardware
3905 and operating system, such as @code{"mips64el-linux-gnu"}
3906 (@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
3907 Configure and Build System}).
3910 @cindex package transformations
3911 @cindex input rewriting
3912 @cindex dependency tree rewriting
3913 Packages can be manipulated in arbitrary ways. An example of a useful
3914 transformation is @dfn{input rewriting}, whereby the dependency tree of
3915 a package is rewritten by replacing specific inputs by others:
3917 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
3918 [@var{rewrite-name}]
3919 Return a procedure that, when passed a package, replaces its direct and
3920 indirect dependencies (but not its implicit inputs) according to
3921 @var{replacements}. @var{replacements} is a list of package pairs; the
3922 first element of each pair is the package to replace, and the second one
3925 Optionally, @var{rewrite-name} is a one-argument procedure that takes
3926 the name of a package and returns its new name after rewrite.
3930 Consider this example:
3933 (define libressl-instead-of-openssl
3934 ;; This is a procedure to replace OPENSSL by LIBRESSL,
3936 (package-input-rewriting `((,openssl . ,libressl))))
3938 (define git-with-libressl
3939 (libressl-instead-of-openssl git))
3943 Here we first define a rewriting procedure that replaces @var{openssl}
3944 with @var{libressl}. Then we use it to define a @dfn{variant} of the
3945 @var{git} package that uses @var{libressl} instead of @var{openssl}.
3946 This is exactly what the @option{--with-input} command-line option does
3947 (@pxref{Package Transformation Options, @option{--with-input}}).
3949 A more generic procedure to rewrite a package dependency graph is
3950 @code{package-mapping}: it supports arbitrary changes to nodes in the
3953 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
3954 Return a procedure that, given a package, applies @var{proc} to all the packages
3955 depended on and returns the resulting package. The procedure stops recursion
3956 when @var{cut?} returns true for a given package.
3960 * package Reference:: The package data type.
3961 * origin Reference:: The origin data type.
3965 @node package Reference
3966 @subsection @code{package} Reference
3968 This section summarizes all the options available in @code{package}
3969 declarations (@pxref{Defining Packages}).
3971 @deftp {Data Type} package
3972 This is the data type representing a package recipe.
3976 The name of the package, as a string.
3978 @item @code{version}
3979 The version of the package, as a string.
3982 An object telling how the source code for the package should be
3983 acquired. Most of the time, this is an @code{origin} object, which
3984 denotes a file fetched from the Internet (@pxref{origin Reference}). It
3985 can also be any other ``file-like'' object such as a @code{local-file},
3986 which denotes a file from the local file system (@pxref{G-Expressions,
3987 @code{local-file}}).
3989 @item @code{build-system}
3990 The build system that should be used to build the package (@pxref{Build
3993 @item @code{arguments} (default: @code{'()})
3994 The arguments that should be passed to the build system. This is a
3995 list, typically containing sequential keyword-value pairs.
3997 @item @code{inputs} (default: @code{'()})
3998 @itemx @code{native-inputs} (default: @code{'()})
3999 @itemx @code{propagated-inputs} (default: @code{'()})
4000 @cindex inputs, of packages
4001 These fields list dependencies of the package. Each one is a list of
4002 tuples, where each tuple has a label for the input (a string) as its
4003 first element, a package, origin, or derivation as its second element,
4004 and optionally the name of the output thereof that should be used, which
4005 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
4006 more on package outputs). For example, the list below specifies three
4010 `(("libffi" ,libffi)
4011 ("libunistring" ,libunistring)
4012 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
4015 @cindex cross compilation, package dependencies
4016 The distinction between @code{native-inputs} and @code{inputs} is
4017 necessary when considering cross-compilation. When cross-compiling,
4018 dependencies listed in @code{inputs} are built for the @emph{target}
4019 architecture; conversely, dependencies listed in @code{native-inputs}
4020 are built for the architecture of the @emph{build} machine.
4022 @code{native-inputs} is typically used to list tools needed at
4023 build time, but not at run time, such as Autoconf, Automake, pkg-config,
4024 Gettext, or Bison. @command{guix lint} can report likely mistakes in
4025 this area (@pxref{Invoking guix lint}).
4027 @anchor{package-propagated-inputs}
4028 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
4029 specified packages will be automatically installed alongside the package
4030 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
4031 package}}, for information on how @command{guix package} deals with
4034 For example this is necessary when a C/C++ library needs headers of
4035 another library to compile, or when a pkg-config file refers to another
4036 one @i{via} its @code{Requires} field.
4038 Another example where @code{propagated-inputs} is useful is for languages
4039 that lack a facility to record the run-time search path akin to the
4040 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
4041 more. To ensure that libraries written in those languages can find
4042 library code they depend on at run time, run-time dependencies must be
4043 listed in @code{propagated-inputs} rather than @code{inputs}.
4045 @item @code{self-native-input?} (default: @code{#f})
4046 This is a Boolean field telling whether the package should use itself as
4047 a native input when cross-compiling.
4049 @item @code{outputs} (default: @code{'("out")})
4050 The list of output names of the package. @xref{Packages with Multiple
4051 Outputs}, for typical uses of additional outputs.
4053 @item @code{native-search-paths} (default: @code{'()})
4054 @itemx @code{search-paths} (default: @code{'()})
4055 A list of @code{search-path-specification} objects describing
4056 search-path environment variables honored by the package.
4058 @item @code{replacement} (default: @code{#f})
4059 This must be either @code{#f} or a package object that will be used as a
4060 @dfn{replacement} for this package. @xref{Security Updates, grafts},
4063 @item @code{synopsis}
4064 A one-line description of the package.
4066 @item @code{description}
4067 A more elaborate description of the package.
4069 @item @code{license}
4070 @cindex license, of packages
4071 The license of the package; a value from @code{(guix licenses)},
4072 or a list of such values.
4074 @item @code{home-page}
4075 The URL to the home-page of the package, as a string.
4077 @item @code{supported-systems} (default: @var{%supported-systems})
4078 The list of systems supported by the package, as strings of the form
4079 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
4081 @item @code{maintainers} (default: @code{'()})
4082 The list of maintainers of the package, as @code{maintainer} objects.
4084 @item @code{location} (default: source location of the @code{package} form)
4085 The source location of the package. It is useful to override this when
4086 inheriting from another package, in which case this field is not
4087 automatically corrected.
4092 @node origin Reference
4093 @subsection @code{origin} Reference
4095 This section summarizes all the options available in @code{origin}
4096 declarations (@pxref{Defining Packages}).
4098 @deftp {Data Type} origin
4099 This is the data type representing a source code origin.
4103 An object containing the URI of the source. The object type depends on
4104 the @code{method} (see below). For example, when using the
4105 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
4106 values are: a URL represented as a string, or a list thereof.
4109 A procedure that handles the URI.
4114 @item @var{url-fetch} from @code{(guix download)}
4115 download a file from the HTTP, HTTPS, or FTP URL specified in the
4119 @item @var{git-fetch} from @code{(guix git-download)}
4120 clone the Git version control repository, and check out the revision
4121 specified in the @code{uri} field as a @code{git-reference} object; a
4122 @code{git-reference} looks like this:
4126 (url "git://git.debian.org/git/pkg-shadow/shadow")
4127 (commit "v4.1.5.1"))
4132 A bytevector containing the SHA-256 hash of the source. Typically the
4133 @code{base32} form is used here to generate the bytevector from a
4136 You can obtain this information using @code{guix download}
4137 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
4140 @item @code{file-name} (default: @code{#f})
4141 The file name under which the source code should be saved. When this is
4142 @code{#f}, a sensible default value will be used in most cases. In case
4143 the source is fetched from a URL, the file name from the URL will be
4144 used. For version control checkouts, it is recommended to provide the
4145 file name explicitly because the default is not very descriptive.
4147 @item @code{patches} (default: @code{'()})
4148 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
4149 file-like objects}) pointing to patches to be applied to the source.
4151 This list of patches must be unconditional. In particular, it cannot
4152 depend on the value of @code{%current-system} or
4153 @code{%current-target-system}.
4155 @item @code{snippet} (default: @code{#f})
4156 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
4157 in the source directory. This is a convenient way to modify the source,
4158 sometimes more convenient than a patch.
4160 @item @code{patch-flags} (default: @code{'("-p1")})
4161 A list of command-line flags that should be passed to the @code{patch}
4164 @item @code{patch-inputs} (default: @code{#f})
4165 Input packages or derivations to the patching process. When this is
4166 @code{#f}, the usual set of inputs necessary for patching are provided,
4167 such as GNU@tie{}Patch.
4169 @item @code{modules} (default: @code{'()})
4170 A list of Guile modules that should be loaded during the patching
4171 process and while running the code in the @code{snippet} field.
4173 @item @code{patch-guile} (default: @code{#f})
4174 The Guile package that should be used in the patching process. When
4175 this is @code{#f}, a sensible default is used.
4181 @section Build Systems
4183 @cindex build system
4184 Each package definition specifies a @dfn{build system} and arguments for
4185 that build system (@pxref{Defining Packages}). This @code{build-system}
4186 field represents the build procedure of the package, as well as implicit
4187 dependencies of that build procedure.
4189 Build systems are @code{<build-system>} objects. The interface to
4190 create and manipulate them is provided by the @code{(guix build-system)}
4191 module, and actual build systems are exported by specific modules.
4193 @cindex bag (low-level package representation)
4194 Under the hood, build systems first compile package objects to
4195 @dfn{bags}. A @dfn{bag} is like a package, but with less
4196 ornamentation---in other words, a bag is a lower-level representation of
4197 a package, which includes all the inputs of that package, including some
4198 that were implicitly added by the build system. This intermediate
4199 representation is then compiled to a derivation (@pxref{Derivations}).
4201 Build systems accept an optional list of @dfn{arguments}. In package
4202 definitions, these are passed @i{via} the @code{arguments} field
4203 (@pxref{Defining Packages}). They are typically keyword arguments
4204 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
4205 Guile Reference Manual}). The value of these arguments is usually
4206 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
4207 by the daemon (@pxref{Derivations}).
4209 The main build system is @var{gnu-build-system}, which implements the
4210 standard build procedure for GNU and many other packages. It
4211 is provided by the @code{(guix build-system gnu)} module.
4213 @defvr {Scheme Variable} gnu-build-system
4214 @var{gnu-build-system} represents the GNU Build System, and variants
4215 thereof (@pxref{Configuration, configuration and makefile conventions,,
4216 standards, GNU Coding Standards}).
4218 @cindex build phases
4219 In a nutshell, packages using it are configured, built, and installed with
4220 the usual @code{./configure && make && make check && make install}
4221 command sequence. In practice, a few additional steps are often needed.
4222 All these steps are split up in separate @dfn{phases},
4223 notably@footnote{Please see the @code{(guix build gnu-build-system)}
4224 modules for more details about the build phases.}:
4228 Unpack the source tarball, and change the current directory to the
4229 extracted source tree. If the source is actually a directory, copy it
4230 to the build tree, and enter that directory.
4232 @item patch-source-shebangs
4233 Patch shebangs encountered in source files so they refer to the right
4234 store file names. For instance, this changes @code{#!/bin/sh} to
4235 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
4238 Run the @file{configure} script with a number of default options, such
4239 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
4240 by the @code{#:configure-flags} argument.
4243 Run @code{make} with the list of flags specified with
4244 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
4245 (the default), build with @code{make -j}.
4248 Run @code{make check}, or some other target specified with
4249 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
4250 @code{#:parallel-tests?} argument is true (the default), run @code{make
4254 Run @code{make install} with the flags listed in @code{#:make-flags}.
4256 @item patch-shebangs
4257 Patch shebangs on the installed executable files.
4260 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
4261 is false), copying them to the @code{debug} output when available
4262 (@pxref{Installing Debugging Files}).
4265 @vindex %standard-phases
4266 The build-side module @code{(guix build gnu-build-system)} defines
4267 @var{%standard-phases} as the default list of build phases.
4268 @var{%standard-phases} is a list of symbol/procedure pairs, where the
4269 procedure implements the actual phase.
4271 The list of phases used for a particular package can be changed with the
4272 @code{#:phases} parameter. For instance, passing:
4275 #:phases (modify-phases %standard-phases (delete 'configure))
4278 means that all the phases described above will be used, except the
4279 @code{configure} phase.
4281 In addition, this build system ensures that the ``standard'' environment
4282 for GNU packages is available. This includes tools such as GCC, libc,
4283 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
4284 build-system gnu)} module for a complete list). We call these the
4285 @dfn{implicit inputs} of a package, because package definitions do not
4286 have to mention them.
4289 Other @code{<build-system>} objects are defined to support other
4290 conventions and tools used by free software packages. They inherit most
4291 of @var{gnu-build-system}, and differ mainly in the set of inputs
4292 implicitly added to the build process, and in the list of phases
4293 executed. Some of these build systems are listed below.
4295 @defvr {Scheme Variable} ant-build-system
4296 This variable is exported by @code{(guix build-system ant)}. It
4297 implements the build procedure for Java packages that can be built with
4298 @url{http://ant.apache.org/, Ant build tool}.
4300 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
4301 provided by the @code{icedtea} package to the set of inputs. Different
4302 packages can be specified with the @code{#:ant} and @code{#:jdk}
4303 parameters, respectively.
4305 When the original package does not provide a suitable Ant build file,
4306 the parameter @code{#:jar-name} can be used to generate a minimal Ant
4307 build file @file{build.xml} with tasks to build the specified jar
4308 archive. In this case the parameter @code{#:source-dir} can be used to
4309 specify the source sub-directory, defaulting to ``src''.
4311 The @code{#:main-class} parameter can be used with the minimal ant
4312 buildfile to specify the main class of the resulting jar. This makes the
4313 jar file executable. The @code{#:test-include} parameter can be used to
4314 specify the list of junit tests to run. It defaults to
4315 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
4316 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
4317 because abstract classes cannot be run as tests.
4319 The parameter @code{#:build-target} can be used to specify the Ant task
4320 that should be run during the @code{build} phase. By default the
4321 ``jar'' task will be run.
4325 @defvr {Scheme Variable} android-ndk-build-system
4326 @cindex Android distribution
4327 @cindex Android NDK build system
4328 This variable is exported by @code{(guix build-system android-ndk)}. It
4329 implements a build procedure for Android NDK (native development kit)
4330 packages using a Guix-specific build process.
4332 The build system assumes that packages install their public interface
4333 (header) files to the subdirectory "include" of the "out" output and
4334 their libraries to the subdirectory "lib" of the "out" output.
4336 It's also assumed that the union of all the dependencies of a package
4337 has no conflicting files.
4339 For the time being, cross-compilation is not supported - so right now
4340 the libraries and header files are assumed to be host tools.
4344 @defvr {Scheme Variable} asdf-build-system/source
4345 @defvrx {Scheme Variable} asdf-build-system/sbcl
4346 @defvrx {Scheme Variable} asdf-build-system/ecl
4348 These variables, exported by @code{(guix build-system asdf)}, implement
4349 build procedures for Common Lisp packages using
4350 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
4351 definition facility for Common Lisp programs and libraries.
4353 The @code{asdf-build-system/source} system installs the packages in
4354 source form, and can be loaded using any common lisp implementation, via
4355 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
4356 systems in the format which a particular implementation understands.
4357 These build systems can also be used to produce executable programs, or
4358 lisp images which contain a set of packages pre-loaded.
4360 The build system uses naming conventions. For binary packages, the
4361 package name should be prefixed with the lisp implementation, such as
4362 @code{sbcl-} for @code{asdf-build-system/sbcl}.
4364 Additionally, the corresponding source package should be labeled using
4365 the same convention as python packages (see @ref{Python Modules}), using
4366 the @code{cl-} prefix.
4368 For binary packages, each system should be defined as a Guix package.
4369 If one package @code{origin} contains several systems, package variants
4370 can be created in order to build all the systems. Source packages,
4371 which use @code{asdf-build-system/source}, may contain several systems.
4373 In order to create executable programs and images, the build-side
4374 procedures @code{build-program} and @code{build-image} can be used.
4375 They should be called in a build phase after the @code{create-symlinks}
4376 phase, so that the system which was just built can be used within the
4377 resulting image. @code{build-program} requires a list of Common Lisp
4378 expressions to be passed as the @code{#:entry-program} argument.
4380 If the system is not defined within its own @code{.asd} file of the same
4381 name, then the @code{#:asd-file} parameter should be used to specify
4382 which file the system is defined in. Furthermore, if the package
4383 defines a system for its tests in a separate file, it will be loaded
4384 before the tests are run if it is specified by the
4385 @code{#:test-asd-file} parameter. If it is not set, the files
4386 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
4387 and @code{test.asd} will be tried if they exist.
4389 If for some reason the package must be named in a different way than the
4390 naming conventions suggest, the @code{#:asd-system-name} parameter can
4391 be used to specify the name of the system.
4395 @defvr {Scheme Variable} cargo-build-system
4396 @cindex Rust programming language
4397 @cindex Cargo (Rust build system)
4398 This variable is exported by @code{(guix build-system cargo)}. It
4399 supports builds of packages using Cargo, the build tool of the
4400 @uref{https://www.rust-lang.org, Rust programming language}.
4402 In its @code{configure} phase, this build system replaces dependencies
4403 specified in the @file{Carto.toml} file with inputs to the Guix package.
4404 The @code{install} phase installs the binaries, and it also installs the
4405 source code and @file{Cargo.toml} file.
4408 @cindex Clojure (programming language)
4409 @cindex simple Clojure build system
4410 @defvr {Scheme Variable} clojure-build-system
4411 This variable is exported by @code{(guix build-system clojure)}. It implements
4412 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
4413 using plain old @code{compile} in Clojure. Cross-compilation is not supported
4416 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
4417 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
4418 @code{#:zip} parameters, respectively.
4420 A list of source directories, test directories and jar names can be specified
4421 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
4422 parameters, respectively. Compile directory and main class can be specified
4423 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
4424 Other parameters are documented below.
4426 This build system is an extension of @var{ant-build-system}, but with the
4427 following phases changed:
4432 This phase calls @code{compile} in Clojure to compile source files and runs
4433 @command{jar} to create jars from both source files and compiled files
4434 according to the include list and exclude list specified in
4435 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
4436 has priority over the include list. These lists consist of symbols
4437 representing Clojure libraries or the special keyword @code{#:all} representing
4438 all Clojure libraries found under the source directories. The parameter
4439 @code{#:omit-source?} decides if source should be included into the jars.
4442 This phase runs tests according to the include list and exclude list specified
4443 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
4444 meanings are analogous to that of @code{#:aot-include} and
4445 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
4446 stands for all Clojure libraries found under the test directories. The
4447 parameter @code{#:tests?} decides if tests should be run.
4450 This phase installs all jars built previously.
4453 Apart from the above, this build system also contains an additional phase:
4458 This phase installs all top-level files with base name matching
4459 @var{%doc-regex}. A different regex can be specified with the
4460 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
4461 directories specified in @code{#:doc-dirs} are installed as well.
4465 @defvr {Scheme Variable} cmake-build-system
4466 This variable is exported by @code{(guix build-system cmake)}. It
4467 implements the build procedure for packages using the
4468 @url{http://www.cmake.org, CMake build tool}.
4470 It automatically adds the @code{cmake} package to the set of inputs.
4471 Which package is used can be specified with the @code{#:cmake}
4474 The @code{#:configure-flags} parameter is taken as a list of flags
4475 passed to the @command{cmake} command. The @code{#:build-type}
4476 parameter specifies in abstract terms the flags passed to the compiler;
4477 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
4478 debugging information''), which roughly means that code is compiled with
4479 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
4482 @defvr {Scheme Variable} go-build-system
4483 This variable is exported by @code{(guix build-system go)}. It
4484 implements a build procedure for Go packages using the standard
4485 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
4486 Go build mechanisms}.
4488 The user is expected to provide a value for the key @code{#:import-path}
4489 and, in some cases, @code{#:unpack-path}. The
4490 @url{https://golang.org/doc/code.html#ImportPaths, import path}
4491 corresponds to the file system path expected by the package's build
4492 scripts and any referring packages, and provides a unique way to
4493 refer to a Go package. It is typically based on a combination of the
4494 package source code's remote URI and file system hierarchy structure. In
4495 some cases, you will need to unpack the package's source code to a
4496 different directory structure than the one indicated by the import path,
4497 and @code{#:unpack-path} should be used in such cases.
4499 Packages that provide Go libraries should be installed along with their
4500 source code. The key @code{#:install-source?}, which defaults to
4501 @code{#t}, controls whether or not the source code is installed. It can
4502 be set to @code{#f} for packages that only provide executable files.
4505 @defvr {Scheme Variable} glib-or-gtk-build-system
4506 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
4507 is intended for use with packages making use of GLib or GTK+.
4509 This build system adds the following two phases to the ones defined by
4510 @var{gnu-build-system}:
4513 @item glib-or-gtk-wrap
4514 The phase @code{glib-or-gtk-wrap} ensures that programs in
4515 @file{bin/} are able to find GLib ``schemas'' and
4516 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
4517 modules}. This is achieved by wrapping the programs in launch scripts
4518 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
4519 environment variables.
4521 It is possible to exclude specific package outputs from that wrapping
4522 process by listing their names in the
4523 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
4524 when an output is known not to contain any GLib or GTK+ binaries, and
4525 where wrapping would gratuitously add a dependency of that output on
4528 @item glib-or-gtk-compile-schemas
4529 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
4530 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
4531 GSettings schemas} of GLib are compiled. Compilation is performed by the
4532 @command{glib-compile-schemas} program. It is provided by the package
4533 @code{glib:bin} which is automatically imported by the build system.
4534 The @code{glib} package providing @command{glib-compile-schemas} can be
4535 specified with the @code{#:glib} parameter.
4538 Both phases are executed after the @code{install} phase.
4541 @defvr {Scheme Variable} guile-build-system
4542 This build system is for Guile packages that consist exclusively of Scheme
4543 code and that are so lean that they don't even have a makefile, let alone a
4544 @file{configure} script. It compiles Scheme code using @command{guild
4545 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
4546 installs the @file{.scm} and @file{.go} files in the right place. It also
4547 installs documentation.
4549 This build system supports cross-compilation by using the @code{--target}
4550 option of @command{guild compile}.
4552 Packages built with @code{guile-build-system} must provide a Guile package in
4553 their @code{native-inputs} field.
4556 @defvr {Scheme Variable} minify-build-system
4557 This variable is exported by @code{(guix build-system minify)}. It
4558 implements a minification procedure for simple JavaScript packages.
4560 It adds @code{uglify-js} to the set of inputs and uses it to compress
4561 all JavaScript files in the @file{src} directory. A different minifier
4562 package can be specified with the @code{#:uglify-js} parameter, but it
4563 is expected that the package writes the minified code to the standard
4566 When the input JavaScript files are not all located in the @file{src}
4567 directory, the parameter @code{#:javascript-files} can be used to
4568 specify a list of file names to feed to the minifier.
4571 @defvr {Scheme Variable} ocaml-build-system
4572 This variable is exported by @code{(guix build-system ocaml)}. It implements
4573 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
4574 of choosing the correct set of commands to run for each package. OCaml
4575 packages can expect many different commands to be run. This build system will
4578 When the package has a @file{setup.ml} file present at the top-level, it will
4579 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
4580 @code{ocaml setup.ml -install}. The build system will assume that this file
4581 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
4582 care of setting the prefix and enabling tests if they are not disabled. You
4583 can pass configure and build flags with the @code{#:configure-flags} and
4584 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
4585 set of flags used to enable tests. The @code{#:use-make?} key can be used to
4586 bypass this system in the build and install phases.
4588 When the package has a @file{configure} file, it is assumed that it is a
4589 hand-made configure script that requires a different argument format than
4590 in the @code{gnu-build-system}. You can add more flags with the
4591 @code{#:configure-flags} key.
4593 When the package has a @file{Makefile} file (or @code{#:use-make?} is
4594 @code{#t}), it will be used and more flags can be passed to the build and
4595 install phases with the @code{#:make-flags} key.
4597 Finally, some packages do not have these files and use a somewhat standard
4598 location for its build system. In that case, the build system will run
4599 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
4600 providing the path to the required findlib module. Additional flags can
4601 be passed via the @code{#:build-flags} key. Install is taken care of by
4602 @command{opam-installer}. In this case, the @code{opam} package must
4603 be added to the @code{native-inputs} field of the package definition.
4605 Note that most OCaml packages assume they will be installed in the same
4606 directory as OCaml, which is not what we want in guix. In particular, they
4607 will install @file{.so} files in their module's directory, which is usually
4608 fine because it is in the OCaml compiler directory. In guix though, these
4609 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
4610 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
4611 @file{.so} libraries should be installed.
4614 @defvr {Scheme Variable} python-build-system
4615 This variable is exported by @code{(guix build-system python)}. It
4616 implements the more or less standard build procedure used by Python
4617 packages, which consists in running @code{python setup.py build} and
4618 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
4620 For packages that install stand-alone Python programs under @code{bin/},
4621 it takes care of wrapping these programs so that their @code{PYTHONPATH}
4622 environment variable points to all the Python libraries they depend on.
4624 Which Python package is used to perform the build can be specified with
4625 the @code{#:python} parameter. This is a useful way to force a package
4626 to be built for a specific version of the Python interpreter, which
4627 might be necessary if the package is only compatible with a single
4628 interpreter version.
4630 By default guix calls @code{setup.py} under control of
4631 @code{setuptools}, much like @command{pip} does. Some packages are not
4632 compatible with setuptools (and pip), thus you can disable this by
4633 setting the @code{#:use-setuptools} parameter to @code{#f}.
4636 @defvr {Scheme Variable} perl-build-system
4637 This variable is exported by @code{(guix build-system perl)}. It
4638 implements the standard build procedure for Perl packages, which either
4639 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
4640 followed by @code{Build} and @code{Build install}; or in running
4641 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
4642 @code{make} and @code{make install}, depending on which of
4643 @code{Build.PL} or @code{Makefile.PL} is present in the package
4644 distribution. Preference is given to the former if both @code{Build.PL}
4645 and @code{Makefile.PL} exist in the package distribution. This
4646 preference can be reversed by specifying @code{#t} for the
4647 @code{#:make-maker?} parameter.
4649 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
4650 passes flags specified by the @code{#:make-maker-flags} or
4651 @code{#:module-build-flags} parameter, respectively.
4653 Which Perl package is used can be specified with @code{#:perl}.
4656 @defvr {Scheme Variable} r-build-system
4657 This variable is exported by @code{(guix build-system r)}. It
4658 implements the build procedure used by @uref{http://r-project.org, R}
4659 packages, which essentially is little more than running @code{R CMD
4660 INSTALL --library=/gnu/store/@dots{}} in an environment where
4661 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
4662 are run after installation using the R function
4663 @code{tools::testInstalledPackage}.
4666 @defvr {Scheme Variable} texlive-build-system
4667 This variable is exported by @code{(guix build-system texlive)}. It is
4668 used to build TeX packages in batch mode with a specified engine. The
4669 build system sets the @code{TEXINPUTS} variable to find all TeX source
4670 files in the inputs.
4672 By default it runs @code{luatex} on all files ending on @code{ins}. A
4673 different engine and format can be specified with the
4674 @code{#:tex-format} argument. Different build targets can be specified
4675 with the @code{#:build-targets} argument, which expects a list of file
4676 names. The build system adds only @code{texlive-bin} and
4677 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
4678 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
4679 and @code{#:texlive-latex-base}, respectively.
4681 The @code{#:tex-directory} parameter tells the build system where to
4682 install the built files under the texmf tree.
4685 @defvr {Scheme Variable} ruby-build-system
4686 This variable is exported by @code{(guix build-system ruby)}. It
4687 implements the RubyGems build procedure used by Ruby packages, which
4688 involves running @code{gem build} followed by @code{gem install}.
4690 The @code{source} field of a package that uses this build system
4691 typically references a gem archive, since this is the format that Ruby
4692 developers use when releasing their software. The build system unpacks
4693 the gem archive, potentially patches the source, runs the test suite,
4694 repackages the gem, and installs it. Additionally, directories and
4695 tarballs may be referenced to allow building unreleased gems from Git or
4696 a traditional source release tarball.
4698 Which Ruby package is used can be specified with the @code{#:ruby}
4699 parameter. A list of additional flags to be passed to the @command{gem}
4700 command can be specified with the @code{#:gem-flags} parameter.
4703 @defvr {Scheme Variable} waf-build-system
4704 This variable is exported by @code{(guix build-system waf)}. It
4705 implements a build procedure around the @code{waf} script. The common
4706 phases---@code{configure}, @code{build}, and @code{install}---are
4707 implemented by passing their names as arguments to the @code{waf}
4710 The @code{waf} script is executed by the Python interpreter. Which
4711 Python package is used to run the script can be specified with the
4712 @code{#:python} parameter.
4715 @defvr {Scheme Variable} scons-build-system
4716 This variable is exported by @code{(guix build-system scons)}. It
4717 implements the build procedure used by the SCons software construction
4718 tool. This build system runs @code{scons} to build the package,
4719 @code{scons test} to run tests, and then @code{scons install} to install
4722 Additional flags to be passed to @code{scons} can be specified with the
4723 @code{#:scons-flags} parameter. The version of Python used to run SCons
4724 can be specified by selecting the appropriate SCons package with the
4725 @code{#:scons} parameter.
4728 @defvr {Scheme Variable} haskell-build-system
4729 This variable is exported by @code{(guix build-system haskell)}. It
4730 implements the Cabal build procedure used by Haskell packages, which
4731 involves running @code{runhaskell Setup.hs configure
4732 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
4733 Instead of installing the package by running @code{runhaskell Setup.hs
4734 install}, to avoid trying to register libraries in the read-only
4735 compiler store directory, the build system uses @code{runhaskell
4736 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
4737 addition, the build system generates the package documentation by
4738 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
4739 is passed. Optional Haddock parameters can be passed with the help of
4740 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
4741 not found, the build system looks for @code{Setup.lhs} instead.
4743 Which Haskell compiler is used can be specified with the @code{#:haskell}
4744 parameter which defaults to @code{ghc}.
4747 @defvr {Scheme Variable} dub-build-system
4748 This variable is exported by @code{(guix build-system dub)}. It
4749 implements the Dub build procedure used by D packages, which
4750 involves running @code{dub build} and @code{dub run}.
4751 Installation is done by copying the files manually.
4753 Which D compiler is used can be specified with the @code{#:ldc}
4754 parameter which defaults to @code{ldc}.
4757 @defvr {Scheme Variable} emacs-build-system
4758 This variable is exported by @code{(guix build-system emacs)}. It
4759 implements an installation procedure similar to the packaging system
4760 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
4762 It first creates the @code{@var{package}-autoloads.el} file, then it
4763 byte compiles all Emacs Lisp files. Differently from the Emacs
4764 packaging system, the Info documentation files are moved to the standard
4765 documentation directory and the @file{dir} file is deleted. Each
4766 package is installed in its own directory under
4767 @file{share/emacs/site-lisp/guix.d}.
4770 @defvr {Scheme Variable} font-build-system
4771 This variable is exported by @code{(guix build-system font)}. It
4772 implements an installation procedure for font packages where upstream
4773 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
4774 need to be copied into place. It copies font files to standard
4775 locations in the output directory.
4778 @defvr {Scheme Variable} meson-build-system
4779 This variable is exported by @code{(guix build-system meson)}. It
4780 implements the build procedure for packages that use
4781 @url{http://mesonbuild.com, Meson} as their build system.
4783 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
4784 of inputs, and they can be changed with the parameters @code{#:meson}
4785 and @code{#:ninja} if needed. The default Meson is
4786 @code{meson-for-build}, which is special because it doesn't clear the
4787 @code{RUNPATH} of binaries and libraries when they are installed.
4789 This build system is an extension of @var{gnu-build-system}, but with the
4790 following phases changed to some specific for Meson:
4795 The phase runs @code{meson} with the flags specified in
4796 @code{#:configure-flags}. The flag @code{--build-type} is always set to
4797 @code{plain} unless something else is specified in @code{#:build-type}.
4800 The phase runs @code{ninja} to build the package in parallel by default, but
4801 this can be changed with @code{#:parallel-build?}.
4804 The phase runs @code{ninja} with the target specified in @code{#:test-target},
4805 which is @code{"test"} by default.
4808 The phase runs @code{ninja install} and can not be changed.
4811 Apart from that, the build system also adds the following phases:
4816 This phase ensures that all binaries can find the libraries they need.
4817 It searches for required libraries in subdirectories of the package being
4818 built, and adds those to @code{RUNPATH} where needed. It also removes
4819 references to libraries left over from the build phase by
4820 @code{meson-for-build}, such as test dependencies, that aren't actually
4821 required for the program to run.
4823 @item glib-or-gtk-wrap
4824 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4825 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4827 @item glib-or-gtk-compile-schemas
4828 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
4829 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
4833 Lastly, for packages that do not need anything as sophisticated, a
4834 ``trivial'' build system is provided. It is trivial in the sense that
4835 it provides basically no support: it does not pull any implicit inputs,
4836 and does not have a notion of build phases.
4838 @defvr {Scheme Variable} trivial-build-system
4839 This variable is exported by @code{(guix build-system trivial)}.
4841 This build system requires a @code{#:builder} argument. This argument
4842 must be a Scheme expression that builds the package output(s)---as
4843 with @code{build-expression->derivation} (@pxref{Derivations,
4844 @code{build-expression->derivation}}).
4854 Conceptually, the @dfn{store} is the place where derivations that have
4855 been built successfully are stored---by default, @file{/gnu/store}.
4856 Sub-directories in the store are referred to as @dfn{store items} or
4857 sometimes @dfn{store paths}. The store has an associated database that
4858 contains information such as the store paths referred to by each store
4859 path, and the list of @emph{valid} store items---results of successful
4860 builds. This database resides in @file{@var{localstatedir}/guix/db},
4861 where @var{localstatedir} is the state directory specified @i{via}
4862 @option{--localstatedir} at configure time, usually @file{/var}.
4864 The store is @emph{always} accessed by the daemon on behalf of its clients
4865 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
4866 connect to the daemon over a Unix-domain socket, send requests to it,
4867 and read the result---these are remote procedure calls, or RPCs.
4870 Users must @emph{never} modify files under @file{/gnu/store} directly.
4871 This would lead to inconsistencies and break the immutability
4872 assumptions of Guix's functional model (@pxref{Introduction}).
4874 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
4875 how to check the integrity of the store and attempt recovery from
4876 accidental modifications.
4879 The @code{(guix store)} module provides procedures to connect to the
4880 daemon, and to perform RPCs. These are described below. By default,
4881 @code{open-connection}, and thus all the @command{guix} commands,
4882 connect to the local daemon or to the URI specified by the
4883 @code{GUIX_DAEMON_SOCKET} environment variable.
4885 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
4886 When set, the value of this variable should be a file name or a URI
4887 designating the daemon endpoint. When it is a file name, it denotes a
4888 Unix-domain socket to connect to. In addition to file names, the
4889 supported URI schemes are:
4894 These are for Unix-domain sockets.
4895 @code{file:///var/guix/daemon-socket/socket} is equivalent to
4896 @file{/var/guix/daemon-socket/socket}.
4899 @cindex daemon, remote access
4900 @cindex remote access to the daemon
4901 @cindex daemon, cluster setup
4902 @cindex clusters, daemon setup
4903 These URIs denote connections over TCP/IP, without encryption nor
4904 authentication of the remote host. The URI must specify the host name
4905 and optionally a port number (by default port 44146 is used):
4908 guix://master.guix.example.org:1234
4911 This setup is suitable on local networks, such as clusters, where only
4912 trusted nodes may connect to the build daemon at
4913 @code{master.guix.example.org}.
4915 The @code{--listen} option of @command{guix-daemon} can be used to
4916 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
4920 @cindex SSH access to build daemons
4921 These URIs allow you to connect to a remote daemon over
4922 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
4923 A typical URL might look like this:
4926 ssh://charlie@@guix.example.org:22
4929 As for @command{guix copy}, the usual OpenSSH client configuration files
4930 are honored (@pxref{Invoking guix copy}).
4933 Additional URI schemes may be supported in the future.
4935 @c XXX: Remove this note when the protocol incurs fewer round trips
4936 @c and when (guix derivations) no longer relies on file system access.
4938 The ability to connect to remote build daemons is considered
4939 experimental as of @value{VERSION}. Please get in touch with us to
4940 share any problems or suggestions you may have (@pxref{Contributing}).
4944 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
4945 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
4946 @var{reserve-space?} is true, instruct it to reserve a little bit of
4947 extra space on the file system so that the garbage collector can still
4948 operate should the disk become full. Return a server object.
4950 @var{file} defaults to @var{%default-socket-path}, which is the normal
4951 location given the options that were passed to @command{configure}.
4954 @deffn {Scheme Procedure} close-connection @var{server}
4955 Close the connection to @var{server}.
4958 @defvr {Scheme Variable} current-build-output-port
4959 This variable is bound to a SRFI-39 parameter, which refers to the port
4960 where build and error logs sent by the daemon should be written.
4963 Procedures that make RPCs all take a server object as their first
4966 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
4967 @cindex invalid store items
4968 Return @code{#t} when @var{path} designates a valid store item and
4969 @code{#f} otherwise (an invalid item may exist on disk but still be
4970 invalid, for instance because it is the result of an aborted or failed
4973 A @code{&nix-protocol-error} condition is raised if @var{path} is not
4974 prefixed by the store directory (@file{/gnu/store}).
4977 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
4978 Add @var{text} under file @var{name} in the store, and return its store
4979 path. @var{references} is the list of store paths referred to by the
4980 resulting store path.
4983 @deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
4984 Build @var{derivations} (a list of @code{<derivation>} objects or
4985 derivation paths), and return when the worker is done building them.
4986 Return @code{#t} on success.
4989 Note that the @code{(guix monads)} module provides a monad as well as
4990 monadic versions of the above procedures, with the goal of making it
4991 more convenient to work with code that accesses the store (@pxref{The
4995 @i{This section is currently incomplete.}
4998 @section Derivations
5001 Low-level build actions and the environment in which they are performed
5002 are represented by @dfn{derivations}. A derivation contains the
5003 following pieces of information:
5007 The outputs of the derivation---derivations produce at least one file or
5008 directory in the store, but may produce more.
5011 The inputs of the derivations, which may be other derivations or plain
5012 files in the store (patches, build scripts, etc.)
5015 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
5018 The file name of a build script in the store, along with the arguments
5022 A list of environment variables to be defined.
5026 @cindex derivation path
5027 Derivations allow clients of the daemon to communicate build actions to
5028 the store. They exist in two forms: as an in-memory representation,
5029 both on the client- and daemon-side, and as files in the store whose
5030 name end in @code{.drv}---these files are referred to as @dfn{derivation
5031 paths}. Derivations paths can be passed to the @code{build-derivations}
5032 procedure to perform the build actions they prescribe (@pxref{The
5035 @cindex fixed-output derivations
5036 Operations such as file downloads and version-control checkouts for
5037 which the expected content hash is known in advance are modeled as
5038 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
5039 of a fixed-output derivation are independent of its inputs---e.g., a
5040 source code download produces the same result regardless of the download
5041 method and tools being used.
5043 The @code{(guix derivations)} module provides a representation of
5044 derivations as Scheme objects, along with procedures to create and
5045 otherwise manipulate derivations. The lowest-level primitive to create
5046 a derivation is the @code{derivation} procedure:
5048 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
5049 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5050 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
5051 [#:system (%current-system)] [#:references-graphs #f] @
5052 [#:allowed-references #f] [#:disallowed-references #f] @
5053 [#:leaked-env-vars #f] [#:local-build? #f] @
5054 [#:substitutable? #t] [#:properties '()]
5055 Build a derivation with the given arguments, and return the resulting
5056 @code{<derivation>} object.
5058 When @var{hash} and @var{hash-algo} are given, a
5059 @dfn{fixed-output derivation} is created---i.e., one whose result is
5060 known in advance, such as a file download. If, in addition,
5061 @var{recursive?} is true, then that fixed output may be an executable
5062 file or a directory and @var{hash} must be the hash of an archive
5063 containing this output.
5065 When @var{references-graphs} is true, it must be a list of file
5066 name/store path pairs. In that case, the reference graph of each store
5067 path is exported in the build environment in the corresponding file, in
5068 a simple text format.
5070 When @var{allowed-references} is true, it must be a list of store items
5071 or outputs that the derivation's output may refer to. Likewise,
5072 @var{disallowed-references}, if true, must be a list of things the
5073 outputs may @emph{not} refer to.
5075 When @var{leaked-env-vars} is true, it must be a list of strings
5076 denoting environment variables that are allowed to ``leak'' from the
5077 daemon's environment to the build environment. This is only applicable
5078 to fixed-output derivations---i.e., when @var{hash} is true. The main
5079 use is to allow variables such as @code{http_proxy} to be passed to
5080 derivations that download files.
5082 When @var{local-build?} is true, declare that the derivation is not a
5083 good candidate for offloading and should rather be built locally
5084 (@pxref{Daemon Offload Setup}). This is the case for small derivations
5085 where the costs of data transfers would outweigh the benefits.
5087 When @var{substitutable?} is false, declare that substitutes of the
5088 derivation's output should not be used (@pxref{Substitutes}). This is
5089 useful, for instance, when building packages that capture details of the
5090 host CPU instruction set.
5092 @var{properties} must be an association list describing ``properties'' of the
5093 derivation. It is kept as-is, uninterpreted, in the derivation.
5097 Here's an example with a shell script as its builder, assuming
5098 @var{store} is an open connection to the daemon, and @var{bash} points
5099 to a Bash executable in the store:
5102 (use-modules (guix utils)
5106 (let ((builder ; add the Bash script to the store
5107 (add-text-to-store store "my-builder.sh"
5108 "echo hello world > $out\n" '())))
5109 (derivation store "foo"
5110 bash `("-e" ,builder)
5111 #:inputs `((,bash) (,builder))
5112 #:env-vars '(("HOME" . "/homeless"))))
5113 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
5116 As can be guessed, this primitive is cumbersome to use directly. A
5117 better approach is to write build scripts in Scheme, of course! The
5118 best course of action for that is to write the build code as a
5119 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
5120 information, @pxref{G-Expressions}.
5122 Once upon a time, @code{gexp->derivation} did not exist and constructing
5123 derivations with build code written in Scheme was achieved with
5124 @code{build-expression->derivation}, documented below. This procedure
5125 is now deprecated in favor of the much nicer @code{gexp->derivation}.
5127 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
5128 @var{name} @var{exp} @
5129 [#:system (%current-system)] [#:inputs '()] @
5130 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
5131 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5132 [#:references-graphs #f] [#:allowed-references #f] @
5133 [#:disallowed-references #f] @
5134 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
5135 Return a derivation that executes Scheme expression @var{exp} as a
5136 builder for derivation @var{name}. @var{inputs} must be a list of
5137 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
5138 @code{"out"} is assumed. @var{modules} is a list of names of Guile
5139 modules from the current search path to be copied in the store,
5140 compiled, and made available in the load path during the execution of
5141 @var{exp}---e.g., @code{((guix build utils) (guix build
5142 gnu-build-system))}.
5144 @var{exp} is evaluated in an environment where @code{%outputs} is bound
5145 to a list of output/path pairs, and where @code{%build-inputs} is bound
5146 to a list of string/output-path pairs made from @var{inputs}.
5147 Optionally, @var{env-vars} is a list of string pairs specifying the name
5148 and value of environment variables visible to the builder. The builder
5149 terminates by passing the result of @var{exp} to @code{exit}; thus, when
5150 @var{exp} returns @code{#f}, the build is considered to have failed.
5152 @var{exp} is built using @var{guile-for-build} (a derivation). When
5153 @var{guile-for-build} is omitted or is @code{#f}, the value of the
5154 @code{%guile-for-build} fluid is used instead.
5156 See the @code{derivation} procedure for the meaning of
5157 @var{references-graphs}, @var{allowed-references},
5158 @var{disallowed-references}, @var{local-build?}, and
5159 @var{substitutable?}.
5163 Here's an example of a single-output derivation that creates a directory
5164 containing one file:
5167 (let ((builder '(let ((out (assoc-ref %outputs "out")))
5168 (mkdir out) ; create /gnu/store/@dots{}-goo
5169 (call-with-output-file (string-append out "/test")
5171 (display '(hello guix) p))))))
5172 (build-expression->derivation store "goo" builder))
5174 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
5178 @node The Store Monad
5179 @section The Store Monad
5183 The procedures that operate on the store described in the previous
5184 sections all take an open connection to the build daemon as their first
5185 argument. Although the underlying model is functional, they either have
5186 side effects or depend on the current state of the store.
5188 The former is inconvenient: the connection to the build daemon has to be
5189 carried around in all those functions, making it impossible to compose
5190 functions that do not take that parameter with functions that do. The
5191 latter can be problematic: since store operations have side effects
5192 and/or depend on external state, they have to be properly sequenced.
5194 @cindex monadic values
5195 @cindex monadic functions
5196 This is where the @code{(guix monads)} module comes in. This module
5197 provides a framework for working with @dfn{monads}, and a particularly
5198 useful monad for our uses, the @dfn{store monad}. Monads are a
5199 construct that allows two things: associating ``context'' with values
5200 (in our case, the context is the store), and building sequences of
5201 computations (here computations include accesses to the store). Values
5202 in a monad---values that carry this additional context---are called
5203 @dfn{monadic values}; procedures that return such values are called
5204 @dfn{monadic procedures}.
5206 Consider this ``normal'' procedure:
5209 (define (sh-symlink store)
5210 ;; Return a derivation that symlinks the 'bash' executable.
5211 (let* ((drv (package-derivation store bash))
5212 (out (derivation->output-path drv))
5213 (sh (string-append out "/bin/bash")))
5214 (build-expression->derivation store "sh"
5215 `(symlink ,sh %output))))
5218 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
5219 as a monadic function:
5222 (define (sh-symlink)
5223 ;; Same, but return a monadic value.
5224 (mlet %store-monad ((drv (package->derivation bash)))
5225 (gexp->derivation "sh"
5226 #~(symlink (string-append #$drv "/bin/bash")
5230 There are several things to note in the second version: the @code{store}
5231 parameter is now implicit and is ``threaded'' in the calls to the
5232 @code{package->derivation} and @code{gexp->derivation} monadic
5233 procedures, and the monadic value returned by @code{package->derivation}
5234 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
5236 As it turns out, the call to @code{package->derivation} can even be
5237 omitted since it will take place implicitly, as we will see later
5238 (@pxref{G-Expressions}):
5241 (define (sh-symlink)
5242 (gexp->derivation "sh"
5243 #~(symlink (string-append #$bash "/bin/bash")
5248 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
5249 @c for the funny quote.
5250 Calling the monadic @code{sh-symlink} has no effect. As someone once
5251 said, ``you exit a monad like you exit a building on fire: by running''.
5252 So, to exit the monad and get the desired effect, one must use
5253 @code{run-with-store}:
5256 (run-with-store (open-connection) (sh-symlink))
5257 @result{} /gnu/store/...-sh-symlink
5260 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
5261 new ``meta-commands'' to make it easier to deal with monadic procedures:
5262 @code{run-in-store}, and @code{enter-store-monad}. The former is used
5263 to ``run'' a single monadic value through the store:
5266 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
5267 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5270 The latter enters a recursive REPL, where all the return values are
5271 automatically run through the store:
5274 scheme@@(guile-user)> ,enter-store-monad
5275 store-monad@@(guile-user) [1]> (package->derivation hello)
5276 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
5277 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
5278 $3 = "/gnu/store/@dots{}-foo"
5279 store-monad@@(guile-user) [1]> ,q
5280 scheme@@(guile-user)>
5284 Note that non-monadic values cannot be returned in the
5285 @code{store-monad} REPL.
5287 The main syntactic forms to deal with monads in general are provided by
5288 the @code{(guix monads)} module and are described below.
5290 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
5291 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
5295 @deffn {Scheme Syntax} return @var{val}
5296 Return a monadic value that encapsulates @var{val}.
5299 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
5300 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
5301 procedures @var{mproc}@dots{}@footnote{This operation is commonly
5302 referred to as ``bind'', but that name denotes an unrelated procedure in
5303 Guile. Thus we use this somewhat cryptic symbol inherited from the
5304 Haskell language.}. There can be one @var{mproc} or several of them, as
5309 (with-monad %state-monad
5311 (lambda (x) (return (+ 1 x)))
5312 (lambda (x) (return (* 2 x)))))
5316 @result{} some-state
5320 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
5322 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
5324 Bind the variables @var{var} to the monadic values @var{mval} in
5325 @var{body}, which is a sequence of expressions. As with the bind
5326 operator, this can be thought of as ``unpacking'' the raw, non-monadic
5327 value ``contained'' in @var{mval} and making @var{var} refer to that
5328 raw, non-monadic value within the scope of the @var{body}. The form
5329 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
5330 @var{val}, as per @code{let}. The binding operations occur in sequence
5331 from left to right. The last expression of @var{body} must be a monadic
5332 expression, and its result will become the result of the @code{mlet} or
5333 @code{mlet*} when run in the @var{monad}.
5335 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
5336 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
5339 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
5340 Bind @var{mexp} and the following monadic expressions in sequence,
5341 returning the result of the last expression. Every expression in the
5342 sequence must be a monadic expression.
5344 This is akin to @code{mlet}, except that the return values of the
5345 monadic expressions are ignored. In that sense, it is analogous to
5346 @code{begin}, but applied to monadic expressions.
5349 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
5350 When @var{condition} is true, evaluate the sequence of monadic
5351 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5352 @var{condition} is false, return @code{*unspecified*} in the current
5353 monad. Every expression in the sequence must be a monadic expression.
5356 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
5357 When @var{condition} is false, evaluate the sequence of monadic
5358 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
5359 @var{condition} is true, return @code{*unspecified*} in the current
5360 monad. Every expression in the sequence must be a monadic expression.
5364 The @code{(guix monads)} module provides the @dfn{state monad}, which
5365 allows an additional value---the state---to be @emph{threaded} through
5366 monadic procedure calls.
5368 @defvr {Scheme Variable} %state-monad
5369 The state monad. Procedures in the state monad can access and change
5370 the state that is threaded.
5372 Consider the example below. The @code{square} procedure returns a value
5373 in the state monad. It returns the square of its argument, but also
5374 increments the current state value:
5378 (mlet %state-monad ((count (current-state)))
5379 (mbegin %state-monad
5380 (set-current-state (+ 1 count))
5383 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
5388 When ``run'' through @var{%state-monad}, we obtain that additional state
5389 value, which is the number of @code{square} calls.
5392 @deffn {Monadic Procedure} current-state
5393 Return the current state as a monadic value.
5396 @deffn {Monadic Procedure} set-current-state @var{value}
5397 Set the current state to @var{value} and return the previous state as a
5401 @deffn {Monadic Procedure} state-push @var{value}
5402 Push @var{value} to the current state, which is assumed to be a list,
5403 and return the previous state as a monadic value.
5406 @deffn {Monadic Procedure} state-pop
5407 Pop a value from the current state and return it as a monadic value.
5408 The state is assumed to be a list.
5411 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
5412 Run monadic value @var{mval} starting with @var{state} as the initial
5413 state. Return two values: the resulting value, and the resulting state.
5416 The main interface to the store monad, provided by the @code{(guix
5417 store)} module, is as follows.
5419 @defvr {Scheme Variable} %store-monad
5420 The store monad---an alias for @var{%state-monad}.
5422 Values in the store monad encapsulate accesses to the store. When its
5423 effect is needed, a value of the store monad must be ``evaluated'' by
5424 passing it to the @code{run-with-store} procedure (see below.)
5427 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
5428 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
5429 open store connection.
5432 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
5433 Return as a monadic value the absolute file name in the store of the file
5434 containing @var{text}, a string. @var{references} is a list of store items that the
5435 resulting text file refers to; it defaults to the empty list.
5438 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
5439 Return as a monadic value the absolute file name in the store of the file
5440 containing @var{data}, a bytevector. @var{references} is a list of store
5441 items that the resulting binary file refers to; it defaults to the empty list.
5444 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
5445 [#:recursive? #t] [#:select? (const #t)]
5446 Return the name of @var{file} once interned in the store. Use
5447 @var{name} as its store name, or the basename of @var{file} if
5448 @var{name} is omitted.
5450 When @var{recursive?} is true, the contents of @var{file} are added
5451 recursively; if @var{file} designates a flat file and @var{recursive?}
5452 is true, its contents are added, and its permission bits are kept.
5454 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5455 @var{stat})} for each directory entry, where @var{file} is the entry's
5456 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5457 entries for which @var{select?} does not return true.
5459 The example below adds a file to the store, under two different names:
5462 (run-with-store (open-connection)
5463 (mlet %store-monad ((a (interned-file "README"))
5464 (b (interned-file "README" "LEGU-MIN")))
5465 (return (list a b))))
5467 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
5472 The @code{(guix packages)} module exports the following package-related
5475 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
5476 [#:system (%current-system)] [#:target #f] @
5479 value in the absolute file name of @var{file} within the @var{output}
5480 directory of @var{package}. When @var{file} is omitted, return the name
5481 of the @var{output} directory of @var{package}. When @var{target} is
5482 true, use it as a cross-compilation target triplet.
5485 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
5486 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
5487 @var{target} [@var{system}]
5488 Monadic version of @code{package-derivation} and
5489 @code{package-cross-derivation} (@pxref{Defining Packages}).
5494 @section G-Expressions
5496 @cindex G-expression
5497 @cindex build code quoting
5498 So we have ``derivations'', which represent a sequence of build actions
5499 to be performed to produce an item in the store (@pxref{Derivations}).
5500 These build actions are performed when asking the daemon to actually
5501 build the derivations; they are run by the daemon in a container
5502 (@pxref{Invoking guix-daemon}).
5504 @cindex strata of code
5505 It should come as no surprise that we like to write these build actions
5506 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
5507 code@footnote{The term @dfn{stratum} in this context was coined by
5508 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
5509 Kiselyov, who has written insightful
5510 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
5511 on this topic}, refers to this kind of code generation as
5512 @dfn{staging}.}: the ``host code''---code that defines packages, talks
5513 to the daemon, etc.---and the ``build code''---code that actually
5514 performs build actions, such as making directories, invoking
5515 @command{make}, etc.
5517 To describe a derivation and its build actions, one typically needs to
5518 embed build code inside host code. It boils down to manipulating build
5519 code as data, and the homoiconicity of Scheme---code has a direct
5520 representation as data---comes in handy for that. But we need more than
5521 the normal @code{quasiquote} mechanism in Scheme to construct build
5524 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
5525 S-expressions adapted to build expressions. G-expressions, or
5526 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
5527 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
5528 @code{#$}, and @code{#$@@}), which are comparable to
5529 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
5530 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
5531 GNU Guile Reference Manual}). However, there are major differences:
5535 Gexps are meant to be written to a file and run or manipulated by other
5539 When a high-level object such as a package or derivation is unquoted
5540 inside a gexp, the result is as if its output file name had been
5544 Gexps carry information about the packages or derivations they refer to,
5545 and these dependencies are automatically added as inputs to the build
5546 processes that use them.
5549 @cindex lowering, of high-level objects in gexps
5550 This mechanism is not limited to package and derivation
5551 objects: @dfn{compilers} able to ``lower'' other high-level objects to
5552 derivations or files in the store can be defined,
5553 such that these objects can also be inserted
5554 into gexps. For example, a useful type of high-level objects that can be
5555 inserted in a gexp is ``file-like objects'', which make it easy to
5556 add files to the store and to refer to them in
5557 derivations and such (see @code{local-file} and @code{plain-file}
5560 To illustrate the idea, here is an example of a gexp:
5567 (symlink (string-append #$coreutils "/bin/ls")
5571 This gexp can be passed to @code{gexp->derivation}; we obtain a
5572 derivation that builds a directory containing exactly one symlink to
5573 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
5576 (gexp->derivation "the-thing" build-exp)
5579 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
5580 substituted to the reference to the @var{coreutils} package in the
5581 actual build code, and @var{coreutils} is automatically made an input to
5582 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
5583 output)}) is replaced by a string containing the directory name of the
5584 output of the derivation.
5586 @cindex cross compilation
5587 In a cross-compilation context, it is useful to distinguish between
5588 references to the @emph{native} build of a package---that can run on the
5589 host---versus references to cross builds of a package. To that end, the
5590 @code{#+} plays the same role as @code{#$}, but is a reference to a
5591 native package build:
5594 (gexp->derivation "vi"
5597 (system* (string-append #+coreutils "/bin/ln")
5599 (string-append #$emacs "/bin/emacs")
5600 (string-append #$output "/bin/vi")))
5601 #:target "mips64el-linux-gnu")
5605 In the example above, the native build of @var{coreutils} is used, so
5606 that @command{ln} can actually run on the host; but then the
5607 cross-compiled build of @var{emacs} is referenced.
5609 @cindex imported modules, for gexps
5610 @findex with-imported-modules
5611 Another gexp feature is @dfn{imported modules}: sometimes you want to be
5612 able to use certain Guile modules from the ``host environment'' in the
5613 gexp, so those modules should be imported in the ``build environment''.
5614 The @code{with-imported-modules} form allows you to express that:
5617 (let ((build (with-imported-modules '((guix build utils))
5619 (use-modules (guix build utils))
5620 (mkdir-p (string-append #$output "/bin"))))))
5621 (gexp->derivation "empty-dir"
5624 (display "success!\n")
5629 In this example, the @code{(guix build utils)} module is automatically
5630 pulled into the isolated build environment of our gexp, such that
5631 @code{(use-modules (guix build utils))} works as expected.
5633 @cindex module closure
5634 @findex source-module-closure
5635 Usually you want the @emph{closure} of the module to be imported---i.e.,
5636 the module itself and all the modules it depends on---rather than just
5637 the module; failing to do that, attempts to use the module will fail
5638 because of missing dependent modules. The @code{source-module-closure}
5639 procedure computes the closure of a module by looking at its source file
5640 headers, which comes in handy in this case:
5643 (use-modules (guix modules)) ;for 'source-module-closure'
5645 (with-imported-modules (source-module-closure
5646 '((guix build utils)
5648 (gexp->derivation "something-with-vms"
5650 (use-modules (guix build utils)
5655 @cindex extensions, for gexps
5656 @findex with-extensions
5657 In the same vein, sometimes you want to import not just pure-Scheme
5658 modules, but also ``extensions'' such as Guile bindings to C libraries
5659 or other ``full-blown'' packages. Say you need the @code{guile-json}
5660 package available on the build side, here's how you would do it:
5663 (use-modules (gnu packages guile)) ;for 'guile-json'
5665 (with-extensions (list guile-json)
5666 (gexp->derivation "something-with-json"
5668 (use-modules (json))
5672 The syntactic form to construct gexps is summarized below.
5674 @deffn {Scheme Syntax} #~@var{exp}
5675 @deffnx {Scheme Syntax} (gexp @var{exp})
5676 Return a G-expression containing @var{exp}. @var{exp} may contain one
5677 or more of the following forms:
5681 @itemx (ungexp @var{obj})
5682 Introduce a reference to @var{obj}. @var{obj} may have one of the
5683 supported types, for example a package or a
5684 derivation, in which case the @code{ungexp} form is replaced by its
5685 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
5687 If @var{obj} is a list, it is traversed and references to supported
5688 objects are substituted similarly.
5690 If @var{obj} is another gexp, its contents are inserted and its
5691 dependencies are added to those of the containing gexp.
5693 If @var{obj} is another kind of object, it is inserted as is.
5695 @item #$@var{obj}:@var{output}
5696 @itemx (ungexp @var{obj} @var{output})
5697 This is like the form above, but referring explicitly to the
5698 @var{output} of @var{obj}---this is useful when @var{obj} produces
5699 multiple outputs (@pxref{Packages with Multiple Outputs}).
5702 @itemx #+@var{obj}:output
5703 @itemx (ungexp-native @var{obj})
5704 @itemx (ungexp-native @var{obj} @var{output})
5705 Same as @code{ungexp}, but produces a reference to the @emph{native}
5706 build of @var{obj} when used in a cross compilation context.
5708 @item #$output[:@var{output}]
5709 @itemx (ungexp output [@var{output}])
5710 Insert a reference to derivation output @var{output}, or to the main
5711 output when @var{output} is omitted.
5713 This only makes sense for gexps passed to @code{gexp->derivation}.
5716 @itemx (ungexp-splicing @var{lst})
5717 Like the above, but splices the contents of @var{lst} inside the
5721 @itemx (ungexp-native-splicing @var{lst})
5722 Like the above, but refers to native builds of the objects listed in
5727 G-expressions created by @code{gexp} or @code{#~} are run-time objects
5728 of the @code{gexp?} type (see below.)
5731 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
5732 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
5733 in their execution environment.
5735 Each item in @var{modules} can be the name of a module, such as
5736 @code{(guix build utils)}, or it can be a module name, followed by an
5737 arrow, followed by a file-like object:
5740 `((guix build utils)
5742 ((guix config) => ,(scheme-file "config.scm"
5743 #~(define-module @dots{}))))
5747 In the example above, the first two modules are taken from the search
5748 path, and the last one is created from the given file-like object.
5750 This form has @emph{lexical} scope: it has an effect on the gexps
5751 directly defined in @var{body}@dots{}, but not on those defined, say, in
5752 procedures called from @var{body}@dots{}.
5755 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
5756 Mark the gexps defined in @var{body}@dots{} as requiring
5757 @var{extensions} in their build and execution environment.
5758 @var{extensions} is typically a list of package objects such as those
5759 defined in the @code{(gnu packages guile)} module.
5761 Concretely, the packages listed in @var{extensions} are added to the
5762 load path while compiling imported modules in @var{body}@dots{}; they
5763 are also added to the load path of the gexp returned by
5767 @deffn {Scheme Procedure} gexp? @var{obj}
5768 Return @code{#t} if @var{obj} is a G-expression.
5771 G-expressions are meant to be written to disk, either as code building
5772 some derivation, or as plain files in the store. The monadic procedures
5773 below allow you to do that (@pxref{The Store Monad}, for more
5774 information about monads.)
5776 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
5777 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
5778 [#:hash #f] [#:hash-algo #f] @
5779 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
5780 [#:module-path @var{%load-path}] @
5781 [#:effective-version "2.2"] @
5782 [#:references-graphs #f] [#:allowed-references #f] @
5783 [#:disallowed-references #f] @
5784 [#:leaked-env-vars #f] @
5785 [#:script-name (string-append @var{name} "-builder")] @
5786 [#:deprecation-warnings #f] @
5787 [#:local-build? #f] [#:substitutable? #t] @
5788 [#:properties '()] [#:guile-for-build #f]
5789 Return a derivation @var{name} that runs @var{exp} (a gexp) with
5790 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
5791 stored in a file called @var{script-name}. When @var{target} is true,
5792 it is used as the cross-compilation target triplet for packages referred
5795 @var{modules} is deprecated in favor of @code{with-imported-modules}.
5797 make @var{modules} available in the evaluation context of @var{exp};
5798 @var{modules} is a list of names of Guile modules searched in
5799 @var{module-path} to be copied in the store, compiled, and made available in
5800 the load path during the execution of @var{exp}---e.g., @code{((guix
5801 build utils) (guix build gnu-build-system))}.
5803 @var{effective-version} determines the string to use when adding extensions of
5804 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
5806 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
5809 When @var{references-graphs} is true, it must be a list of tuples of one of the
5813 (@var{file-name} @var{package})
5814 (@var{file-name} @var{package} @var{output})
5815 (@var{file-name} @var{derivation})
5816 (@var{file-name} @var{derivation} @var{output})
5817 (@var{file-name} @var{store-item})
5820 The right-hand-side of each element of @var{references-graphs} is automatically made
5821 an input of the build process of @var{exp}. In the build environment, each
5822 @var{file-name} contains the reference graph of the corresponding item, in a simple
5825 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
5826 In the latter case, the list denotes store items that the result is allowed to
5827 refer to. Any reference to another store item will lead to a build error.
5828 Similarly for @var{disallowed-references}, which can list items that must not be
5829 referenced by the outputs.
5831 @var{deprecation-warnings} determines whether to show deprecation warnings while
5832 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
5834 The other arguments are as for @code{derivation} (@pxref{Derivations}).
5837 @cindex file-like objects
5838 The @code{local-file}, @code{plain-file}, @code{computed-file},
5839 @code{program-file}, and @code{scheme-file} procedures below return
5840 @dfn{file-like objects}. That is, when unquoted in a G-expression,
5841 these objects lead to a file in the store. Consider this G-expression:
5844 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
5845 #$(local-file "/tmp/my-nscd.conf"))
5848 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
5849 to the store. Once expanded, for instance @i{via}
5850 @code{gexp->derivation}, the G-expression refers to that copy under
5851 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
5852 does not have any effect on what the G-expression does.
5853 @code{plain-file} can be used similarly; it differs in that the file
5854 content is directly passed as a string.
5856 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
5857 [#:recursive? #f] [#:select? (const #t)]
5858 Return an object representing local file @var{file} to add to the store; this
5859 object can be used in a gexp. If @var{file} is a relative file name, it is looked
5860 up relative to the source file where this form appears. @var{file} will be added to
5861 the store under @var{name}--by default the base name of @var{file}.
5863 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
5864 designates a flat file and @var{recursive?} is true, its contents are added, and its
5865 permission bits are kept.
5867 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
5868 @var{stat})} for each directory entry, where @var{file} is the entry's
5869 absolute file name and @var{stat} is the result of @code{lstat}; exclude
5870 entries for which @var{select?} does not return true.
5872 This is the declarative counterpart of the @code{interned-file} monadic
5873 procedure (@pxref{The Store Monad, @code{interned-file}}).
5876 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
5877 Return an object representing a text file called @var{name} with the given
5878 @var{content} (a string or a bytevector) to be added to the store.
5880 This is the declarative counterpart of @code{text-file}.
5883 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
5884 [#:options '(#:local-build? #t)]
5885 Return an object representing the store item @var{name}, a file or
5886 directory computed by @var{gexp}. @var{options}
5887 is a list of additional arguments to pass to @code{gexp->derivation}.
5889 This is the declarative counterpart of @code{gexp->derivation}.
5892 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
5893 [#:guile (default-guile)] [#:module-path %load-path]
5894 Return an executable script @var{name} that runs @var{exp} using
5895 @var{guile}, with @var{exp}'s imported modules in its search path.
5896 Look up @var{exp}'s modules in @var{module-path}.
5898 The example below builds a script that simply invokes the @command{ls}
5902 (use-modules (guix gexp) (gnu packages base))
5904 (gexp->script "list-files"
5905 #~(execl #$(file-append coreutils "/bin/ls")
5909 When ``running'' it through the store (@pxref{The Store Monad,
5910 @code{run-with-store}}), we obtain a derivation that produces an
5911 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
5914 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
5916 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
5920 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
5921 [#:guile #f] [#:module-path %load-path]
5922 Return an object representing the executable store item @var{name} that
5923 runs @var{gexp}. @var{guile} is the Guile package used to execute that
5924 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
5926 This is the declarative counterpart of @code{gexp->script}.
5929 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
5930 [#:set-load-path? #t] [#:module-path %load-path] @
5932 [#:guile (default-guile)]
5933 Return a derivation that builds a file @var{name} containing @var{exp}.
5934 When @var{splice?} is true, @var{exp} is considered to be a list of
5935 expressions that will be spliced in the resulting file.
5937 When @var{set-load-path?} is true, emit code in the resulting file to
5938 set @code{%load-path} and @code{%load-compiled-path} to honor
5939 @var{exp}'s imported modules. Look up @var{exp}'s modules in
5942 The resulting file holds references to all the dependencies of @var{exp}
5943 or a subset thereof.
5946 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
5947 Return an object representing the Scheme file @var{name} that contains
5950 This is the declarative counterpart of @code{gexp->file}.
5953 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
5954 Return as a monadic value a derivation that builds a text file
5955 containing all of @var{text}. @var{text} may list, in addition to
5956 strings, objects of any type that can be used in a gexp: packages,
5957 derivations, local file objects, etc. The resulting store file holds
5958 references to all these.
5960 This variant should be preferred over @code{text-file} anytime the file
5961 to create will reference items from the store. This is typically the
5962 case when building a configuration file that embeds store file names,
5966 (define (profile.sh)
5967 ;; Return the name of a shell script in the store that
5968 ;; initializes the 'PATH' environment variable.
5969 (text-file* "profile.sh"
5970 "export PATH=" coreutils "/bin:"
5971 grep "/bin:" sed "/bin\n"))
5974 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
5975 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
5976 preventing them from being garbage-collected during its lifetime.
5979 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
5980 Return an object representing store file @var{name} containing
5981 @var{text}. @var{text} is a sequence of strings and file-like objects,
5985 (mixed-text-file "profile"
5986 "export PATH=" coreutils "/bin:" grep "/bin")
5989 This is the declarative counterpart of @code{text-file*}.
5992 @deffn {Scheme Procedure} file-union @var{name} @var{files}
5993 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
5994 Each item in @var{files} must be a two-element list where the first element is the
5995 file name to use in the new directory, and the second element is a gexp
5996 denoting the target file. Here's an example:
6000 `(("hosts" ,(plain-file "hosts"
6001 "127.0.0.1 localhost"))
6002 ("bashrc" ,(plain-file "bashrc"
6003 "alias ls='ls --color=auto'"))))
6006 This yields an @code{etc} directory containing these two files.
6009 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
6010 Return a directory that is the union of @var{things}, where @var{things} is a list of
6011 file-like objects denoting directories. For example:
6014 (directory-union "guile+emacs" (list guile emacs))
6017 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
6020 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
6021 Return a file-like object that expands to the concatenation of @var{obj}
6022 and @var{suffix}, where @var{obj} is a lowerable object and each
6023 @var{suffix} is a string.
6025 As an example, consider this gexp:
6028 (gexp->script "run-uname"
6029 #~(system* #$(file-append coreutils
6033 The same effect could be achieved with:
6036 (gexp->script "run-uname"
6037 #~(system* (string-append #$coreutils
6041 There is one difference though: in the @code{file-append} case, the
6042 resulting script contains the absolute file name as a string, whereas in
6043 the second case, the resulting script contains a @code{(string-append
6044 @dots{})} expression to construct the file name @emph{at run time}.
6048 Of course, in addition to gexps embedded in ``host'' code, there are
6049 also modules containing build tools. To make it clear that they are
6050 meant to be used in the build stratum, these modules are kept in the
6051 @code{(guix build @dots{})} name space.
6053 @cindex lowering, of high-level objects in gexps
6054 Internally, high-level objects are @dfn{lowered}, using their compiler,
6055 to either derivations or store items. For instance, lowering a package
6056 yields a derivation, and lowering a @code{plain-file} yields a store
6057 item. This is achieved using the @code{lower-object} monadic procedure.
6059 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
6061 Return as a value in @var{%store-monad} the derivation or store item
6062 corresponding to @var{obj} for @var{system}, cross-compiling for
6063 @var{target} if @var{target} is true. @var{obj} must be an object that
6064 has an associated gexp compiler, such as a @code{<package>}.
6067 @node Invoking guix repl
6068 @section Invoking @command{guix repl}
6070 @cindex REPL, read-eval-print loop
6071 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
6072 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
6073 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
6074 command, @command{guix repl} guarantees that all the Guix modules and all its
6075 dependencies are available in the search path. You can use it this way:
6079 scheme@@(guile-user)> ,use (gnu packages base)
6080 scheme@@(guile-user)> coreutils
6081 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
6085 In addition, @command{guix repl} implements a simple machine-readable REPL
6086 protocol for use by @code{(guix inferior)}, a facility to interact with
6087 @dfn{inferiors}, separate processes running a potentially different revision
6090 The available options are as follows:
6093 @item --type=@var{type}
6094 @itemx -t @var{type}
6095 Start a REPL of the given @var{TYPE}, which can be one of the following:
6099 This is default, and it spawns a standard full-featured Guile REPL.
6101 Spawn a REPL that uses the machine-readable protocol. This is the protocol
6102 that the @code{(guix inferior)} module speaks.
6105 @item --listen=@var{endpoint}
6106 By default, @command{guix repl} reads from standard input and writes to
6107 standard output. When this option is passed, it will instead listen for
6108 connections on @var{endpoint}. Here are examples of valid options:
6111 @item --listen=tcp:37146
6112 Accept connections on localhost on port 37146.
6114 @item --listen=unix:/tmp/socket
6115 Accept connections on the Unix-domain socket @file{/tmp/socket}.
6119 @c *********************************************************************
6123 This section describes Guix command-line utilities. Some of them are
6124 primarily targeted at developers and users who write new package
6125 definitions, while others are more generally useful. They complement
6126 the Scheme programming interface of Guix in a convenient way.
6129 * Invoking guix build:: Building packages from the command line.
6130 * Invoking guix edit:: Editing package definitions.
6131 * Invoking guix download:: Downloading a file and printing its hash.
6132 * Invoking guix hash:: Computing the cryptographic hash of a file.
6133 * Invoking guix import:: Importing package definitions.
6134 * Invoking guix refresh:: Updating package definitions.
6135 * Invoking guix lint:: Finding errors in package definitions.
6136 * Invoking guix size:: Profiling disk usage.
6137 * Invoking guix graph:: Visualizing the graph of packages.
6138 * Invoking guix environment:: Setting up development environments.
6139 * Invoking guix publish:: Sharing substitutes.
6140 * Invoking guix challenge:: Challenging substitute servers.
6141 * Invoking guix copy:: Copying to and from a remote store.
6142 * Invoking guix container:: Process isolation.
6143 * Invoking guix weather:: Assessing substitute availability.
6144 * Invoking guix processes:: Listing client processes.
6147 @node Invoking guix build
6148 @section Invoking @command{guix build}
6150 @cindex package building
6151 @cindex @command{guix build}
6152 The @command{guix build} command builds packages or derivations and
6153 their dependencies, and prints the resulting store paths. Note that it
6154 does not modify the user's profile---this is the job of the
6155 @command{guix package} command (@pxref{Invoking guix package}). Thus,
6156 it is mainly useful for distribution developers.
6158 The general syntax is:
6161 guix build @var{options} @var{package-or-derivation}@dots{}
6164 As an example, the following command builds the latest versions of Emacs
6165 and of Guile, displays their build logs, and finally displays the
6166 resulting directories:
6169 guix build emacs guile
6172 Similarly, the following command builds all the available packages:
6175 guix build --quiet --keep-going \
6176 `guix package -A | cut -f1,2 --output-delimiter=@@`
6179 @var{package-or-derivation} may be either the name of a package found in
6180 the software distribution such as @code{coreutils} or
6181 @code{coreutils@@8.20}, or a derivation such as
6182 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
6183 package with the corresponding name (and optionally version) is searched
6184 for among the GNU distribution modules (@pxref{Package Modules}).
6186 Alternatively, the @code{--expression} option may be used to specify a
6187 Scheme expression that evaluates to a package; this is useful when
6188 disambiguating among several same-named packages or package variants is
6191 There may be zero or more @var{options}. The available options are
6192 described in the subsections below.
6195 * Common Build Options:: Build options for most commands.
6196 * Package Transformation Options:: Creating variants of packages.
6197 * Additional Build Options:: Options specific to 'guix build'.
6198 * Debugging Build Failures:: Real life packaging experience.
6201 @node Common Build Options
6202 @subsection Common Build Options
6204 A number of options that control the build process are common to
6205 @command{guix build} and other commands that can spawn builds, such as
6206 @command{guix package} or @command{guix archive}. These are the
6211 @item --load-path=@var{directory}
6212 @itemx -L @var{directory}
6213 Add @var{directory} to the front of the package module search path
6214 (@pxref{Package Modules}).
6216 This allows users to define their own packages and make them visible to
6217 the command-line tools.
6221 Keep the build tree of failed builds. Thus, if a build fails, its build
6222 tree is kept under @file{/tmp}, in a directory whose name is shown at
6223 the end of the build log. This is useful when debugging build issues.
6224 @xref{Debugging Build Failures}, for tips and tricks on how to debug
6227 This option has no effect when connecting to a remote daemon with a
6228 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
6233 Keep going when some of the derivations fail to build; return only once
6234 all the builds have either completed or failed.
6236 The default behavior is to stop as soon as one of the specified
6237 derivations has failed.
6241 Do not build the derivations.
6243 @anchor{fallback-option}
6245 When substituting a pre-built binary fails, fall back to building
6246 packages locally (@pxref{Substitution Failure}).
6248 @item --substitute-urls=@var{urls}
6249 @anchor{client-substitute-urls}
6250 Consider @var{urls} the whitespace-separated list of substitute source
6251 URLs, overriding the default list of URLs of @command{guix-daemon}
6252 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
6254 This means that substitutes may be downloaded from @var{urls}, provided
6255 they are signed by a key authorized by the system administrator
6256 (@pxref{Substitutes}).
6258 When @var{urls} is the empty string, substitutes are effectively
6261 @item --no-substitutes
6262 Do not use substitutes for build products. That is, always build things
6263 locally instead of allowing downloads of pre-built binaries
6264 (@pxref{Substitutes}).
6267 Do not ``graft'' packages. In practice, this means that package updates
6268 available as grafts are not applied. @xref{Security Updates}, for more
6269 information on grafts.
6271 @item --rounds=@var{n}
6272 Build each derivation @var{n} times in a row, and raise an error if
6273 consecutive build results are not bit-for-bit identical.
6275 This is a useful way to detect non-deterministic builds processes.
6276 Non-deterministic build processes are a problem because they make it
6277 practically impossible for users to @emph{verify} whether third-party
6278 binaries are genuine. @xref{Invoking guix challenge}, for more.
6280 Note that, currently, the differing build results are not kept around,
6281 so you will have to manually investigate in case of an error---e.g., by
6282 stashing one of the build results with @code{guix archive --export}
6283 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
6286 @item --no-build-hook
6287 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
6288 (@pxref{Daemon Offload Setup}). That is, always build things locally
6289 instead of offloading builds to remote machines.
6291 @item --max-silent-time=@var{seconds}
6292 When the build or substitution process remains silent for more than
6293 @var{seconds}, terminate it and report a build failure.
6295 By default, the daemon's setting is honored (@pxref{Invoking
6296 guix-daemon, @code{--max-silent-time}}).
6298 @item --timeout=@var{seconds}
6299 Likewise, when the build or substitution process lasts for more than
6300 @var{seconds}, terminate it and report a build failure.
6302 By default, the daemon's setting is honored (@pxref{Invoking
6303 guix-daemon, @code{--timeout}}).
6305 @item --verbosity=@var{level}
6306 Use the given verbosity level. @var{level} must be an integer between 0
6307 and 5; higher means more verbose output. Setting a level of 4 or more
6308 may be helpful when debugging setup issues with the build daemon.
6310 @item --cores=@var{n}
6312 Allow the use of up to @var{n} CPU cores for the build. The special
6313 value @code{0} means to use as many CPU cores as available.
6315 @item --max-jobs=@var{n}
6317 Allow at most @var{n} build jobs in parallel. @xref{Invoking
6318 guix-daemon, @code{--max-jobs}}, for details about this option and the
6319 equivalent @command{guix-daemon} option.
6323 Behind the scenes, @command{guix build} is essentially an interface to
6324 the @code{package-derivation} procedure of the @code{(guix packages)}
6325 module, and to the @code{build-derivations} procedure of the @code{(guix
6326 derivations)} module.
6328 In addition to options explicitly passed on the command line,
6329 @command{guix build} and other @command{guix} commands that support
6330 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
6332 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
6333 Users can define this variable to a list of command line options that
6334 will automatically be used by @command{guix build} and other
6335 @command{guix} commands that can perform builds, as in the example
6339 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
6342 These options are parsed independently, and the result is appended to
6343 the parsed command-line options.
6347 @node Package Transformation Options
6348 @subsection Package Transformation Options
6350 @cindex package variants
6351 Another set of command-line options supported by @command{guix build}
6352 and also @command{guix package} are @dfn{package transformation
6353 options}. These are options that make it possible to define @dfn{package
6354 variants}---for instance, packages built from different source code.
6355 This is a convenient way to create customized packages on the fly
6356 without having to type in the definitions of package variants
6357 (@pxref{Defining Packages}).
6361 @item --with-source=@var{source}
6362 @itemx --with-source=@var{package}=@var{source}
6363 @itemx --with-source=@var{package}@@@var{version}=@var{source}
6364 Use @var{source} as the source of @var{package}, and @var{version} as
6366 @var{source} must be a file name or a URL, as for @command{guix
6367 download} (@pxref{Invoking guix download}).
6369 When @var{package} is omitted,
6370 it is taken to be the package name specified on the
6371 command line that matches the base of @var{source}---e.g.,
6372 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
6373 package is @code{guile}.
6375 Likewise, when @var{version} is omitted, the version string is inferred from
6376 @var{source}; in the previous example, it is @code{2.0.10}.
6378 This option allows users to try out versions of packages other than the
6379 one provided by the distribution. The example below downloads
6380 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
6381 the @code{ed} package:
6384 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
6387 As a developer, @code{--with-source} makes it easy to test release
6391 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
6394 @dots{} or to build from a checkout in a pristine environment:
6397 $ git clone git://git.sv.gnu.org/guix.git
6398 $ guix build guix --with-source=guix@@1.0=./guix
6401 @item --with-input=@var{package}=@var{replacement}
6402 Replace dependency on @var{package} by a dependency on
6403 @var{replacement}. @var{package} must be a package name, and
6404 @var{replacement} must be a package specification such as @code{guile}
6405 or @code{guile@@1.8}.
6407 For instance, the following command builds Guix, but replaces its
6408 dependency on the current stable version of Guile with a dependency on
6409 the legacy version of Guile, @code{guile@@2.0}:
6412 guix build --with-input=guile=guile@@2.0 guix
6415 This is a recursive, deep replacement. So in this example, both
6416 @code{guix} and its dependency @code{guile-json} (which also depends on
6417 @code{guile}) get rebuilt against @code{guile@@2.0}.
6419 This is implemented using the @code{package-input-rewriting} Scheme
6420 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
6422 @item --with-graft=@var{package}=@var{replacement}
6423 This is similar to @code{--with-input} but with an important difference:
6424 instead of rebuilding the whole dependency chain, @var{replacement} is
6425 built and then @dfn{grafted} onto the binaries that were initially
6426 referring to @var{package}. @xref{Security Updates}, for more
6427 information on grafts.
6429 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
6430 and all its dependencies, replacing references to the version of GnuTLS
6431 they currently refer to:
6434 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
6437 This has the advantage of being much faster than rebuilding everything.
6438 But there is a caveat: it works if and only if @var{package} and
6439 @var{replacement} are strictly compatible---for example, if they provide
6440 a library, the application binary interface (ABI) of those libraries
6441 must be compatible. If @var{replacement} is somehow incompatible with
6442 @var{package}, then the resulting package may be unusable. Use with
6445 @item --with-branch=@var{package}=@var{branch}
6446 @cindex Git, using the latest commit
6447 @cindex latest commit, building
6448 Build @var{package} from the latest commit of @var{branch}. The @code{source}
6449 field of @var{package} must be an origin with the @code{git-fetch} method
6450 (@pxref{origin Reference}) or a @code{git-checkout} object; the repository URL
6451 is taken from that @code{source}.
6453 For instance, the following command builds @code{guile-sqlite3} from the
6454 latest commit of its @code{master} branch, and then builds @code{guix} (which
6455 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
6456 specific @code{guile-sqlite3} build:
6459 guix build --with-branch=guile-sqlite3=master cuirass
6462 @cindex continuous integration
6463 Obviously, since it uses the latest commit of the given branch, the result of
6464 such a command varies over time. Nevertheless it is a convenient way to
6465 rebuild entire software stacks against the latest commit of one or more
6466 packages. This is particularly useful in the context of continuous
6469 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
6470 consecutive accesses to the same repository. You may want to clean it up once
6471 in a while to save disk space.
6473 @item --with-commit=@var{package}=@var{commit}
6474 This is similar to @code{--with-branch}, except that it builds from
6475 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
6476 Git commit SHA1 identifier.
6479 @node Additional Build Options
6480 @subsection Additional Build Options
6482 The command-line options presented below are specific to @command{guix
6489 Build quietly, without displaying the build log. Upon completion, the
6490 build log is kept in @file{/var} (or similar) and can always be
6491 retrieved using the @option{--log-file} option.
6493 @item --file=@var{file}
6494 @itemx -f @var{file}
6495 Build the package, derivation, or other file-like object that the code within
6496 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
6498 As an example, @var{file} might contain a package definition like this
6499 (@pxref{Defining Packages}):
6502 @verbatiminclude package-hello.scm
6505 @item --expression=@var{expr}
6506 @itemx -e @var{expr}
6507 Build the package or derivation @var{expr} evaluates to.
6509 For example, @var{expr} may be @code{(@@ (gnu packages guile)
6510 guile-1.8)}, which unambiguously designates this specific variant of
6511 version 1.8 of Guile.
6513 Alternatively, @var{expr} may be a G-expression, in which case it is used
6514 as a build program passed to @code{gexp->derivation}
6515 (@pxref{G-Expressions}).
6517 Lastly, @var{expr} may refer to a zero-argument monadic procedure
6518 (@pxref{The Store Monad}). The procedure must return a derivation as a
6519 monadic value, which is then passed through @code{run-with-store}.
6523 Build the source derivations of the packages, rather than the packages
6526 For instance, @code{guix build -S gcc} returns something like
6527 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
6530 The returned source tarball is the result of applying any patches and
6531 code snippets specified in the package @code{origin} (@pxref{Defining
6535 Fetch and return the source of @var{package-or-derivation} and all their
6536 dependencies, recursively. This is a handy way to obtain a local copy
6537 of all the source code needed to build @var{packages}, allowing you to
6538 eventually build them even without network access. It is an extension
6539 of the @code{--source} option and can accept one of the following
6540 optional argument values:
6544 This value causes the @code{--sources} option to behave in the same way
6545 as the @code{--source} option.
6548 Build the source derivations of all packages, including any source that
6549 might be listed as @code{inputs}. This is the default value.
6552 $ guix build --sources tzdata
6553 The following derivations will be built:
6554 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
6555 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6559 Build the source derivations of all packages, as well of all transitive
6560 inputs to the packages. This can be used e.g.@: to
6561 prefetch package source for later offline building.
6564 $ guix build --sources=transitive tzdata
6565 The following derivations will be built:
6566 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
6567 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
6568 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
6569 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
6570 /gnu/store/@dots{}-make-4.1.tar.xz.drv
6571 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
6577 @item --system=@var{system}
6578 @itemx -s @var{system}
6579 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6580 the system type of the build host.
6583 The @code{--system} flag is for @emph{native} compilation and must not
6584 be confused with cross-compilation. See @code{--target} below for
6585 information on cross-compilation.
6588 An example use of this is on Linux-based systems, which can emulate
6589 different personalities. For instance, passing
6590 @code{--system=i686-linux} on an @code{x86_64-linux} system or
6591 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
6592 to build packages in a complete 32-bit environment.
6595 Building for an @code{armhf-linux} system is unconditionally enabled on
6596 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
6597 allow for this functionality, notably the ThunderX.
6600 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
6601 is enabled (@pxref{Virtualization Services,
6602 @code{qemu-binfmt-service-type}}), you can build for any system for
6603 which a QEMU @code{binfmt_misc} handler is installed.
6605 Builds for a system other than that of the machine you are using can
6606 also be offloaded to a remote machine of the right architecture.
6607 @xref{Daemon Offload Setup}, for more information on offloading.
6609 @item --target=@var{triplet}
6610 @cindex cross-compilation
6611 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6612 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
6613 configuration triplets,, autoconf, Autoconf}).
6615 @anchor{build-check}
6617 @cindex determinism, checking
6618 @cindex reproducibility, checking
6619 Rebuild @var{package-or-derivation}, which are already available in the
6620 store, and raise an error if the build results are not bit-for-bit
6623 This mechanism allows you to check whether previously installed
6624 substitutes are genuine (@pxref{Substitutes}), or whether the build result
6625 of a package is deterministic. @xref{Invoking guix challenge}, for more
6626 background information and tools.
6628 When used in conjunction with @option{--keep-failed}, the differing
6629 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
6630 This makes it easy to look for differences between the two results.
6633 @cindex repairing store items
6634 @cindex corruption, recovering from
6635 Attempt to repair the specified store items, if they are corrupt, by
6636 re-downloading or rebuilding them.
6638 This operation is not atomic and thus restricted to @code{root}.
6642 Return the derivation paths, not the output paths, of the given
6645 @item --root=@var{file}
6646 @itemx -r @var{file}
6647 @cindex GC roots, adding
6648 @cindex garbage collector roots, adding
6649 Make @var{file} a symlink to the result, and register it as a garbage
6652 Consequently, the results of this @command{guix build} invocation are
6653 protected from garbage collection until @var{file} is removed. When
6654 that option is omitted, build results are eligible for garbage
6655 collection as soon as the build completes. @xref{Invoking guix gc}, for
6659 @cindex build logs, access
6660 Return the build log file names or URLs for the given
6661 @var{package-or-derivation}, or raise an error if build logs are
6664 This works regardless of how packages or derivations are specified. For
6665 instance, the following invocations are equivalent:
6668 guix build --log-file `guix build -d guile`
6669 guix build --log-file `guix build guile`
6670 guix build --log-file guile
6671 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
6674 If a log is unavailable locally, and unless @code{--no-substitutes} is
6675 passed, the command looks for a corresponding log on one of the
6676 substitute servers (as specified with @code{--substitute-urls}.)
6678 So for instance, imagine you want to see the build log of GDB on MIPS,
6679 but you are actually on an @code{x86_64} machine:
6682 $ guix build --log-file gdb -s mips64el-linux
6683 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
6686 You can freely access a huge library of build logs!
6689 @node Debugging Build Failures
6690 @subsection Debugging Build Failures
6692 @cindex build failures, debugging
6693 When defining a new package (@pxref{Defining Packages}), you will
6694 probably find yourself spending some time debugging and tweaking the
6695 build until it succeeds. To do that, you need to operate the build
6696 commands yourself in an environment as close as possible to the one the
6699 To that end, the first thing to do is to use the @option{--keep-failed}
6700 or @option{-K} option of @command{guix build}, which will keep the
6701 failed build tree in @file{/tmp} or whatever directory you specified as
6702 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
6704 From there on, you can @command{cd} to the failed build tree and source
6705 the @file{environment-variables} file, which contains all the
6706 environment variable definitions that were in place when the build
6707 failed. So let's say you're debugging a build failure in package
6708 @code{foo}; a typical session would look like this:
6712 @dots{} @i{build fails}
6713 $ cd /tmp/guix-build-foo.drv-0
6714 $ source ./environment-variables
6718 Now, you can invoke commands as if you were the daemon (almost) and
6719 troubleshoot your build process.
6721 Sometimes it happens that, for example, a package's tests pass when you
6722 run them manually but they fail when the daemon runs them. This can
6723 happen because the daemon runs builds in containers where, unlike in our
6724 environment above, network access is missing, @file{/bin/sh} does not
6725 exist, etc. (@pxref{Build Environment Setup}).
6727 In such cases, you may need to run inspect the build process from within
6728 a container similar to the one the build daemon creates:
6733 $ cd /tmp/guix-build-foo.drv-0
6734 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
6735 [env]# source ./environment-variables
6739 Here, @command{guix environment -C} creates a container and spawns a new
6740 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
6741 strace gdb} part adds the @command{strace} and @command{gdb} commands to
6742 the container, which would may find handy while debugging. The
6743 @option{--no-grafts} option makes sure we get the exact same
6744 environment, with ungrafted packages (@pxref{Security Updates}, for more
6747 To get closer to a container like that used by the build daemon, we can
6748 remove @file{/bin/sh}:
6754 (Don't worry, this is harmless: this is all happening in the throw-away
6755 container created by @command{guix environment}.)
6757 The @command{strace} command is probably not in the search path, but we
6761 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
6764 In this way, not only you will have reproduced the environment variables
6765 the daemon uses, you will also be running the build process in a container
6766 similar to the one the daemon uses.
6769 @node Invoking guix edit
6770 @section Invoking @command{guix edit}
6772 @cindex @command{guix edit}
6773 @cindex package definition, editing
6774 So many packages, so many source files! The @command{guix edit} command
6775 facilitates the life of users and packagers by pointing their editor at
6776 the source file containing the definition of the specified packages.
6780 guix edit gcc@@4.9 vim
6784 launches the program specified in the @code{VISUAL} or in the
6785 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
6788 If you are using a Guix Git checkout (@pxref{Building from Git}), or
6789 have created your own packages on @code{GUIX_PACKAGE_PATH}
6790 (@pxref{Package Modules}), you will be able to edit the package
6791 recipes. In other cases, you will be able to examine the read-only recipes
6792 for packages currently in the store.
6795 @node Invoking guix download
6796 @section Invoking @command{guix download}
6798 @cindex @command{guix download}
6799 @cindex downloading package sources
6800 When writing a package definition, developers typically need to download
6801 a source tarball, compute its SHA256 hash, and write that
6802 hash in the package definition (@pxref{Defining Packages}). The
6803 @command{guix download} tool helps with this task: it downloads a file
6804 from the given URI, adds it to the store, and prints both its file name
6805 in the store and its SHA256 hash.
6807 The fact that the downloaded file is added to the store saves bandwidth:
6808 when the developer eventually tries to build the newly defined package
6809 with @command{guix build}, the source tarball will not have to be
6810 downloaded again because it is already in the store. It is also a
6811 convenient way to temporarily stash files, which may be deleted
6812 eventually (@pxref{Invoking guix gc}).
6814 The @command{guix download} command supports the same URIs as used in
6815 package definitions. In particular, it supports @code{mirror://} URIs.
6816 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
6817 Guile bindings for GnuTLS are available in the user's environment; when
6818 they are not available, an error is raised. @xref{Guile Preparations,
6819 how to install the GnuTLS bindings for Guile,, gnutls-guile,
6820 GnuTLS-Guile}, for more information.
6822 @command{guix download} verifies HTTPS server certificates by loading
6823 the certificates of X.509 authorities from the directory pointed to by
6824 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
6825 Certificates}), unless @option{--no-check-certificate} is used.
6827 The following options are available:
6830 @item --format=@var{fmt}
6832 Write the hash in the format specified by @var{fmt}. For more
6833 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
6835 @item --no-check-certificate
6836 Do not validate the X.509 certificates of HTTPS servers.
6838 When using this option, you have @emph{absolutely no guarantee} that you
6839 are communicating with the authentic server responsible for the given
6840 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
6842 @item --output=@var{file}
6843 @itemx -o @var{file}
6844 Save the downloaded file to @var{file} instead of adding it to the
6848 @node Invoking guix hash
6849 @section Invoking @command{guix hash}
6851 @cindex @command{guix hash}
6852 The @command{guix hash} command computes the SHA256 hash of a file.
6853 It is primarily a convenience tool for anyone contributing to the
6854 distribution: it computes the cryptographic hash of a file, which can be
6855 used in the definition of a package (@pxref{Defining Packages}).
6857 The general syntax is:
6860 guix hash @var{option} @var{file}
6863 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
6864 hash of data read from standard input. @command{guix hash} has the
6869 @item --format=@var{fmt}
6871 Write the hash in the format specified by @var{fmt}.
6873 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
6874 (@code{hex} and @code{hexadecimal} can be used as well).
6876 If the @option{--format} option is not specified, @command{guix hash}
6877 will output the hash in @code{nix-base32}. This representation is used
6878 in the definitions of packages.
6882 Compute the hash on @var{file} recursively.
6884 In this case, the hash is computed on an archive containing @var{file},
6885 including its children if it is a directory. Some of the metadata of
6886 @var{file} is part of the archive; for instance, when @var{file} is a
6887 regular file, the hash is different depending on whether @var{file} is
6888 executable or not. Metadata such as time stamps has no impact on the
6889 hash (@pxref{Invoking guix archive}).
6890 @c FIXME: Replace xref above with xref to an ``Archive'' section when
6895 When combined with @option{--recursive}, exclude version control system
6896 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
6899 As an example, here is how you would compute the hash of a Git checkout,
6900 which is useful when using the @code{git-fetch} method (@pxref{origin
6904 $ git clone http://example.org/foo.git
6910 @node Invoking guix import
6911 @section Invoking @command{guix import}
6913 @cindex importing packages
6914 @cindex package import
6915 @cindex package conversion
6916 @cindex Invoking @command{guix import}
6917 The @command{guix import} command is useful for people who would like to
6918 add a package to the distribution with as little work as
6919 possible---a legitimate demand. The command knows of a few
6920 repositories from which it can ``import'' package metadata. The result
6921 is a package definition, or a template thereof, in the format we know
6922 (@pxref{Defining Packages}).
6924 The general syntax is:
6927 guix import @var{importer} @var{options}@dots{}
6930 @var{importer} specifies the source from which to import package
6931 metadata, and @var{options} specifies a package identifier and other
6932 options specific to @var{importer}. Currently, the available
6937 Import metadata for the given GNU package. This provides a template
6938 for the latest version of that GNU package, including the hash of its
6939 source tarball, and its canonical synopsis and description.
6941 Additional information such as the package dependencies and its
6942 license needs to be figured out manually.
6944 For example, the following command returns a package definition for
6948 guix import gnu hello
6951 Specific command-line options are:
6954 @item --key-download=@var{policy}
6955 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
6956 keys when verifying the package signature. @xref{Invoking guix
6957 refresh, @code{--key-download}}.
6962 Import metadata from the @uref{https://pypi.python.org/, Python Package
6963 Index}. Information is taken from the JSON-formatted description
6964 available at @code{pypi.python.org} and usually includes all the relevant
6965 information, including package dependencies. For maximum efficiency, it
6966 is recommended to install the @command{unzip} utility, so that the
6967 importer can unzip Python wheels and gather data from them.
6969 The command below imports metadata for the @code{itsdangerous} Python
6973 guix import pypi itsdangerous
6979 Traverse the dependency graph of the given upstream package recursively
6980 and generate package expressions for all those packages that are not yet
6986 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
6987 is taken from the JSON-formatted description available at
6988 @code{rubygems.org} and includes most relevant information, including
6989 runtime dependencies. There are some caveats, however. The metadata
6990 doesn't distinguish between synopses and descriptions, so the same string
6991 is used for both fields. Additionally, the details of non-Ruby
6992 dependencies required to build native extensions is unavailable and left
6993 as an exercise to the packager.
6995 The command below imports metadata for the @code{rails} Ruby package:
6998 guix import gem rails
7004 Traverse the dependency graph of the given upstream package recursively
7005 and generate package expressions for all those packages that are not yet
7011 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
7012 Information is taken from the JSON-formatted metadata provided through
7013 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
7014 relevant information, such as module dependencies. License information
7015 should be checked closely. If Perl is available in the store, then the
7016 @code{corelist} utility will be used to filter core modules out of the
7017 list of dependencies.
7019 The command command below imports metadata for the @code{Acme::Boolean}
7023 guix import cpan Acme::Boolean
7028 @cindex Bioconductor
7029 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
7030 central repository for the @uref{http://r-project.org, GNU@tie{}R
7031 statistical and graphical environment}.
7033 Information is extracted from the @code{DESCRIPTION} file of the package.
7035 The command command below imports metadata for the @code{Cairo}
7039 guix import cran Cairo
7042 When @code{--recursive} is added, the importer will traverse the
7043 dependency graph of the given upstream package recursively and generate
7044 package expressions for all those packages that are not yet in Guix.
7046 When @code{--archive=bioconductor} is added, metadata is imported from
7047 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
7048 packages for for the analysis and comprehension of high-throughput
7049 genomic data in bioinformatics.
7051 Information is extracted from the @code{DESCRIPTION} file of a package
7052 published on the web interface of the Bioconductor SVN repository.
7054 The command below imports metadata for the @code{GenomicRanges}
7058 guix import cran --archive=bioconductor GenomicRanges
7064 Import metadata from @uref{http://www.ctan.org/, CTAN}, the
7065 comprehensive TeX archive network for TeX packages that are part of the
7066 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
7068 Information about the package is obtained through the XML API provided
7069 by CTAN, while the source code is downloaded from the SVN repository of
7070 the Tex Live project. This is done because the CTAN does not keep
7073 The command command below imports metadata for the @code{fontspec}
7077 guix import texlive fontspec
7080 When @code{--archive=DIRECTORY} is added, the source code is downloaded
7081 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
7082 tree in the TeX Live SVN repository, but from the specified sibling
7083 directory under the same root.
7085 The command below imports metadata for the @code{ifxetex} package from
7086 CTAN while fetching the sources from the directory
7087 @file{texmf/source/generic}:
7090 guix import texlive --archive=generic ifxetex
7094 @cindex JSON, import
7095 Import package metadata from a local JSON file. Consider the following
7096 example package definition in JSON format:
7102 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
7103 "build-system": "gnu",
7104 "home-page": "https://www.gnu.org/software/hello/",
7105 "synopsis": "Hello, GNU world: An example GNU package",
7106 "description": "GNU Hello prints a greeting.",
7107 "license": "GPL-3.0+",
7108 "native-inputs": ["gcc@@6"]
7112 The field names are the same as for the @code{<package>} record
7113 (@xref{Defining Packages}). References to other packages are provided
7114 as JSON lists of quoted package specification strings such as
7115 @code{guile} or @code{guile@@2.0}.
7117 The importer also supports a more explicit source definition using the
7118 common fields for @code{<origin>} records:
7124 "method": "url-fetch",
7125 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
7127 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
7134 The command below reads metadata from the JSON file @code{hello.json}
7135 and outputs a package expression:
7138 guix import json hello.json
7142 Import metadata from a local copy of the source of the
7143 @uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
7144 relies on the @command{nix-instantiate} command of
7145 @uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
7146 typically written in a mixture of Nix-language and Bash code. This
7147 command only imports the high-level package structure that is written in
7148 the Nix language. It normally includes all the basic fields of a
7151 When importing a GNU package, the synopsis and descriptions are replaced
7152 by their canonical upstream variant.
7154 Usually, you will first need to do:
7157 export NIX_REMOTE=daemon
7161 so that @command{nix-instantiate} does not try to open the Nix database.
7163 As an example, the command below imports the package definition of
7164 LibreOffice (more precisely, it imports the definition of the package
7165 bound to the @code{libreoffice} top-level attribute):
7168 guix import nix ~/path/to/nixpkgs libreoffice
7173 Import metadata from the Haskell community's central package archive
7174 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
7175 Cabal files and includes all the relevant information, including package
7178 Specific command-line options are:
7183 Read a Cabal file from standard input.
7184 @item --no-test-dependencies
7186 Do not include dependencies required only by the test suites.
7187 @item --cabal-environment=@var{alist}
7188 @itemx -e @var{alist}
7189 @var{alist} is a Scheme alist defining the environment in which the
7190 Cabal conditionals are evaluated. The accepted keys are: @code{os},
7191 @code{arch}, @code{impl} and a string representing the name of a flag.
7192 The value associated with a flag has to be either the symbol
7193 @code{true} or @code{false}. The value associated with other keys
7194 has to conform to the Cabal file format definition. The default value
7195 associated with the keys @code{os}, @code{arch} and @code{impl} is
7196 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
7199 Traverse the dependency graph of the given upstream package recursively
7200 and generate package expressions for all those packages that are not yet
7204 The command below imports metadata for the latest version of the
7205 @code{HTTP} Haskell package without including test dependencies and
7206 specifying the value of the flag @samp{network-uri} as @code{false}:
7209 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
7212 A specific package version may optionally be specified by following the
7213 package name by an at-sign and a version number as in the following example:
7216 guix import hackage mtl@@2.1.3.1
7221 The @code{stackage} importer is a wrapper around the @code{hackage} one.
7222 It takes a package name, looks up the package version included in a
7223 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
7224 release and uses the @code{hackage} importer to retrieve its metadata.
7225 Note that it is up to you to select an LTS release compatible with the
7226 GHC compiler used by Guix.
7228 Specific command-line options are:
7231 @item --no-test-dependencies
7233 Do not include dependencies required only by the test suites.
7234 @item --lts-version=@var{version}
7235 @itemx -l @var{version}
7236 @var{version} is the desired LTS release version. If omitted the latest
7240 Traverse the dependency graph of the given upstream package recursively
7241 and generate package expressions for all those packages that are not yet
7245 The command below imports metadata for the @code{HTTP} Haskell package
7246 included in the LTS Stackage release version 7.18:
7249 guix import stackage --lts-version=7.18 HTTP
7254 Import metadata from an Emacs Lisp Package Archive (ELPA) package
7255 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7257 Specific command-line options are:
7260 @item --archive=@var{repo}
7261 @itemx -a @var{repo}
7262 @var{repo} identifies the archive repository from which to retrieve the
7263 information. Currently the supported repositories and their identifiers
7267 @uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
7268 identifier. This is the default.
7270 Packages from @code{elpa.gnu.org} are signed with one of the keys
7271 contained in the GnuPG keyring at
7272 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
7273 @code{emacs} package (@pxref{Package Installation, ELPA package
7274 signatures,, emacs, The GNU Emacs Manual}).
7277 @uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
7278 @code{melpa-stable} identifier.
7281 @uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
7287 Traverse the dependency graph of the given upstream package recursively
7288 and generate package expressions for all those packages that are not yet
7294 Import metadata from the crates.io Rust package repository
7295 @uref{https://crates.io, crates.io}.
7300 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
7301 repository used by the OCaml community.
7304 The structure of the @command{guix import} code is modular. It would be
7305 useful to have more importers for other package formats, and your help
7306 is welcome here (@pxref{Contributing}).
7308 @node Invoking guix refresh
7309 @section Invoking @command{guix refresh}
7311 @cindex @command {guix refresh}
7312 The primary audience of the @command{guix refresh} command is developers
7313 of the GNU software distribution. By default, it reports any packages
7314 provided by the distribution that are outdated compared to the latest
7315 upstream version, like this:
7319 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
7320 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
7323 Alternately, one can specify packages to consider, in which case a
7324 warning is emitted for packages that lack an updater:
7327 $ guix refresh coreutils guile guile-ssh
7328 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
7329 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
7332 @command{guix refresh} browses the upstream repository of each package and determines
7333 the highest version number of the releases therein. The command
7334 knows how to update specific types of packages: GNU packages, ELPA
7335 packages, etc.---see the documentation for @option{--type} below. There
7336 are many packages, though, for which it lacks a method to determine
7337 whether a new upstream release is available. However, the mechanism is
7338 extensible, so feel free to get in touch with us to add a new method!
7340 Sometimes the upstream name differs from the package name used in Guix,
7341 and @command{guix refresh} needs a little help. Most updaters honor the
7342 @code{upstream-name} property in package definitions, which can be used
7346 (define-public network-manager
7348 (name "network-manager")
7350 (properties '((upstream-name . "NetworkManager")))))
7353 When passed @code{--update}, it modifies distribution source files to
7354 update the version numbers and source tarball hashes of those package
7355 recipes (@pxref{Defining Packages}). This is achieved by downloading
7356 each package's latest source tarball and its associated OpenPGP
7357 signature, authenticating the downloaded tarball against its signature
7358 using @command{gpg}, and finally computing its hash. When the public
7359 key used to sign the tarball is missing from the user's keyring, an
7360 attempt is made to automatically retrieve it from a public key server;
7361 when this is successful, the key is added to the user's keyring; otherwise,
7362 @command{guix refresh} reports an error.
7364 The following options are supported:
7368 @item --expression=@var{expr}
7369 @itemx -e @var{expr}
7370 Consider the package @var{expr} evaluates to.
7372 This is useful to precisely refer to a package, as in this example:
7375 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
7378 This command lists the dependents of the ``final'' libc (essentially all
7383 Update distribution source files (package recipes) in place. This is
7384 usually run from a checkout of the Guix source tree (@pxref{Running
7385 Guix Before It Is Installed}):
7388 $ ./pre-inst-env guix refresh -s non-core -u
7391 @xref{Defining Packages}, for more information on package definitions.
7393 @item --select=[@var{subset}]
7394 @itemx -s @var{subset}
7395 Select all the packages in @var{subset}, one of @code{core} or
7398 The @code{core} subset refers to all the packages at the core of the
7399 distribution---i.e., packages that are used to build ``everything
7400 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
7401 changing one of these packages in the distribution entails a rebuild of
7402 all the others. Thus, such updates are an inconvenience to users in
7403 terms of build time or bandwidth used to achieve the upgrade.
7405 The @code{non-core} subset refers to the remaining packages. It is
7406 typically useful in cases where an update of the core packages would be
7409 @item --manifest=@var{file}
7410 @itemx -m @var{file}
7411 Select all the packages from the manifest in @var{file}. This is useful to
7412 check if any packages of the user manifest can be updated.
7414 @item --type=@var{updater}
7415 @itemx -t @var{updater}
7416 Select only packages handled by @var{updater} (may be a comma-separated
7417 list of updaters). Currently, @var{updater} may be one of:
7421 the updater for GNU packages;
7423 the updater for GNOME packages;
7425 the updater for KDE packages;
7427 the updater for X.org packages;
7429 the updater for packages hosted on kernel.org;
7431 the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
7433 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
7435 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
7437 the updater for @uref{http://www.cpan.org/, CPAN} packages;
7439 the updater for @uref{https://pypi.python.org, PyPI} packages.
7441 the updater for @uref{https://rubygems.org, RubyGems} packages.
7443 the updater for @uref{https://github.com, GitHub} packages.
7445 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
7447 the updater for @uref{https://www.stackage.org, Stackage} packages.
7449 the updater for @uref{https://crates.io, Crates} packages.
7452 For instance, the following command only checks for updates of Emacs
7453 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
7456 $ guix refresh --type=elpa,cran
7457 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
7458 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
7463 In addition, @command{guix refresh} can be passed one or more package
7464 names, as in this example:
7467 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
7471 The command above specifically updates the @code{emacs} and
7472 @code{idutils} packages. The @code{--select} option would have no
7473 effect in this case.
7475 When considering whether to upgrade a package, it is sometimes
7476 convenient to know which packages would be affected by the upgrade and
7477 should be checked for compatibility. For this the following option may
7478 be used when passing @command{guix refresh} one or more package names:
7482 @item --list-updaters
7484 List available updaters and exit (see @option{--type} above.)
7486 For each updater, display the fraction of packages it covers; at the
7487 end, display the fraction of packages covered by all these updaters.
7489 @item --list-dependent
7491 List top-level dependent packages that would need to be rebuilt as a
7492 result of upgrading one or more packages.
7494 @xref{Invoking guix graph, the @code{reverse-package} type of
7495 @command{guix graph}}, for information on how to visualize the list of
7496 dependents of a package.
7500 Be aware that the @code{--list-dependent} option only
7501 @emph{approximates} the rebuilds that would be required as a result of
7502 an upgrade. More rebuilds might be required under some circumstances.
7505 $ guix refresh --list-dependent flex
7506 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
7507 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
7510 The command above lists a set of packages that could be built to check
7511 for compatibility with an upgraded @code{flex} package.
7513 The following options can be used to customize GnuPG operation:
7517 @item --gpg=@var{command}
7518 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
7519 for in @code{$PATH}.
7521 @item --keyring=@var{file}
7522 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
7523 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
7524 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
7525 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
7526 information on a tool to manipulate keybox files).
7528 When this option is omitted, @command{guix refresh} uses
7529 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
7530 signing keys. OpenPGP signatures are checked against keys from this keyring;
7531 missing keys are downloaded to this keyring as well (see
7532 @option{--key-download} below.)
7534 You can export keys from your default GPG keyring into a keybox file using
7535 commands like this one:
7538 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
7541 Likewise, you can fetch keys to a specific keybox file like this:
7544 gpg --no-default-keyring --keyring mykeyring.kbx \
7545 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
7548 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
7549 Privacy Guard}, for more information on GPG's @option{--keyring} option.
7551 @item --key-download=@var{policy}
7552 Handle missing OpenPGP keys according to @var{policy}, which may be one
7557 Always download missing OpenPGP keys from the key server, and add them
7558 to the user's GnuPG keyring.
7561 Never try to download missing OpenPGP keys. Instead just bail out.
7564 When a package signed with an unknown OpenPGP key is encountered, ask
7565 the user whether to download it or not. This is the default behavior.
7568 @item --key-server=@var{host}
7569 Use @var{host} as the OpenPGP key server when importing a public key.
7573 The @code{github} updater uses the
7574 @uref{https://developer.github.com/v3/, GitHub API} to query for new
7575 releases. When used repeatedly e.g.@: when refreshing all packages,
7576 GitHub will eventually refuse to answer any further API requests. By
7577 default 60 API requests per hour are allowed, and a full refresh on all
7578 GitHub packages in Guix requires more than this. Authentication with
7579 GitHub through the use of an API token alleviates these limits. To use
7580 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
7581 token procured from @uref{https://github.com/settings/tokens} or
7585 @node Invoking guix lint
7586 @section Invoking @command{guix lint}
7588 @cindex @command{guix lint}
7589 @cindex package, checking for errors
7590 The @command{guix lint} command is meant to help package developers avoid
7591 common errors and use a consistent style. It runs a number of checks on
7592 a given set of packages in order to find common mistakes in their
7593 definitions. Available @dfn{checkers} include (see
7594 @code{--list-checkers} for a complete list):
7599 Validate certain typographical and stylistic rules about package
7600 descriptions and synopses.
7602 @item inputs-should-be-native
7603 Identify inputs that should most likely be native inputs.
7608 @itemx source-file-name
7609 Probe @code{home-page} and @code{source} URLs and report those that are
7610 invalid. Suggest a @code{mirror://} URL when applicable. Check that
7611 the source file name is meaningful, e.g.@: is not
7612 just a version number or ``git-checkout'', without a declared
7613 @code{file-name} (@pxref{origin Reference}).
7616 @cindex security vulnerabilities
7617 @cindex CVE, Common Vulnerabilities and Exposures
7618 Report known vulnerabilities found in the Common Vulnerabilities and
7619 Exposures (CVE) databases of the current and past year
7620 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
7623 To view information about a particular vulnerability, visit pages such as:
7627 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
7629 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
7633 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
7634 @code{CVE-2015-7554}.
7636 Package developers can specify in package recipes the
7637 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
7638 name and version of the package when they differ from the name or version
7639 that Guix uses, as in this example:
7645 ;; CPE calls this package "grub2".
7646 (properties '((cpe-name . "grub2")
7647 (cpe-version . "2.3")))
7650 @c See <http://www.openwall.com/lists/oss-security/2017/03/15/3>.
7651 Some entries in the CVE database do not specify which version of a
7652 package they apply to, and would thus ``stick around'' forever. Package
7653 developers who found CVE alerts and verified they can be ignored can
7654 declare them as in this example:
7660 ;; These CVEs no longer apply and can be safely ignored.
7661 (properties `((lint-hidden-cve . ("CVE-2011-0433"
7664 "CVE-2011-5244")))))
7668 Warn about obvious source code formatting issues: trailing white space,
7669 use of tabulations, etc.
7672 The general syntax is:
7675 guix lint @var{options} @var{package}@dots{}
7678 If no package is given on the command line, then all packages are checked.
7679 The @var{options} may be zero or more of the following:
7682 @item --list-checkers
7684 List and describe all the available checkers that will be run on packages
7689 Only enable the checkers specified in a comma-separated list using the
7690 names returned by @code{--list-checkers}.
7694 @node Invoking guix size
7695 @section Invoking @command{guix size}
7698 @cindex package size
7700 @cindex @command{guix size}
7701 The @command{guix size} command helps package developers profile the
7702 disk usage of packages. It is easy to overlook the impact of an
7703 additional dependency added to a package, or the impact of using a
7704 single output for a package that could easily be split (@pxref{Packages
7705 with Multiple Outputs}). Such are the typical issues that
7706 @command{guix size} can highlight.
7708 The command can be passed one or more package specifications
7709 such as @code{gcc@@4.8}
7710 or @code{guile:debug}, or a file name in the store. Consider this
7714 $ guix size coreutils
7715 store item total self
7716 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
7717 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
7718 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
7719 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
7720 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
7721 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
7722 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
7723 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
7728 The store items listed here constitute the @dfn{transitive closure} of
7729 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
7730 would be returned by:
7733 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
7736 Here the output shows three columns next to store items. The first column,
7737 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
7738 the store item---that is, its own size plus the size of all its
7739 dependencies. The next column, labeled ``self'', shows the size of the
7740 item itself. The last column shows the ratio of the size of the item
7741 itself to the space occupied by all the items listed here.
7743 In this example, we see that the closure of Coreutils weighs in at
7744 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
7745 libraries. (That libc and GCC's libraries represent a large fraction of
7746 the closure is not a problem @i{per se} because they are always available
7747 on the system anyway.)
7749 When the package(s) passed to @command{guix size} are available in the
7750 store@footnote{More precisely, @command{guix size} looks for the
7751 @emph{ungrafted} variant of the given package(s), as returned by
7752 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
7753 for information on grafts.}, @command{guix size} queries the daemon to determine its
7754 dependencies, and measures its size in the store, similar to @command{du
7755 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
7758 When the given packages are @emph{not} in the store, @command{guix size}
7759 reports information based on the available substitutes
7760 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
7761 store items that are not even on disk, only available remotely.
7763 You can also specify several package names:
7766 $ guix size coreutils grep sed bash
7767 store item total self
7768 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
7769 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
7770 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
7771 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
7777 In this example we see that the combination of the four packages takes
7778 102.3@tie{}MiB in total, which is much less than the sum of each closure
7779 since they have a lot of dependencies in common.
7781 The available options are:
7785 @item --substitute-urls=@var{urls}
7786 Use substitute information from @var{urls}.
7787 @xref{client-substitute-urls, the same option for @code{guix build}}.
7789 @item --sort=@var{key}
7790 Sort lines according to @var{key}, one of the following options:
7794 the size of each item (the default);
7796 the total size of the item's closure.
7799 @item --map-file=@var{file}
7800 Write a graphical map of disk usage in PNG format to @var{file}.
7802 For the example above, the map looks like this:
7804 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
7805 produced by @command{guix size}}
7807 This option requires that
7808 @uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
7809 installed and visible in Guile's module search path. When that is not
7810 the case, @command{guix size} fails as it tries to load it.
7812 @item --system=@var{system}
7813 @itemx -s @var{system}
7814 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
7818 @node Invoking guix graph
7819 @section Invoking @command{guix graph}
7822 @cindex @command{guix graph}
7823 @cindex package dependencies
7824 Packages and their dependencies form a @dfn{graph}, specifically a
7825 directed acyclic graph (DAG). It can quickly become difficult to have a
7826 mental model of the package DAG, so the @command{guix graph} command
7827 provides a visual representation of the DAG. By default,
7828 @command{guix graph} emits a DAG representation in the input format of
7829 @uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
7830 directly to the @command{dot} command of Graphviz. It can also emit an
7831 HTML page with embedded JavaScript code to display a ``chord diagram''
7832 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
7833 emit Cypher queries to construct a graph in a graph database supporting
7834 the @uref{http://www.opencypher.org/, openCypher} query language.
7835 The general syntax is:
7838 guix graph @var{options} @var{package}@dots{}
7841 For example, the following command generates a PDF file representing the
7842 package DAG for the GNU@tie{}Core Utilities, showing its build-time
7846 guix graph coreutils | dot -Tpdf > dag.pdf
7849 The output looks like this:
7851 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
7853 Nice little graph, no?
7855 But there is more than one graph! The one above is concise: it is the
7856 graph of package objects, omitting implicit inputs such as GCC, libc,
7857 grep, etc. It is often useful to have such a concise graph, but
7858 sometimes one may want to see more details. @command{guix graph} supports
7859 several types of graphs, allowing you to choose the level of detail:
7863 This is the default type used in the example above. It shows the DAG of
7864 package objects, excluding implicit dependencies. It is concise, but
7865 filters out many details.
7867 @item reverse-package
7868 This shows the @emph{reverse} DAG of packages. For example:
7871 guix graph --type=reverse-package ocaml
7874 ...@: yields the graph of packages that depend on OCaml.
7876 Note that for core packages this can yield huge graphs. If all you want
7877 is to know the number of packages that depend on a given package, use
7878 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
7879 @option{--list-dependent}}).
7882 This is the package DAG, @emph{including} implicit inputs.
7884 For instance, the following command:
7887 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
7890 ...@: yields this bigger graph:
7892 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
7894 At the bottom of the graph, we see all the implicit inputs of
7895 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
7897 Now, note that the dependencies of these implicit inputs---that is, the
7898 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
7899 here, for conciseness.
7902 Similar to @code{bag-emerged}, but this time including all the bootstrap
7905 @item bag-with-origins
7906 Similar to @code{bag}, but also showing origins and their dependencies.
7909 This is the most detailed representation: It shows the DAG of
7910 derivations (@pxref{Derivations}) and plain store items. Compared to
7911 the above representation, many additional nodes are visible, including
7912 build scripts, patches, Guile modules, etc.
7914 For this type of graph, it is also possible to pass a @file{.drv} file
7915 name instead of a package name, as in:
7918 guix graph -t derivation `guix system build -d my-config.scm`
7922 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
7923 For example, the following command shows the graph for the package
7924 module that defines the @code{guile} package:
7927 guix graph -t module guile | dot -Tpdf > module-graph.pdf
7931 All the types above correspond to @emph{build-time dependencies}. The
7932 following graph type represents the @emph{run-time dependencies}:
7936 This is the graph of @dfn{references} of a package output, as returned
7937 by @command{guix gc --references} (@pxref{Invoking guix gc}).
7939 If the given package output is not available in the store, @command{guix
7940 graph} attempts to obtain dependency information from substitutes.
7942 Here you can also pass a store file name instead of a package name. For
7943 example, the command below produces the reference graph of your profile
7944 (which can be big!):
7947 guix graph -t references `readlink -f ~/.guix-profile`
7951 This is the graph of the @dfn{referrers} of a store item, as returned by
7952 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
7954 This relies exclusively on local information from your store. For
7955 instance, let us suppose that the current Inkscape is available in 10
7956 profiles on your machine; @command{guix graph -t referrers inkscape}
7957 will show a graph rooted at Inkscape and with those 10 profiles linked
7960 It can help determine what is preventing a store item from being garbage
7965 The available options are the following:
7968 @item --type=@var{type}
7969 @itemx -t @var{type}
7970 Produce a graph output of @var{type}, where @var{type} must be one of
7971 the values listed above.
7974 List the supported graph types.
7976 @item --backend=@var{backend}
7977 @itemx -b @var{backend}
7978 Produce a graph using the selected @var{backend}.
7980 @item --list-backends
7981 List the supported graph backends.
7983 Currently, the available backends are Graphviz and d3.js.
7985 @item --expression=@var{expr}
7986 @itemx -e @var{expr}
7987 Consider the package @var{expr} evaluates to.
7989 This is useful to precisely refer to a package, as in this example:
7992 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
7995 @item --system=@var{system}
7996 @itemx -s @var{system}
7997 Display the graph for @var{system}---e.g., @code{i686-linux}.
7999 The package dependency graph is largely architecture-independent, but there
8000 are some architecture-dependent bits that this option allows you to visualize.
8004 @node Invoking guix environment
8005 @section Invoking @command{guix environment}
8007 @cindex reproducible build environments
8008 @cindex development environments
8009 @cindex @command{guix environment}
8010 @cindex environment, package build environment
8011 The purpose of @command{guix environment} is to assist hackers in
8012 creating reproducible development environments without polluting their
8013 package profile. The @command{guix environment} tool takes one or more
8014 packages, builds all of their inputs, and creates a shell
8015 environment to use them.
8017 The general syntax is:
8020 guix environment @var{options} @var{package}@dots{}
8023 The following example spawns a new shell set up for the development of
8027 guix environment guile
8030 If the needed dependencies are not built yet, @command{guix environment}
8031 automatically builds them. The environment of the new shell is an augmented
8032 version of the environment that @command{guix environment} was run in.
8033 It contains the necessary search paths for building the given package
8034 added to the existing environment variables. To create a ``pure''
8035 environment, in which the original environment variables have been unset,
8036 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
8037 environment variables such as @code{PATH} in their @file{~/.bashrc}
8038 file. As a consequence, when @code{guix environment} launches it, Bash
8039 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
8040 environment variables. It is an error to define such environment
8041 variables in @file{.bashrc}; instead, they should be defined in
8042 @file{.bash_profile}, which is sourced only by log-in shells.
8043 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
8044 details on Bash start-up files.}.
8046 @vindex GUIX_ENVIRONMENT
8047 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
8048 variable in the shell it spawns; its value is the file name of the
8049 profile of this environment. This allows users to, say, define a
8050 specific prompt for development environments in their @file{.bashrc}
8051 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
8054 if [ -n "$GUIX_ENVIRONMENT" ]
8056 export PS1="\u@@\h \w [dev]\$ "
8061 ...@: or to browse the profile:
8064 $ ls "$GUIX_ENVIRONMENT/bin"
8067 Additionally, more than one package may be specified, in which case the
8068 union of the inputs for the given packages are used. For example, the
8069 command below spawns a shell where all of the dependencies of both Guile
8070 and Emacs are available:
8073 guix environment guile emacs
8076 Sometimes an interactive shell session is not desired. An arbitrary
8077 command may be invoked by placing the @code{--} token to separate the
8078 command from the rest of the arguments:
8081 guix environment guile -- make -j4
8084 In other situations, it is more convenient to specify the list of
8085 packages needed in the environment. For example, the following command
8086 runs @command{python} from an environment containing Python@tie{}2.7 and
8090 guix environment --ad-hoc python2-numpy python-2.7 -- python
8093 Furthermore, one might want the dependencies of a package and also some
8094 additional packages that are not build-time or runtime dependencies, but
8095 are useful when developing nonetheless. Because of this, the
8096 @code{--ad-hoc} flag is positional. Packages appearing before
8097 @code{--ad-hoc} are interpreted as packages whose dependencies will be
8098 added to the environment. Packages appearing after are interpreted as
8099 packages that will be added to the environment directly. For example,
8100 the following command creates a Guix development environment that
8101 additionally includes Git and strace:
8104 guix environment guix --ad-hoc git strace
8107 Sometimes it is desirable to isolate the environment as much as
8108 possible, for maximal purity and reproducibility. In particular, when
8109 using Guix on a host distro that is not GuixSD, it is desirable to
8110 prevent access to @file{/usr/bin} and other system-wide resources from
8111 the development environment. For example, the following command spawns
8112 a Guile REPL in a ``container'' where only the store and the current
8113 working directory are mounted:
8116 guix environment --ad-hoc --container guile -- guile
8120 The @code{--container} option requires Linux-libre 3.19 or newer.
8123 The available options are summarized below.
8126 @item --root=@var{file}
8127 @itemx -r @var{file}
8128 @cindex persistent environment
8129 @cindex garbage collector root, for environments
8130 Make @var{file} a symlink to the profile for this environment, and
8131 register it as a garbage collector root.
8133 This is useful if you want to protect your environment from garbage
8134 collection, to make it ``persistent''.
8136 When this option is omitted, the environment is protected from garbage
8137 collection only for the duration of the @command{guix environment}
8138 session. This means that next time you recreate the same environment,
8139 you could have to rebuild or re-download packages. @xref{Invoking guix
8140 gc}, for more on GC roots.
8142 @item --expression=@var{expr}
8143 @itemx -e @var{expr}
8144 Create an environment for the package or list of packages that
8145 @var{expr} evaluates to.
8147 For example, running:
8150 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
8153 starts a shell with the environment for this specific variant of the
8159 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
8162 starts a shell with all the GuixSD base packages available.
8164 The above commands only use the default output of the given packages.
8165 To select other outputs, two element tuples can be specified:
8168 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
8171 @item --load=@var{file}
8172 @itemx -l @var{file}
8173 Create an environment for the package or list of packages that the code
8174 within @var{file} evaluates to.
8176 As an example, @var{file} might contain a definition like this
8177 (@pxref{Defining Packages}):
8180 @verbatiminclude environment-gdb.scm
8183 @item --manifest=@var{file}
8184 @itemx -m @var{file}
8185 Create an environment for the packages contained in the manifest object
8186 returned by the Scheme code in @var{file}.
8188 This is similar to the same-named option in @command{guix package}
8189 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
8193 Include all specified packages in the resulting environment, as if an
8194 @i{ad hoc} package were defined with them as inputs. This option is
8195 useful for quickly creating an environment without having to write a
8196 package expression to contain the desired inputs.
8198 For instance, the command:
8201 guix environment --ad-hoc guile guile-sdl -- guile
8204 runs @command{guile} in an environment where Guile and Guile-SDL are
8207 Note that this example implicitly asks for the default output of
8208 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
8209 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
8210 of @code{glib} (@pxref{Packages with Multiple Outputs}).
8212 This option may be composed with the default behavior of @command{guix
8213 environment}. Packages appearing before @code{--ad-hoc} are interpreted
8214 as packages whose dependencies will be added to the environment, the
8215 default behavior. Packages appearing after are interpreted as packages
8216 that will be added to the environment directly.
8219 Unset existing environment variables when building the new environment.
8220 This has the effect of creating an environment in which search paths
8221 only contain package inputs.
8223 @item --search-paths
8224 Display the environment variable definitions that make up the
8227 @item --system=@var{system}
8228 @itemx -s @var{system}
8229 Attempt to build for @var{system}---e.g., @code{i686-linux}.
8234 Run @var{command} within an isolated container. The current working
8235 directory outside the container is mapped inside the container.
8236 Additionally, unless overridden with @code{--user}, a dummy home
8237 directory is created that matches the current user's home directory, and
8238 @file{/etc/passwd} is configured accordingly. The spawned process runs
8239 as the current user outside the container, but has root privileges in
8240 the context of the container.
8244 For containers, share the network namespace with the host system.
8245 Containers created without this flag only have access to the loopback
8248 @item --link-profile
8250 For containers, link the environment profile to
8251 @file{~/.guix-profile} within the container. This is equivalent to
8252 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
8253 within the container. Linking will fail and abort the environment if
8254 the directory already exists, which will certainly be the case if
8255 @command{guix environment} was invoked in the user's home directory.
8257 Certain packages are configured to look in
8258 @code{~/.guix-profile} for configuration files and data;@footnote{For
8259 example, the @code{fontconfig} package inspects
8260 @file{~/.guix-profile/share/fonts} for additional fonts.}
8261 @code{--link-profile} allows these programs to behave as expected within
8264 @item --user=@var{user}
8265 @itemx -u @var{user}
8266 For containers, use the username @var{user} in place of the current
8267 user. The generated @file{/etc/passwd} entry within the container will
8268 contain the name @var{user}; the home directory will be
8269 @file{/home/USER}; and no user GECOS data will be copied. @var{user}
8270 need not exist on the system.
8272 Additionally, any shared or exposed path (see @code{--share} and
8273 @code{--expose} respectively) whose target is within the current user's
8274 home directory will be remapped relative to @file{/home/USER}; this
8275 includes the automatic mapping of the current working directory.
8278 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
8280 guix environment --container --user=foo \
8281 --expose=$HOME/test \
8282 --expose=/tmp/target=$HOME/target
8285 While this will limit the leaking of user identity through home paths
8286 and each of the user fields, this is only one useful component of a
8287 broader privacy/anonymity solution---not one in and of itself.
8289 @item --expose=@var{source}[=@var{target}]
8290 For containers, expose the file system @var{source} from the host system
8291 as the read-only file system @var{target} within the container. If
8292 @var{target} is not specified, @var{source} is used as the target mount
8293 point in the container.
8295 The example below spawns a Guile REPL in a container in which the user's
8296 home directory is accessible read-only via the @file{/exchange}
8300 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
8303 @item --share=@var{source}[=@var{target}]
8304 For containers, share the file system @var{source} from the host system
8305 as the writable file system @var{target} within the container. If
8306 @var{target} is not specified, @var{source} is used as the target mount
8307 point in the container.
8309 The example below spawns a Guile REPL in a container in which the user's
8310 home directory is accessible for both reading and writing via the
8311 @file{/exchange} directory:
8314 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
8318 @command{guix environment}
8319 also supports all of the common build options that @command{guix
8320 build} supports (@pxref{Common Build Options}).
8323 @node Invoking guix publish
8324 @section Invoking @command{guix publish}
8326 @cindex @command{guix publish}
8327 The purpose of @command{guix publish} is to enable users to easily share
8328 their store with others, who can then use it as a substitute server
8329 (@pxref{Substitutes}).
8331 When @command{guix publish} runs, it spawns an HTTP server which allows
8332 anyone with network access to obtain substitutes from it. This means
8333 that any machine running Guix can also act as if it were a build farm,
8334 since the HTTP interface is compatible with Hydra, the software behind
8335 the @code{@value{SUBSTITUTE-SERVER}} build farm.
8337 For security, each substitute is signed, allowing recipients to check
8338 their authenticity and integrity (@pxref{Substitutes}). Because
8339 @command{guix publish} uses the signing key of the system, which is only
8340 readable by the system administrator, it must be started as root; the
8341 @code{--user} option makes it drop root privileges early on.
8343 The signing key pair must be generated before @command{guix publish} is
8344 launched, using @command{guix archive --generate-key} (@pxref{Invoking
8347 The general syntax is:
8350 guix publish @var{options}@dots{}
8353 Running @command{guix publish} without any additional arguments will
8354 spawn an HTTP server on port 8080:
8360 Once a publishing server has been authorized (@pxref{Invoking guix
8361 archive}), the daemon may download substitutes from it:
8364 guix-daemon --substitute-urls=http://example.org:8080
8367 By default, @command{guix publish} compresses archives on the fly as it
8368 serves them. This ``on-the-fly'' mode is convenient in that it requires
8369 no setup and is immediately available. However, when serving lots of
8370 clients, we recommend using the @option{--cache} option, which enables
8371 caching of the archives before they are sent to clients---see below for
8372 details. The @command{guix weather} command provides a handy way to
8373 check what a server provides (@pxref{Invoking guix weather}).
8375 As a bonus, @command{guix publish} also serves as a content-addressed
8376 mirror for source files referenced in @code{origin} records
8377 (@pxref{origin Reference}). For instance, assuming @command{guix
8378 publish} is running on @code{example.org}, the following URL returns the
8379 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
8380 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
8383 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
8386 Obviously, these URLs only work for files that are in the store; in
8387 other cases, they return 404 (``Not Found'').
8389 @cindex build logs, publication
8390 Build logs are available from @code{/log} URLs like:
8393 http://example.org/log/gwspk@dots{}-guile-2.2.3
8397 When @command{guix-daemon} is configured to save compressed build logs,
8398 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
8399 URLs return the compressed log as-is, with an appropriate
8400 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
8401 running @command{guix-daemon} with @code{--log-compression=gzip} since
8402 Web browsers can automatically decompress it, which is not the case with
8405 The following options are available:
8408 @item --port=@var{port}
8409 @itemx -p @var{port}
8410 Listen for HTTP requests on @var{port}.
8412 @item --listen=@var{host}
8413 Listen on the network interface for @var{host}. The default is to
8414 accept connections from any interface.
8416 @item --user=@var{user}
8417 @itemx -u @var{user}
8418 Change privileges to @var{user} as soon as possible---i.e., once the
8419 server socket is open and the signing key has been read.
8421 @item --compression[=@var{level}]
8422 @itemx -C [@var{level}]
8423 Compress data using the given @var{level}. When @var{level} is zero,
8424 disable compression. The range 1 to 9 corresponds to different gzip
8425 compression levels: 1 is the fastest, and 9 is the best (CPU-intensive).
8428 Unless @option{--cache} is used, compression occurs on the fly and
8429 the compressed streams are not
8430 cached. Thus, to reduce load on the machine that runs @command{guix
8431 publish}, it may be a good idea to choose a low compression level, to
8432 run @command{guix publish} behind a caching proxy, or to use
8433 @option{--cache}. Using @option{--cache} has the advantage that it
8434 allows @command{guix publish} to add @code{Content-Length} HTTP header
8437 @item --cache=@var{directory}
8438 @itemx -c @var{directory}
8439 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
8440 and only serve archives that are in cache.
8442 When this option is omitted, archives and meta-data are created
8443 on-the-fly. This can reduce the available bandwidth, especially when
8444 compression is enabled, since this may become CPU-bound. Another
8445 drawback of the default mode is that the length of archives is not known
8446 in advance, so @command{guix publish} does not add a
8447 @code{Content-Length} HTTP header to its responses, which in turn
8448 prevents clients from knowing the amount of data being downloaded.
8450 Conversely, when @option{--cache} is used, the first request for a store
8451 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
8452 background process to @dfn{bake} the archive---computing its
8453 @code{.narinfo} and compressing the archive, if needed. Once the
8454 archive is cached in @var{directory}, subsequent requests succeed and
8455 are served directly from the cache, which guarantees that clients get
8456 the best possible bandwidth.
8458 The ``baking'' process is performed by worker threads. By default, one
8459 thread per CPU core is created, but this can be customized. See
8460 @option{--workers} below.
8462 When @option{--ttl} is used, cached entries are automatically deleted
8463 when they have expired.
8465 @item --workers=@var{N}
8466 When @option{--cache} is used, request the allocation of @var{N} worker
8467 threads to ``bake'' archives.
8469 @item --ttl=@var{ttl}
8470 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
8471 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
8472 days, @code{1m} means 1 month, and so on.
8474 This allows the user's Guix to keep substitute information in cache for
8475 @var{ttl}. However, note that @code{guix publish} does not itself
8476 guarantee that the store items it provides will indeed remain available
8477 for as long as @var{ttl}.
8479 Additionally, when @option{--cache} is used, cached entries that have
8480 not been accessed for @var{ttl} and that no longer have a corresponding
8481 item in the store, may be deleted.
8483 @item --nar-path=@var{path}
8484 Use @var{path} as the prefix for the URLs of ``nar'' files
8485 (@pxref{Invoking guix archive, normalized archives}).
8487 By default, nars are served at a URL such as
8488 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
8489 change the @code{/nar} part to @var{path}.
8491 @item --public-key=@var{file}
8492 @itemx --private-key=@var{file}
8493 Use the specific @var{file}s as the public/private key pair used to sign
8494 the store items being published.
8496 The files must correspond to the same key pair (the private key is used
8497 for signing and the public key is merely advertised in the signature
8498 metadata). They must contain keys in the canonical s-expression format
8499 as produced by @command{guix archive --generate-key} (@pxref{Invoking
8500 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
8501 @file{/etc/guix/signing-key.sec} are used.
8503 @item --repl[=@var{port}]
8504 @itemx -r [@var{port}]
8505 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
8506 Reference Manual}) on @var{port} (37146 by default). This is used
8507 primarily for debugging a running @command{guix publish} server.
8510 Enabling @command{guix publish} on a GuixSD system is a one-liner: just
8511 instantiate a @code{guix-publish-service-type} service in the @code{services} field
8512 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
8513 @code{guix-publish-service-type}}).
8515 If you are instead running Guix on a ``foreign distro'', follow these
8520 If your host distro uses the systemd init system:
8523 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
8524 /etc/systemd/system/
8525 # systemctl start guix-publish && systemctl enable guix-publish
8529 If your host distro uses the Upstart init system:
8532 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
8533 # start guix-publish
8537 Otherwise, proceed similarly with your distro's init system.
8540 @node Invoking guix challenge
8541 @section Invoking @command{guix challenge}
8543 @cindex reproducible builds
8544 @cindex verifiable builds
8545 @cindex @command{guix challenge}
8547 Do the binaries provided by this server really correspond to the source
8548 code it claims to build? Is a package build process deterministic?
8549 These are the questions the @command{guix challenge} command attempts to
8552 The former is obviously an important question: Before using a substitute
8553 server (@pxref{Substitutes}), one had better @emph{verify} that it
8554 provides the right binaries, and thus @emph{challenge} it. The latter
8555 is what enables the former: If package builds are deterministic, then
8556 independent builds of the package should yield the exact same result,
8557 bit for bit; if a server provides a binary different from the one
8558 obtained locally, it may be either corrupt or malicious.
8560 We know that the hash that shows up in @file{/gnu/store} file names is
8561 the hash of all the inputs of the process that built the file or
8562 directory---compilers, libraries, build scripts,
8563 etc. (@pxref{Introduction}). Assuming deterministic build processes,
8564 one store file name should map to exactly one build output.
8565 @command{guix challenge} checks whether there is, indeed, a single
8566 mapping by comparing the build outputs of several independent builds of
8567 any given store item.
8569 The command output looks like this:
8572 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
8573 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
8574 updating list of substitutes from 'https://guix.example.org'... 100.0%
8575 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
8576 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8577 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
8578 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
8579 /gnu/store/@dots{}-git-2.5.0 contents differ:
8580 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
8581 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
8582 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
8583 /gnu/store/@dots{}-pius-2.1.1 contents differ:
8584 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8585 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
8586 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
8590 6,406 store items were analyzed:
8591 - 4,749 (74.1%) were identical
8592 - 525 (8.2%) differed
8593 - 1,132 (17.7%) were inconclusive
8597 In this example, @command{guix challenge} first scans the store to
8598 determine the set of locally-built derivations---as opposed to store
8599 items that were downloaded from a substitute server---and then queries
8600 all the substitute servers. It then reports those store items for which
8601 the servers obtained a result different from the local build.
8603 @cindex non-determinism, in package builds
8604 As an example, @code{guix.example.org} always gets a different answer.
8605 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
8606 case of Git. This might indicate that the build process of Git is
8607 non-deterministic, meaning that its output varies as a function of
8608 various things that Guix does not fully control, in spite of building
8609 packages in isolated environments (@pxref{Features}). Most common
8610 sources of non-determinism include the addition of timestamps in build
8611 results, the inclusion of random numbers, and directory listings sorted
8612 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
8615 To find out what is wrong with this Git binary, we can do something along
8616 these lines (@pxref{Invoking guix archive}):
8619 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
8620 | guix archive -x /tmp/git
8621 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
8624 This command shows the difference between the files resulting from the
8625 local build, and the files resulting from the build on
8626 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
8627 diffutils, Comparing and Merging Files}). The @command{diff} command
8628 works great for text files. When binary files differ, a better option
8629 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
8630 visualize differences for all kinds of files.
8632 Once you have done that work, you can tell whether the differences are due
8633 to a non-deterministic build process or to a malicious server. We try
8634 hard to remove sources of non-determinism in packages to make it easier
8635 to verify substitutes, but of course, this is a process that
8636 involves not just Guix, but a large part of the free software community.
8637 In the meantime, @command{guix challenge} is one tool to help address
8640 If you are writing packages for Guix, you are encouraged to check
8641 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
8642 same build result as you did with:
8645 $ guix challenge @var{package}
8649 where @var{package} is a package specification such as
8650 @code{guile@@2.0} or @code{glibc:debug}.
8652 The general syntax is:
8655 guix challenge @var{options} [@var{packages}@dots{}]
8658 When a difference is found between the hash of a locally-built item and
8659 that of a server-provided substitute, or among substitutes provided by
8660 different servers, the command displays it as in the example above and
8661 its exit code is 2 (other non-zero exit codes denote other kinds of
8664 The one option that matters is:
8668 @item --substitute-urls=@var{urls}
8669 Consider @var{urls} the whitespace-separated list of substitute source
8674 Show details about matches (identical contents) in addition to
8675 information about mismatches.
8679 @node Invoking guix copy
8680 @section Invoking @command{guix copy}
8682 @cindex copy, of store items, over SSH
8683 @cindex SSH, copy of store items
8684 @cindex sharing store items across machines
8685 @cindex transferring store items across machines
8686 The @command{guix copy} command copies items from the store of one
8687 machine to that of another machine over a secure shell (SSH)
8688 connection@footnote{This command is available only when Guile-SSH was
8689 found. @xref{Requirements}, for details.}. For example, the following
8690 command copies the @code{coreutils} package, the user's profile, and all
8691 their dependencies over to @var{host}, logged in as @var{user}:
8694 guix copy --to=@var{user}@@@var{host} \
8695 coreutils `readlink -f ~/.guix-profile`
8698 If some of the items to be copied are already present on @var{host},
8699 they are not actually sent.
8701 The command below retrieves @code{libreoffice} and @code{gimp} from
8702 @var{host}, assuming they are available there:
8705 guix copy --from=@var{host} libreoffice gimp
8708 The SSH connection is established using the Guile-SSH client, which is
8709 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
8710 @file{~/.ssh/config}, and uses the SSH agent for authentication.
8712 The key used to sign items that are sent must be accepted by the remote
8713 machine. Likewise, the key used by the remote machine to sign items you
8714 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
8715 own daemon. @xref{Invoking guix archive}, for more information about
8716 store item authentication.
8718 The general syntax is:
8721 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
8724 You must always specify one of the following options:
8727 @item --to=@var{spec}
8728 @itemx --from=@var{spec}
8729 Specify the host to send to or receive from. @var{spec} must be an SSH
8730 spec such as @code{example.org}, @code{charlie@@example.org}, or
8731 @code{charlie@@example.org:2222}.
8734 The @var{items} can be either package names, such as @code{gimp}, or
8735 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
8737 When specifying the name of a package to send, it is first built if
8738 needed, unless @option{--dry-run} was specified. Common build options
8739 are supported (@pxref{Common Build Options}).
8742 @node Invoking guix container
8743 @section Invoking @command{guix container}
8745 @cindex @command{guix container}
8747 As of version @value{VERSION}, this tool is experimental. The interface
8748 is subject to radical change in the future.
8751 The purpose of @command{guix container} is to manipulate processes
8752 running within an isolated environment, commonly known as a
8753 ``container'', typically created by the @command{guix environment}
8754 (@pxref{Invoking guix environment}) and @command{guix system container}
8755 (@pxref{Invoking guix system}) commands.
8757 The general syntax is:
8760 guix container @var{action} @var{options}@dots{}
8763 @var{action} specifies the operation to perform with a container, and
8764 @var{options} specifies the context-specific arguments for the action.
8766 The following actions are available:
8770 Execute a command within the context of a running container.
8775 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
8778 @var{pid} specifies the process ID of the running container.
8779 @var{program} specifies an executable file name within the root file
8780 system of the container. @var{arguments} are the additional options that
8781 will be passed to @var{program}.
8783 The following command launches an interactive login shell inside a
8784 GuixSD container, started by @command{guix system container}, and whose
8788 guix container exec 9001 /run/current-system/profile/bin/bash --login
8791 Note that the @var{pid} cannot be the parent process of a container. It
8792 must be PID 1 of the container or one of its child processes.
8796 @node Invoking guix weather
8797 @section Invoking @command{guix weather}
8799 Occasionally you're grumpy because substitutes are lacking and you end
8800 up building packages by yourself (@pxref{Substitutes}). The
8801 @command{guix weather} command reports on substitute availability on the
8802 specified servers so you can have an idea of whether you'll be grumpy
8803 today. It can sometimes be useful info as a user, but it is primarily
8804 useful to people running @command{guix publish} (@pxref{Invoking guix
8807 @cindex statistics, for substitutes
8808 @cindex availability of substitutes
8809 @cindex substitute availability
8810 @cindex weather, substitute availability
8811 Here's a sample run:
8814 $ guix weather --substitute-urls=https://guix.example.org
8815 computing 5,872 package derivations for x86_64-linux...
8816 looking for 6,128 store items on https://guix.example.org..
8817 updating list of substitutes from 'https://guix.example.org'... 100.0%
8818 https://guix.example.org
8819 43.4% substitutes available (2,658 out of 6,128)
8820 7,032.5 MiB of nars (compressed)
8821 19,824.2 MiB on disk (uncompressed)
8822 0.030 seconds per request (182.9 seconds in total)
8823 33.5 requests per second
8825 9.8% (342 out of 3,470) of the missing items are queued
8827 x86_64-linux: 518 (59.7%)
8828 i686-linux: 221 (25.5%)
8829 aarch64-linux: 128 (14.8%)
8830 build rate: 23.41 builds per hour
8831 x86_64-linux: 11.16 builds per hour
8832 i686-linux: 6.03 builds per hour
8833 aarch64-linux: 6.41 builds per hour
8836 @cindex continuous integration, statistics
8837 As you can see, it reports the fraction of all the packages for which
8838 substitutes are available on the server---regardless of whether
8839 substitutes are enabled, and regardless of whether this server's signing
8840 key is authorized. It also reports the size of the compressed archives
8841 (``nars'') provided by the server, the size the corresponding store
8842 items occupy in the store (assuming deduplication is turned off), and
8843 the server's throughput. The second part gives continuous integration
8844 (CI) statistics, if the server supports it.
8846 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
8847 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
8848 challenge}, it ignores signatures on those substitutes, which is
8849 innocuous since the command only gathers statistics and cannot install
8852 Among other things, it is possible to query specific system types and
8853 specific package sets. The available options are listed below.
8856 @item --substitute-urls=@var{urls}
8857 @var{urls} is the space-separated list of substitute server URLs to
8858 query. When this option is omitted, the default set of substitute
8861 @item --system=@var{system}
8862 @itemx -s @var{system}
8863 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
8864 option can be repeated, in which case @command{guix weather} will query
8865 substitutes for several system types.
8867 @item --manifest=@var{file}
8868 Instead of querying substitutes for all the packages, only ask for those
8869 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
8870 with the @code{-m} option of @command{guix package} (@pxref{Invoking
8874 @node Invoking guix processes
8875 @section Invoking @command{guix processes}
8877 The @command{guix processes} command can be useful to developers and system
8878 administrators, especially on multi-user machines and on build farms: it lists
8879 the current sessions (connections to the daemon), as well as information about
8880 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
8881 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
8882 listed.}. Here's an example of the information it returns:
8885 $ sudo guix processes
8888 ClientCommand: guix environment --ad-hoc python
8892 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
8896 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
8897 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
8898 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
8899 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
8900 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
8901 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
8902 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
8905 In this example we see that @command{guix-daemon} has three clients:
8906 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
8907 integration tool; their process identifier (PID) is given by the
8908 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
8909 @command{guix-daemon} sub-process of this particular session.
8911 The @code{LockHeld} fields show which store items are currently locked by this
8912 session, which corresponds to store items being built or substituted (the
8913 @code{LockHeld} field is not displayed when @command{guix processes} is not
8914 running as root.) Last, by looking at the @code{ChildProcess} field, we
8915 understand that these three builds are being offloaded (@pxref{Daemon Offload
8918 The output is in Recutils format so we can use the handy @command{recsel}
8919 command to select sessions of interest (@pxref{Selection Expressions,,,
8920 recutils, GNU recutils manual}). As an example, the command shows the command
8921 line and PID of the client that triggered the build of a Perl package:
8924 $ sudo guix processes | \
8925 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
8927 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
8930 @c *********************************************************************
8931 @node GNU Distribution
8932 @chapter GNU Distribution
8934 @cindex Guix System Distribution
8936 Guix comes with a distribution of the GNU system consisting entirely of
8937 free software@footnote{The term ``free'' here refers to the
8938 @url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
8939 users of that software}.}. The
8940 distribution can be installed on its own (@pxref{System Installation}),
8941 but it is also possible to install Guix as a package manager on top of
8942 an installed GNU/Linux system (@pxref{Installation}). To distinguish
8943 between the two, we refer to the standalone distribution as the Guix
8944 System Distribution, or GuixSD.
8946 The distribution provides core GNU packages such as GNU libc, GCC, and
8947 Binutils, as well as many GNU and non-GNU applications. The complete
8948 list of available packages can be browsed
8949 @url{http://www.gnu.org/software/guix/packages,on-line} or by
8950 running @command{guix package} (@pxref{Invoking guix package}):
8953 guix package --list-available
8956 Our goal is to provide a practical 100% free software distribution of
8957 Linux-based and other variants of GNU, with a focus on the promotion and
8958 tight integration of GNU components, and an emphasis on programs and
8959 tools that help users exert that freedom.
8961 Packages are currently available on the following platforms:
8966 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
8969 Intel 32-bit architecture (IA32), Linux-Libre kernel;
8972 ARMv7-A architecture with hard float, Thumb-2 and NEON,
8973 using the EABI hard-float application binary interface (ABI),
8974 and Linux-Libre kernel.
8977 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel. This is
8978 currently in an experimental stage, with limited support.
8979 @xref{Contributing}, for how to help!
8981 @item mips64el-linux
8982 little-endian 64-bit MIPS processors, specifically the Loongson series,
8983 n32 ABI, and Linux-Libre kernel.
8987 GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
8990 For information on porting to other architectures or kernels,
8994 * System Installation:: Installing the whole operating system.
8995 * System Configuration:: Configuring the operating system.
8996 * Documentation:: Browsing software user manuals.
8997 * Installing Debugging Files:: Feeding the debugger.
8998 * Security Updates:: Deploying security fixes quickly.
8999 * Package Modules:: Packages from the programmer's viewpoint.
9000 * Packaging Guidelines:: Growing the distribution.
9001 * Bootstrapping:: GNU/Linux built from scratch.
9002 * Porting:: Targeting another platform or kernel.
9005 Building this distribution is a cooperative effort, and you are invited
9006 to join! @xref{Contributing}, for information about how you can help.
9008 @node System Installation
9009 @section System Installation
9011 @cindex installing GuixSD
9012 @cindex Guix System Distribution
9013 This section explains how to install the Guix System Distribution (GuixSD)
9014 on a machine. The Guix package manager can
9015 also be installed on top of a running GNU/Linux system,
9016 @pxref{Installation}.
9020 @c This paragraph is for people reading this from tty2 of the
9021 @c installation image.
9022 You are reading this documentation with an Info reader. For details on
9023 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
9024 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
9025 Info}. Hit @kbd{l} afterwards to come back here.
9027 Alternately, run @command{info info} in another tty to keep the manual
9033 * Limitations:: What you can expect.
9034 * Hardware Considerations:: Supported hardware.
9035 * USB Stick and DVD Installation:: Preparing the installation medium.
9036 * Preparing for Installation:: Networking, partitioning, etc.
9037 * Proceeding with the Installation:: The real thing.
9038 * Installing GuixSD in a VM:: GuixSD playground.
9039 * Building the Installation Image:: How this comes to be.
9043 @subsection Limitations
9045 As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
9046 not production-ready. It may contain bugs and lack important
9047 features. Thus, if you are looking for a stable production system that
9048 respects your freedom as a computer user, a good solution at this point
9049 is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
9050 the more established GNU/Linux distributions}. We hope you can soon switch
9051 to the GuixSD without fear, of course. In the meantime, you can
9052 also keep using your distribution and try out the package manager on top
9053 of it (@pxref{Installation}).
9055 Before you proceed with the installation, be aware of the following
9056 noteworthy limitations applicable to version @value{VERSION}:
9060 The installation process does not include a graphical user interface and
9061 requires familiarity with GNU/Linux (see the following subsections to
9062 get a feel of what that means.)
9065 Support for the Logical Volume Manager (LVM) is missing.
9068 More and more system services are provided (@pxref{Services}), but some
9072 More than 8,500 packages are available, but you might
9073 occasionally find that a useful package is missing.
9076 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
9077 as well as a number of X11 window managers. However, some graphical
9078 applications may be missing, as well as KDE.
9081 You have been warned! But more than a disclaimer, this is an invitation
9082 to report issues (and success stories!), and to join us in improving it.
9083 @xref{Contributing}, for more info.
9086 @node Hardware Considerations
9087 @subsection Hardware Considerations
9089 @cindex hardware support on GuixSD
9090 GNU@tie{}GuixSD focuses on respecting the user's computing freedom. It
9091 builds around the kernel Linux-libre, which means that only hardware for
9092 which free software drivers and firmware exist is supported. Nowadays,
9093 a wide range of off-the-shelf hardware is supported on
9094 GNU/Linux-libre---from keyboards to graphics cards to scanners and
9095 Ethernet controllers. Unfortunately, there are still areas where
9096 hardware vendors deny users control over their own computing, and such
9097 hardware is not supported on GuixSD.
9099 @cindex WiFi, hardware support
9100 One of the main areas where free drivers or firmware are lacking is WiFi
9101 devices. WiFi devices known to work include those using Atheros chips
9102 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
9103 driver, and those using Broadcom/AirForce chips (BCM43xx with
9104 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
9105 Linux-libre driver. Free firmware exists for both and is available
9106 out-of-the-box on GuixSD, as part of @var{%base-firmware}
9107 (@pxref{operating-system Reference, @code{firmware}}).
9109 @cindex RYF, Respects Your Freedom
9110 The @uref{https://www.fsf.org/, Free Software Foundation} runs
9111 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
9112 certification program for hardware products that respect your freedom
9113 and your privacy and ensure that you have control over your device. We
9114 encourage you to check the list of RYF-certified devices.
9116 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
9117 web site. It contains a catalog of hardware devices with information
9118 about their support in GNU/Linux.
9121 @node USB Stick and DVD Installation
9122 @subsection USB Stick and DVD Installation
9124 An ISO-9660 installation image that can be written to a USB stick or
9125 burnt to a DVD can be downloaded from
9126 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz},
9127 where @var{system} is one of:
9131 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
9134 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
9137 @c start duplication of authentication part from ``Binary Installation''
9138 Make sure to download the associated @file{.sig} file and to verify the
9139 authenticity of the image against it, along these lines:
9142 $ wget https://alpha.gnu.org/gnu/guix/guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9143 $ gpg --verify guixsd-install-@value{VERSION}.@var{system}.iso.xz.sig
9146 If that command fails because you do not have the required public key,
9147 then run this command to import it:
9150 $ gpg --keyserver @value{KEY-SERVER} \
9151 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9155 and rerun the @code{gpg --verify} command.
9158 This image contains the tools necessary for an installation.
9159 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
9161 @unnumberedsubsubsec Copying to a USB Stick
9163 To copy the image to a USB stick, follow these steps:
9167 Decompress the image using the @command{xz} command:
9170 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9174 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
9175 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
9176 copy the image with:
9179 dd if=guixsd-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
9183 Access to @file{/dev/sdX} usually requires root privileges.
9186 @unnumberedsubsubsec Burning on a DVD
9188 To copy the image to a DVD, follow these steps:
9192 Decompress the image using the @command{xz} command:
9195 xz -d guixsd-install-@value{VERSION}.@var{system}.iso.xz
9199 Insert a blank DVD into your machine, and determine
9200 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
9201 copy the image with:
9204 growisofs -dvd-compat -Z /dev/srX=guixsd-install-@value{VERSION}.@var{system}.iso
9207 Access to @file{/dev/srX} usually requires root privileges.
9210 @unnumberedsubsubsec Booting
9212 Once this is done, you should be able to reboot the system and boot from
9213 the USB stick or DVD. The latter usually requires you to get in the
9214 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
9216 @xref{Installing GuixSD in a VM}, if, instead, you would like to install
9217 GuixSD in a virtual machine (VM).
9220 @node Preparing for Installation
9221 @subsection Preparing for Installation
9223 Once you have successfully booted your computer using the installation medium,
9224 you should end up with a root prompt. Several console TTYs are configured
9225 and can be used to run commands as root. TTY2 shows this documentation,
9226 browsable using the Info reader commands (@pxref{Top,,, info-stnd,
9227 Stand-alone GNU Info}). The installation system runs the GPM mouse
9228 daemon, which allows you to select text with the left mouse button and
9229 to paste it with the middle button.
9232 Installation requires access to the Internet so that any missing
9233 dependencies of your system configuration can be downloaded. See the
9234 ``Networking'' section below.
9237 The installation system includes many common tools needed for this task.
9238 But it is also a full-blown GuixSD system, which means that you can
9239 install additional packages, should you need it, using @command{guix
9240 package} (@pxref{Invoking guix package}).
9242 @subsubsection Keyboard Layout
9244 @cindex keyboard layout
9245 The installation image uses the US qwerty keyboard layout. If you want
9246 to change it, you can use the @command{loadkeys} command. For example,
9247 the following command selects the Dvorak keyboard layout:
9253 See the files under @file{/run/current-system/profile/share/keymaps} for
9254 a list of available keyboard layouts. Run @command{man loadkeys} for
9257 @subsubsection Networking
9259 Run the following command to see what your network interfaces are called:
9266 @dots{} or, using the GNU/Linux-specific @command{ip} command:
9272 @c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
9273 Wired interfaces have a name starting with @samp{e}; for example, the
9274 interface corresponding to the first on-board Ethernet controller is
9275 called @samp{eno1}. Wireless interfaces have a name starting with
9276 @samp{w}, like @samp{w1p2s0}.
9279 @item Wired connection
9280 To configure a wired network run the following command, substituting
9281 @var{interface} with the name of the wired interface you want to use.
9284 ifconfig @var{interface} up
9287 @item Wireless connection
9290 To configure wireless networking, you can create a configuration file
9291 for the @command{wpa_supplicant} configuration tool (its location is not
9292 important) using one of the available text editors such as
9296 nano wpa_supplicant.conf
9299 As an example, the following stanza can go to this file and will work
9300 for many wireless networks, provided you give the actual SSID and
9301 passphrase for the network you are connecting to:
9305 ssid="@var{my-ssid}"
9307 psk="the network's secret passphrase"
9311 Start the wireless service and run it in the background with the
9312 following command (substitute @var{interface} with the name of the
9313 network interface you want to use):
9316 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
9319 Run @command{man wpa_supplicant} for more information.
9323 At this point, you need to acquire an IP address. On a network where IP
9324 addresses are automatically assigned @i{via} DHCP, you can run:
9327 dhclient -v @var{interface}
9330 Try to ping a server to see if networking is up and running:
9336 Setting up network access is almost always a requirement because the
9337 image does not contain all the software and tools that may be needed.
9339 @cindex installing over SSH
9340 If you want to, you can continue the installation remotely by starting
9344 herd start ssh-daemon
9347 Make sure to either set a password with @command{passwd}, or configure
9348 OpenSSH public key authentication before logging in.
9350 @subsubsection Disk Partitioning
9352 Unless this has already been done, the next step is to partition, and
9353 then format the target partition(s).
9355 The installation image includes several partitioning tools, including
9356 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
9357 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
9358 the partition layout you want:
9364 If your disk uses the GUID Partition Table (GPT) format and you plan to
9365 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
9366 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
9369 @cindex EFI, installation
9370 @cindex UEFI, installation
9371 @cindex ESP, EFI system partition
9372 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
9373 (ESP) is required. This partition should be mounted at @file{/boot/efi} and
9374 must have the @code{esp} flag set. E.g., for @command{parted}:
9377 parted /dev/sda set 1 esp on
9381 @vindex grub-bootloader
9382 @vindex grub-efi-bootloader
9383 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
9384 @file{/sys/firmware/efi} exists in the installation image, then you should
9385 probably perform an EFI installation, using @code{grub-efi-bootloader}.
9386 Otherwise you should use the BIOS-based GRUB, known as
9387 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
9391 Once you are done partitioning the target hard disk drive, you have to
9392 create a file system on the relevant partition(s)@footnote{Currently
9393 GuixSD only supports ext4 and btrfs file systems. In particular, code
9394 that reads file system UUIDs and labels only works for these file system
9395 types.}. For the ESP, if you have one and assuming it is
9396 @file{/dev/sda1}, run:
9399 mkfs.fat -F32 /dev/sda1
9402 Preferably, assign file systems a label so that you can easily and
9403 reliably refer to them in @code{file-system} declarations (@pxref{File
9404 Systems}). This is typically done using the @code{-L} option of
9405 @command{mkfs.ext4} and related commands. So, assuming the target root
9406 partition lives at @file{/dev/sda2}, a file system with the label
9407 @code{my-root} can be created with:
9410 mkfs.ext4 -L my-root /dev/sda2
9413 @cindex encrypted disk
9414 If you are instead planning to encrypt the root partition, you can use
9415 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
9416 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
9417 @code{man cryptsetup}} for more information.) Assuming you want to
9418 store the root partition on @file{/dev/sda2}, the command sequence would
9419 be along these lines:
9422 cryptsetup luksFormat /dev/sda2
9423 cryptsetup open --type luks /dev/sda2 my-partition
9424 mkfs.ext4 -L my-root /dev/mapper/my-partition
9427 Once that is done, mount the target file system under @file{/mnt}
9428 with a command like (again, assuming @code{my-root} is the label of the
9432 mount LABEL=my-root /mnt
9435 Also mount any other file systems you would like to use on the target
9436 system relative to this path. If you have @file{/boot} on a separate
9437 partition for example, mount it at @file{/mnt/boot} now so it is found
9438 by @code{guix system init} afterwards.
9440 Finally, if you plan to use one or more swap partitions (@pxref{Memory
9441 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
9442 sure to initialize them with @command{mkswap}. Assuming you have one
9443 swap partition on @file{/dev/sda3}, you would run:
9450 Alternatively, you may use a swap file. For example, assuming that in
9451 the new system you want to use the file @file{/swapfile} as a swap file,
9452 you would run@footnote{This example will work for many types of file
9453 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
9454 btrfs), the required steps may be different. For details, see the
9455 manual pages for @command{mkswap} and @command{swapon}.}:
9458 # This is 10 GiB of swap space. Adjust "count" to change the size.
9459 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
9460 # For security, make the file readable and writable only by root.
9461 chmod 600 /mnt/swapfile
9462 mkswap /mnt/swapfile
9463 swapon /mnt/swapfile
9466 Note that if you have encrypted the root partition and created a swap
9467 file in its file system as described above, then the encryption also
9468 protects the swap file, just like any other file in that file system.
9470 @node Proceeding with the Installation
9471 @subsection Proceeding with the Installation
9473 With the target partitions ready and the target root mounted on
9474 @file{/mnt}, we're ready to go. First, run:
9477 herd start cow-store /mnt
9480 This makes @file{/gnu/store} copy-on-write, such that packages added to it
9481 during the installation phase are written to the target disk on @file{/mnt}
9482 rather than kept in memory. This is necessary because the first phase of
9483 the @command{guix system init} command (see below) entails downloads or
9484 builds to @file{/gnu/store} which, initially, is an in-memory file system.
9486 Next, you have to edit a file and
9487 provide the declaration of the operating system to be installed. To
9488 that end, the installation system comes with three text editors. We
9489 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
9490 supports syntax highlighting and parentheses matching; other editors
9491 include GNU Zile (an Emacs clone), and
9492 nvi (a clone of the original BSD @command{vi} editor).
9493 We strongly recommend storing that file on the target root file system, say,
9494 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
9495 configuration file once you have rebooted into the newly-installed system.
9497 @xref{Using the Configuration System}, for an overview of the
9498 configuration file. The example configurations discussed in that
9499 section are available under @file{/etc/configuration} in the
9500 installation image. Thus, to get started with a system configuration
9501 providing a graphical display server (a ``desktop'' system), you can run
9502 something along these lines:
9506 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
9507 # nano /mnt/etc/config.scm
9510 You should pay attention to what your configuration file contains, and
9515 Make sure the @code{bootloader-configuration} form refers to the target
9516 you want to install GRUB on. It should mention @code{grub-bootloader} if
9517 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
9518 for newer UEFI systems. For legacy systems, the @code{target} field
9519 names a device, like @code{/dev/sda}; for UEFI systems it names a path
9520 to a mounted EFI partition, like @code{/boot/efi}, and do make sure the
9521 path is actually mounted.
9524 Be sure that your file system labels match the value of their respective
9525 @code{device} fields in your @code{file-system} configuration, assuming
9526 your @code{file-system} configuration uses the @code{file-system-label}
9527 procedure in its @code{device} field.
9530 If there are encrypted or RAID partitions, make sure to add a
9531 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
9534 Once you are done preparing the configuration file, the new system must
9535 be initialized (remember that the target root file system is mounted
9539 guix system init /mnt/etc/config.scm /mnt
9543 This copies all the necessary files and installs GRUB on
9544 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
9545 more information, @pxref{Invoking guix system}. This command may trigger
9546 downloads or builds of missing packages, which can take some time.
9548 Once that command has completed---and hopefully succeeded!---you can run
9549 @command{reboot} and boot into the new system. The @code{root} password
9550 in the new system is initially empty; other users' passwords need to be
9551 initialized by running the @command{passwd} command as @code{root},
9552 unless your configuration specifies otherwise
9553 (@pxref{user-account-password, user account passwords}).
9555 @cindex upgrading GuixSD
9556 From then on, you can update GuixSD whenever you want by running
9557 @command{guix pull} as @code{root} (@pxref{Invoking guix pull}), and
9558 then running @command{guix system reconfigure} to build a new system
9559 generation with the latest packages and services (@pxref{Invoking guix
9560 system}). We recommend doing that regularly so that your system
9561 includes the latest security updates (@pxref{Security Updates}).
9563 Join us on @code{#guix} on the Freenode IRC network or on
9564 @email{guix-devel@@gnu.org} to share your experience---good or not so
9567 @node Installing GuixSD in a VM
9568 @subsection Installing GuixSD in a Virtual Machine
9570 @cindex virtual machine, GuixSD installation
9571 @cindex virtual private server (VPS)
9572 @cindex VPS (virtual private server)
9573 If you'd like to install GuixSD in a virtual machine (VM) or on a
9574 virtual private server (VPS) rather than on your beloved machine, this
9577 To boot a @uref{http://qemu.org/,QEMU} VM for installing GuixSD in a
9578 disk image, follow these steps:
9582 First, retrieve and decompress the GuixSD installation image as
9583 described previously (@pxref{USB Stick and DVD Installation}).
9586 Create a disk image that will hold the installed system. To make a
9587 qcow2-formatted disk image, use the @command{qemu-img} command:
9590 qemu-img create -f qcow2 guixsd.img 50G
9593 The resulting file will be much smaller than 50 GB (typically less than
9594 1 MB), but it will grow as the virtualized storage device is filled up.
9597 Boot the USB installation image in an VM:
9600 qemu-system-x86_64 -m 1024 -smp 1 \
9601 -net user -net nic,model=virtio -boot menu=on \
9602 -drive file=guixsd-install-@value{VERSION}.@var{system}.iso \
9603 -drive file=guixsd.img
9606 The ordering of the drives matters.
9608 In the VM console, quickly press the @kbd{F12} key to enter the boot
9609 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
9613 You're now root in the VM, proceed with the installation process.
9614 @xref{Preparing for Installation}, and follow the instructions.
9617 Once installation is complete, you can boot the system that's on your
9618 @file{guixsd.img} image. @xref{Running GuixSD in a VM}, for how to do
9621 @node Building the Installation Image
9622 @subsection Building the Installation Image
9624 @cindex installation image
9625 The installation image described above was built using the @command{guix
9626 system} command, specifically:
9629 guix system disk-image gnu/system/install.scm
9632 Have a look at @file{gnu/system/install.scm} in the source tree,
9633 and see also @ref{Invoking guix system} for more information
9634 about the installation image.
9636 @subsection Building the Installation Image for ARM Boards
9638 Many ARM boards require a specific variant of the
9639 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
9641 If you build a disk image and the bootloader is not available otherwise
9642 (on another boot drive etc), it's advisable to build an image that
9643 includes the bootloader, specifically:
9646 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
9649 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
9650 board, a list of possible boards will be printed.
9652 @node System Configuration
9653 @section System Configuration
9655 @cindex system configuration
9656 The Guix System Distribution supports a consistent whole-system configuration
9657 mechanism. By that we mean that all aspects of the global system
9658 configuration---such as the available system services, timezone and
9659 locale settings, user accounts---are declared in a single place. Such
9660 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
9662 One of the advantages of putting all the system configuration under the
9663 control of Guix is that it supports transactional system upgrades, and
9664 makes it possible to roll back to a previous system instantiation,
9665 should something go wrong with the new one (@pxref{Features}). Another
9666 advantage is that it makes it easy to replicate the exact same configuration
9667 across different machines, or at different points in time, without
9668 having to resort to additional administration tools layered on top of
9669 the own tools of the system.
9670 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
9672 This section describes this mechanism. First we focus on the system
9673 administrator's viewpoint---explaining how the system is configured and
9674 instantiated. Then we show how this mechanism can be extended, for
9675 instance to support new system services.
9678 * Using the Configuration System:: Customizing your GNU system.
9679 * operating-system Reference:: Detail of operating-system declarations.
9680 * File Systems:: Configuring file system mounts.
9681 * Mapped Devices:: Block device extra processing.
9682 * User Accounts:: Specifying user accounts.
9683 * Locales:: Language and cultural convention settings.
9684 * Services:: Specifying system services.
9685 * Setuid Programs:: Programs running with root privileges.
9686 * X.509 Certificates:: Authenticating HTTPS servers.
9687 * Name Service Switch:: Configuring libc's name service switch.
9688 * Initial RAM Disk:: Linux-Libre bootstrapping.
9689 * Bootloader Configuration:: Configuring the boot loader.
9690 * Invoking guix system:: Instantiating a system configuration.
9691 * Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
9692 * Defining Services:: Adding new service definitions.
9695 @node Using the Configuration System
9696 @subsection Using the Configuration System
9698 The operating system is configured by providing an
9699 @code{operating-system} declaration in a file that can then be passed to
9700 the @command{guix system} command (@pxref{Invoking guix system}). A
9701 simple setup, with the default system services, the default Linux-Libre
9702 kernel, initial RAM disk, and boot loader looks like this:
9704 @findex operating-system
9706 @include os-config-bare-bones.texi
9709 This example should be self-describing. Some of the fields defined
9710 above, such as @code{host-name} and @code{bootloader}, are mandatory.
9711 Others, such as @code{packages} and @code{services}, can be omitted, in
9712 which case they get a default value.
9714 Below we discuss the effect of some of the most important fields
9715 (@pxref{operating-system Reference}, for details about all the available
9716 fields), and how to @dfn{instantiate} the operating system using
9717 @command{guix system}.
9719 @unnumberedsubsubsec Bootloader
9721 @cindex legacy boot, on Intel machines
9722 @cindex BIOS boot, on Intel machines
9725 The @code{bootloader} field describes the method that will be used to boot
9726 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
9727 mode, as in the example above. However, more recent machines rely instead on
9728 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
9729 the @code{bootloader} field should contain something along these lines:
9732 (bootloader-configuration
9733 (bootloader grub-efi-bootloader)
9734 (target "/boot/efi"))
9737 @xref{Bootloader Configuration}, for more information on the available
9738 configuration options.
9740 @unnumberedsubsubsec Globally-Visible Packages
9742 @vindex %base-packages
9743 The @code{packages} field lists packages that will be globally visible
9744 on the system, for all user accounts---i.e., in every user's @code{PATH}
9745 environment variable---in addition to the per-user profiles
9746 (@pxref{Invoking guix package}). The @var{%base-packages} variable
9747 provides all the tools one would expect for basic user and administrator
9748 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
9749 the GNU Zile lightweight text editor, @command{find}, @command{grep},
9750 etc. The example above adds GNU@tie{}Screen to those,
9751 taken from the @code{(gnu packages screen)}
9752 module (@pxref{Package Modules}). The
9753 @code{(list package output)} syntax can be used to add a specific output
9757 (use-modules (gnu packages))
9758 (use-modules (gnu packages dns))
9762 (packages (cons (list bind "utils")
9766 @findex specification->package
9767 Referring to packages by variable name, like @code{bind} above, has
9768 the advantage of being unambiguous; it also allows typos and such to be
9769 diagnosed right away as ``unbound variables''. The downside is that one
9770 needs to know which module defines which package, and to augment the
9771 @code{use-package-modules} line accordingly. To avoid that, one can use
9772 the @code{specification->package} procedure of the @code{(gnu packages)}
9773 module, which returns the best package for a given name or name and
9777 (use-modules (gnu packages))
9781 (packages (append (map specification->package
9782 '("tcpdump" "htop" "gnupg@@2.0"))
9786 @unnumberedsubsubsec System Services
9789 @vindex %base-services
9790 The @code{services} field lists @dfn{system services} to be made
9791 available when the system starts (@pxref{Services}).
9792 The @code{operating-system} declaration above specifies that, in
9793 addition to the basic services, we want the @command{lshd} secure shell
9794 daemon listening on port 2222 (@pxref{Networking Services,
9795 @code{lsh-service}}). Under the hood,
9796 @code{lsh-service} arranges so that @code{lshd} is started with the
9797 right command-line options, possibly with supporting configuration files
9798 generated as needed (@pxref{Defining Services}).
9800 @cindex customization, of services
9801 @findex modify-services
9802 Occasionally, instead of using the base services as is, you will want to
9803 customize them. To do this, use @code{modify-services} (@pxref{Service
9804 Reference, @code{modify-services}}) to modify the list.
9806 For example, suppose you want to modify @code{guix-daemon} and Mingetty
9807 (the console log-in) in the @var{%base-services} list (@pxref{Base
9808 Services, @code{%base-services}}). To do that, you can write the
9809 following in your operating system declaration:
9812 (define %my-services
9813 ;; My very own list of services.
9814 (modify-services %base-services
9815 (guix-service-type config =>
9818 (use-substitutes? #f)
9819 (extra-options '("--gc-keep-derivations"))))
9820 (mingetty-service-type config =>
9821 (mingetty-configuration
9822 (inherit config)))))
9826 (services %my-services))
9829 This changes the configuration---i.e., the service parameters---of the
9830 @code{guix-service-type} instance, and that of all the
9831 @code{mingetty-service-type} instances in the @var{%base-services} list.
9832 Observe how this is accomplished: first, we arrange for the original
9833 configuration to be bound to the identifier @code{config} in the
9834 @var{body}, and then we write the @var{body} so that it evaluates to the
9835 desired configuration. In particular, notice how we use @code{inherit}
9836 to create a new configuration which has the same values as the old
9837 configuration, but with a few modifications.
9839 @cindex encrypted disk
9840 The configuration for a typical ``desktop'' usage, with an encrypted
9841 root partition, the X11 display
9842 server, GNOME and Xfce (users can choose which of these desktop
9843 environments to use at the log-in screen by pressing @kbd{F1}), network
9844 management, power management, and more, would look like this:
9847 @include os-config-desktop.texi
9850 A graphical system with a choice of lightweight window managers
9851 instead of full-blown desktop environments would look like this:
9854 @include os-config-lightweight-desktop.texi
9857 This example refers to the @file{/boot/efi} file system by its UUID,
9858 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
9859 as returned by the @command{blkid} command.
9861 @xref{Desktop Services}, for the exact list of services provided by
9862 @var{%desktop-services}. @xref{X.509 Certificates}, for background
9863 information about the @code{nss-certs} package that is used here.
9865 Again, @var{%desktop-services} is just a list of service objects. If
9866 you want to remove services from there, you can do so using the
9867 procedures for list filtering (@pxref{SRFI-1 Filtering and
9868 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
9869 following expression returns a list that contains all the services in
9870 @var{%desktop-services} minus the Avahi service:
9873 (remove (lambda (service)
9874 (eq? (service-kind service) avahi-service-type))
9878 @unnumberedsubsubsec Instantiating the System
9880 Assuming the @code{operating-system} declaration
9881 is stored in the @file{my-system-config.scm}
9882 file, the @command{guix system reconfigure my-system-config.scm} command
9883 instantiates that configuration, and makes it the default GRUB boot
9884 entry (@pxref{Invoking guix system}).
9886 The normal way to change the system configuration is by updating this
9887 file and re-running @command{guix system reconfigure}. One should never
9888 have to touch files in @file{/etc} or to run commands that modify the
9889 system state such as @command{useradd} or @command{grub-install}. In
9890 fact, you must avoid that since that would not only void your warranty
9891 but also prevent you from rolling back to previous versions of your
9892 system, should you ever need to.
9894 @cindex roll-back, of the operating system
9895 Speaking of roll-back, each time you run @command{guix system
9896 reconfigure}, a new @dfn{generation} of the system is created---without
9897 modifying or deleting previous generations. Old system generations get
9898 an entry in the bootloader boot menu, allowing you to boot them in case
9899 something went wrong with the latest generation. Reassuring, no? The
9900 @command{guix system list-generations} command lists the system
9901 generations available on disk. It is also possible to roll back the
9902 system via the commands @command{guix system roll-back} and
9903 @command{guix system switch-generation}.
9905 Although the @command{guix system reconfigure} command will not modify
9906 previous generations, you must take care when the current generation is not
9907 the latest (e.g., after invoking @command{guix system roll-back}), since
9908 the operation might overwrite a later generation (@pxref{Invoking guix
9911 @unnumberedsubsubsec The Programming Interface
9913 At the Scheme level, the bulk of an @code{operating-system} declaration
9914 is instantiated with the following monadic procedure (@pxref{The Store
9917 @deffn {Monadic Procedure} operating-system-derivation os
9918 Return a derivation that builds @var{os}, an @code{operating-system}
9919 object (@pxref{Derivations}).
9921 The output of the derivation is a single directory that refers to all
9922 the packages, configuration files, and other supporting files needed to
9923 instantiate @var{os}.
9926 This procedure is provided by the @code{(gnu system)} module. Along
9927 with @code{(gnu services)} (@pxref{Services}), this module contains the
9928 guts of GuixSD. Make sure to visit it!
9931 @node operating-system Reference
9932 @subsection @code{operating-system} Reference
9934 This section summarizes all the options available in
9935 @code{operating-system} declarations (@pxref{Using the Configuration
9938 @deftp {Data Type} operating-system
9939 This is the data type representing an operating system configuration.
9940 By that, we mean all the global system configuration, not per-user
9941 configuration (@pxref{Using the Configuration System}).
9944 @item @code{kernel} (default: @var{linux-libre})
9945 The package object of the operating system kernel to use@footnote{Currently
9946 only the Linux-libre kernel is supported. In the future, it will be
9947 possible to use the GNU@tie{}Hurd.}.
9949 @item @code{kernel-arguments} (default: @code{'()})
9950 List of strings or gexps representing additional arguments to pass on
9951 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
9953 @item @code{bootloader}
9954 The system bootloader configuration object. @xref{Bootloader Configuration}.
9956 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
9958 @cindex initial RAM disk
9959 The list of Linux kernel modules that need to be available in the
9960 initial RAM disk. @xref{Initial RAM Disk}.
9962 @item @code{initrd} (default: @code{base-initrd})
9963 A procedure that returns an initial RAM disk for the Linux
9964 kernel. This field is provided to support low-level customization and
9965 should rarely be needed for casual use. @xref{Initial RAM Disk}.
9967 @item @code{firmware} (default: @var{%base-firmware})
9969 List of firmware packages loadable by the operating system kernel.
9971 The default includes firmware needed for Atheros- and Broadcom-based
9972 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
9973 respectively). @xref{Hardware Considerations}, for more info on
9976 @item @code{host-name}
9979 @item @code{hosts-file}
9981 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
9982 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
9983 Reference Manual}). The default is a file with entries for
9984 @code{localhost} and @var{host-name}.
9986 @item @code{mapped-devices} (default: @code{'()})
9987 A list of mapped devices. @xref{Mapped Devices}.
9989 @item @code{file-systems}
9990 A list of file systems. @xref{File Systems}.
9992 @item @code{swap-devices} (default: @code{'()})
9993 @cindex swap devices
9994 A list of strings identifying devices or files to be used for ``swap
9995 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
9996 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
9997 It is possible to specify a swap file in a file system on a mapped
9998 device, provided that the necessary device mapping and file system are
9999 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10001 @item @code{users} (default: @code{%base-user-accounts})
10002 @itemx @code{groups} (default: @var{%base-groups})
10003 List of user accounts and groups. @xref{User Accounts}.
10005 If the @code{users} list lacks a user account with UID@tie{}0, a
10006 ``root'' account with UID@tie{}0 is automatically added.
10008 @item @code{skeletons} (default: @code{(default-skeletons)})
10009 A list target file name/file-like object tuples (@pxref{G-Expressions,
10010 file-like objects}). These are the skeleton files that will be added to
10011 the home directory of newly-created user accounts.
10013 For instance, a valid value may look like this:
10016 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10017 (".guile" ,(plain-file "guile"
10018 "(use-modules (ice-9 readline))
10019 (activate-readline)")))
10022 @item @code{issue} (default: @var{%default-issue})
10023 A string denoting the contents of the @file{/etc/issue} file, which is
10024 displayed when users log in on a text console.
10026 @item @code{packages} (default: @var{%base-packages})
10027 The set of packages installed in the global profile, which is accessible
10028 at @file{/run/current-system/profile}.
10030 The default set includes core utilities and it is good practice to
10031 install non-core utilities in user profiles (@pxref{Invoking guix
10034 @item @code{timezone}
10035 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10037 You can run the @command{tzselect} command to find out which timezone
10038 string corresponds to your region. Choosing an invalid timezone name
10039 causes @command{guix system} to fail.
10041 @item @code{locale} (default: @code{"en_US.utf8"})
10042 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10043 Library Reference Manual}). @xref{Locales}, for more information.
10045 @item @code{locale-definitions} (default: @var{%default-locale-definitions})
10046 The list of locale definitions to be compiled and that may be used at
10047 run time. @xref{Locales}.
10049 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10050 The list of GNU@tie{}libc packages whose locale data and tools are used
10051 to build the locale definitions. @xref{Locales}, for compatibility
10052 considerations that justify this option.
10054 @item @code{name-service-switch} (default: @var{%default-nss})
10055 Configuration of the libc name service switch (NSS)---a
10056 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10059 @item @code{services} (default: @var{%base-services})
10060 A list of service objects denoting system services. @xref{Services}.
10062 @item @code{pam-services} (default: @code{(base-pam-services)})
10064 @cindex pluggable authentication modules
10065 Linux @dfn{pluggable authentication module} (PAM) services.
10066 @c FIXME: Add xref to PAM services section.
10068 @item @code{setuid-programs} (default: @var{%setuid-programs})
10069 List of string-valued G-expressions denoting setuid programs.
10070 @xref{Setuid Programs}.
10072 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10073 @cindex sudoers file
10074 The contents of the @file{/etc/sudoers} file as a file-like object
10075 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10077 This file specifies which users can use the @command{sudo} command, what
10078 they are allowed to do, and what privileges they may gain. The default
10079 is that only @code{root} and members of the @code{wheel} group may use
10086 @subsection File Systems
10088 The list of file systems to be mounted is specified in the
10089 @code{file-systems} field of the operating system declaration
10090 (@pxref{Using the Configuration System}). Each file system is declared
10091 using the @code{file-system} form, like this:
10095 (mount-point "/home")
10096 (device "/dev/sda3")
10100 As usual, some of the fields are mandatory---those shown in the example
10101 above---while others can be omitted. These are described below.
10103 @deftp {Data Type} file-system
10104 Objects of this type represent file systems to be mounted. They
10105 contain the following members:
10109 This is a string specifying the type of the file system---e.g.,
10112 @item @code{mount-point}
10113 This designates the place where the file system is to be mounted.
10115 @item @code{device}
10116 This names the ``source'' of the file system. It can be one of three
10117 things: a file system label, a file system UUID, or the name of a
10118 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10119 systems without having to hard-code their actual device
10120 name@footnote{Note that, while it is tempting to use
10121 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10122 result, this is not recommended: These special device nodes are created
10123 by the udev daemon and may be unavailable at the time the device is
10126 @findex file-system-label
10127 File system labels are created using the @code{file-system-label}
10128 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10129 plain strings. Here's an example of a file system referred to by its
10130 label, as shown by the @command{e2label} command:
10134 (mount-point "/home")
10136 (device (file-system-label "my-home")))
10140 UUIDs are converted from their string representation (as shown by the
10141 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10142 @code{uuid} form expects 16-byte UUIDs as defined in
10143 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10144 form of UUID used by the ext2 family of file systems and others, but it
10145 is different from ``UUIDs'' found in FAT file systems, for instance.},
10150 (mount-point "/home")
10152 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10155 When the source of a file system is a mapped device (@pxref{Mapped
10156 Devices}), its @code{device} field @emph{must} refer to the mapped
10157 device name---e.g., @file{"/dev/mapper/root-partition"}.
10158 This is required so that
10159 the system knows that mounting the file system depends on having the
10160 corresponding device mapping established.
10162 @item @code{flags} (default: @code{'()})
10163 This is a list of symbols denoting mount flags. Recognized flags
10164 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10165 access to special files), @code{no-suid} (ignore setuid and setgid
10166 bits), and @code{no-exec} (disallow program execution.)
10168 @item @code{options} (default: @code{#f})
10169 This is either @code{#f}, or a string denoting mount options.
10171 @item @code{mount?} (default: @code{#t})
10172 This value indicates whether to automatically mount the file system when
10173 the system is brought up. When set to @code{#f}, the file system gets
10174 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10175 is not automatically mounted.
10177 @item @code{needed-for-boot?} (default: @code{#f})
10178 This Boolean value indicates whether the file system is needed when
10179 booting. If that is true, then the file system is mounted when the
10180 initial RAM disk (initrd) is loaded. This is always the case, for
10181 instance, for the root file system.
10183 @item @code{check?} (default: @code{#t})
10184 This Boolean indicates whether the file system needs to be checked for
10185 errors before being mounted.
10187 @item @code{create-mount-point?} (default: @code{#f})
10188 When true, the mount point is created if it does not exist yet.
10190 @item @code{dependencies} (default: @code{'()})
10191 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10192 representing file systems that must be mounted or mapped devices that
10193 must be opened before (and unmounted or closed after) this one.
10195 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10196 a dependency of @file{/sys/fs/cgroup/cpu} and
10197 @file{/sys/fs/cgroup/memory}.
10199 Another example is a file system that depends on a mapped device, for
10200 example for an encrypted partition (@pxref{Mapped Devices}).
10204 The @code{(gnu system file-systems)} exports the following useful
10207 @defvr {Scheme Variable} %base-file-systems
10208 These are essential file systems that are required on normal systems,
10209 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10210 below.) Operating system declarations should always contain at least
10214 @defvr {Scheme Variable} %pseudo-terminal-file-system
10215 This is the file system to be mounted as @file{/dev/pts}. It supports
10216 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10217 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10218 Manual}). Pseudo-terminals are used by terminal emulators such as
10222 @defvr {Scheme Variable} %shared-memory-file-system
10223 This file system is mounted as @file{/dev/shm} and is used to support
10224 memory sharing across processes (@pxref{Memory-mapped I/O,
10225 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10228 @defvr {Scheme Variable} %immutable-store
10229 This file system performs a read-only ``bind mount'' of
10230 @file{/gnu/store}, making it read-only for all the users including
10231 @code{root}. This prevents against accidental modification by software
10232 running as @code{root} or by system administrators.
10234 The daemon itself is still able to write to the store: it remounts it
10235 read-write in its own ``name space.''
10238 @defvr {Scheme Variable} %binary-format-file-system
10239 The @code{binfmt_misc} file system, which allows handling of arbitrary
10240 executable file types to be delegated to user space. This requires the
10241 @code{binfmt.ko} kernel module to be loaded.
10244 @defvr {Scheme Variable} %fuse-control-file-system
10245 The @code{fusectl} file system, which allows unprivileged users to mount
10246 and unmount user-space FUSE file systems. This requires the
10247 @code{fuse.ko} kernel module to be loaded.
10250 @node Mapped Devices
10251 @subsection Mapped Devices
10253 @cindex device mapping
10254 @cindex mapped devices
10255 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10256 such as a hard disk partition, can be @dfn{mapped} into another device,
10257 usually in @code{/dev/mapper/},
10258 with additional processing over the data that flows through
10259 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10260 concept of a ``mapped device'' and that of a file system: both boil down
10261 to @emph{translating} input/output operations made on a file to
10262 operations on its backing store. Thus, the Hurd implements mapped
10263 devices, like file systems, using the generic @dfn{translator} mechanism
10264 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10265 typical example is encryption device mapping: all writes to the mapped
10266 device are encrypted, and all reads are deciphered, transparently.
10267 Guix extends this notion by considering any device or set of devices that
10268 are @dfn{transformed} in some way to create a new device; for instance,
10269 RAID devices are obtained by @dfn{assembling} several other devices, such
10270 as hard disks or partitions, into a new one that behaves as one partition.
10271 Other examples, not yet implemented, are LVM logical volumes.
10273 Mapped devices are declared using the @code{mapped-device} form,
10274 defined as follows; for examples, see below.
10276 @deftp {Data Type} mapped-device
10277 Objects of this type represent device mappings that will be made when
10278 the system boots up.
10282 This is either a string specifying the name of the block device to be mapped,
10283 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10284 need to be assembled for creating a new one.
10287 This string specifies the name of the resulting mapped device. For
10288 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10289 specifying @code{"my-partition"} leads to the creation of
10290 the @code{"/dev/mapper/my-partition"} device.
10291 For RAID devices of type @code{raid-device-mapping}, the full device name
10292 such as @code{"/dev/md0"} needs to be given.
10295 This must be a @code{mapped-device-kind} object, which specifies how
10296 @var{source} is mapped to @var{target}.
10300 @defvr {Scheme Variable} luks-device-mapping
10301 This defines LUKS block device encryption using the @command{cryptsetup}
10302 command from the package with the same name. It relies on the
10303 @code{dm-crypt} Linux kernel module.
10306 @defvr {Scheme Variable} raid-device-mapping
10307 This defines a RAID device, which is assembled using the @code{mdadm}
10308 command from the package with the same name. It requires a Linux kernel
10309 module for the appropriate RAID level to be loaded, such as @code{raid456}
10310 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10313 @cindex disk encryption
10315 The following example specifies a mapping from @file{/dev/sda3} to
10316 @file{/dev/mapper/home} using LUKS---the
10317 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10318 standard mechanism for disk encryption.
10319 The @file{/dev/mapper/home}
10320 device can then be used as the @code{device} of a @code{file-system}
10321 declaration (@pxref{File Systems}).
10325 (source "/dev/sda3")
10327 (type luks-device-mapping))
10330 Alternatively, to become independent of device numbering, one may obtain
10331 the LUKS UUID (@dfn{unique identifier}) of the source device by a
10335 cryptsetup luksUUID /dev/sda3
10338 and use it as follows:
10342 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
10344 (type luks-device-mapping))
10347 @cindex swap encryption
10348 It is also desirable to encrypt swap space, since swap space may contain
10349 sensitive data. One way to accomplish that is to use a swap file in a
10350 file system on a device mapped via LUKS encryption. In this way, the
10351 swap file is encrypted because the entire device is encrypted.
10352 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
10354 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
10355 may be declared as follows:
10359 (source (list "/dev/sda1" "/dev/sdb1"))
10360 (target "/dev/md0")
10361 (type raid-device-mapping))
10364 The @file{/dev/md0} device can then be used as the @code{device} of a
10365 @code{file-system} declaration (@pxref{File Systems}).
10366 Note that the RAID level need not be given; it is chosen during the
10367 initial creation and formatting of the RAID device and is determined
10368 automatically later.
10371 @node User Accounts
10372 @subsection User Accounts
10376 @cindex user accounts
10377 User accounts and groups are entirely managed through the
10378 @code{operating-system} declaration. They are specified with the
10379 @code{user-account} and @code{user-group} forms:
10385 (supplementary-groups '("wheel" ;allow use of sudo, etc.
10386 "audio" ;sound card
10387 "video" ;video devices such as webcams
10388 "cdrom")) ;the good ol' CD-ROM
10389 (comment "Bob's sister")
10390 (home-directory "/home/alice"))
10393 When booting or upon completion of @command{guix system reconfigure},
10394 the system ensures that only the user accounts and groups specified in
10395 the @code{operating-system} declaration exist, and with the specified
10396 properties. Thus, account or group creations or modifications made by
10397 directly invoking commands such as @command{useradd} are lost upon
10398 reconfiguration or reboot. This ensures that the system remains exactly
10401 @deftp {Data Type} user-account
10402 Objects of this type represent user accounts. The following members may
10407 The name of the user account.
10411 This is the name (a string) or identifier (a number) of the user group
10412 this account belongs to.
10414 @item @code{supplementary-groups} (default: @code{'()})
10415 Optionally, this can be defined as a list of group names that this
10416 account belongs to.
10418 @item @code{uid} (default: @code{#f})
10419 This is the user ID for this account (a number), or @code{#f}. In the
10420 latter case, a number is automatically chosen by the system when the
10421 account is created.
10423 @item @code{comment} (default: @code{""})
10424 A comment about the account, such as the account owner's full name.
10426 @item @code{home-directory}
10427 This is the name of the home directory for the account.
10429 @item @code{create-home-directory?} (default: @code{#t})
10430 Indicates whether the home directory of this account should be created
10431 if it does not exist yet.
10433 @item @code{shell} (default: Bash)
10434 This is a G-expression denoting the file name of a program to be used as
10435 the shell (@pxref{G-Expressions}).
10437 @item @code{system?} (default: @code{#f})
10438 This Boolean value indicates whether the account is a ``system''
10439 account. System accounts are sometimes treated specially; for instance,
10440 graphical login managers do not list them.
10442 @anchor{user-account-password}
10443 @item @code{password} (default: @code{#f})
10444 You would normally leave this field to @code{#f}, initialize user
10445 passwords as @code{root} with the @command{passwd} command, and then let
10446 users change it with @command{passwd}. Passwords set with
10447 @command{passwd} are of course preserved across reboot and
10450 If you @emph{do} want to have a preset password for an account, then
10451 this field must contain the encrypted password, as a string.
10452 @xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
10453 on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
10454 Manual}, for information on Guile's @code{crypt} procedure.
10460 User group declarations are even simpler:
10463 (user-group (name "students"))
10466 @deftp {Data Type} user-group
10467 This type is for, well, user groups. There are just a few fields:
10471 The name of the group.
10473 @item @code{id} (default: @code{#f})
10474 The group identifier (a number). If @code{#f}, a new number is
10475 automatically allocated when the group is created.
10477 @item @code{system?} (default: @code{#f})
10478 This Boolean value indicates whether the group is a ``system'' group.
10479 System groups have low numerical IDs.
10481 @item @code{password} (default: @code{#f})
10482 What, user groups can have a password? Well, apparently yes. Unless
10483 @code{#f}, this field specifies the password of the group.
10488 For convenience, a variable lists all the basic user groups one may
10491 @defvr {Scheme Variable} %base-groups
10492 This is the list of basic user groups that users and/or packages expect
10493 to be present on the system. This includes groups such as ``root'',
10494 ``wheel'', and ``users'', as well as groups used to control access to
10495 specific devices such as ``audio'', ``disk'', and ``cdrom''.
10498 @defvr {Scheme Variable} %base-user-accounts
10499 This is the list of basic system accounts that programs may expect to
10500 find on a GNU/Linux system, such as the ``nobody'' account.
10502 Note that the ``root'' account is not included here. It is a
10503 special-case and is automatically added whether or not it is specified.
10507 @subsection Locales
10510 A @dfn{locale} defines cultural conventions for a particular language
10511 and region of the world (@pxref{Locales,,, libc, The GNU C Library
10512 Reference Manual}). Each locale has a name that typically has the form
10513 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
10514 @code{fr_LU.utf8} designates the locale for the French language, with
10515 cultural conventions from Luxembourg, and using the UTF-8 encoding.
10517 @cindex locale definition
10518 Usually, you will want to specify the default locale for the machine
10519 using the @code{locale} field of the @code{operating-system} declaration
10520 (@pxref{operating-system Reference, @code{locale}}).
10522 The selected locale is automatically added to the @dfn{locale
10523 definitions} known to the system if needed, with its codeset inferred
10524 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
10525 @code{UTF-8} codeset. Additional locale definitions can be specified in
10526 the @code{locale-definitions} slot of @code{operating-system}---this is
10527 useful, for instance, if the codeset could not be inferred from the
10528 locale name. The default set of locale definitions includes some widely
10529 used locales, but not all the available locales, in order to save space.
10531 For instance, to add the North Frisian locale for Germany, the value of
10535 (cons (locale-definition
10536 (name "fy_DE.utf8") (source "fy_DE"))
10537 %default-locale-definitions)
10540 Likewise, to save space, one might want @code{locale-definitions} to
10541 list only the locales that are actually used, as in:
10544 (list (locale-definition
10545 (name "ja_JP.eucjp") (source "ja_JP")
10546 (charset "EUC-JP")))
10550 The compiled locale definitions are available at
10551 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
10552 version, which is the default location where the GNU@tie{}libc provided
10553 by Guix looks for locale data. This can be overridden using the
10554 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
10555 @code{LOCPATH} and locale packages}).
10557 The @code{locale-definition} form is provided by the @code{(gnu system
10558 locale)} module. Details are given below.
10560 @deftp {Data Type} locale-definition
10561 This is the data type of a locale definition.
10566 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
10567 Reference Manual}, for more information on locale names.
10569 @item @code{source}
10570 The name of the source for that locale. This is typically the
10571 @code{@var{language}_@var{territory}} part of the locale name.
10573 @item @code{charset} (default: @code{"UTF-8"})
10574 The ``character set'' or ``code set'' for that locale,
10575 @uref{http://www.iana.org/assignments/character-sets, as defined by
10581 @defvr {Scheme Variable} %default-locale-definitions
10582 A list of commonly used UTF-8 locales, used as the default
10583 value of the @code{locale-definitions} field of @code{operating-system}
10586 @cindex locale name
10587 @cindex normalized codeset in locale names
10588 These locale definitions use the @dfn{normalized codeset} for the part
10589 that follows the dot in the name (@pxref{Using gettextized software,
10590 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
10591 instance it has @code{uk_UA.utf8} but @emph{not}, say,
10592 @code{uk_UA.UTF-8}.
10595 @subsubsection Locale Data Compatibility Considerations
10597 @cindex incompatibility, of locale data
10598 @code{operating-system} declarations provide a @code{locale-libcs} field
10599 to specify the GNU@tie{}libc packages that are used to compile locale
10600 declarations (@pxref{operating-system Reference}). ``Why would I
10601 care?'', you may ask. Well, it turns out that the binary format of
10602 locale data is occasionally incompatible from one libc version to
10605 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
10606 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
10607 For instance, a program linked against libc version 2.21 is unable to
10608 read locale data produced with libc 2.22; worse, that program
10609 @emph{aborts} instead of simply ignoring the incompatible locale
10610 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
10611 the incompatible locale data, which is already an improvement.}.
10612 Similarly, a program linked against libc 2.22 can read most, but not
10613 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
10614 data is incompatible); thus calls to @code{setlocale} may fail, but
10615 programs will not abort.
10617 The ``problem'' in GuixSD is that users have a lot of freedom: They can
10618 choose whether and when to upgrade software in their profiles, and might
10619 be using a libc version different from the one the system administrator
10620 used to build the system-wide locale data.
10622 Fortunately, unprivileged users can also install their own locale data
10623 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
10624 @code{GUIX_LOCPATH} and locale packages}).
10626 Still, it is best if the system-wide locale data at
10627 @file{/run/current-system/locale} is built for all the libc versions
10628 actually in use on the system, so that all the programs can access
10629 it---this is especially crucial on a multi-user system. To do that, the
10630 administrator can specify several libc packages in the
10631 @code{locale-libcs} field of @code{operating-system}:
10634 (use-package-modules base)
10638 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
10641 This example would lead to a system containing locale definitions for
10642 both libc 2.21 and the current version of libc in
10643 @file{/run/current-system/locale}.
10647 @subsection Services
10649 @cindex system services
10650 An important part of preparing an @code{operating-system} declaration is
10651 listing @dfn{system services} and their configuration (@pxref{Using the
10652 Configuration System}). System services are typically daemons launched
10653 when the system boots, or other actions needed at that time---e.g.,
10654 configuring network access.
10656 GuixSD has a broad definition of ``service'' (@pxref{Service
10657 Composition}), but many services are managed by the GNU@tie{}Shepherd
10658 (@pxref{Shepherd Services}). On a running system, the @command{herd}
10659 command allows you to list the available services, show their status,
10660 start and stop them, or do other specific operations (@pxref{Jump
10661 Start,,, shepherd, The GNU Shepherd Manual}). For example:
10667 The above command, run as @code{root}, lists the currently defined
10668 services. The @command{herd doc} command shows a synopsis of the given
10669 service and its associated actions:
10673 Run libc's name service cache daemon (nscd).
10675 # herd doc nscd action invalidate
10676 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
10679 The @command{start}, @command{stop}, and @command{restart} sub-commands
10680 have the effect you would expect. For instance, the commands below stop
10681 the nscd service and restart the Xorg display server:
10685 Service nscd has been stopped.
10686 # herd restart xorg-server
10687 Service xorg-server has been stopped.
10688 Service xorg-server has been started.
10691 The following sections document the available services, starting with
10692 the core services, that may be used in an @code{operating-system}
10696 * Base Services:: Essential system services.
10697 * Scheduled Job Execution:: The mcron service.
10698 * Log Rotation:: The rottlog service.
10699 * Networking Services:: Network setup, SSH daemon, etc.
10700 * X Window:: Graphical display.
10701 * Printing Services:: Local and remote printer support.
10702 * Desktop Services:: D-Bus and desktop services.
10703 * Sound Services:: ALSA and Pulseaudio services.
10704 * Database Services:: SQL databases, key-value stores, etc.
10705 * Mail Services:: IMAP, POP3, SMTP, and all that.
10706 * Messaging Services:: Messaging services.
10707 * Telephony Services:: Telephony services.
10708 * Monitoring Services:: Monitoring services.
10709 * Kerberos Services:: Kerberos services.
10710 * Web Services:: Web servers.
10711 * Certificate Services:: TLS certificates via Let's Encrypt.
10712 * DNS Services:: DNS daemons.
10713 * VPN Services:: VPN daemons.
10714 * Network File System:: NFS related services.
10715 * Continuous Integration:: The Cuirass service.
10716 * Power Management Services:: Extending battery life.
10717 * Audio Services:: The MPD.
10718 * Virtualization Services:: Virtualization services.
10719 * Version Control Services:: Providing remote access to Git repositories.
10720 * Game Services:: Game servers.
10721 * Miscellaneous Services:: Other services.
10724 @node Base Services
10725 @subsubsection Base Services
10727 The @code{(gnu services base)} module provides definitions for the basic
10728 services that one expects from the system. The services exported by
10729 this module are listed below.
10731 @defvr {Scheme Variable} %base-services
10732 This variable contains a list of basic services (@pxref{Service Types
10733 and Services}, for more information on service objects) one would
10734 expect from the system: a login service (mingetty) on each tty, syslogd,
10735 the libc name service cache daemon (nscd), the udev device manager, and
10738 This is the default value of the @code{services} field of
10739 @code{operating-system} declarations. Usually, when customizing a
10740 system, you will want to append services to @var{%base-services}, like
10744 (cons* (avahi-service) (lsh-service) %base-services)
10748 @defvr {Scheme Variable} special-files-service-type
10749 This is the service that sets up ``special files'' such as
10750 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
10752 The value associated with @code{special-files-service-type} services
10753 must be a list of tuples where the first element is the ``special file''
10754 and the second element is its target. By default it is:
10756 @cindex @file{/bin/sh}
10757 @cindex @file{sh}, in @file{/bin}
10759 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
10762 @cindex @file{/usr/bin/env}
10763 @cindex @file{env}, in @file{/usr/bin}
10764 If you want to add, say, @code{/usr/bin/env} to your system, you can
10768 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
10769 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
10772 Since this is part of @code{%base-services}, you can use
10773 @code{modify-services} to customize the set of special files
10774 (@pxref{Service Reference, @code{modify-services}}). But the simple way
10775 to add a special file is @i{via} the @code{extra-special-file} procedure
10779 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
10780 Use @var{target} as the ``special file'' @var{file}.
10782 For example, adding the following lines to the @code{services} field of
10783 your operating system declaration leads to a @file{/usr/bin/env}
10787 (extra-special-file "/usr/bin/env"
10788 (file-append coreutils "/bin/env"))
10792 @deffn {Scheme Procedure} host-name-service @var{name}
10793 Return a service that sets the host name to @var{name}.
10796 @deffn {Scheme Procedure} login-service @var{config}
10797 Return a service to run login according to @var{config}, a
10798 @code{<login-configuration>} object, which specifies the message of the day,
10799 among other things.
10802 @deftp {Data Type} login-configuration
10803 This is the data type representing the configuration of login.
10808 @cindex message of the day
10809 A file-like object containing the ``message of the day''.
10811 @item @code{allow-empty-passwords?} (default: @code{#t})
10812 Allow empty passwords by default so that first-time users can log in when
10813 the 'root' account has just been created.
10818 @deffn {Scheme Procedure} mingetty-service @var{config}
10819 Return a service to run mingetty according to @var{config}, a
10820 @code{<mingetty-configuration>} object, which specifies the tty to run, among
10824 @deftp {Data Type} mingetty-configuration
10825 This is the data type representing the configuration of Mingetty, which
10826 provides the default implementation of virtual console log-in.
10831 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
10833 @item @code{auto-login} (default: @code{#f})
10834 When true, this field must be a string denoting the user name under
10835 which the system automatically logs in. When it is @code{#f}, a
10836 user name and password must be entered to log in.
10838 @item @code{login-program} (default: @code{#f})
10839 This must be either @code{#f}, in which case the default log-in program
10840 is used (@command{login} from the Shadow tool suite), or a gexp denoting
10841 the name of the log-in program.
10843 @item @code{login-pause?} (default: @code{#f})
10844 When set to @code{#t} in conjunction with @var{auto-login}, the user
10845 will have to press a key before the log-in shell is launched.
10847 @item @code{mingetty} (default: @var{mingetty})
10848 The Mingetty package to use.
10853 @deffn {Scheme Procedure} agetty-service @var{config}
10854 Return a service to run agetty according to @var{config}, an
10855 @code{<agetty-configuration>} object, which specifies the tty to run,
10856 among other things.
10859 @deftp {Data Type} agetty-configuration
10860 This is the data type representing the configuration of agetty, which
10861 implements virtual and serial console log-in. See the @code{agetty(8)}
10862 man page for more information.
10867 The name of the console this agetty runs on, as a string---e.g.,
10868 @code{"ttyS0"}. This argument is optional, it will default to
10869 a reasonable default serial port used by the kernel Linux.
10871 For this, if there is a value for an option @code{agetty.tty} in the kernel
10872 command line, agetty will extract the device name of the serial port
10873 from it and use that.
10875 If not and if there is a value for an option @code{console} with a tty in
10876 the Linux command line, agetty will extract the device name of the
10877 serial port from it and use that.
10879 In both cases, agetty will leave the other serial device settings
10880 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
10883 @item @code{baud-rate} (default: @code{#f})
10884 A string containing a comma-separated list of one or more baud rates, in
10887 @item @code{term} (default: @code{#f})
10888 A string containing the value used for the @code{TERM} environment
10891 @item @code{eight-bits?} (default: @code{#f})
10892 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
10895 @item @code{auto-login} (default: @code{#f})
10896 When passed a login name, as a string, the specified user will be logged
10897 in automatically without prompting for their login name or password.
10899 @item @code{no-reset?} (default: @code{#f})
10900 When @code{#t}, don't reset terminal cflags (control modes).
10902 @item @code{host} (default: @code{#f})
10903 This accepts a string containing the "login_host", which will be written
10904 into the @file{/var/run/utmpx} file.
10906 @item @code{remote?} (default: @code{#f})
10907 When set to @code{#t} in conjunction with @var{host}, this will add an
10908 @code{-r} fakehost option to the command line of the login program
10909 specified in @var{login-program}.
10911 @item @code{flow-control?} (default: @code{#f})
10912 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
10914 @item @code{no-issue?} (default: @code{#f})
10915 When set to @code{#t}, the contents of the @file{/etc/issue} file will
10916 not be displayed before presenting the login prompt.
10918 @item @code{init-string} (default: @code{#f})
10919 This accepts a string that will be sent to the tty or modem before
10920 sending anything else. It can be used to initialize a modem.
10922 @item @code{no-clear?} (default: @code{#f})
10923 When set to @code{#t}, agetty will not clear the screen before showing
10926 @item @code{login-program} (default: (file-append shadow "/bin/login"))
10927 This must be either a gexp denoting the name of a log-in program, or
10928 unset, in which case the default value is the @command{login} from the
10931 @item @code{local-line} (default: @code{#f})
10932 Control the CLOCAL line flag. This accepts one of three symbols as
10933 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
10934 the default value chosen by agetty is @code{'auto}.
10936 @item @code{extract-baud?} (default: @code{#f})
10937 When set to @code{#t}, instruct agetty to try to extract the baud rate
10938 from the status messages produced by certain types of modems.
10940 @item @code{skip-login?} (default: @code{#f})
10941 When set to @code{#t}, do not prompt the user for a login name. This
10942 can be used with @var{login-program} field to use non-standard login
10945 @item @code{no-newline?} (default: @code{#f})
10946 When set to @code{#t}, do not print a newline before printing the
10947 @file{/etc/issue} file.
10949 @c Is this dangerous only when used with login-program, or always?
10950 @item @code{login-options} (default: @code{#f})
10951 This option accepts a string containing options that are passed to the
10952 login program. When used with the @var{login-program}, be aware that a
10953 malicious user could try to enter a login name containing embedded
10954 options that could be parsed by the login program.
10956 @item @code{login-pause} (default: @code{#f})
10957 When set to @code{#t}, wait for any key before showing the login prompt.
10958 This can be used in conjunction with @var{auto-login} to save memory by
10959 lazily spawning shells.
10961 @item @code{chroot} (default: @code{#f})
10962 Change root to the specified directory. This option accepts a directory
10965 @item @code{hangup?} (default: @code{#f})
10966 Use the Linux system call @code{vhangup} to do a virtual hangup of the
10967 specified terminal.
10969 @item @code{keep-baud?} (default: @code{#f})
10970 When set to @code{#t}, try to keep the existing baud rate. The baud
10971 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
10974 @item @code{timeout} (default: @code{#f})
10975 When set to an integer value, terminate if no user name could be read
10976 within @var{timeout} seconds.
10978 @item @code{detect-case?} (default: @code{#f})
10979 When set to @code{#t}, turn on support for detecting an uppercase-only
10980 terminal. This setting will detect a login name containing only
10981 uppercase letters as indicating an uppercase-only terminal and turn on
10982 some upper-to-lower case conversions. Note that this will not support
10983 Unicode characters.
10985 @item @code{wait-cr?} (default: @code{#f})
10986 When set to @code{#t}, wait for the user or modem to send a
10987 carriage-return or linefeed character before displaying
10988 @file{/etc/issue} or login prompt. This is typically used with the
10989 @var{init-string} option.
10991 @item @code{no-hints?} (default: @code{#f})
10992 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
10995 @item @code{no-hostname?} (default: @code{#f})
10996 By default, the hostname is printed. When this option is set to
10997 @code{#t}, no hostname will be shown at all.
10999 @item @code{long-hostname?} (default: @code{#f})
11000 By default, the hostname is only printed until the first dot. When this
11001 option is set to @code{#t}, the fully qualified hostname by
11002 @code{gethostname} or @code{getaddrinfo} is shown.
11004 @item @code{erase-characters} (default: @code{#f})
11005 This option accepts a string of additional characters that should be
11006 interpreted as backspace when the user types their login name.
11008 @item @code{kill-characters} (default: @code{#f})
11009 This option accepts a string that should be interpreted to mean "ignore
11010 all previous characters" (also called a "kill" character) when the types
11013 @item @code{chdir} (default: @code{#f})
11014 This option accepts, as a string, a directory path that will be changed
11017 @item @code{delay} (default: @code{#f})
11018 This options accepts, as an integer, the number of seconds to sleep
11019 before opening the tty and displaying the login prompt.
11021 @item @code{nice} (default: @code{#f})
11022 This option accepts, as an integer, the nice value with which to run the
11023 @command{login} program.
11025 @item @code{extra-options} (default: @code{'()})
11026 This option provides an "escape hatch" for the user to provide arbitrary
11027 command-line arguments to @command{agetty} as a list of strings.
11032 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11033 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11034 according to @var{config}, a @code{<kmscon-configuration>} object, which
11035 specifies the tty to run, among other things.
11038 @deftp {Data Type} kmscon-configuration
11039 This is the data type representing the configuration of Kmscon, which
11040 implements virtual console log-in.
11044 @item @code{virtual-terminal}
11045 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11047 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11048 A gexp denoting the name of the log-in program. The default log-in program is
11049 @command{login} from the Shadow tool suite.
11051 @item @code{login-arguments} (default: @code{'("-p")})
11052 A list of arguments to pass to @command{login}.
11054 @item @code{auto-login} (default: @code{#f})
11055 When passed a login name, as a string, the specified user will be logged
11056 in automatically without prompting for their login name or password.
11058 @item @code{hardware-acceleration?} (default: #f)
11059 Whether to use hardware acceleration.
11061 @item @code{kmscon} (default: @var{kmscon})
11062 The Kmscon package to use.
11067 @cindex name service cache daemon
11069 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11070 [#:name-services '()]
11071 Return a service that runs the libc name service cache daemon (nscd) with the
11072 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11073 Service Switch}, for an example.
11075 For convenience, the Shepherd service for nscd provides the following actions:
11079 @cindex cache invalidation, nscd
11080 @cindex nscd, cache invalidation
11081 This invalidate the given cache. For instance, running:
11084 herd invalidate nscd hosts
11088 invalidates the host name lookup cache of nscd.
11091 Running @command{herd statistics nscd} displays information about nscd usage
11097 @defvr {Scheme Variable} %nscd-default-configuration
11098 This is the default @code{<nscd-configuration>} value (see below) used
11099 by @code{nscd-service}. It uses the caches defined by
11100 @var{%nscd-default-caches}; see below.
11103 @deftp {Data Type} nscd-configuration
11104 This is the data type representing the name service cache daemon (nscd)
11109 @item @code{name-services} (default: @code{'()})
11110 List of packages denoting @dfn{name services} that must be visible to
11111 the nscd---e.g., @code{(list @var{nss-mdns})}.
11113 @item @code{glibc} (default: @var{glibc})
11114 Package object denoting the GNU C Library providing the @command{nscd}
11117 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11118 Name of the nscd log file. This is where debugging output goes when
11119 @code{debug-level} is strictly positive.
11121 @item @code{debug-level} (default: @code{0})
11122 Integer denoting the debugging levels. Higher numbers mean that more
11123 debugging output is logged.
11125 @item @code{caches} (default: @var{%nscd-default-caches})
11126 List of @code{<nscd-cache>} objects denoting things to be cached; see
11132 @deftp {Data Type} nscd-cache
11133 Data type representing a cache database of nscd and its parameters.
11137 @item @code{database}
11138 This is a symbol representing the name of the database to be cached.
11139 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11140 @code{services}, which designate the corresponding NSS database
11141 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11143 @item @code{positive-time-to-live}
11144 @itemx @code{negative-time-to-live} (default: @code{20})
11145 A number representing the number of seconds during which a positive or
11146 negative lookup result remains in cache.
11148 @item @code{check-files?} (default: @code{#t})
11149 Whether to check for updates of the files corresponding to
11152 For instance, when @var{database} is @code{hosts}, setting this flag
11153 instructs nscd to check for updates in @file{/etc/hosts} and to take
11156 @item @code{persistent?} (default: @code{#t})
11157 Whether the cache should be stored persistently on disk.
11159 @item @code{shared?} (default: @code{#t})
11160 Whether the cache should be shared among users.
11162 @item @code{max-database-size} (default: 32@tie{}MiB)
11163 Maximum size in bytes of the database cache.
11165 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11166 @c settings, so leave them out.
11171 @defvr {Scheme Variable} %nscd-default-caches
11172 List of @code{<nscd-cache>} objects used by default by
11173 @code{nscd-configuration} (see above).
11175 It enables persistent and aggressive caching of service and host name
11176 lookups. The latter provides better host name lookup performance,
11177 resilience in the face of unreliable name servers, and also better
11178 privacy---often the result of host name lookups is in local cache, so
11179 external name servers do not even need to be queried.
11182 @anchor{syslog-configuration-type}
11185 @deftp {Data Type} syslog-configuration
11186 This data type represents the configuration of the syslog daemon.
11189 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
11190 The syslog daemon to use.
11192 @item @code{config-file} (default: @code{%default-syslog.conf})
11193 The syslog configuration file to use.
11198 @anchor{syslog-service}
11200 @deffn {Scheme Procedure} syslog-service @var{config}
11201 Return a service that runs a syslog daemon according to @var{config}.
11203 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
11204 information on the configuration file syntax.
11207 @defvr {Scheme Variable} guix-service-type
11208 This is the type of the service that runs the build daemon,
11209 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
11210 @code{guix-configuration} record as described below.
11213 @anchor{guix-configuration-type}
11214 @deftp {Data Type} guix-configuration
11215 This data type represents the configuration of the Guix build daemon.
11216 @xref{Invoking guix-daemon}, for more information.
11219 @item @code{guix} (default: @var{guix})
11220 The Guix package to use.
11222 @item @code{build-group} (default: @code{"guixbuild"})
11223 Name of the group for build user accounts.
11225 @item @code{build-accounts} (default: @code{10})
11226 Number of build user accounts to create.
11228 @item @code{authorize-key?} (default: @code{#t})
11229 @cindex substitutes, authorization thereof
11230 Whether to authorize the substitute keys listed in
11231 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
11232 (@pxref{Substitutes}).
11234 @vindex %default-authorized-guix-keys
11235 @item @code{authorized-keys} (default: @var{%default-authorized-guix-keys})
11236 The list of authorized key files for archive imports, as a list of
11237 string-valued gexps (@pxref{Invoking guix archive}). By default, it
11238 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
11240 @item @code{use-substitutes?} (default: @code{#t})
11241 Whether to use substitutes.
11243 @item @code{substitute-urls} (default: @var{%default-substitute-urls})
11244 The list of URLs where to look for substitutes by default.
11246 @item @code{max-silent-time} (default: @code{0})
11247 @itemx @code{timeout} (default: @code{0})
11248 The number of seconds of silence and the number of seconds of activity,
11249 respectively, after which a build process times out. A value of zero
11250 disables the timeout.
11252 @item @code{log-compression} (default: @code{'bzip2})
11253 The type of compression used for build logs---one of @code{gzip},
11254 @code{bzip2}, or @code{none}.
11256 @item @code{extra-options} (default: @code{'()})
11257 List of extra command-line options for @command{guix-daemon}.
11259 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
11260 File where @command{guix-daemon}'s standard output and standard error
11263 @item @code{http-proxy} (default: @code{#f})
11264 The HTTP proxy used for downloading fixed-output derivations and
11267 @item @code{tmpdir} (default: @code{#f})
11268 A directory path where the @command{guix-daemon} will perform builds.
11273 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
11274 Run @var{udev}, which populates the @file{/dev} directory dynamically.
11275 udev rules can be provided as a list of files through the @var{rules}
11276 variable. The procedures @var{udev-rule} and @var{file->udev-rule} from
11277 @code{(gnu services base)} simplify the creation of such rule files.
11279 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
11280 Return a udev-rule file named @var{file-name} containing the rules
11281 defined by the @var{contents} literal.
11283 In the following example, a rule for a USB device is defined to be
11284 stored in the file @file{90-usb-thing.rules}. The rule runs a script
11285 upon detecting a USB device with a given product identifier.
11288 (define %example-udev-rule
11290 "90-usb-thing.rules"
11291 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
11292 "ATTR@{product@}==\"Example\", "
11293 "RUN+=\"/path/to/script\"")))
11297 Here we show how the default @var{udev-service} can be extended with it.
11303 (modify-services %desktop-services
11304 (udev-service-type config =>
11305 (udev-configuration (inherit config)
11306 (rules (append (udev-configuration-rules config)
11307 (list %example-udev-rule))))))))
11310 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
11311 Return a udev file named @var{file-name} containing the rules defined
11312 within @var{file}, a file-like object.
11314 The following example showcases how we can use an existing rule file.
11317 (use-modules (guix download) ;for url-fetch
11318 (guix packages) ;for origin
11321 (define %android-udev-rules
11323 "51-android-udev.rules"
11324 (let ((version "20170910"))
11327 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
11328 "android-udev-rules/" version "/51-android.rules"))
11330 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
11334 Additionally, Guix package definitions can be included in @var{rules} in
11335 order to extend the udev rules with the definitions found under their
11336 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
11337 @var{file->udev-rule} example, we could have used the
11338 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
11339 packages android)} module.
11341 The following example shows how to use the @var{android-udev-rules}
11342 package so that the Android tool @command{adb} can detect devices
11343 without root privileges. It also details how to create the
11344 @code{adbusers} group, which is required for the proper functioning of
11345 the rules defined within the @var{android-udev-rules} package. To
11346 create such a group, we must define it both as part of the
11347 @var{supplementary-groups} of our @var{user-account} declaration, as
11348 well as in the @var{groups} field of the @var{operating-system} record.
11351 (use-modules (gnu packages android) ;for android-udev-rules
11352 (gnu system shadow) ;for user-group
11357 (users (cons (user-acount
11359 (supplementary-groups
11360 '("adbusers" ;for adb
11361 "wheel" "netdev" "audio" "video"))
11364 (groups (cons (user-group (system? #t) (name "adbusers"))
11370 (modify-services %desktop-services
11371 (udev-service-type config =>
11372 (udev-configuration (inherit config)
11373 (rules (cons* android-udev-rules
11374 (udev-configuration-rules config))))))))
11378 @defvr {Scheme Variable} urandom-seed-service-type
11379 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
11380 when rebooting. It also tries to seed @file{/dev/urandom} from
11381 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
11385 @defvr {Scheme Variable} %random-seed-file
11386 This is the name of the file where some random bytes are saved by
11387 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
11388 It defaults to @file{/var/lib/random-seed}.
11393 @deffn {Scheme Procedure} console-keymap-service @var{files} ...
11394 @cindex keyboard layout
11395 Return a service to load console keymaps from @var{files} using
11396 @command{loadkeys} command. Most likely, you want to load some default
11397 keymap, which can be done like this:
11400 (console-keymap-service "dvorak")
11403 Or, for example, for a Swedish keyboard, you may need to combine
11404 the following keymaps:
11406 (console-keymap-service "se-lat6" "se-fi-lat6")
11409 Also you can specify a full file name (or file names) of your keymap(s).
11410 See @code{man loadkeys} for details.
11416 @defvr {Scheme Variable} gpm-service-type
11417 This is the type of the service that runs GPM, the @dfn{general-purpose
11418 mouse daemon}, which provides mouse support to the Linux console. GPM
11419 allows users to use the mouse in the console, notably to select, copy,
11422 The value for services of this type must be a @code{gpm-configuration}
11423 (see below). This service is not part of @var{%base-services}.
11426 @deftp {Data Type} gpm-configuration
11427 Data type representing the configuration of GPM.
11430 @item @code{options} (default: @code{%default-gpm-options})
11431 Command-line options passed to @command{gpm}. The default set of
11432 options instruct @command{gpm} to listen to mouse events on
11433 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
11436 @item @code{gpm} (default: @code{gpm})
11437 The GPM package to use.
11442 @anchor{guix-publish-service-type}
11443 @deffn {Scheme Variable} guix-publish-service-type
11444 This is the service type for @command{guix publish} (@pxref{Invoking
11445 guix publish}). Its value must be a @code{guix-configuration}
11446 object, as described below.
11448 This assumes that @file{/etc/guix} already contains a signing key pair as
11449 created by @command{guix archive --generate-key} (@pxref{Invoking guix
11450 archive}). If that is not the case, the service will fail to start.
11453 @deftp {Data Type} guix-publish-configuration
11454 Data type representing the configuration of the @code{guix publish}
11458 @item @code{guix} (default: @code{guix})
11459 The Guix package to use.
11461 @item @code{port} (default: @code{80})
11462 The TCP port to listen for connections.
11464 @item @code{host} (default: @code{"localhost"})
11465 The host (and thus, network interface) to listen to. Use
11466 @code{"0.0.0.0"} to listen on all the network interfaces.
11468 @item @code{compression-level} (default: @code{3})
11469 The gzip compression level at which substitutes are compressed. Use
11470 @code{0} to disable compression altogether, and @code{9} to get the best
11471 compression ratio at the expense of increased CPU usage.
11473 @item @code{nar-path} (default: @code{"nar"})
11474 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
11475 publish, @code{--nar-path}}, for details.
11477 @item @code{cache} (default: @code{#f})
11478 When it is @code{#f}, disable caching and instead generate archives on
11479 demand. Otherwise, this should be the name of a directory---e.g.,
11480 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
11481 archives and meta-data ready to be sent. @xref{Invoking guix publish,
11482 @option{--cache}}, for more information on the tradeoffs involved.
11484 @item @code{workers} (default: @code{#f})
11485 When it is an integer, this is the number of worker threads used for
11486 caching; when @code{#f}, the number of processors is used.
11487 @xref{Invoking guix publish, @option{--workers}}, for more information.
11489 @item @code{ttl} (default: @code{#f})
11490 When it is an integer, this denotes the @dfn{time-to-live} in seconds
11491 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
11492 for more information.
11496 @anchor{rngd-service}
11497 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
11498 [#:device "/dev/hwrng"]
11499 Return a service that runs the @command{rngd} program from @var{rng-tools}
11500 to add @var{device} to the kernel's entropy pool. The service will fail if
11501 @var{device} does not exist.
11504 @anchor{pam-limits-service}
11505 @cindex session limits
11510 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
11512 Return a service that installs a configuration file for the
11513 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
11514 @code{pam_limits} module}. The procedure optionally takes a list of
11515 @code{pam-limits-entry} values, which can be used to specify
11516 @code{ulimit} limits and nice priority limits to user sessions.
11518 The following limits definition sets two hard and soft limits for all
11519 login sessions of users in the @code{realtime} group:
11522 (pam-limits-service
11524 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
11525 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
11528 The first entry increases the maximum realtime priority for
11529 non-privileged processes; the second entry lifts any restriction of the
11530 maximum address space that can be locked in memory. These settings are
11531 commonly used for real-time audio systems.
11534 @node Scheduled Job Execution
11535 @subsubsection Scheduled Job Execution
11539 @cindex scheduling jobs
11540 The @code{(gnu services mcron)} module provides an interface to
11541 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
11542 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
11543 Unix @command{cron} daemon; the main difference is that it is
11544 implemented in Guile Scheme, which provides a lot of flexibility when
11545 specifying the scheduling of jobs and their actions.
11547 The example below defines an operating system that runs the
11548 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
11549 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
11550 well as the @command{mkid} command on behalf of an unprivileged user
11551 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
11552 gexps to introduce job definitions that are passed to mcron
11553 (@pxref{G-Expressions}).
11556 (use-modules (guix) (gnu) (gnu services mcron))
11557 (use-package-modules base idutils)
11559 (define updatedb-job
11560 ;; Run 'updatedb' at 3AM every day. Here we write the
11561 ;; job's action as a Scheme procedure.
11562 #~(job '(next-hour '(3))
11564 (execl (string-append #$findutils "/bin/updatedb")
11566 "--prunepaths=/tmp /var/tmp /gnu/store"))))
11568 (define garbage-collector-job
11569 ;; Collect garbage 5 minutes after midnight every day.
11570 ;; The job's action is a shell command.
11571 #~(job "5 0 * * *" ;Vixie cron syntax
11574 (define idutils-job
11575 ;; Update the index database as user "charlie" at 12:15PM
11576 ;; and 19:15PM. This runs from the user's home directory.
11577 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
11578 (string-append #$idutils "/bin/mkid src")
11583 (services (cons (mcron-service (list garbage-collector-job
11589 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
11590 for more information on mcron job specifications. Below is the
11591 reference of the mcron service.
11593 On a running system, you can use the @code{schedule} action of the service to
11594 visualize the mcron jobs that will be executed next:
11597 # herd schedule mcron
11601 The example above lists the next five tasks that will be executed, but you can
11602 also specify the number of tasks to display:
11605 # herd schedule mcron 10
11608 @deffn {Scheme Procedure} mcron-service @var{jobs} [#:mcron @var{mcron}]
11609 Return an mcron service running @var{mcron} that schedules @var{jobs}, a
11610 list of gexps denoting mcron job specifications.
11612 This is a shorthand for:
11614 (service mcron-service-type
11615 (mcron-configuration (mcron mcron) (jobs jobs)))
11619 @defvr {Scheme Variable} mcron-service-type
11620 This is the type of the @code{mcron} service, whose value is an
11621 @code{mcron-configuration} object.
11623 This service type can be the target of a service extension that provides
11624 it additional job specifications (@pxref{Service Composition}). In
11625 other words, it is possible to define services that provide additional
11629 @deftp {Data Type} mcron-configuration
11630 Data type representing the configuration of mcron.
11633 @item @code{mcron} (default: @var{mcron})
11634 The mcron package to use.
11637 This is a list of gexps (@pxref{G-Expressions}), where each gexp
11638 corresponds to an mcron job specification (@pxref{Syntax, mcron job
11639 specifications,, mcron, GNU@tie{}mcron}).
11645 @subsubsection Log Rotation
11648 @cindex log rotation
11650 Log files such as those found in @file{/var/log} tend to grow endlessly,
11651 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
11652 their contents in separate files, possibly compressed. The @code{(gnu
11653 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
11654 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
11656 The example below defines an operating system that provides log rotation
11657 with the default settings, for commonly encountered log files.
11660 (use-modules (guix) (gnu))
11661 (use-service-modules admin mcron)
11662 (use-package-modules base idutils)
11666 (services (cons (service rottlog-service-type)
11670 @defvr {Scheme Variable} rottlog-service-type
11671 This is the type of the Rottlog service, whose value is a
11672 @code{rottlog-configuration} object.
11674 Other services can extend this one with new @code{log-rotation} objects
11675 (see below), thereby augmenting the set of files to be rotated.
11677 This service type can define mcron jobs (@pxref{Scheduled Job
11678 Execution}) to run the rottlog service.
11681 @deftp {Data Type} rottlog-configuration
11682 Data type representing the configuration of rottlog.
11685 @item @code{rottlog} (default: @code{rottlog})
11686 The Rottlog package to use.
11688 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
11689 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
11690 rottlog, GNU Rot[t]log Manual}).
11692 @item @code{rotations} (default: @code{%default-rotations})
11693 A list of @code{log-rotation} objects as defined below.
11696 This is a list of gexps where each gexp corresponds to an mcron job
11697 specification (@pxref{Scheduled Job Execution}).
11701 @deftp {Data Type} log-rotation
11702 Data type representing the rotation of a group of log files.
11704 Taking an example from the Rottlog manual (@pxref{Period Related File
11705 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
11711 (files '("/var/log/apache/*"))
11712 (options '("storedir apache-archives"
11718 The list of fields is as follows:
11721 @item @code{frequency} (default: @code{'weekly})
11722 The log rotation frequency, a symbol.
11725 The list of files or file glob patterns to rotate.
11727 @item @code{options} (default: @code{'()})
11728 The list of rottlog options for this rotation (@pxref{Configuration
11729 parameters,,, rottlog, GNU Rot[t]lg Manual}).
11731 @item @code{post-rotate} (default: @code{#f})
11732 Either @code{#f} or a gexp to execute once the rotation has completed.
11736 @defvr {Scheme Variable} %default-rotations
11737 Specifies weekly rotation of @var{%rotated-files} and
11738 a couple of other files.
11741 @defvr {Scheme Variable} %rotated-files
11742 The list of syslog-controlled files to be rotated. By default it is:
11743 @code{'("/var/log/messages" "/var/log/secure")}.
11746 @node Networking Services
11747 @subsubsection Networking Services
11749 The @code{(gnu services networking)} module provides services to configure
11750 the network interface.
11752 @cindex DHCP, networking service
11753 @defvr {Scheme Variable} dhcp-client-service-type
11754 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
11755 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
11756 is the DHCP client package to use, @code{isc-dhcp} by default.
11759 @deffn {Scheme Procedure} dhcpd-service-type
11760 This type defines a service that runs a DHCP daemon. To create a
11761 service of this type, you must supply a @code{<dhcpd-configuration>}.
11765 (service dhcpd-service-type
11766 (dhcpd-configuration
11767 (config-file (local-file "my-dhcpd.conf"))
11768 (interfaces '("enp0s25"))))
11772 @deftp {Data Type} dhcpd-configuration
11774 @item @code{package} (default: @code{isc-dhcp})
11775 The package that provides the DHCP daemon. This package is expected to
11776 provide the daemon at @file{sbin/dhcpd} relative to its output
11777 directory. The default package is the
11778 @uref{http://www.isc.org/products/DHCP, ISC's DHCP server}.
11779 @item @code{config-file} (default: @code{#f})
11780 The configuration file to use. This is required. It will be passed to
11781 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
11782 object (@pxref{G-Expressions, file-like objects}). See @code{man
11783 dhcpd.conf} for details on the configuration file syntax.
11784 @item @code{version} (default: @code{"4"})
11785 The DHCP version to use. The ISC DHCP server supports the values ``4'',
11786 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
11787 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
11789 @item @code{run-directory} (default: @code{"/run/dhcpd"})
11790 The run directory to use. At service activation time, this directory
11791 will be created if it does not exist.
11792 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
11793 The PID file to use. This corresponds to the @code{-pf} option of
11794 @code{dhcpd}. See @code{man dhcpd} for details.
11795 @item @code{interfaces} (default: @code{'()})
11796 The names of the network interfaces on which dhcpd should listen for
11797 broadcasts. If this list is not empty, then its elements (which must be
11798 strings) will be appended to the @code{dhcpd} invocation when starting
11799 the daemon. It may not be necessary to explicitly specify any
11800 interfaces here; see @code{man dhcpd} for details.
11804 @defvr {Scheme Variable} static-networking-service-type
11805 This is the type for statically-configured network interfaces.
11806 @c TODO Document <static-networking> data structures.
11809 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
11810 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
11811 [#:requirement @code{'(udev)}]
11812 Return a service that starts @var{interface} with address @var{ip}. If
11813 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
11814 it must be a string specifying the default network gateway. @var{requirement}
11815 can be used to declare a dependency on another service before configuring the
11818 This procedure can be called several times, one for each network
11819 interface of interest. Behind the scenes what it does is extend
11820 @code{static-networking-service-type} with additional network interfaces
11826 (static-networking-service "eno1" "192.168.1.82"
11827 #:gateway "192.168.1.2"
11828 #:name-servers '("192.168.1.2"))
11835 @cindex network management
11836 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
11837 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
11838 management daemon that aims to simplify wired and wireless networking.
11840 This service adds the @var{wicd} package to the global profile, providing
11841 several commands to interact with the daemon and configure networking:
11842 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
11843 and @command{wicd-curses} user interfaces.
11846 @cindex ModemManager
11848 @defvr {Scheme Variable} modem-manager-service-type
11849 This is the service type for the
11850 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
11851 service. The value for this service type is a
11852 @code{modem-manager-configuration} record.
11854 This service is part of @code{%desktop-services} (@pxref{Desktop
11858 @deftp {Data Type} modem-manager-configuration
11859 Data type representing the configuration of ModemManager.
11862 @item @code{modem-manager} (default: @code{modem-manager})
11863 The ModemManager package to use.
11868 @cindex NetworkManager
11870 @defvr {Scheme Variable} network-manager-service-type
11871 This is the service type for the
11872 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
11873 service. The value for this service type is a
11874 @code{network-manager-configuration} record.
11876 This service is part of @code{%desktop-services} (@pxref{Desktop
11880 @deftp {Data Type} network-manager-configuration
11881 Data type representing the configuration of NetworkManager.
11884 @item @code{network-manager} (default: @code{network-manager})
11885 The NetworkManager package to use.
11887 @item @code{dns} (default: @code{"default"})
11888 Processing mode for DNS, which affects how NetworkManager uses the
11889 @code{resolv.conf} configuration file.
11893 NetworkManager will update @code{resolv.conf} to reflect the nameservers
11894 provided by currently active connections.
11897 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
11898 using a "split DNS" configuration if you are connected to a VPN, and
11899 then update @code{resolv.conf} to point to the local nameserver.
11902 NetworkManager will not modify @code{resolv.conf}.
11905 @item @code{vpn-plugins} (default: @code{'()})
11906 This is the list of available plugins for virtual private networks
11907 (VPNs). An example of this is the @code{network-manager-openvpn}
11908 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
11914 @deffn {Scheme Variable} connman-service-type
11915 This is the service type to run @url{https://01.org/connman,Connman},
11916 a network connection manager.
11918 Its value must be an
11919 @code{connman-configuration} record as in this example:
11922 (service connman-service-type
11923 (connman-configuration
11924 (disable-vpn? #t)))
11927 See below for details about @code{connman-configuration}.
11930 @deftp {Data Type} connman-configuration
11931 Data Type representing the configuration of connman.
11934 @item @code{connman} (default: @var{connman})
11935 The connman package to use.
11937 @item @code{disable-vpn?} (default: @code{#f})
11938 When true, disable connman's vpn plugin.
11942 @cindex WPA Supplicant
11943 @defvr {Scheme Variable} wpa-supplicant-service-type
11944 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
11945 supplicant}, an authentication daemon required to authenticate against
11946 encrypted WiFi or ethernet networks.
11949 @deftp {Data Type} wpa-supplicant-configuration
11950 Data type representing the configuration of WPA Supplicant.
11952 It takes the following parameters:
11955 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
11956 The WPA Supplicant package to use.
11958 @item @code{dbus?} (default: @code{#t})
11959 Whether to listen for requests on D-Bus.
11961 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
11962 Where to store the PID file.
11964 @item @code{interface} (default: @code{#f})
11965 If this is set, it must specify the name of a network interface that
11966 WPA supplicant will control.
11968 @item @code{config-file} (default: @code{#f})
11969 Optional configuration file to use.
11971 @item @code{extra-options} (default: @code{'()})
11972 List of additional command-line arguments to pass to the daemon.
11977 @defvr {Scheme Variable} iptables-service-type
11978 This is the service type to set up an iptables configuration. iptables is a
11979 packet filtering framework supported by the Linux kernel. This service
11980 supports configuring iptables for both IPv4 and IPv6. A simple example
11981 configuration rejecting all incoming connections except those to the ssh port
11985 (service iptables-service-type
11986 (iptables-configuration
11987 (ipv4-rules (plain-file "iptables.rules" "*filter
11991 -A INPUT -p tcp --dport 22 -j ACCEPT
11992 -A INPUT -j REJECT --reject-with icmp-port-unreachable
11995 (ipv6-rules (plain-file "ip6tables.rules" "*filter
11999 -A INPUT -p tcp --dport 22 -j ACCEPT
12000 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12006 @deftp {Data Type} iptables-configuration
12007 The data type representing the configuration of iptables.
12010 @item @code{iptables} (default: @code{iptables})
12011 The iptables package that provides @code{iptables-restore} and
12012 @code{ip6tables-restore}.
12013 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12014 The iptables rules to use. It will be passed to @code{iptables-restore}.
12015 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12017 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12018 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12019 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12024 @cindex NTP (Network Time Protocol), service
12025 @cindex real time clock
12026 @defvr {Scheme Variable} ntp-service-type
12027 This is the type of the service running the @uref{http://www.ntp.org,
12028 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12029 system clock synchronized with that of the specified NTP servers.
12031 The value of this service is an @code{ntpd-configuration} object, as described
12035 @deftp {Data Type} ntp-configuration
12036 This is the data type for the NTP service configuration.
12039 @item @code{servers} (default: @code{%ntp-servers})
12040 This is the list of servers (host names) with which @command{ntpd} will be
12043 @item @code{allow-large-adjustment?} (default: @code{#f})
12044 This determines whether @command{ntpd} is allowed to make an initial
12045 adjustment of more than 1,000 seconds.
12047 @item @code{ntp} (default: @code{ntp})
12048 The NTP package to use.
12052 @defvr {Scheme Variable} %ntp-servers
12053 List of host names used as the default NTP servers. These are servers of the
12054 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12058 @deffn {Scheme Procedure} openntpd-service-type
12059 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12060 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12061 clock synchronized with that of the given servers.
12065 openntpd-service-type
12066 (openntpd-configuration
12067 (listen-on '("127.0.0.1" "::1"))
12068 (sensor '("udcf0 correction 70000"))
12069 (constraint-from '("www.gnu.org"))
12070 (constraints-from '("https://www.google.com/"))
12071 (allow-large-adjustment? #t)))
12076 @deftp {Data Type} openntpd-configuration
12078 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12079 The openntpd executable to use.
12080 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12081 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12082 @item @code{query-from} (default: @code{'()})
12083 A list of local IP address the ntpd daemon should use for outgoing queries.
12084 @item @code{sensor} (default: @code{'()})
12085 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12086 will listen to each sensor that acutally exists and ignore non-existant ones.
12087 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12089 @item @code{server} (default: @var{%ntp-servers})
12090 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12091 @item @code{servers} (default: @code{'()})
12092 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12093 @item @code{constraint-from} (default: @code{'()})
12094 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12095 This time information is not used for precision but acts as an authenticated
12096 constraint, thereby reducing the impact of unauthenticated NTP
12097 man-in-the-middle attacks.
12098 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12100 @item @code{constraints-from} (default: @code{'()})
12101 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12102 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12103 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12104 @item @code{allow-large-adjustment?} (default: @code{#f})
12105 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12111 @deffn {Scheme variable} inetd-service-type
12112 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12113 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12114 connections on internet sockets, and lazily starts the specified server
12115 program when a connection is made on one of these sockets.
12117 The value of this service is an @code{inetd-configuration} object. The
12118 following example configures the @command{inetd} daemon to provide the
12119 built-in @command{echo} service, as well as an smtp service which
12120 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12121 gateway @code{hostname}:
12126 (inetd-configuration
12130 (socket-type 'stream)
12137 (socket-type 'stream)
12141 (program (file-append openssh "/bin/ssh"))
12143 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12144 "-W" "smtp-server:25" "user@@hostname")))))
12147 See below for more details about @code{inetd-configuration}.
12150 @deftp {Data Type} inetd-configuration
12151 Data type representing the configuration of @command{inetd}.
12154 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12155 The @command{inetd} executable to use.
12157 @item @code{entries} (default: @code{'()})
12158 A list of @command{inetd} service entries. Each entry should be created
12159 by the @code{inetd-entry} constructor.
12163 @deftp {Data Type} inetd-entry
12164 Data type representing an entry in the @command{inetd} configuration.
12165 Each entry corresponds to a socket where @command{inetd} will listen for
12169 @item @code{node} (default: @code{#f})
12170 Optional string, a comma-separated list of local addresses
12171 @command{inetd} should use when listening for this service.
12172 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
12173 description of all options.
12175 A string, the name must correspond to an entry in @code{/etc/services}.
12176 @item @code{socket-type}
12177 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
12179 @item @code{protocol}
12180 A string, must correspond to an entry in @code{/etc/protocols}.
12181 @item @code{wait?} (default: @code{#t})
12182 Whether @command{inetd} should wait for the server to exit before
12183 listening to new service requests.
12185 A string containing the user (and, optionally, group) name of the user
12186 as whom the server should run. The group name can be specified in a
12187 suffix, separated by a colon or period, i.e.@: @code{"user"},
12188 @code{"user:group"} or @code{"user.group"}.
12189 @item @code{program} (default: @code{"internal"})
12190 The server program which will serve the requests, or @code{"internal"}
12191 if @command{inetd} should use a built-in service.
12192 @item @code{arguments} (default: @code{'()})
12193 A list strings or file-like objects, which are the server program's
12194 arguments, starting with the zeroth argument, i.e.@: the name of the
12195 program itself. For @command{inetd}'s internal services, this entry
12196 must be @code{'()} or @code{'("internal")}.
12199 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
12200 detailed discussion of each configuration field.
12204 @defvr {Scheme Variable} tor-service-type
12205 This is the type for a service that runs the @uref{https://torproject.org,
12206 Tor} anonymous networking daemon. The service is configured using a
12207 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
12208 @code{tor} unprivileged user, which is a member of the @code{tor} group.
12212 @deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
12213 This procedure is deprecated and will be removed in a future release. Return
12214 a service of the @code{tor-service-type} type. @var{config-file} and
12215 @var{tor} have the same meaning as in @code{<tor-configuration>}.
12218 @deftp {Data Type} tor-configuration
12220 @item @code{tor} (default: @code{tor})
12221 The package that provides the Tor daemon. This package is expected to provide
12222 the daemon at @file{bin/tor} relative to its output directory. The default
12223 package is the @uref{https://www.torproject.org, Tor Project's}
12226 @item @code{config-file} (default: @code{(plain-file "empty" "")})
12227 The configuration file to use. It will be appended to a default configuration
12228 file, and the final configuration file will be passed to @code{tor} via its
12229 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
12230 file-like objects}). See @code{man tor} for details on the configuration file
12233 @item @code{hidden-services} (default: @code{'()})
12234 The list of @code{<hidden-service>} records to use. For any hidden service
12235 you include in this list, appropriate configuration to enable the hidden
12236 service will be automatically added to the default configuration file. You
12237 may conveniently create @code{<hidden-service>} records using the
12238 @code{tor-hidden-service} procedure described below.
12240 @item @code{socks-socket-type} (default: @code{'tcp})
12241 The default socket type that Tor should use for its SOCKS socket. This must
12242 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
12243 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
12244 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
12245 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
12248 If you want to customize the SOCKS socket in more detail, leave
12249 @code{socks-socket-type} at its default value of @code{'tcp} and use
12250 @code{config-file} to override the default by providing your own
12251 @code{SocksPort} option.
12255 @cindex hidden service
12256 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
12257 Define a new Tor @dfn{hidden service} called @var{name} and implementing
12258 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
12261 '((22 "127.0.0.1:22")
12262 (80 "127.0.0.1:8080"))
12265 In this example, port 22 of the hidden service is mapped to local port 22, and
12266 port 80 is mapped to local port 8080.
12268 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
12269 the @file{hostname} file contains the @code{.onion} host name for the hidden
12272 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
12273 project's documentation} for more information.
12276 The @code{(gnu services rsync)} module provides the following services:
12278 You might want an rsync daemon if you have files that you want available
12279 so anyone (or just yourself) can download existing files or upload new
12282 @deffn {Scheme Variable} rsync-service-type
12283 This is the type for the @uref{https://rsync.samba.org, rsync} rsync daemon,
12284 @command{rsync-configuration} record as in this example:
12287 (service rsync-service-type)
12290 See below for details about @code{rsync-configuration}.
12293 @deftp {Data Type} rsync-configuration
12294 Data type representing the configuration for @code{rsync-service}.
12297 @item @code{package} (default: @var{rsync})
12298 @code{rsync} package to use.
12300 @item @code{port-number} (default: @code{873})
12301 TCP port on which @command{rsync} listens for incoming connections. If port
12302 is less than @code{1024} @command{rsync} needs to be started as the
12303 @code{root} user and group.
12305 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
12306 Name of the file where @command{rsync} writes its PID.
12308 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
12309 Name of the file where @command{rsync} writes its lock file.
12311 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
12312 Name of the file where @command{rsync} writes its log file.
12314 @item @code{use-chroot?} (default: @var{#t})
12315 Whether to use chroot for @command{rsync} shared directory.
12317 @item @code{share-path} (default: @file{/srv/rsync})
12318 Location of the @command{rsync} shared directory.
12320 @item @code{share-comment} (default: @code{"Rsync share"})
12321 Comment of the @command{rsync} shared directory.
12323 @item @code{read-only?} (default: @var{#f})
12324 Read-write permissions to shared directory.
12326 @item @code{timeout} (default: @code{300})
12327 I/O timeout in seconds.
12329 @item @code{user} (default: @var{"root"})
12330 Owner of the @code{rsync} process.
12332 @item @code{group} (default: @var{"root"})
12333 Group of the @code{rsync} process.
12335 @item @code{uid} (default: @var{"rsyncd"})
12336 User name or user ID that file transfers to and from that module should take
12337 place as when the daemon was run as @code{root}.
12339 @item @code{gid} (default: @var{"rsyncd"})
12340 Group name or group ID that will be used when accessing the module.
12345 Furthermore, @code{(gnu services ssh)} provides the following services.
12349 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
12350 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
12351 [#:allow-empty-passwords? #f] [#:root-login? #f] @
12352 [#:syslog-output? #t] [#:x11-forwarding? #t] @
12353 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
12354 [#:public-key-authentication? #t] [#:initialize? #t]
12355 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
12356 @var{host-key} must designate a file containing the host key, and readable
12359 When @var{daemonic?} is true, @command{lshd} will detach from the
12360 controlling terminal and log its output to syslogd, unless one sets
12361 @var{syslog-output?} to false. Obviously, it also makes lsh-service
12362 depend on existence of syslogd service. When @var{pid-file?} is true,
12363 @command{lshd} writes its PID to the file called @var{pid-file}.
12365 When @var{initialize?} is true, automatically create the seed and host key
12366 upon service activation if they do not exist yet. This may take long and
12367 require interaction.
12369 When @var{initialize?} is false, it is up to the user to initialize the
12370 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
12371 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
12372 basics,,, lsh, LSH Manual}).
12374 When @var{interfaces} is empty, lshd listens for connections on all the
12375 network interfaces; otherwise, @var{interfaces} must be a list of host names
12378 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
12379 passwords, and @var{root-login?} specifies whether to accept log-ins as
12382 The other options should be self-descriptive.
12387 @deffn {Scheme Variable} openssh-service-type
12388 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
12389 shell daemon, @command{sshd}. Its value must be an
12390 @code{openssh-configuration} record as in this example:
12393 (service openssh-service-type
12394 (openssh-configuration
12395 (x11-forwarding? #t)
12396 (permit-root-login 'without-password)
12398 `(("alice" ,(local-file "alice.pub"))
12399 ("bob" ,(local-file "bob.pub"))))))
12402 See below for details about @code{openssh-configuration}.
12404 This service can be extended with extra authorized keys, as in this
12408 (service-extension openssh-service-type
12409 (const `(("charlie"
12410 ,(local-file "charlie.pub")))))
12414 @deftp {Data Type} openssh-configuration
12415 This is the configuration record for OpenSSH's @command{sshd}.
12418 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
12419 Name of the file where @command{sshd} writes its PID.
12421 @item @code{port-number} (default: @code{22})
12422 TCP port on which @command{sshd} listens for incoming connections.
12424 @item @code{permit-root-login} (default: @code{#f})
12425 This field determines whether and when to allow logins as root. If
12426 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
12427 If it's the symbol @code{'without-password}, then root logins are
12428 permitted but not with password-based authentication.
12430 @item @code{allow-empty-passwords?} (default: @code{#f})
12431 When true, users with empty passwords may log in. When false, they may
12434 @item @code{password-authentication?} (default: @code{#t})
12435 When true, users may log in with their password. When false, they have
12436 other authentication methods.
12438 @item @code{public-key-authentication?} (default: @code{#t})
12439 When true, users may log in using public key authentication. When
12440 false, users have to use other authentication method.
12442 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
12443 This is used only by protocol version 2.
12445 @item @code{x11-forwarding?} (default: @code{#f})
12446 When true, forwarding of X11 graphical client connections is
12447 enabled---in other words, @command{ssh} options @option{-X} and
12448 @option{-Y} will work.
12450 @item @code{allow-agent-forwarding?} (default: @code{#t})
12451 Whether to allow agent forwarding.
12453 @item @code{allow-tcp-forwarding?} (default: @code{#t})
12454 Whether to allow TCP forwarding.
12456 @item @code{gateway-ports?} (default: @code{#f})
12457 Whether to allow gateway ports.
12459 @item @code{challenge-response-authentication?} (default: @code{#f})
12460 Specifies whether challenge response authentication is allowed (e.g.@: via
12463 @item @code{use-pam?} (default: @code{#t})
12464 Enables the Pluggable Authentication Module interface. If set to
12465 @code{#t}, this will enable PAM authentication using
12466 @code{challenge-response-authentication?} and
12467 @code{password-authentication?}, in addition to PAM account and session
12468 module processing for all authentication types.
12470 Because PAM challenge response authentication usually serves an
12471 equivalent role to password authentication, you should disable either
12472 @code{challenge-response-authentication?} or
12473 @code{password-authentication?}.
12475 @item @code{print-last-log?} (default: @code{#t})
12476 Specifies whether @command{sshd} should print the date and time of the
12477 last user login when a user logs in interactively.
12479 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
12480 Configures external subsystems (e.g.@: file transfer daemon).
12482 This is a list of two-element lists, each of which containing the
12483 subsystem name and a command (with optional arguments) to execute upon
12486 The command @command{internal-sftp} implements an in-process SFTP
12487 server. Alternately, one can specify the @command{sftp-server} command:
12489 (service openssh-service-type
12490 (openssh-configuration
12492 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
12495 @item @code{accepted-environment} (default: @code{'()})
12496 List of strings describing which environment variables may be exported.
12498 Each string gets on its own line. See the @code{AcceptEnv} option in
12499 @code{man sshd_config}.
12501 This example allows ssh-clients to export the @code{COLORTERM} variable.
12502 It is set by terminal emulators, which support colors. You can use it in
12503 your shell's ressource file to enable colors for the prompt and commands
12504 if this variable is set.
12507 (service openssh-service-type
12508 (openssh-configuration
12509 (accepted-environment '("COLORTERM"))))
12512 @item @code{authorized-keys} (default: @code{'()})
12513 @cindex authorized keys, SSH
12514 @cindex SSH authorized keys
12515 This is the list of authorized keys. Each element of the list is a user
12516 name followed by one or more file-like objects that represent SSH public
12520 (openssh-configuration
12522 `(("rekado" ,(local-file "rekado.pub"))
12523 ("chris" ,(local-file "chris.pub"))
12524 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
12528 registers the specified public keys for user accounts @code{rekado},
12529 @code{chris}, and @code{root}.
12531 Additional authorized keys can be specified @i{via}
12532 @code{service-extension}.
12534 Note that this does @emph{not} interfere with the use of
12535 @file{~/.ssh/authorized_keys}.
12537 @item @code{log-level} (default: @code{'info})
12538 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
12539 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
12540 page for @file{sshd_config} for the full list of level names.
12545 @deffn {Scheme Procedure} dropbear-service [@var{config}]
12546 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
12547 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
12550 For example, to specify a Dropbear service listening on port 1234, add
12551 this call to the operating system's @code{services} field:
12554 (dropbear-service (dropbear-configuration
12555 (port-number 1234)))
12559 @deftp {Data Type} dropbear-configuration
12560 This data type represents the configuration of a Dropbear SSH daemon.
12563 @item @code{dropbear} (default: @var{dropbear})
12564 The Dropbear package to use.
12566 @item @code{port-number} (default: 22)
12567 The TCP port where the daemon waits for incoming connections.
12569 @item @code{syslog-output?} (default: @code{#t})
12570 Whether to enable syslog output.
12572 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
12573 File name of the daemon's PID file.
12575 @item @code{root-login?} (default: @code{#f})
12576 Whether to allow @code{root} logins.
12578 @item @code{allow-empty-passwords?} (default: @code{#f})
12579 Whether to allow empty passwords.
12581 @item @code{password-authentication?} (default: @code{#t})
12582 Whether to enable password-based authentication.
12586 @defvr {Scheme Variable} %facebook-host-aliases
12587 This variable contains a string for use in @file{/etc/hosts}
12588 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
12589 line contains a entry that maps a known server name of the Facebook
12590 on-line service---e.g., @code{www.facebook.com}---to the local
12591 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
12593 This variable is typically used in the @code{hosts-file} field of an
12594 @code{operating-system} declaration (@pxref{operating-system Reference,
12595 @file{/etc/hosts}}):
12598 (use-modules (gnu) (guix))
12601 (host-name "mymachine")
12604 ;; Create a /etc/hosts file with aliases for "localhost"
12605 ;; and "mymachine", as well as for Facebook servers.
12606 (plain-file "hosts"
12607 (string-append (local-host-aliases host-name)
12608 %facebook-host-aliases))))
12611 This mechanism can prevent programs running locally, such as Web
12612 browsers, from accessing Facebook.
12615 The @code{(gnu services avahi)} provides the following definition.
12617 @deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
12618 [#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
12619 [#:ipv6? #t] [#:wide-area? #f] @
12620 [#:domains-to-browse '()] [#:debug? #f]
12621 Return a service that runs @command{avahi-daemon}, a system-wide
12622 mDNS/DNS-SD responder that allows for service discovery and
12623 "zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
12624 extends the name service cache daemon (nscd) so that it can resolve
12625 @code{.local} host names using
12626 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
12627 add the @var{avahi} package to the system profile so that commands such as
12628 @command{avahi-browse} are directly usable.
12630 If @var{host-name} is different from @code{#f}, use that as the host name to
12631 publish for this machine; otherwise, use the machine's actual host name.
12633 When @var{publish?} is true, publishing of host names and services is allowed;
12634 in particular, avahi-daemon will publish the machine's host name and IP
12635 address via mDNS on the local network.
12637 When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
12639 Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
12643 @deffn {Scheme Variable} openvswitch-service-type
12644 This is the type of the @uref{http://www.openvswitch.org, Open vSwitch}
12645 service, whose value should be an @code{openvswitch-configuration}
12649 @deftp {Data Type} openvswitch-configuration
12650 Data type representing the configuration of Open vSwitch, a multilayer
12651 virtual switch which is designed to enable massive network automation
12652 through programmatic extension.
12655 @item @code{package} (default: @var{openvswitch})
12656 Package object of the Open vSwitch.
12662 @subsubsection X Window
12665 @cindex X Window System
12666 @cindex login manager
12667 Support for the X Window graphical display system---specifically
12668 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
12669 there is no @code{xorg-service} procedure. Instead, the X server is
12670 started by the @dfn{login manager}, by default SLiM.
12672 @cindex window manager
12673 To use X11, you must install at least one @dfn{window manager}---for
12674 example the @code{windowmaker} or @code{openbox} packages---preferably
12675 by adding it to the @code{packages} field of your operating system
12676 definition (@pxref{operating-system Reference, system-wide packages}).
12678 @defvr {Scheme Variable} slim-service-type
12679 This is the type for the SLiM graphical login manager for X11.
12681 @cindex session types (X11)
12682 @cindex X11 session types
12683 SLiM looks for @dfn{session types} described by the @file{.desktop} files in
12684 @file{/run/current-system/profile/share/xsessions} and allows users to
12685 choose a session from the log-in screen using @kbd{F1}. Packages such
12686 as @code{xfce}, @code{sawfish}, and @code{ratpoison} provide
12687 @file{.desktop} files; adding them to the system-wide set of packages
12688 automatically makes them available at the log-in screen.
12690 In addition, @file{~/.xsession} files are honored. When available,
12691 @file{~/.xsession} must be an executable that starts a window manager
12692 and/or other X clients.
12695 @deftp {Data Type} slim-configuration
12696 Data type representing the configuration of @code{slim-service-type}.
12699 @item @code{allow-empty-passwords?} (default: @code{#t})
12700 Whether to allow logins with empty passwords.
12702 @item @code{auto-login?} (default: @code{#f})
12703 @itemx @code{default-user} (default: @code{""})
12704 When @code{auto-login?} is false, SLiM presents a log-in screen.
12706 When @code{auto-login?} is true, SLiM logs in directly as
12707 @code{default-user}.
12709 @item @code{theme} (default: @code{%default-slim-theme})
12710 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
12711 The graphical theme to use and its name.
12713 @item @code{auto-login-session} (default: @code{#f})
12714 If true, this must be the name of the executable to start as the default
12715 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
12717 If false, a session described by one of the available @file{.desktop}
12718 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
12722 You must install at least one window manager in the system profile or in
12723 your user profile. Failing to do that, if @code{auto-login-session} is
12724 false, you will be unable to log in.
12727 @item @code{startx} (default: @code{(xorg-start-command)})
12728 The command used to start the X11 graphical server.
12730 @item @code{xauth} (default: @code{xauth})
12731 The XAuth package to use.
12733 @item @code{shepherd} (default: @code{shepherd})
12734 The Shepherd package used when invoking @command{halt} and
12737 @item @code{sessreg} (default: @code{sessreg})
12738 The sessreg package used in order to register the session.
12740 @item @code{slim} (default: @code{slim})
12741 The SLiM package to use.
12745 @defvr {Scheme Variable} %default-theme
12746 @defvrx {Scheme Variable} %default-theme-name
12747 The default SLiM theme and its name.
12751 @deftp {Data Type} sddm-configuration
12752 This is the data type representing the sddm service configuration.
12755 @item @code{display-server} (default: "x11")
12756 Select display server to use for the greeter. Valid values are "x11"
12759 @item @code{numlock} (default: "on")
12760 Valid values are "on", "off" or "none".
12762 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
12763 Command to run when halting.
12765 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
12766 Command to run when rebooting.
12768 @item @code{theme} (default "maldives")
12769 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
12771 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
12772 Directory to look for themes.
12774 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
12775 Directory to look for faces.
12777 @item @code{default-path} (default "/run/current-system/profile/bin")
12778 Default PATH to use.
12780 @item @code{minimum-uid} (default 1000)
12781 Minimum UID to display in SDDM.
12783 @item @code{maximum-uid} (default 2000)
12784 Maximum UID to display in SDDM
12786 @item @code{remember-last-user?} (default #t)
12787 Remember last user.
12789 @item @code{remember-last-session?} (default #t)
12790 Remember last session.
12792 @item @code{hide-users} (default "")
12793 Usernames to hide from SDDM greeter.
12795 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
12796 Users with shells listed will be hidden from the SDDM greeter.
12798 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
12799 Script to run before starting a wayland session.
12801 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
12802 Directory to look for desktop files starting wayland sessions.
12804 @item @code{xorg-server-path} (default @code{xorg-start-command})
12805 Path to xorg-server.
12807 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
12810 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
12813 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
12814 Script to run after starting xorg-server.
12816 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
12817 Script to run before stopping xorg-server.
12819 @item @code{xsession-command} (default: @code{xinitrc})
12820 Script to run before starting a X session.
12822 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
12823 Directory to look for desktop files starting X sessions.
12825 @item @code{minimum-vt} (default: 7)
12828 @item @code{xserver-arguments} (default "-nolisten tcp")
12829 Arguments to pass to xorg-server.
12831 @item @code{auto-login-user} (default "")
12832 User to use for auto-login.
12834 @item @code{auto-login-session} (default "")
12835 Desktop file to use for auto-login.
12837 @item @code{relogin?} (default #f)
12838 Relogin after logout.
12843 @cindex login manager
12845 @deffn {Scheme Procedure} sddm-service config
12846 Return a service that spawns the SDDM graphical login manager for config of
12847 type @code{<sddm-configuration>}.
12850 (sddm-service (sddm-configuration
12851 (auto-login-user "Alice")
12852 (auto-login-session "xfce.desktop")))
12856 @deffn {Scheme Procedure} xorg-start-command [#:guile] @
12857 [#:modules %default-xorg-modules] @
12858 [#:fonts %default-xorg-fonts] @
12859 [#:configuration-file (xorg-configuration-file @dots{})] @
12860 [#:xorg-server @var{xorg-server}]
12861 Return a @code{startx} script in which @var{modules}, a list of X module
12862 packages, and @var{fonts}, a list of X font directories, are available. See
12863 @code{xorg-wrapper} for more details on the arguments. The result should be
12864 used in place of @code{startx}.
12866 Usually the X server is started by a login manager.
12869 @deffn {Scheme Procedure} xorg-configuration-file @
12870 [#:modules %default-xorg-modules] @
12871 [#:fonts %default-xorg-fonts] @
12872 [#:drivers '()] [#:resolutions '()] [#:extra-config '()]
12873 Return a configuration file for the Xorg server containing search paths for
12874 all the common drivers.
12876 @var{modules} must be a list of @dfn{module packages} loaded by the Xorg
12877 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
12878 @var{fonts} must be a list of font directories to add to the server's
12881 @var{drivers} must be either the empty list, in which case Xorg chooses a
12882 graphics driver automatically, or a list of driver names that will be tried in
12883 this order---e.g., @code{("modesetting" "vesa")}.
12885 Likewise, when @var{resolutions} is the empty list, Xorg chooses an
12886 appropriate screen resolution; otherwise, it must be a list of
12887 resolutions---e.g., @code{((1024 768) (640 480))}.
12889 Last, @var{extra-config} is a list of strings or objects appended to the
12890 configuration file. It is used to pass extra text to be
12891 added verbatim to the configuration file.
12894 @cindex keyboard layout
12895 This procedure is especially useful to configure a different keyboard layout
12896 than the default US keymap. For instance, to use the ``bépo'' keymap by
12897 default on the display manager:
12901 "Section \"InputClass\"
12902 Identifier \"evdev keyboard catchall\"
12904 MatchIsKeyboard \"on\"
12905 Option \"xkb_layout\" \"fr\"
12906 Option \"xkb_variant\" \"bepo\"
12912 (modify-services %desktop-services
12913 (slim-service-type config =>
12914 (slim-configuration
12916 (startx (xorg-start-command
12917 #:configuration-file
12918 (xorg-configuration-file
12920 (list bepo-evdev)))))))))
12923 The @code{MatchIsKeyboard} line specifies that we only apply the configuration
12924 to keyboards. Without this line, other devices such as touchpad may not work
12925 correctly because they will be attached to the wrong driver. In this example,
12926 the user typically used @code{setxkbmap fr bepo} to set their favorite keymap
12927 once logged in. The first argument corresponds to the layout, while the second
12928 argument corresponds to the variant. The @code{xkb_variant} line can be omitted
12929 to select the default variant.
12932 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
12933 Add @var{package}, a package for a screen locker or screen saver whose
12934 command is @var{program}, to the set of setuid programs and add a PAM entry
12935 for it. For example:
12938 (screen-locker-service xlockmore "xlock")
12941 makes the good ol' XlockMore usable.
12945 @node Printing Services
12946 @subsubsection Printing Services
12948 @cindex printer support with CUPS
12949 The @code{(gnu services cups)} module provides a Guix service definition
12950 for the CUPS printing service. To add printer support to a GuixSD
12951 system, add a @code{cups-service} to the operating system definition:
12953 @deffn {Scheme Variable} cups-service-type
12954 The service type for the CUPS print server. Its value should be a valid
12955 CUPS configuration (see below). To use the default settings, simply
12958 (service cups-service-type)
12962 The CUPS configuration controls the basic things about your CUPS
12963 installation: what interfaces it listens on, what to do if a print job
12964 fails, how much logging to do, and so on. To actually add a printer,
12965 you have to visit the @url{http://localhost:631} URL, or use a tool such
12966 as GNOME's printer configuration services. By default, configuring a
12967 CUPS service will generate a self-signed certificate if needed, for
12968 secure connections to the print server.
12970 Suppose you want to enable the Web interface of CUPS and also add
12971 support for Epson printers @i{via} the @code{escpr} package and for HP
12972 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
12973 like this (you need to use the @code{(gnu packages cups)} module):
12976 (service cups-service-type
12977 (cups-configuration
12978 (web-interface? #t)
12980 (list cups-filters escpr hplip-minimal))))
12983 Note: If you wish to use the Qt5 based GUI which comes with the hplip
12984 package then it is suggested that you install the @code{hplip} package,
12985 either in your OS configuration file or as your user.
12987 The available configuration parameters follow. Each parameter
12988 definition is preceded by its type; for example, @samp{string-list foo}
12989 indicates that the @code{foo} parameter should be specified as a list of
12990 strings. There is also a way to specify the configuration as a string,
12991 if you have an old @code{cupsd.conf} file that you want to port over
12992 from some other system; see the end for more details.
12994 @c The following documentation was initially generated by
12995 @c (generate-documentation) in (gnu services cups). Manually maintained
12996 @c documentation is better, so we shouldn't hesitate to edit below as
12997 @c needed. However if the change you want to make to this documentation
12998 @c can be done in an automated way, it's probably easier to change
12999 @c (generate-documentation) than to make it below and have to deal with
13000 @c the churn as CUPS updates.
13003 Available @code{cups-configuration} fields are:
13005 @deftypevr {@code{cups-configuration} parameter} package cups
13009 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13010 Drivers and other extensions to the CUPS package.
13013 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13014 Configuration of where to write logs, what directories to use for print
13015 spools, and related privileged configuration parameters.
13017 Available @code{files-configuration} fields are:
13019 @deftypevr {@code{files-configuration} parameter} log-location access-log
13020 Defines the access log filename. Specifying a blank filename disables
13021 access log generation. The value @code{stderr} causes log entries to be
13022 sent to the standard error file when the scheduler is running in the
13023 foreground, or to the system log daemon when run in the background. The
13024 value @code{syslog} causes log entries to be sent to the system log
13025 daemon. The server name may be included in filenames using the string
13026 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13028 Defaults to @samp{"/var/log/cups/access_log"}.
13031 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13032 Where CUPS should cache data.
13034 Defaults to @samp{"/var/cache/cups"}.
13037 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13038 Specifies the permissions for all configuration files that the scheduler
13041 Note that the permissions for the printers.conf file are currently
13042 masked to only allow access from the scheduler user (typically root).
13043 This is done because printer device URIs sometimes contain sensitive
13044 authentication information that should not be generally known on the
13045 system. There is no way to disable this security feature.
13047 Defaults to @samp{"0640"}.
13050 @deftypevr {@code{files-configuration} parameter} log-location error-log
13051 Defines the error log filename. Specifying a blank filename disables
13052 access log generation. The value @code{stderr} causes log entries to be
13053 sent to the standard error file when the scheduler is running in the
13054 foreground, or to the system log daemon when run in the background. The
13055 value @code{syslog} causes log entries to be sent to the system log
13056 daemon. The server name may be included in filenames using the string
13057 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13059 Defaults to @samp{"/var/log/cups/error_log"}.
13062 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13063 Specifies which errors are fatal, causing the scheduler to exit. The
13068 No errors are fatal.
13071 All of the errors below are fatal.
13074 Browsing initialization errors are fatal, for example failed connections
13075 to the DNS-SD daemon.
13078 Configuration file syntax errors are fatal.
13081 Listen or Port errors are fatal, except for IPv6 failures on the
13082 loopback or @code{any} addresses.
13085 Log file creation or write errors are fatal.
13088 Bad startup file permissions are fatal, for example shared TLS
13089 certificate and key files with world-read permissions.
13092 Defaults to @samp{"all -browse"}.
13095 @deftypevr {@code{files-configuration} parameter} boolean file-device?
13096 Specifies whether the file pseudo-device can be used for new printer
13097 queues. The URI @uref{file:///dev/null} is always allowed.
13099 Defaults to @samp{#f}.
13102 @deftypevr {@code{files-configuration} parameter} string group
13103 Specifies the group name or ID that will be used when executing external
13106 Defaults to @samp{"lp"}.
13109 @deftypevr {@code{files-configuration} parameter} string log-file-perm
13110 Specifies the permissions for all log files that the scheduler writes.
13112 Defaults to @samp{"0644"}.
13115 @deftypevr {@code{files-configuration} parameter} log-location page-log
13116 Defines the page log filename. Specifying a blank filename disables
13117 access log generation. The value @code{stderr} causes log entries to be
13118 sent to the standard error file when the scheduler is running in the
13119 foreground, or to the system log daemon when run in the background. The
13120 value @code{syslog} causes log entries to be sent to the system log
13121 daemon. The server name may be included in filenames using the string
13122 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
13124 Defaults to @samp{"/var/log/cups/page_log"}.
13127 @deftypevr {@code{files-configuration} parameter} string remote-root
13128 Specifies the username that is associated with unauthenticated accesses
13129 by clients claiming to be the root user. The default is @code{remroot}.
13131 Defaults to @samp{"remroot"}.
13134 @deftypevr {@code{files-configuration} parameter} file-name request-root
13135 Specifies the directory that contains print jobs and other HTTP request
13138 Defaults to @samp{"/var/spool/cups"}.
13141 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
13142 Specifies the level of security sandboxing that is applied to print
13143 filters, backends, and other child processes of the scheduler; either
13144 @code{relaxed} or @code{strict}. This directive is currently only
13145 used/supported on macOS.
13147 Defaults to @samp{strict}.
13150 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
13151 Specifies the location of TLS certificates and private keys. CUPS will
13152 look for public and private keys in this directory: a @code{.crt} files
13153 for PEM-encoded certificates and corresponding @code{.key} files for
13154 PEM-encoded private keys.
13156 Defaults to @samp{"/etc/cups/ssl"}.
13159 @deftypevr {@code{files-configuration} parameter} file-name server-root
13160 Specifies the directory containing the server configuration files.
13162 Defaults to @samp{"/etc/cups"}.
13165 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
13166 Specifies whether the scheduler calls fsync(2) after writing
13167 configuration or state files.
13169 Defaults to @samp{#f}.
13172 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
13173 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
13176 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
13177 Specifies the directory where temporary files are stored.
13179 Defaults to @samp{"/var/spool/cups/tmp"}.
13182 @deftypevr {@code{files-configuration} parameter} string user
13183 Specifies the user name or ID that is used when running external
13186 Defaults to @samp{"lp"}.
13190 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
13191 Specifies the logging level for the AccessLog file. The @code{config}
13192 level logs when printers and classes are added, deleted, or modified and
13193 when configuration files are accessed or updated. The @code{actions}
13194 level logs when print jobs are submitted, held, released, modified, or
13195 canceled, and any of the conditions for @code{config}. The @code{all}
13196 level logs all requests.
13198 Defaults to @samp{actions}.
13201 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
13202 Specifies whether to purge job history data automatically when it is no
13203 longer required for quotas.
13205 Defaults to @samp{#f}.
13208 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
13209 Specifies which protocols to use for local printer sharing.
13211 Defaults to @samp{dnssd}.
13214 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
13215 Specifies whether the CUPS web interface is advertised.
13217 Defaults to @samp{#f}.
13220 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
13221 Specifies whether shared printers are advertised.
13223 Defaults to @samp{#f}.
13226 @deftypevr {@code{cups-configuration} parameter} string classification
13227 Specifies the security classification of the server. Any valid banner
13228 name can be used, including "classified", "confidential", "secret",
13229 "topsecret", and "unclassified", or the banner can be omitted to disable
13230 secure printing functions.
13232 Defaults to @samp{""}.
13235 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
13236 Specifies whether users may override the classification (cover page) of
13237 individual print jobs using the @code{job-sheets} option.
13239 Defaults to @samp{#f}.
13242 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
13243 Specifies the default type of authentication to use.
13245 Defaults to @samp{Basic}.
13248 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
13249 Specifies whether encryption will be used for authenticated requests.
13251 Defaults to @samp{Required}.
13254 @deftypevr {@code{cups-configuration} parameter} string default-language
13255 Specifies the default language to use for text and web content.
13257 Defaults to @samp{"en"}.
13260 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
13261 Specifies the default paper size for new print queues. @samp{"Auto"}
13262 uses a locale-specific default, while @samp{"None"} specifies there is
13263 no default paper size. Specific size names are typically
13264 @samp{"Letter"} or @samp{"A4"}.
13266 Defaults to @samp{"Auto"}.
13269 @deftypevr {@code{cups-configuration} parameter} string default-policy
13270 Specifies the default access policy to use.
13272 Defaults to @samp{"default"}.
13275 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
13276 Specifies whether local printers are shared by default.
13278 Defaults to @samp{#t}.
13281 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
13282 Specifies the delay for updating of configuration and state files, in
13283 seconds. A value of 0 causes the update to happen as soon as possible,
13284 typically within a few milliseconds.
13286 Defaults to @samp{30}.
13289 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
13290 Specifies what to do when an error occurs. Possible values are
13291 @code{abort-job}, which will discard the failed print job;
13292 @code{retry-job}, which will retry the job at a later time;
13293 @code{retry-this-job}, which retries the failed job immediately; and
13294 @code{stop-printer}, which stops the printer.
13296 Defaults to @samp{stop-printer}.
13299 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
13300 Specifies the maximum cost of filters that are run concurrently, which
13301 can be used to minimize disk, memory, and CPU resource problems. A
13302 limit of 0 disables filter limiting. An average print to a
13303 non-PostScript printer needs a filter limit of about 200. A PostScript
13304 printer needs about half that (100). Setting the limit below these
13305 thresholds will effectively limit the scheduler to printing a single job
13308 Defaults to @samp{0}.
13311 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
13312 Specifies the scheduling priority of filters that are run to print a
13313 job. The nice value ranges from 0, the highest priority, to 19, the
13316 Defaults to @samp{0}.
13319 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
13320 Specifies whether to do reverse lookups on connecting clients. The
13321 @code{double} setting causes @code{cupsd} to verify that the hostname
13322 resolved from the address matches one of the addresses returned for that
13323 hostname. Double lookups also prevent clients with unregistered
13324 addresses from connecting to your server. Only set this option to
13325 @code{#t} or @code{double} if absolutely required.
13327 Defaults to @samp{#f}.
13330 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
13331 Specifies the number of seconds to wait before killing the filters and
13332 backend associated with a canceled or held job.
13334 Defaults to @samp{30}.
13337 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
13338 Specifies the interval between retries of jobs in seconds. This is
13339 typically used for fax queues but can also be used with normal print
13340 queues whose error policy is @code{retry-job} or
13341 @code{retry-current-job}.
13343 Defaults to @samp{30}.
13346 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
13347 Specifies the number of retries that are done for jobs. This is
13348 typically used for fax queues but can also be used with normal print
13349 queues whose error policy is @code{retry-job} or
13350 @code{retry-current-job}.
13352 Defaults to @samp{5}.
13355 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
13356 Specifies whether to support HTTP keep-alive connections.
13358 Defaults to @samp{#t}.
13361 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
13362 Specifies how long an idle client connection remains open, in seconds.
13364 Defaults to @samp{30}.
13367 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
13368 Specifies the maximum size of print files, IPP requests, and HTML form
13369 data. A limit of 0 disables the limit check.
13371 Defaults to @samp{0}.
13374 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
13375 Listens on the specified interfaces for connections. Valid values are
13376 of the form @var{address}:@var{port}, where @var{address} is either an
13377 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
13378 indicate all addresses. Values can also be file names of local UNIX
13379 domain sockets. The Listen directive is similar to the Port directive
13380 but allows you to restrict access to specific interfaces or networks.
13383 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
13384 Specifies the number of pending connections that will be allowed. This
13385 normally only affects very busy servers that have reached the MaxClients
13386 limit, but can also be triggered by large numbers of simultaneous
13387 connections. When the limit is reached, the operating system will
13388 refuse additional connections until the scheduler can accept the pending
13391 Defaults to @samp{128}.
13394 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
13395 Specifies a set of additional access controls.
13397 Available @code{location-access-controls} fields are:
13399 @deftypevr {@code{location-access-controls} parameter} file-name path
13400 Specifies the URI path to which the access control applies.
13403 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
13404 Access controls for all access to this path, in the same format as the
13405 @code{access-controls} of @code{operation-access-control}.
13407 Defaults to @samp{()}.
13410 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
13411 Access controls for method-specific access to this path.
13413 Defaults to @samp{()}.
13415 Available @code{method-access-controls} fields are:
13417 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
13418 If @code{#t}, apply access controls to all methods except the listed
13419 methods. Otherwise apply to only the listed methods.
13421 Defaults to @samp{#f}.
13424 @deftypevr {@code{method-access-controls} parameter} method-list methods
13425 Methods to which this access control applies.
13427 Defaults to @samp{()}.
13430 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
13431 Access control directives, as a list of strings. Each string should be
13432 one directive, such as "Order allow,deny".
13434 Defaults to @samp{()}.
13439 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
13440 Specifies the number of debugging messages that are retained for logging
13441 if an error occurs in a print job. Debug messages are logged regardless
13442 of the LogLevel setting.
13444 Defaults to @samp{100}.
13447 @deftypevr {@code{cups-configuration} parameter} log-level log-level
13448 Specifies the level of logging for the ErrorLog file. The value
13449 @code{none} stops all logging while @code{debug2} logs everything.
13451 Defaults to @samp{info}.
13454 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
13455 Specifies the format of the date and time in the log files. The value
13456 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
13458 Defaults to @samp{standard}.
13461 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
13462 Specifies the maximum number of simultaneous clients that are allowed by
13465 Defaults to @samp{100}.
13468 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
13469 Specifies the maximum number of simultaneous clients that are allowed
13470 from a single address.
13472 Defaults to @samp{100}.
13475 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
13476 Specifies the maximum number of copies that a user can print of each
13479 Defaults to @samp{9999}.
13482 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
13483 Specifies the maximum time a job may remain in the @code{indefinite}
13484 hold state before it is canceled. A value of 0 disables cancellation of
13487 Defaults to @samp{0}.
13490 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
13491 Specifies the maximum number of simultaneous jobs that are allowed. Set
13492 to 0 to allow an unlimited number of jobs.
13494 Defaults to @samp{500}.
13497 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
13498 Specifies the maximum number of simultaneous jobs that are allowed per
13499 printer. A value of 0 allows up to MaxJobs jobs per printer.
13501 Defaults to @samp{0}.
13504 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
13505 Specifies the maximum number of simultaneous jobs that are allowed per
13506 user. A value of 0 allows up to MaxJobs jobs per user.
13508 Defaults to @samp{0}.
13511 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
13512 Specifies the maximum time a job may take to print before it is
13513 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
13515 Defaults to @samp{10800}.
13518 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
13519 Specifies the maximum size of the log files before they are rotated, in
13520 bytes. The value 0 disables log rotation.
13522 Defaults to @samp{1048576}.
13525 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
13526 Specifies the maximum amount of time to allow between files in a
13527 multiple file print job, in seconds.
13529 Defaults to @samp{300}.
13532 @deftypevr {@code{cups-configuration} parameter} string page-log-format
13533 Specifies the format of PageLog lines. Sequences beginning with percent
13534 (@samp{%}) characters are replaced with the corresponding information,
13535 while all other characters are copied literally. The following percent
13536 sequences are recognized:
13540 insert a single percent character
13543 insert the value of the specified IPP attribute
13546 insert the number of copies for the current page
13549 insert the current page number
13552 insert the current date and time in common log format
13558 insert the printer name
13561 insert the username
13564 A value of the empty string disables page logging. The string @code{%p
13565 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
13566 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
13569 Defaults to @samp{""}.
13572 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
13573 Passes the specified environment variable(s) to child processes; a list
13576 Defaults to @samp{()}.
13579 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
13580 Specifies named access control policies.
13582 Available @code{policy-configuration} fields are:
13584 @deftypevr {@code{policy-configuration} parameter} string name
13585 Name of the policy.
13588 @deftypevr {@code{policy-configuration} parameter} string job-private-access
13589 Specifies an access list for a job's private values. @code{@@ACL} maps
13590 to the printer's requesting-user-name-allowed or
13591 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13592 owner. @code{@@SYSTEM} maps to the groups listed for the
13593 @code{system-group} field of the @code{files-config} configuration,
13594 which is reified into the @code{cups-files.conf(5)} file. Other
13595 possible elements of the access list include specific user names, and
13596 @code{@@@var{group}} to indicate members of a specific group. The
13597 access list may also be simply @code{all} or @code{default}.
13599 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13602 @deftypevr {@code{policy-configuration} parameter} string job-private-values
13603 Specifies the list of job values to make private, or @code{all},
13604 @code{default}, or @code{none}.
13606 Defaults to @samp{"job-name job-originating-host-name
13607 job-originating-user-name phone"}.
13610 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
13611 Specifies an access list for a subscription's private values.
13612 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
13613 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
13614 owner. @code{@@SYSTEM} maps to the groups listed for the
13615 @code{system-group} field of the @code{files-config} configuration,
13616 which is reified into the @code{cups-files.conf(5)} file. Other
13617 possible elements of the access list include specific user names, and
13618 @code{@@@var{group}} to indicate members of a specific group. The
13619 access list may also be simply @code{all} or @code{default}.
13621 Defaults to @samp{"@@OWNER @@SYSTEM"}.
13624 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
13625 Specifies the list of job values to make private, or @code{all},
13626 @code{default}, or @code{none}.
13628 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
13629 notify-subscriber-user-name notify-user-data"}.
13632 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
13633 Access control by IPP operation.
13635 Defaults to @samp{()}.
13639 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
13640 Specifies whether job files (documents) are preserved after a job is
13641 printed. If a numeric value is specified, job files are preserved for
13642 the indicated number of seconds after printing. Otherwise a boolean
13643 value applies indefinitely.
13645 Defaults to @samp{86400}.
13648 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
13649 Specifies whether the job history is preserved after a job is printed.
13650 If a numeric value is specified, the job history is preserved for the
13651 indicated number of seconds after printing. If @code{#t}, the job
13652 history is preserved until the MaxJobs limit is reached.
13654 Defaults to @samp{#t}.
13657 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
13658 Specifies the amount of time to wait for job completion before
13659 restarting the scheduler.
13661 Defaults to @samp{30}.
13664 @deftypevr {@code{cups-configuration} parameter} string rip-cache
13665 Specifies the maximum amount of memory to use when converting documents
13666 into bitmaps for a printer.
13668 Defaults to @samp{"128m"}.
13671 @deftypevr {@code{cups-configuration} parameter} string server-admin
13672 Specifies the email address of the server administrator.
13674 Defaults to @samp{"root@@localhost.localdomain"}.
13677 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
13678 The ServerAlias directive is used for HTTP Host header validation when
13679 clients connect to the scheduler from external interfaces. Using the
13680 special name @code{*} can expose your system to known browser-based DNS
13681 rebinding attacks, even when accessing sites through a firewall. If the
13682 auto-discovery of alternate names does not work, we recommend listing
13683 each alternate name with a ServerAlias directive instead of using
13686 Defaults to @samp{*}.
13689 @deftypevr {@code{cups-configuration} parameter} string server-name
13690 Specifies the fully-qualified host name of the server.
13692 Defaults to @samp{"localhost"}.
13695 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
13696 Specifies what information is included in the Server header of HTTP
13697 responses. @code{None} disables the Server header. @code{ProductOnly}
13698 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
13699 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
13700 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
13701 the output of the @code{uname} command. @code{Full} reports @code{CUPS
13702 2.0.0 (@var{uname}) IPP/2.0}.
13704 Defaults to @samp{Minimal}.
13707 @deftypevr {@code{cups-configuration} parameter} string set-env
13708 Set the specified environment variable to be passed to child processes.
13710 Defaults to @samp{"variable value"}.
13713 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
13714 Listens on the specified interfaces for encrypted connections. Valid
13715 values are of the form @var{address}:@var{port}, where @var{address} is
13716 either an IPv6 address enclosed in brackets, an IPv4 address, or
13717 @code{*} to indicate all addresses.
13719 Defaults to @samp{()}.
13722 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
13723 Sets encryption options. By default, CUPS only supports encryption
13724 using TLS v1.0 or higher using known secure cipher suites. The
13725 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
13726 required for some older clients that do not implement newer ones. The
13727 @code{AllowSSL3} option enables SSL v3.0, which is required for some
13728 older clients that do not support TLS v1.0.
13730 Defaults to @samp{()}.
13733 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
13734 Specifies whether the scheduler requires clients to strictly adhere to
13735 the IPP specifications.
13737 Defaults to @samp{#f}.
13740 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
13741 Specifies the HTTP request timeout, in seconds.
13743 Defaults to @samp{300}.
13747 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
13748 Specifies whether the web interface is enabled.
13750 Defaults to @samp{#f}.
13753 At this point you're probably thinking ``oh dear, Guix manual, I like
13754 you but you can stop already with the configuration options''. Indeed.
13755 However, one more point: it could be that you have an existing
13756 @code{cupsd.conf} that you want to use. In that case, you can pass an
13757 @code{opaque-cups-configuration} as the configuration of a
13758 @code{cups-service-type}.
13760 Available @code{opaque-cups-configuration} fields are:
13762 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
13766 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
13767 The contents of the @code{cupsd.conf}, as a string.
13770 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
13771 The contents of the @code{cups-files.conf} file, as a string.
13774 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
13775 strings of the same name, you could instantiate a CUPS service like
13779 (service cups-service-type
13780 (opaque-cups-configuration
13781 (cupsd.conf cupsd.conf)
13782 (cups-files.conf cups-files.conf)))
13786 @node Desktop Services
13787 @subsubsection Desktop Services
13789 The @code{(gnu services desktop)} module provides services that are
13790 usually useful in the context of a ``desktop'' setup---that is, on a
13791 machine running a graphical display server, possibly with graphical user
13792 interfaces, etc. It also defines services that provide specific desktop
13793 environments like GNOME, XFCE or MATE.
13795 To simplify things, the module defines a variable containing the set of
13796 services that users typically expect on a machine with a graphical
13797 environment and networking:
13799 @defvr {Scheme Variable} %desktop-services
13800 This is a list of services that builds upon @var{%base-services} and
13801 adds or adjusts services for a typical ``desktop'' setup.
13803 In particular, it adds a graphical login manager (@pxref{X Window,
13804 @code{slim-service}}), screen lockers, a network management tool
13805 (@pxref{Networking Services, @code{network-manager-service-type}}), energy and color
13806 management services, the @code{elogind} login and seat manager, the
13807 Polkit privilege service, the GeoClue location service, the
13808 AccountsService daemon that allows authorized users change system
13809 passwords, an NTP client (@pxref{Networking Services}), the Avahi
13810 daemon, and has the name service switch service configured to be able to
13811 use @code{nss-mdns} (@pxref{Name Service Switch, mDNS}).
13814 The @var{%desktop-services} variable can be used as the @code{services}
13815 field of an @code{operating-system} declaration (@pxref{operating-system
13816 Reference, @code{services}}).
13818 Additionally, the @code{gnome-desktop-service},
13819 @code{xfce-desktop-service}, @code{mate-desktop-service} and
13820 @code{enlightenment-desktop-service-type} procedures can add GNOME, XFCE, MATE
13821 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
13822 services like the backlight adjustment helpers and the power management
13823 utilities are added to the system, extending @code{polkit} and @code{dbus}
13824 appropriately, allowing GNOME to operate with elevated privileges on a
13825 limited number of special-purpose system interfaces. Additionally,
13826 adding a service made by @code{gnome-desktop-service} adds the GNOME
13827 metapackage to the system profile. Likewise, adding the XFCE service
13828 not only adds the @code{xfce} metapackage to the system profile, but it
13829 also gives the Thunar file manager the ability to open a ``root-mode''
13830 file management window, if the user authenticates using the
13831 administrator's password via the standard polkit graphical interface.
13832 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
13833 appropriately, allowing MATE to operate with elevated privileges on a
13834 limited number of special-purpose system interfaces. Additionally,
13835 adding a service made by @code{mate-desktop-service} adds the MATE
13836 metapackage to the system profile. ``Adding ENLIGHTENMENT'' means that
13837 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
13838 are set as setuid, allowing Enlightenment's screen locker and other
13839 functionality to work as expetected.
13841 The desktop environments in Guix use the Xorg display server by
13842 default. If you'd like to use the newer display server protocol
13843 called Wayland, you need to use the @code{sddm-service} instead of the
13844 @code{slim-service} for the graphical login manager. You should then
13845 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
13846 also try starting GNOME on Wayland manually from a TTY with the
13847 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
13848 gnome-session``. Currently only GNOME has support for Wayland.
13850 @deffn {Scheme Procedure} gnome-desktop-service
13851 Return a service that adds the @code{gnome} package to the system
13852 profile, and extends polkit with the actions from
13853 @code{gnome-settings-daemon}.
13856 @deffn {Scheme Procedure} xfce-desktop-service
13857 Return a service that adds the @code{xfce} package to the system profile,
13858 and extends polkit with the ability for @code{thunar} to manipulate the
13859 file system as root from within a user session, after the user has
13860 authenticated with the administrator's password.
13863 @deffn {Scheme Procedure} mate-desktop-service
13864 Return a service that adds the @code{mate} package to the system
13865 profile, and extends polkit with the actions from
13866 @code{mate-settings-daemon}.
13869 @deffn {Scheme Procedure} enlightenment-desktop-service-type
13870 Return a service that adds the @code{enlightenment} package to the system
13871 profile, and extends dbus with actions from @code{efl}.
13874 @deftp {Data Type} enlightenment-desktop-service-configuration
13876 @item @code{enlightenment} (default @code{enlightenment})
13877 The enlightenment package to use.
13881 Because the GNOME, XFCE and MATE desktop services pull in so many packages,
13882 the default @code{%desktop-services} variable doesn't include any of
13883 them by default. To add GNOME, XFCE or MATE, just @code{cons} them onto
13884 @code{%desktop-services} in the @code{services} field of your
13885 @code{operating-system}:
13888 (use-modules (gnu))
13889 (use-service-modules desktop)
13892 ;; cons* adds items to the list given as its last argument.
13893 (services (cons* (gnome-desktop-service)
13894 (xfce-desktop-service)
13895 %desktop-services))
13899 These desktop environments will then be available as options in the
13900 graphical login window.
13902 The actual service definitions included in @code{%desktop-services} and
13903 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
13904 are described below.
13906 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
13907 Return a service that runs the ``system bus'', using @var{dbus}, with
13908 support for @var{services}.
13910 @uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
13911 facility. Its system bus is used to allow system services to communicate
13912 and to be notified of system-wide events.
13914 @var{services} must be a list of packages that provide an
13915 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
13916 and policy files. For example, to allow avahi-daemon to use the system bus,
13917 @var{services} must be equal to @code{(list avahi)}.
13920 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
13921 Return a service that runs the @code{elogind} login and
13922 seat management daemon. @uref{https://github.com/elogind/elogind,
13923 Elogind} exposes a D-Bus interface that can be used to know which users
13924 are logged in, know what kind of sessions they have open, suspend the
13925 system, inhibit system suspend, reboot the system, and other tasks.
13927 Elogind handles most system-level power events for a computer, for
13928 example suspending the system when a lid is closed, or shutting it down
13929 when the power button is pressed.
13931 The @var{config} keyword argument specifies the configuration for
13932 elogind, and should be the result of an @code{(elogind-configuration
13933 (@var{parameter} @var{value})...)} invocation. Available parameters and
13934 their default values are:
13937 @item kill-user-processes?
13939 @item kill-only-users
13941 @item kill-exclude-users
13943 @item inhibit-delay-max-seconds
13945 @item handle-power-key
13947 @item handle-suspend-key
13949 @item handle-hibernate-key
13951 @item handle-lid-switch
13953 @item handle-lid-switch-docked
13955 @item power-key-ignore-inhibited?
13957 @item suspend-key-ignore-inhibited?
13959 @item hibernate-key-ignore-inhibited?
13961 @item lid-switch-ignore-inhibited?
13963 @item holdoff-timeout-seconds
13967 @item idle-action-seconds
13969 @item runtime-directory-size-percent
13971 @item runtime-directory-size
13975 @item suspend-state
13976 @code{("mem" "standby" "freeze")}
13979 @item hibernate-state
13981 @item hibernate-mode
13982 @code{("platform" "shutdown")}
13983 @item hybrid-sleep-state
13985 @item hybrid-sleep-mode
13986 @code{("suspend" "platform" "shutdown")}
13990 @deffn {Scheme Procedure} accountsservice-service @
13991 [#:accountsservice @var{accountsservice}]
13992 Return a service that runs AccountsService, a system service that can
13993 list available accounts, change their passwords, and so on.
13994 AccountsService integrates with PolicyKit to enable unprivileged users
13995 to acquire the capability to modify their system configuration.
13996 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
13997 accountsservice web site} for more information.
13999 The @var{accountsservice} keyword argument is the @code{accountsservice}
14000 package to expose as a service.
14003 @deffn {Scheme Procedure} polkit-service @
14004 [#:polkit @var{polkit}]
14005 Return a service that runs the
14006 @uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14007 management service}, which allows system administrators to grant access to
14008 privileged operations in a structured way. By querying the Polkit service, a
14009 privileged system component can know when it should grant additional
14010 capabilities to ordinary users. For example, an ordinary user can be granted
14011 the capability to suspend the system if the user is logged in locally.
14014 @deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
14015 [#:watts-up-pro? #f] @
14016 [#:poll-batteries? #t] @
14017 [#:ignore-lid? #f] @
14018 [#:use-percentage-for-policy? #f] @
14019 [#:percentage-low 10] @
14020 [#:percentage-critical 3] @
14021 [#:percentage-action 2] @
14022 [#:time-low 1200] @
14023 [#:time-critical 300] @
14024 [#:time-action 120] @
14025 [#:critical-power-action 'hybrid-sleep]
14026 Return a service that runs @uref{http://upower.freedesktop.org/,
14027 @command{upowerd}}, a system-wide monitor for power consumption and battery
14028 levels, with the given configuration settings. It implements the
14029 @code{org.freedesktop.UPower} D-Bus interface, and is notably used by
14033 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
14034 Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
14035 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
14036 notifications and ways to mount/unmount disks. Programs that talk to UDisks
14037 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
14040 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
14041 Return a service that runs @command{colord}, a system service with a D-Bus
14042 interface to manage the color profiles of input and output devices such as
14043 screens and scanners. It is notably used by the GNOME Color Manager graphical
14044 tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
14045 site} for more information.
14048 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
14049 Return a configuration allowing an application to access GeoClue
14050 location data. @var{name} is the Desktop ID of the application, without
14051 the @code{.desktop} part. If @var{allowed?} is true, the application
14052 will have access to location information by default. The boolean
14053 @var{system?} value indicates whether an application is a system component
14054 or not. Finally @var{users} is a list of UIDs of all users for which
14055 this application is allowed location info access. An empty users list
14056 means that all users are allowed.
14059 @defvr {Scheme Variable} %standard-geoclue-applications
14060 The standard list of well-known GeoClue application configurations,
14061 granting authority to the GNOME date-and-time utility to ask for the
14062 current location in order to set the time zone, and allowing the
14063 IceCat and Epiphany web browsers to request location information.
14064 IceCat and Epiphany both query the user before allowing a web page to
14065 know the user's location.
14068 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
14069 [#:whitelist '()] @
14070 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
14071 [#:submit-data? #f]
14072 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
14073 [#:submission-nick "geoclue"] @
14074 [#:applications %standard-geoclue-applications]
14075 Return a service that runs the GeoClue location service. This service
14076 provides a D-Bus interface to allow applications to request access to a
14077 user's physical location, and optionally to add information to online
14078 location databases. See
14079 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
14080 web site} for more information.
14083 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
14084 [@w{#:auto-enable? #f}]
14085 Return a service that runs the @command{bluetoothd} daemon, which
14086 manages all the Bluetooth devices and provides a number of D-Bus
14087 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
14088 powered automatically at boot, which can be useful when using a
14089 bluetooth keyboard or mouse.
14091 Users need to be in the @code{lp} group to access the D-Bus service.
14094 @node Sound Services
14095 @subsubsection Sound Services
14097 @cindex sound support
14099 @cindex PulseAudio, sound support
14101 The @code{(gnu services sound)} module provides a service to configure the
14102 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
14103 preferred ALSA output driver.
14105 @deffn {Scheme Variable} alsa-service-type
14106 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
14107 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
14108 configuration file. The value for this type is a @command{alsa-configuration}
14109 record as in this example:
14112 (service alsa-service-type)
14115 See below for details about @code{alsa-configuration}.
14118 @deftp {Data Type} alsa-configuration
14119 Data type representing the configuration for @code{alsa-service}.
14122 @item @code{alsa-plugins} (default: @var{alsa-plugins})
14123 @code{alsa-plugins} package to use.
14125 @item @code{pulseaudio?} (default: @var{#t})
14126 Whether ALSA applications should transparently be made to use the
14127 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
14129 Using PulseAudio allows you to run several sound-producing applications
14130 at the same time and to individual control them @i{via}
14131 @command{pavucontrol}, among other things.
14133 @item @code{extra-options} (default: @var{""})
14134 String to append to the @file{/etc/asound.conf} file.
14139 Individual users who want to override the system configuration of ALSA can do
14140 it with the @file{~/.asoundrc} file:
14143 # In guix, we have to specify the absolute path for plugins.
14145 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
14148 # Routing ALSA to jack:
14149 # <http://jackaudio.org/faq/routing_alsa.html>.
14153 0 system:playback_1
14154 1 system:playback_2
14171 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
14175 @node Database Services
14176 @subsubsection Database Services
14180 The @code{(gnu services databases)} module provides the following services.
14182 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
14183 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
14184 [#:port 5432] [#:locale ``en_US.utf8'']
14185 Return a service that runs @var{postgresql}, the PostgreSQL database
14188 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
14189 creates a database cluster with @var{locale} as the default
14190 locale, stored in @var{data-directory}. It then listens on @var{port}.
14193 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
14194 Return a service that runs @command{mysqld}, the MySQL or MariaDB
14197 The optional @var{config} argument specifies the configuration for
14198 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
14201 @deftp {Data Type} mysql-configuration
14202 Data type representing the configuration of @var{mysql-service}.
14205 @item @code{mysql} (default: @var{mariadb})
14206 Package object of the MySQL database server, can be either @var{mariadb}
14209 For MySQL, a temporary root password will be displayed at activation time.
14210 For MariaDB, the root password is empty.
14212 @item @code{port} (default: @code{3306})
14213 TCP port on which the database server listens for incoming connections.
14217 @defvr {Scheme Variable} memcached-service-type
14218 This is the service type for the @uref{https://memcached.org/,
14219 Memcached} service, which provides a distributed in memory cache. The
14220 value for the service type is a @code{memcached-configuration} object.
14224 (service memcached-service-type)
14227 @deftp {Data Type} memcached-configuration
14228 Data type representing the configuration of memcached.
14231 @item @code{memcached} (default: @code{memcached})
14232 The Memcached package to use.
14234 @item @code{interfaces} (default: @code{'("0.0.0.0")})
14235 Network interfaces on which to listen.
14237 @item @code{tcp-port} (default: @code{11211})
14238 Port on which to accept connections on,
14240 @item @code{udp-port} (default: @code{11211})
14241 Port on which to accept UDP connections on, a value of 0 will disable
14242 listening on a UDP socket.
14244 @item @code{additional-options} (default: @code{'()})
14245 Additional command line options to pass to @code{memcached}.
14249 @defvr {Scheme Variable} mongodb-service-type
14250 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
14251 The value for the service type is a @code{mongodb-configuration} object.
14255 (service mongodb-service-type)
14258 @deftp {Data Type} mongodb-configuration
14259 Data type representing the configuration of mongodb.
14262 @item @code{mongodb} (default: @code{mongodb})
14263 The MongoDB package to use.
14265 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
14266 The configuration file for MongoDB.
14268 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
14269 This value is used to create the directory, so that it exists and is
14270 owned by the mongodb user. It should match the data-directory which
14271 MongoDB is configured to use through the configuration file.
14275 @defvr {Scheme Variable} redis-service-type
14276 This is the service type for the @uref{https://redis.io/, Redis}
14277 key/value store, whose value is a @code{redis-configuration} object.
14280 @deftp {Data Type} redis-configuration
14281 Data type representing the configuration of redis.
14284 @item @code{redis} (default: @code{redis})
14285 The Redis package to use.
14287 @item @code{bind} (default: @code{"127.0.0.1"})
14288 Network interface on which to listen.
14290 @item @code{port} (default: @code{6379})
14291 Port on which to accept connections on, a value of 0 will disable
14292 listening on a TCP socket.
14294 @item @code{working-directory} (default: @code{"/var/lib/redis"})
14295 Directory in which to store the database and related files.
14299 @node Mail Services
14300 @subsubsection Mail Services
14304 The @code{(gnu services mail)} module provides Guix service definitions
14305 for email services: IMAP, POP3, and LMTP servers, as well as mail
14306 transport agents (MTAs). Lots of acronyms! These services are detailed
14307 in the subsections below.
14309 @subsubheading Dovecot Service
14311 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
14312 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
14315 By default, Dovecot does not need much configuration; the default
14316 configuration object created by @code{(dovecot-configuration)} will
14317 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
14318 certificate will be generated for TLS-protected connections, though
14319 Dovecot will also listen on cleartext ports by default. There are a
14320 number of options, though, which mail administrators might need to change,
14321 and as is the case with other services, Guix allows the system
14322 administrator to specify these parameters via a uniform Scheme interface.
14324 For example, to specify that mail is located at @code{maildir~/.mail},
14325 one would instantiate the Dovecot service like this:
14328 (dovecot-service #:config
14329 (dovecot-configuration
14330 (mail-location "maildir:~/.mail")))
14333 The available configuration parameters follow. Each parameter
14334 definition is preceded by its type; for example, @samp{string-list foo}
14335 indicates that the @code{foo} parameter should be specified as a list of
14336 strings. There is also a way to specify the configuration as a string,
14337 if you have an old @code{dovecot.conf} file that you want to port over
14338 from some other system; see the end for more details.
14340 @c The following documentation was initially generated by
14341 @c (generate-documentation) in (gnu services mail). Manually maintained
14342 @c documentation is better, so we shouldn't hesitate to edit below as
14343 @c needed. However if the change you want to make to this documentation
14344 @c can be done in an automated way, it's probably easier to change
14345 @c (generate-documentation) than to make it below and have to deal with
14346 @c the churn as dovecot updates.
14348 Available @code{dovecot-configuration} fields are:
14350 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
14351 The dovecot package.
14354 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
14355 A list of IPs or hosts where to listen for connections. @samp{*}
14356 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
14357 interfaces. If you want to specify non-default ports or anything more
14358 complex, customize the address and port fields of the
14359 @samp{inet-listener} of the specific services you are interested in.
14362 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
14363 List of protocols we want to serve. Available protocols include
14364 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
14366 Available @code{protocol-configuration} fields are:
14368 @deftypevr {@code{protocol-configuration} parameter} string name
14369 The name of the protocol.
14372 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
14373 UNIX socket path to the master authentication server to find users.
14374 This is used by imap (for shared users) and lda.
14375 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
14378 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
14379 Space separated list of plugins to load.
14382 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
14383 Maximum number of IMAP connections allowed for a user from each IP
14384 address. NOTE: The username is compared case-sensitively.
14385 Defaults to @samp{10}.
14390 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
14391 List of services to enable. Available services include @samp{imap},
14392 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
14395 Available @code{service-configuration} fields are:
14397 @deftypevr {@code{service-configuration} parameter} string kind
14398 The service kind. Valid values include @code{director},
14399 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
14400 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
14401 @code{tcpwrap}, @code{quota-warning}, or anything else.
14404 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
14405 Listeners for the service. A listener is either a
14406 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
14407 an @code{inet-listener-configuration}.
14408 Defaults to @samp{()}.
14410 Available @code{unix-listener-configuration} fields are:
14412 @deftypevr {@code{unix-listener-configuration} parameter} string path
14413 Path to the file, relative to @code{base-dir} field. This is also used as
14417 @deftypevr {@code{unix-listener-configuration} parameter} string mode
14418 The access mode for the socket.
14419 Defaults to @samp{"0600"}.
14422 @deftypevr {@code{unix-listener-configuration} parameter} string user
14423 The user to own the socket.
14424 Defaults to @samp{""}.
14427 @deftypevr {@code{unix-listener-configuration} parameter} string group
14428 The group to own the socket.
14429 Defaults to @samp{""}.
14433 Available @code{fifo-listener-configuration} fields are:
14435 @deftypevr {@code{fifo-listener-configuration} parameter} string path
14436 Path to the file, relative to @code{base-dir} field. This is also used as
14440 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
14441 The access mode for the socket.
14442 Defaults to @samp{"0600"}.
14445 @deftypevr {@code{fifo-listener-configuration} parameter} string user
14446 The user to own the socket.
14447 Defaults to @samp{""}.
14450 @deftypevr {@code{fifo-listener-configuration} parameter} string group
14451 The group to own the socket.
14452 Defaults to @samp{""}.
14456 Available @code{inet-listener-configuration} fields are:
14458 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
14459 The protocol to listen for.
14462 @deftypevr {@code{inet-listener-configuration} parameter} string address
14463 The address on which to listen, or empty for all addresses.
14464 Defaults to @samp{""}.
14467 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
14468 The port on which to listen.
14471 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
14472 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
14474 Defaults to @samp{#t}.
14479 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
14480 Maximum number of simultaneous client connections per process. Once
14481 this number of connections is received, the next incoming connection
14482 will prompt Dovecot to spawn another process. If set to 0,
14483 @code{default-client-limit} is used instead.
14485 Defaults to @samp{0}.
14489 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
14490 Number of connections to handle before starting a new process.
14491 Typically the only useful values are 0 (unlimited) or 1. 1 is more
14492 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
14493 Defaults to @samp{1}.
14497 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
14498 Maximum number of processes that can exist for this service. If set to
14499 0, @code{default-process-limit} is used instead.
14501 Defaults to @samp{0}.
14505 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
14506 Number of processes to always keep waiting for more connections.
14507 Defaults to @samp{0}.
14510 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
14511 If you set @samp{service-count 0}, you probably need to grow
14513 Defaults to @samp{256000000}.
14518 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
14519 Dict configuration, as created by the @code{dict-configuration}
14522 Available @code{dict-configuration} fields are:
14524 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
14525 A list of key-value pairs that this dict should hold.
14526 Defaults to @samp{()}.
14531 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
14532 A list of passdb configurations, each one created by the
14533 @code{passdb-configuration} constructor.
14535 Available @code{passdb-configuration} fields are:
14537 @deftypevr {@code{passdb-configuration} parameter} string driver
14538 The driver that the passdb should use. Valid values include
14539 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
14541 Defaults to @samp{"pam"}.
14544 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
14545 Space separated list of arguments to the passdb driver.
14546 Defaults to @samp{""}.
14551 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
14552 List of userdb configurations, each one created by the
14553 @code{userdb-configuration} constructor.
14555 Available @code{userdb-configuration} fields are:
14557 @deftypevr {@code{userdb-configuration} parameter} string driver
14558 The driver that the userdb should use. Valid values include
14559 @samp{passwd} and @samp{static}.
14560 Defaults to @samp{"passwd"}.
14563 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
14564 Space separated list of arguments to the userdb driver.
14565 Defaults to @samp{""}.
14568 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
14569 Override fields from passwd.
14570 Defaults to @samp{()}.
14575 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
14576 Plug-in configuration, created by the @code{plugin-configuration}
14580 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
14581 List of namespaces. Each item in the list is created by the
14582 @code{namespace-configuration} constructor.
14584 Available @code{namespace-configuration} fields are:
14586 @deftypevr {@code{namespace-configuration} parameter} string name
14587 Name for this namespace.
14590 @deftypevr {@code{namespace-configuration} parameter} string type
14591 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
14592 Defaults to @samp{"private"}.
14595 @deftypevr {@code{namespace-configuration} parameter} string separator
14596 Hierarchy separator to use. You should use the same separator for
14597 all namespaces or some clients get confused. @samp{/} is usually a good
14598 one. The default however depends on the underlying mail storage
14600 Defaults to @samp{""}.
14603 @deftypevr {@code{namespace-configuration} parameter} string prefix
14604 Prefix required to access this namespace. This needs to be
14605 different for all namespaces. For example @samp{Public/}.
14606 Defaults to @samp{""}.
14609 @deftypevr {@code{namespace-configuration} parameter} string location
14610 Physical location of the mailbox. This is in the same format as
14611 mail_location, which is also the default for it.
14612 Defaults to @samp{""}.
14615 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
14616 There can be only one INBOX, and this setting defines which
14618 Defaults to @samp{#f}.
14621 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
14622 If namespace is hidden, it's not advertised to clients via NAMESPACE
14623 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
14624 useful when converting from another server with different namespaces
14625 which you want to deprecate but still keep working. For example you can
14626 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
14628 Defaults to @samp{#f}.
14631 @deftypevr {@code{namespace-configuration} parameter} boolean list?
14632 Show the mailboxes under this namespace with the LIST command. This
14633 makes the namespace visible for clients that do not support the NAMESPACE
14634 extension. The special @code{children} value lists child mailboxes, but
14635 hides the namespace prefix.
14636 Defaults to @samp{#t}.
14639 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
14640 Namespace handles its own subscriptions. If set to @code{#f}, the
14641 parent namespace handles them. The empty prefix should always have this
14643 Defaults to @samp{#t}.
14646 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
14647 List of predefined mailboxes in this namespace.
14648 Defaults to @samp{()}.
14650 Available @code{mailbox-configuration} fields are:
14652 @deftypevr {@code{mailbox-configuration} parameter} string name
14653 Name for this mailbox.
14656 @deftypevr {@code{mailbox-configuration} parameter} string auto
14657 @samp{create} will automatically create this mailbox.
14658 @samp{subscribe} will both create and subscribe to the mailbox.
14659 Defaults to @samp{"no"}.
14662 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
14663 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
14664 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
14665 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
14666 Defaults to @samp{()}.
14673 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
14674 Base directory where to store runtime data.
14675 Defaults to @samp{"/var/run/dovecot/"}.
14678 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
14679 Greeting message for clients.
14680 Defaults to @samp{"Dovecot ready."}.
14683 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
14684 List of trusted network ranges. Connections from these IPs are
14685 allowed to override their IP addresses and ports (for logging and for
14686 authentication checks). @samp{disable-plaintext-auth} is also ignored
14687 for these networks. Typically you would specify your IMAP proxy servers
14689 Defaults to @samp{()}.
14692 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
14693 List of login access check sockets (e.g.@: tcpwrap).
14694 Defaults to @samp{()}.
14697 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
14698 Show more verbose process titles (in ps). Currently shows user name
14699 and IP address. Useful for seeing who is actually using the IMAP
14700 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
14702 Defaults to @samp{#f}.
14705 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
14706 Should all processes be killed when Dovecot master process shuts down.
14707 Setting this to @code{#f} means that Dovecot can be upgraded without
14708 forcing existing client connections to close (although that could also
14709 be a problem if the upgrade is e.g.@: due to a security fix).
14710 Defaults to @samp{#t}.
14713 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
14714 If non-zero, run mail commands via this many connections to doveadm
14715 server, instead of running them directly in the same process.
14716 Defaults to @samp{0}.
14719 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
14720 UNIX socket or host:port used for connecting to doveadm server.
14721 Defaults to @samp{"doveadm-server"}.
14724 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
14725 List of environment variables that are preserved on Dovecot startup
14726 and passed down to all of its child processes. You can also give
14727 key=value pairs to always set specific settings.
14730 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
14731 Disable LOGIN command and all other plaintext authentications unless
14732 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
14733 matches the local IP (i.e.@: you're connecting from the same computer),
14734 the connection is considered secure and plaintext authentication is
14735 allowed. See also ssl=required setting.
14736 Defaults to @samp{#t}.
14739 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
14740 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
14741 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
14742 for caching to be used.
14743 Defaults to @samp{0}.
14746 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
14747 Time to live for cached data. After TTL expires the cached record
14748 is no longer used, *except* if the main database lookup returns internal
14749 failure. We also try to handle password changes automatically: If
14750 user's previous authentication was successful, but this one wasn't, the
14751 cache isn't used. For now this works only with plaintext
14753 Defaults to @samp{"1 hour"}.
14756 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
14757 TTL for negative hits (user not found, password mismatch).
14758 0 disables caching them completely.
14759 Defaults to @samp{"1 hour"}.
14762 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
14763 List of realms for SASL authentication mechanisms that need them.
14764 You can leave it empty if you don't want to support multiple realms.
14765 Many clients simply use the first one listed here, so keep the default
14767 Defaults to @samp{()}.
14770 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
14771 Default realm/domain to use if none was specified. This is used for
14772 both SASL realms and appending @@domain to username in plaintext
14774 Defaults to @samp{""}.
14777 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
14778 List of allowed characters in username. If the user-given username
14779 contains a character not listed in here, the login automatically fails.
14780 This is just an extra check to make sure user can't exploit any
14781 potential quote escaping vulnerabilities with SQL/LDAP databases. If
14782 you want to allow all characters, set this value to empty.
14783 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
14786 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
14787 Username character translations before it's looked up from
14788 databases. The value contains series of from -> to characters. For
14789 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
14790 translated to @samp{@@}.
14791 Defaults to @samp{""}.
14794 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
14795 Username formatting before it's looked up from databases. You can
14796 use the standard variables here, e.g.@: %Lu would lowercase the username,
14797 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
14798 change the @samp{@@} into @samp{-AT-}. This translation is done after
14799 @samp{auth-username-translation} changes.
14800 Defaults to @samp{"%Lu"}.
14803 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
14804 If you want to allow master users to log in by specifying the master
14805 username within the normal username string (i.e.@: not using SASL
14806 mechanism's support for it), you can specify the separator character
14807 here. The format is then <username><separator><master username>.
14808 UW-IMAP uses @samp{*} as the separator, so that could be a good
14810 Defaults to @samp{""}.
14813 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
14814 Username to use for users logging in with ANONYMOUS SASL
14816 Defaults to @samp{"anonymous"}.
14819 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
14820 Maximum number of dovecot-auth worker processes. They're used to
14821 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
14822 They're automatically created and destroyed as needed.
14823 Defaults to @samp{30}.
14826 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
14827 Host name to use in GSSAPI principal names. The default is to use
14828 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
14829 allow all keytab entries.
14830 Defaults to @samp{""}.
14833 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
14834 Kerberos keytab to use for the GSSAPI mechanism. Will use the
14835 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
14836 need to change the auth service to run as root to be able to read this
14838 Defaults to @samp{""}.
14841 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
14842 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
14843 and @samp{ntlm-auth} helper.
14844 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
14845 Defaults to @samp{#f}.
14848 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
14849 Path for Samba's @samp{ntlm-auth} helper binary.
14850 Defaults to @samp{"/usr/bin/ntlm_auth"}.
14853 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
14854 Time to delay before replying to failed authentications.
14855 Defaults to @samp{"2 secs"}.
14858 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
14859 Require a valid SSL client certificate or the authentication
14861 Defaults to @samp{#f}.
14864 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
14865 Take the username from client's SSL certificate, using
14866 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
14868 Defaults to @samp{#f}.
14871 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
14872 List of wanted authentication mechanisms. Supported mechanisms are:
14873 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
14874 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
14875 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
14876 @samp{disable-plaintext-auth} setting.
14879 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
14880 List of IPs or hostnames to all director servers, including ourself.
14881 Ports can be specified as ip:port. The default port is the same as what
14882 director service's @samp{inet-listener} is using.
14883 Defaults to @samp{()}.
14886 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
14887 List of IPs or hostnames to all backend mail servers. Ranges are
14888 allowed too, like 10.0.0.10-10.0.0.30.
14889 Defaults to @samp{()}.
14892 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
14893 How long to redirect users to a specific server after it no longer
14894 has any connections.
14895 Defaults to @samp{"15 min"}.
14898 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
14899 How the username is translated before being hashed. Useful values
14900 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
14901 are shared within domain.
14902 Defaults to @samp{"%Lu"}.
14905 @deftypevr {@code{dovecot-configuration} parameter} string log-path
14906 Log file to use for error messages. @samp{syslog} logs to syslog,
14907 @samp{/dev/stderr} logs to stderr.
14908 Defaults to @samp{"syslog"}.
14911 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
14912 Log file to use for informational messages. Defaults to
14914 Defaults to @samp{""}.
14917 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
14918 Log file to use for debug messages. Defaults to
14919 @samp{info-log-path}.
14920 Defaults to @samp{""}.
14923 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
14924 Syslog facility to use if you're logging to syslog. Usually if you
14925 don't want to use @samp{mail}, you'll use local0..local7. Also other
14926 standard facilities are supported.
14927 Defaults to @samp{"mail"}.
14930 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
14931 Log unsuccessful authentication attempts and the reasons why they
14933 Defaults to @samp{#f}.
14936 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
14937 In case of password mismatches, log the attempted password. Valid
14938 values are no, plain and sha1. sha1 can be useful for detecting brute
14939 force password attempts vs. user simply trying the same password over
14940 and over again. You can also truncate the value to n chars by appending
14941 ":n" (e.g.@: sha1:6).
14942 Defaults to @samp{#f}.
14945 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
14946 Even more verbose logging for debugging purposes. Shows for example
14948 Defaults to @samp{#f}.
14951 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
14952 In case of password mismatches, log the passwords and used scheme so
14953 the problem can be debugged. Enabling this also enables
14955 Defaults to @samp{#f}.
14958 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
14959 Enable mail process debugging. This can help you figure out why
14960 Dovecot isn't finding your mails.
14961 Defaults to @samp{#f}.
14964 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
14965 Show protocol level SSL errors.
14966 Defaults to @samp{#f}.
14969 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
14970 Prefix for each line written to log file. % codes are in
14971 strftime(3) format.
14972 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
14975 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
14976 List of elements we want to log. The elements which have a
14977 non-empty variable value are joined together to form a comma-separated
14981 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
14982 Login log format. %s contains @samp{login-log-format-elements}
14983 string, %$ contains the data we want to log.
14984 Defaults to @samp{"%$: %s"}.
14987 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
14988 Log prefix for mail processes. See doc/wiki/Variables.txt for list
14989 of possible variables you can use.
14990 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
14993 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
14994 Format to use for logging mail deliveries. You can use variables:
14997 Delivery status message (e.g.@: @samp{saved to INBOX})
15009 Defaults to @samp{"msgid=%m: %$"}.
15012 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
15013 Location for users' mailboxes. The default is empty, which means
15014 that Dovecot tries to find the mailboxes automatically. This won't work
15015 if the user doesn't yet have any mail, so you should explicitly tell
15016 Dovecot the full location.
15018 If you're using mbox, giving a path to the INBOX
15019 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
15020 where the other mailboxes are kept. This is called the "root mail
15021 directory", and it must be the first path given in the
15022 @samp{mail-location} setting.
15024 There are a few special variables you can use, eg.:
15030 user part in user@@domain, same as %u if there's no domain
15032 domain part in user@@domain, empty if there's no domain
15037 See doc/wiki/Variables.txt for full list. Some examples:
15039 @item maildir:~/Maildir
15040 @item mbox:~/mail:INBOX=/var/mail/%u
15041 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
15043 Defaults to @samp{""}.
15046 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
15047 System user and group used to access mails. If you use multiple,
15048 userdb can override these by returning uid or gid fields. You can use
15049 either numbers or names. <doc/wiki/UserIds.txt>.
15050 Defaults to @samp{""}.
15053 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
15055 Defaults to @samp{""}.
15058 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
15059 Group to enable temporarily for privileged operations. Currently
15060 this is used only with INBOX when either its initial creation or
15061 dotlocking fails. Typically this is set to "mail" to give access to
15063 Defaults to @samp{""}.
15066 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
15067 Grant access to these supplementary groups for mail processes.
15068 Typically these are used to set up access to shared mailboxes. Note
15069 that it may be dangerous to set these if users can create
15070 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
15071 could allow a user to delete others' mailboxes, or ln -s
15072 /secret/shared/box ~/mail/mybox would allow reading it).
15073 Defaults to @samp{""}.
15076 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
15077 Allow full file system access to clients. There's no access checks
15078 other than what the operating system does for the active UID/GID. It
15079 works with both maildir and mboxes, allowing you to prefix mailboxes
15080 names with e.g.@: /path/ or ~user/.
15081 Defaults to @samp{#f}.
15084 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
15085 Don't use mmap() at all. This is required if you store indexes to
15086 shared file systems (NFS or clustered file system).
15087 Defaults to @samp{#f}.
15090 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
15091 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
15092 supports @samp{O_EXCL} since version 3, so this should be safe to use
15093 nowadays by default.
15094 Defaults to @samp{#t}.
15097 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
15098 When to use fsync() or fdatasync() calls:
15101 Whenever necessary to avoid losing important data
15103 Useful with e.g.@: NFS when write()s are delayed
15105 Never use it (best performance, but crashes can lose data).
15107 Defaults to @samp{"optimized"}.
15110 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
15111 Mail storage exists in NFS. Set this to yes to make Dovecot flush
15112 NFS caches whenever needed. If you're using only a single mail server
15114 Defaults to @samp{#f}.
15117 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
15118 Mail index files also exist in NFS. Setting this to yes requires
15119 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
15120 Defaults to @samp{#f}.
15123 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
15124 Locking method for index files. Alternatives are fcntl, flock and
15125 dotlock. Dotlocking uses some tricks which may create more disk I/O
15126 than other locking methods. NFS users: flock doesn't work, remember to
15127 change @samp{mmap-disable}.
15128 Defaults to @samp{"fcntl"}.
15131 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
15132 Directory in which LDA/LMTP temporarily stores incoming mails >128
15134 Defaults to @samp{"/tmp"}.
15137 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
15138 Valid UID range for users. This is mostly to make sure that users can't
15139 log in as daemons or other system users. Note that denying root logins is
15140 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
15142 Defaults to @samp{500}.
15145 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
15147 Defaults to @samp{0}.
15150 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
15151 Valid GID range for users. Users having non-valid GID as primary group ID
15152 aren't allowed to log in. If user belongs to supplementary groups with
15153 non-valid GIDs, those groups are not set.
15154 Defaults to @samp{1}.
15157 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
15159 Defaults to @samp{0}.
15162 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
15163 Maximum allowed length for mail keyword name. It's only forced when
15164 trying to create new keywords.
15165 Defaults to @samp{50}.
15168 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
15169 List of directories under which chrooting is allowed for mail
15170 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
15171 too). This setting doesn't affect @samp{login-chroot}
15172 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
15173 "/./" in home dirs are ignored. WARNING: Never add directories here
15174 which local users can modify, that may lead to root exploit. Usually
15175 this should be done only if you don't allow shell access for users.
15176 <doc/wiki/Chrooting.txt>.
15177 Defaults to @samp{()}.
15180 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
15181 Default chroot directory for mail processes. This can be overridden
15182 for specific users in user database by giving /./ in user's home
15183 directory (e.g.@: /home/./user chroots into /home). Note that usually
15184 there is no real need to do chrooting, Dovecot doesn't allow users to
15185 access files outside their mail directory anyway. If your home
15186 directories are prefixed with the chroot directory, append "/."@: to
15187 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
15188 Defaults to @samp{""}.
15191 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
15192 UNIX socket path to master authentication server to find users.
15193 This is used by imap (for shared users) and lda.
15194 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15197 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
15198 Directory where to look up mail plugins.
15199 Defaults to @samp{"/usr/lib/dovecot"}.
15202 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
15203 List of plugins to load for all services. Plugins specific to IMAP,
15204 LDA, etc.@: are added to this list in their own .conf files.
15205 Defaults to @samp{()}.
15208 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
15209 The minimum number of mails in a mailbox before updates are done to
15210 cache file. This allows optimizing Dovecot's behavior to do less disk
15211 writes at the cost of more disk reads.
15212 Defaults to @samp{0}.
15215 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
15216 When IDLE command is running, mailbox is checked once in a while to
15217 see if there are any new mails or other changes. This setting defines
15218 the minimum time to wait between those checks. Dovecot can also use
15219 dnotify, inotify and kqueue to find out immediately when changes
15221 Defaults to @samp{"30 secs"}.
15224 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
15225 Save mails with CR+LF instead of plain LF. This makes sending those
15226 mails take less CPU, especially with sendfile() syscall with Linux and
15227 FreeBSD. But it also creates a bit more disk I/O which may just make it
15228 slower. Also note that if other software reads the mboxes/maildirs,
15229 they may handle the extra CRs wrong and cause problems.
15230 Defaults to @samp{#f}.
15233 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
15234 By default LIST command returns all entries in maildir beginning
15235 with a dot. Enabling this option makes Dovecot return only entries
15236 which are directories. This is done by stat()ing each entry, so it
15237 causes more disk I/O.
15238 (For systems setting struct @samp{dirent->d_type} this check is free
15239 and it's done always regardless of this setting).
15240 Defaults to @samp{#f}.
15243 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
15244 When copying a message, do it with hard links whenever possible.
15245 This makes the performance much better, and it's unlikely to have any
15247 Defaults to @samp{#t}.
15250 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
15251 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
15252 directory only when its mtime changes unexpectedly or when we can't find
15253 the mail otherwise.
15254 Defaults to @samp{#f}.
15257 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
15258 Which locking methods to use for locking mbox. There are four
15263 Create <mailbox>.lock file. This is the oldest and most NFS-safe
15264 solution. If you want to use /var/mail/ like directory, the users will
15265 need write access to that directory.
15267 Same as dotlock, but if it fails because of permissions or because there
15268 isn't enough disk space, just skip it.
15270 Use this if possible. Works with NFS too if lockd is used.
15272 May not exist in all systems. Doesn't work with NFS.
15274 May not exist in all systems. Doesn't work with NFS.
15277 You can use multiple locking methods; if you do the order they're declared
15278 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
15279 locking methods as well. Some operating systems don't allow using some of
15280 them simultaneously.
15283 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
15287 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
15288 Maximum time to wait for lock (all of them) before aborting.
15289 Defaults to @samp{"5 mins"}.
15292 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
15293 If dotlock exists but the mailbox isn't modified in any way,
15294 override the lock file after this much time.
15295 Defaults to @samp{"2 mins"}.
15298 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
15299 When mbox changes unexpectedly we have to fully read it to find out
15300 what changed. If the mbox is large this can take a long time. Since
15301 the change is usually just a newly appended mail, it'd be faster to
15302 simply read the new mails. If this setting is enabled, Dovecot does
15303 this but still safely fallbacks to re-reading the whole mbox file
15304 whenever something in mbox isn't how it's expected to be. The only real
15305 downside to this setting is that if some other MUA changes message
15306 flags, Dovecot doesn't notice it immediately. Note that a full sync is
15307 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
15308 Defaults to @samp{#t}.
15311 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
15312 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
15313 EXAMINE, EXPUNGE or CHECK commands. If this is set,
15314 @samp{mbox-dirty-syncs} is ignored.
15315 Defaults to @samp{#f}.
15318 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
15319 Delay writing mbox headers until doing a full write sync (EXPUNGE
15320 and CHECK commands and when closing the mailbox). This is especially
15321 useful for POP3 where clients often delete all mails. The downside is
15322 that our changes aren't immediately visible to other MUAs.
15323 Defaults to @samp{#t}.
15326 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
15327 If mbox size is smaller than this (e.g.@: 100k), don't write index
15328 files. If an index file already exists it's still read, just not
15330 Defaults to @samp{0}.
15333 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
15334 Maximum dbox file size until it's rotated.
15335 Defaults to @samp{10000000}.
15338 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
15339 Maximum dbox file age until it's rotated. Typically in days. Day
15340 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
15342 Defaults to @samp{"1d"}.
15345 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
15346 When creating new mdbox files, immediately preallocate their size to
15347 @samp{mdbox-rotate-size}. This setting currently works only in Linux
15348 with some file systems (ext4, xfs).
15349 Defaults to @samp{#f}.
15352 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
15353 sdbox and mdbox support saving mail attachments to external files,
15354 which also allows single instance storage for them. Other backends
15355 don't support this for now.
15357 WARNING: This feature hasn't been tested much yet. Use at your own risk.
15359 Directory root where to store mail attachments. Disabled, if empty.
15360 Defaults to @samp{""}.
15363 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
15364 Attachments smaller than this aren't saved externally. It's also
15365 possible to write a plugin to disable saving specific attachments
15367 Defaults to @samp{128000}.
15370 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
15371 File system backend to use for saving attachments:
15374 No SiS done by Dovecot (but this might help FS's own deduplication)
15376 SiS with immediate byte-by-byte comparison during saving
15377 @item sis-queue posix
15378 SiS with delayed comparison and deduplication.
15380 Defaults to @samp{"sis posix"}.
15383 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
15384 Hash format to use in attachment filenames. You can add any text and
15385 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
15386 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
15387 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
15388 Defaults to @samp{"%@{sha1@}"}.
15391 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
15393 Defaults to @samp{100}.
15396 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
15398 Defaults to @samp{1000}.
15401 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
15402 Default VSZ (virtual memory size) limit for service processes.
15403 This is mainly intended to catch and kill processes that leak memory
15404 before they eat up everything.
15405 Defaults to @samp{256000000}.
15408 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
15409 Login user is internally used by login processes. This is the most
15410 untrusted user in Dovecot system. It shouldn't have access to anything
15412 Defaults to @samp{"dovenull"}.
15415 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
15416 Internal user is used by unprivileged processes. It should be
15417 separate from login user, so that login processes can't disturb other
15419 Defaults to @samp{"dovecot"}.
15422 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
15423 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
15424 Defaults to @samp{"required"}.
15427 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
15428 PEM encoded X.509 SSL/TLS certificate (public key).
15429 Defaults to @samp{"</etc/dovecot/default.pem"}.
15432 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
15433 PEM encoded SSL/TLS private key. The key is opened before
15434 dropping root privileges, so keep the key file unreadable by anyone but
15436 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
15439 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
15440 If key file is password protected, give the password here.
15441 Alternatively give it when starting dovecot with -p parameter. Since
15442 this file is often world-readable, you may want to place this setting
15443 instead to a different.
15444 Defaults to @samp{""}.
15447 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
15448 PEM encoded trusted certificate authority. Set this only if you
15449 intend to use @samp{ssl-verify-client-cert? #t}. The file should
15450 contain the CA certificate(s) followed by the matching
15451 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
15452 Defaults to @samp{""}.
15455 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
15456 Require that CRL check succeeds for client certificates.
15457 Defaults to @samp{#t}.
15460 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
15461 Request client to send a certificate. If you also want to require
15462 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
15463 Defaults to @samp{#f}.
15466 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
15467 Which field from certificate to use for username. commonName and
15468 x500UniqueIdentifier are the usual choices. You'll also need to set
15469 @samp{auth-ssl-username-from-cert? #t}.
15470 Defaults to @samp{"commonName"}.
15473 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
15474 Minimum SSL protocol version to accept.
15475 Defaults to @samp{"TLSv1"}.
15478 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
15479 SSL ciphers to use.
15480 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
15483 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
15484 SSL crypto device to use, for valid values run "openssl engine".
15485 Defaults to @samp{""}.
15488 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
15489 Address to use when sending rejection mails.
15490 %d expands to recipient domain.
15491 Defaults to @samp{"postmaster@@%d"}.
15494 @deftypevr {@code{dovecot-configuration} parameter} string hostname
15495 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
15496 and in LMTP replies. Default is the system's real hostname@@domain.
15497 Defaults to @samp{""}.
15500 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
15501 If user is over quota, return with temporary failure instead of
15503 Defaults to @samp{#f}.
15506 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
15507 Binary to use for sending mails.
15508 Defaults to @samp{"/usr/sbin/sendmail"}.
15511 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
15512 If non-empty, send mails via this SMTP host[:port] instead of
15514 Defaults to @samp{""}.
15517 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
15518 Subject: header to use for rejection mails. You can use the same
15519 variables as for @samp{rejection-reason} below.
15520 Defaults to @samp{"Rejected: %s"}.
15523 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
15524 Human readable error message for rejection mails. You can use
15537 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
15540 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
15541 Delimiter character between local-part and detail in email
15543 Defaults to @samp{"+"}.
15546 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
15547 Header where the original recipient address (SMTP's RCPT TO:
15548 address) is taken from if not available elsewhere. With dovecot-lda -a
15549 parameter overrides this. A commonly used header for this is
15551 Defaults to @samp{""}.
15554 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
15555 Should saving a mail to a nonexistent mailbox automatically create
15557 Defaults to @samp{#f}.
15560 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
15561 Should automatically created mailboxes be also automatically
15563 Defaults to @samp{#f}.
15566 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
15567 Maximum IMAP command line length. Some clients generate very long
15568 command lines with huge mailboxes, so you may need to raise this if you
15569 get "Too long argument" or "IMAP command line too large" errors
15571 Defaults to @samp{64000}.
15574 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
15575 IMAP logout format string:
15578 total number of bytes read from client
15580 total number of bytes sent to client.
15582 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
15583 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@}"}.
15586 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
15587 Override the IMAP CAPABILITY response. If the value begins with '+',
15588 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
15589 Defaults to @samp{""}.
15592 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
15593 How long to wait between "OK Still here" notifications when client
15595 Defaults to @samp{"2 mins"}.
15598 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
15599 ID field names and values to send to clients. Using * as the value
15600 makes Dovecot use the default value. The following fields have default
15601 values currently: name, version, os, os-version, support-url,
15603 Defaults to @samp{""}.
15606 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
15607 ID fields sent by client to log. * means everything.
15608 Defaults to @samp{""}.
15611 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
15612 Workarounds for various client bugs:
15615 @item delay-newmail
15616 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
15617 CHECK commands. Some clients ignore them otherwise, for example OSX
15618 Mail (<v2.1). Outlook Express breaks more badly though, without this it
15619 may show user "Message no longer in server" errors. Note that OE6
15620 still breaks even with this workaround if synchronization is set to
15623 @item tb-extra-mailbox-sep
15624 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
15625 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
15626 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
15628 @item tb-lsub-flags
15629 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
15630 This makes Thunderbird realize they aren't selectable and show them
15631 greyed out, instead of only later giving "not selectable" popup error.
15633 Defaults to @samp{()}.
15636 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
15637 Host allowed in URLAUTH URLs sent by client. "*" allows all.
15638 Defaults to @samp{""}.
15642 Whew! Lots of configuration options. The nice thing about it though is
15643 that GuixSD has a complete interface to Dovecot's configuration
15644 language. This allows not only a nice way to declare configurations,
15645 but also offers reflective capabilities as well: users can write code to
15646 inspect and transform configurations from within Scheme.
15648 However, it could be that you just want to get a @code{dovecot.conf} up
15649 and running. In that case, you can pass an
15650 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
15651 @code{dovecot-service}. As its name indicates, an opaque configuration
15652 does not have easy reflective capabilities.
15654 Available @code{opaque-dovecot-configuration} fields are:
15656 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
15657 The dovecot package.
15660 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
15661 The contents of the @code{dovecot.conf}, as a string.
15664 For example, if your @code{dovecot.conf} is just the empty string, you
15665 could instantiate a dovecot service like this:
15668 (dovecot-service #:config
15669 (opaque-dovecot-configuration
15673 @subsubheading OpenSMTPD Service
15675 @deffn {Scheme Variable} opensmtpd-service-type
15676 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
15677 service, whose value should be an @code{opensmtpd-configuration} object
15678 as in this example:
15681 (service opensmtpd-service-type
15682 (opensmtpd-configuration
15683 (config-file (local-file "./my-smtpd.conf"))))
15687 @deftp {Data Type} opensmtpd-configuration
15688 Data type representing the configuration of opensmtpd.
15691 @item @code{package} (default: @var{opensmtpd})
15692 Package object of the OpenSMTPD SMTP server.
15694 @item @code{config-file} (default: @var{%default-opensmtpd-file})
15695 File-like object of the OpenSMTPD configuration file to use. By default
15696 it listens on the loopback network interface, and allows for mail from
15697 users and daemons on the local machine, as well as permitting email to
15698 remote servers. Run @command{man smtpd.conf} for more information.
15703 @subsubheading Exim Service
15705 @cindex mail transfer agent (MTA)
15706 @cindex MTA (mail transfer agent)
15709 @deffn {Scheme Variable} exim-service-type
15710 This is the type of the @uref{https://exim.org, Exim} mail transfer
15711 agent (MTA), whose value should be an @code{exim-configuration} object
15712 as in this example:
15715 (service exim-service-type
15716 (exim-configuration
15717 (config-file (local-file "./my-exim.conf"))))
15721 In order to use an @code{exim-service-type} service you must also have a
15722 @code{mail-aliases-service-type} service present in your
15723 @code{operating-system} (even if it has no aliases).
15725 @deftp {Data Type} exim-configuration
15726 Data type representing the configuration of exim.
15729 @item @code{package} (default: @var{exim})
15730 Package object of the Exim server.
15732 @item @code{config-file} (default: @code{#f})
15733 File-like object of the Exim configuration file to use. If its value is
15734 @code{#f} then use the default configuration file from the package
15735 provided in @code{package}. The resulting configuration file is loaded
15736 after setting the @code{exim_user} and @code{exim_group} configuration
15742 @subsubheading Mail Aliases Service
15744 @cindex email aliases
15745 @cindex aliases, for email addresses
15747 @deffn {Scheme Variable} mail-aliases-service-type
15748 This is the type of the service which provides @code{/etc/aliases},
15749 specifying how to deliver mail to users on this system.
15752 (service mail-aliases-service-type
15753 '(("postmaster" "bob")
15754 ("bob" "bob@@example.com" "bob@@example2.com")))
15758 The configuration for a @code{mail-aliases-service-type} service is an
15759 association list denoting how to deliver mail that comes to this
15760 system. Each entry is of the form @code{(alias addresses ...)}, with
15761 @code{alias} specifying the local alias and @code{addresses} specifying
15762 where to deliver this user's mail.
15764 The aliases aren't required to exist as users on the local system. In
15765 the above example, there doesn't need to be a @code{postmaster} entry in
15766 the @code{operating-system}'s @code{user-accounts} in order to deliver
15767 the @code{postmaster} mail to @code{bob} (which subsequently would
15768 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
15770 @node Messaging Services
15771 @subsubsection Messaging Services
15776 The @code{(gnu services messaging)} module provides Guix service
15777 definitions for messaging services: currently only Prosody is supported.
15779 @subsubheading Prosody Service
15781 @deffn {Scheme Variable} prosody-service-type
15782 This is the type for the @uref{https://prosody.im, Prosody XMPP
15783 communication server}. Its value must be a @code{prosody-configuration}
15784 record as in this example:
15787 (service prosody-service-type
15788 (prosody-configuration
15789 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
15792 (int-component-configuration
15793 (hostname "conference.example.net")
15795 (mod-muc (mod-muc-configuration)))))
15798 (virtualhost-configuration
15799 (domain "example.net"))))))
15802 See below for details about @code{prosody-configuration}.
15806 By default, Prosody does not need much configuration. Only one
15807 @code{virtualhosts} field is needed: it specifies the domain you wish
15810 You can perform various sanity checks on the generated configuration
15811 with the @code{prosodyctl check} command.
15813 Prosodyctl will also help you to import certificates from the
15814 @code{letsencrypt} directory so that the @code{prosody} user can access
15815 them. See @url{https://prosody.im/doc/letsencrypt}.
15818 prosodyctl --root cert import /etc/letsencrypt/live
15821 The available configuration parameters follow. Each parameter
15822 definition is preceded by its type; for example, @samp{string-list foo}
15823 indicates that the @code{foo} parameter should be specified as a list of
15824 strings. Types starting with @code{maybe-} denote parameters that won't
15825 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
15827 There is also a way to specify the configuration as a string, if you
15828 have an old @code{prosody.cfg.lua} file that you want to port over from
15829 some other system; see the end for more details.
15831 The @code{file-object} type designates either a file-like object
15832 (@pxref{G-Expressions, file-like objects}) or a file name.
15834 @c The following documentation was initially generated by
15835 @c (generate-documentation) in (gnu services messaging). Manually maintained
15836 @c documentation is better, so we shouldn't hesitate to edit below as
15837 @c needed. However if the change you want to make to this documentation
15838 @c can be done in an automated way, it's probably easier to change
15839 @c (generate-documentation) than to make it below and have to deal with
15840 @c the churn as Prosody updates.
15842 Available @code{prosody-configuration} fields are:
15844 @deftypevr {@code{prosody-configuration} parameter} package prosody
15845 The Prosody package.
15848 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
15849 Location of the Prosody data storage directory. See
15850 @url{https://prosody.im/doc/configure}.
15851 Defaults to @samp{"/var/lib/prosody"}.
15854 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
15855 Additional plugin directories. They are searched in all the specified
15856 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
15857 Defaults to @samp{()}.
15860 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
15861 Every virtual host and component needs a certificate so that clients and
15862 servers can securely verify its identity. Prosody will automatically load
15863 certificates/keys from the directory specified here.
15864 Defaults to @samp{"/etc/prosody/certs"}.
15867 @deftypevr {@code{prosody-configuration} parameter} string-list admins
15868 This is a list of accounts that are admins for the server. Note that you
15869 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
15870 @url{https://prosody.im/doc/creating_accounts}.
15871 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
15872 Defaults to @samp{()}.
15875 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
15876 Enable use of libevent for better performance under high load. See
15877 @url{https://prosody.im/doc/libevent}.
15878 Defaults to @samp{#f}.
15881 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
15882 This is the list of modules Prosody will load on startup. It looks for
15883 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
15884 Documentation on modules can be found at:
15885 @url{https://prosody.im/doc/modules}.
15886 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
15889 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
15890 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
15891 should you want to disable them then add them to this list.
15892 Defaults to @samp{()}.
15895 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
15896 Path to a text file where the shared groups are defined. If this path is
15897 empty then @samp{mod_groups} does nothing. See
15898 @url{https://prosody.im/doc/modules/mod_groups}.
15899 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
15902 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
15903 Disable account creation by default, for security. See
15904 @url{https://prosody.im/doc/creating_accounts}.
15905 Defaults to @samp{#f}.
15908 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
15909 These are the SSL/TLS-related settings. Most of them are disabled so to
15910 use Prosody's defaults. If you do not completely understand these options, do
15911 not add them to your config, it is easy to lower the security of your server
15912 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
15914 Available @code{ssl-configuration} fields are:
15916 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
15917 This determines what handshake to use.
15920 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
15921 Path to your private key file.
15924 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
15925 Path to your certificate file.
15928 @deftypevr {@code{ssl-configuration} parameter} file-object capath
15929 Path to directory containing root certificates that you wish Prosody to
15930 trust when verifying the certificates of remote servers.
15931 Defaults to @samp{"/etc/ssl/certs"}.
15934 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
15935 Path to a file containing root certificates that you wish Prosody to trust.
15936 Similar to @code{capath} but with all certificates concatenated together.
15939 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
15940 A list of verification options (these mostly map to OpenSSL's
15941 @code{set_verify()} flags).
15944 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
15945 A list of general options relating to SSL/TLS. These map to OpenSSL's
15946 @code{set_options()}. For a full list of options available in LuaSec, see the
15950 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
15951 How long a chain of certificate authorities to check when looking for a
15952 trusted root certificate.
15955 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
15956 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
15957 clients, and in what order.
15960 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
15961 A path to a file containing parameters for Diffie-Hellman key exchange. You
15962 can create such a file with:
15963 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
15966 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
15967 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
15968 @samp{"secp384r1"}.
15971 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
15972 A list of "extra" verification options.
15975 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
15976 Password for encrypted private keys.
15981 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
15982 Whether to force all client-to-server connections to be encrypted or not.
15983 See @url{https://prosody.im/doc/modules/mod_tls}.
15984 Defaults to @samp{#f}.
15987 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
15988 Set of mechanisms that will never be offered. See
15989 @url{https://prosody.im/doc/modules/mod_saslauth}.
15990 Defaults to @samp{("DIGEST-MD5")}.
15993 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
15994 Whether to force all server-to-server connections to be encrypted or not.
15995 See @url{https://prosody.im/doc/modules/mod_tls}.
15996 Defaults to @samp{#f}.
15999 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
16000 Whether to require encryption and certificate authentication. This
16001 provides ideal security, but requires servers you communicate with to support
16002 encryption AND present valid, trusted certificates. See
16003 @url{https://prosody.im/doc/s2s#security}.
16004 Defaults to @samp{#f}.
16007 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
16008 Many servers don't support encryption or have invalid or self-signed
16009 certificates. You can list domains here that will not be required to
16010 authenticate using certificates. They will be authenticated using DNS. See
16011 @url{https://prosody.im/doc/s2s#security}.
16012 Defaults to @samp{()}.
16015 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
16016 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
16017 valid certificates for some domains by specifying a list here. See
16018 @url{https://prosody.im/doc/s2s#security}.
16019 Defaults to @samp{()}.
16022 @deftypevr {@code{prosody-configuration} parameter} string authentication
16023 Select the authentication backend to use. The default provider stores
16024 passwords in plaintext and uses Prosody's configured data storage to store the
16025 authentication data. If you do not trust your server please see
16026 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
16027 about using the hashed backend. See also
16028 @url{https://prosody.im/doc/authentication}
16029 Defaults to @samp{"internal_plain"}.
16032 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
16033 Set logging options. Advanced logging configuration is not yet supported
16034 by the GuixSD Prosody Service. See @url{https://prosody.im/doc/logging}.
16035 Defaults to @samp{"*syslog"}.
16038 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
16039 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
16040 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
16043 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
16044 Maximum allowed size of the HTTP body (in bytes).
16047 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
16048 Some modules expose their own URL in various ways. This URL is built
16049 from the protocol, host and port used. If Prosody sits behind a proxy, the
16050 public URL will be @code{http-external-url} instead. See
16051 @url{https://prosody.im/doc/http#external_url}.
16054 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
16055 A host in Prosody is a domain on which user accounts can be created. For
16056 example if you want your users to have addresses like
16057 @samp{"john.smith@@example.com"} then you need to add a host
16058 @samp{"example.com"}. All options in this list will apply only to this host.
16060 Note: the name "virtual" host is used in configuration to avoid confusion with
16061 the actual physical host that Prosody is installed on. A single Prosody
16062 instance can serve many domains, each one defined as a VirtualHost entry in
16063 Prosody's configuration. Conversely a server that hosts a single domain would
16064 have just one VirtualHost entry.
16066 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
16068 Available @code{virtualhost-configuration} fields are:
16070 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:
16071 @deftypevr {@code{virtualhost-configuration} parameter} string domain
16072 Domain you wish Prosody to serve.
16077 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
16078 Components are extra services on a server which are available to clients,
16079 usually on a subdomain of the main server (such as
16080 @samp{"mycomponent.example.com"}). Example components might be chatroom
16081 servers, user directories, or gateways to other protocols.
16083 Internal components are implemented with Prosody-specific plugins. To add an
16084 internal component, you simply fill the hostname field, and the plugin you wish
16085 to use for the component.
16087 See @url{https://prosody.im/doc/components}.
16088 Defaults to @samp{()}.
16090 Available @code{int-component-configuration} fields are:
16092 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:
16093 @deftypevr {@code{int-component-configuration} parameter} string hostname
16094 Hostname of the component.
16097 @deftypevr {@code{int-component-configuration} parameter} string plugin
16098 Plugin you wish to use for the component.
16101 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
16102 Multi-user chat (MUC) is Prosody's module for allowing you to create
16103 hosted chatrooms/conferences for XMPP users.
16105 General information on setting up and using multi-user chatrooms can be found
16106 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
16107 which you should read if you are new to XMPP chatrooms.
16109 See also @url{https://prosody.im/doc/modules/mod_muc}.
16111 Available @code{mod-muc-configuration} fields are:
16113 @deftypevr {@code{mod-muc-configuration} parameter} string name
16114 The name to return in service discovery responses.
16115 Defaults to @samp{"Prosody Chatrooms"}.
16118 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
16119 If @samp{#t}, this will only allow admins to create new chatrooms.
16120 Otherwise anyone can create a room. The value @samp{"local"} restricts room
16121 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
16122 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
16123 restricts to service administrators only.
16124 Defaults to @samp{#f}.
16127 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
16128 Maximum number of history messages that will be sent to the member that has
16129 just joined the room.
16130 Defaults to @samp{20}.
16137 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
16138 External components use XEP-0114, which most standalone components
16139 support. To add an external component, you simply fill the hostname field. See
16140 @url{https://prosody.im/doc/components}.
16141 Defaults to @samp{()}.
16143 Available @code{ext-component-configuration} fields are:
16145 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:
16146 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
16147 Password which the component will use to log in.
16150 @deftypevr {@code{ext-component-configuration} parameter} string hostname
16151 Hostname of the component.
16156 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
16157 Port(s) Prosody listens on for component connections.
16158 Defaults to @samp{(5347)}.
16161 @deftypevr {@code{prosody-configuration} parameter} string component-interface
16162 Interface Prosody listens on for component connections.
16163 Defaults to @samp{"127.0.0.1"}.
16166 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
16167 Raw content that will be added to the configuration file.
16170 It could be that you just want to get a @code{prosody.cfg.lua}
16171 up and running. In that case, you can pass an
16172 @code{opaque-prosody-configuration} record as the value of
16173 @code{prosody-service-type}. As its name indicates, an opaque configuration
16174 does not have easy reflective capabilities.
16175 Available @code{opaque-prosody-configuration} fields are:
16177 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
16178 The prosody package.
16181 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
16182 The contents of the @code{prosody.cfg.lua} to use.
16185 For example, if your @code{prosody.cfg.lua} is just the empty
16186 string, you could instantiate a prosody service like this:
16189 (service prosody-service-type
16190 (opaque-prosody-configuration
16191 (prosody.cfg.lua "")))
16194 @c end of Prosody auto-generated documentation
16196 @subsubheading BitlBee Service
16198 @cindex IRC (Internet Relay Chat)
16199 @cindex IRC gateway
16200 @url{http://bitlbee.org,BitlBee} is a gateway that provides an IRC
16201 interface to a variety of messaging protocols such as XMPP.
16203 @defvr {Scheme Variable} bitlbee-service-type
16204 This is the service type for the @url{http://bitlbee.org,BitlBee} IRC
16205 gateway daemon. Its value is a @code{bitlbee-configuration} (see
16208 To have BitlBee listen on port 6667 on localhost, add this line to your
16212 (service bitlbee-service-type)
16216 @deftp {Data Type} bitlbee-configuration
16217 This is the configuration for BitlBee, with the following fields:
16220 @item @code{interface} (default: @code{"127.0.0.1"})
16221 @itemx @code{port} (default: @code{6667})
16222 Listen on the network interface corresponding to the IP address
16223 specified in @var{interface}, on @var{port}.
16225 When @var{interface} is @code{127.0.0.1}, only local clients can
16226 connect; when it is @code{0.0.0.0}, connections can come from any
16227 networking interface.
16229 @item @code{package} (default: @code{bitlbee})
16230 The BitlBee package to use.
16232 @item @code{plugins} (default: @code{'()})
16233 List of plugin packages to use---e.g., @code{bitlbee-discord}.
16235 @item @code{extra-settings} (default: @code{""})
16236 Configuration snippet added as-is to the BitlBee configuration file.
16241 @node Telephony Services
16242 @subsubsection Telephony Services
16244 @cindex Murmur (VoIP server)
16245 @cindex VoIP server
16246 This section describes how to set up and run a Murmur server. Murmur is
16247 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
16250 @deftp {Data Type} murmur-configuration
16251 The service type for the Murmur server. An example configuration can
16255 (service murmur-service-type
16256 (murmur-configuration
16258 "Welcome to this Mumble server running on GuixSD!")
16259 (cert-required? #t) ;disallow text password logins
16260 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
16261 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
16264 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
16265 password with the command that is printed during the activation phase.
16267 It is recommended to register a normal Mumble user account
16268 and grant it admin or moderator rights.
16269 You can use the @code{mumble} client to
16270 login as new normal user, register yourself, and log out.
16271 For the next step login with the name @code{SuperUser} use
16272 the @code{SuperUser} password that you set previously,
16273 and grant your newly registered mumble user administrator or moderator
16274 rights and create some channels.
16276 Available @code{murmur-configuration} fields are:
16279 @item @code{package} (default: @code{mumble})
16280 Package that contains @code{bin/murmurd}.
16282 @item @code{user} (default: @code{"murmur"})
16283 User who will run the Murmur server.
16285 @item @code{group} (default: @code{"murmur"})
16286 Group of the user who will run the murmur server.
16288 @item @code{port} (default: @code{64738})
16289 Port on which the server will listen.
16291 @item @code{welcome-text} (default: @code{""})
16292 Welcome text sent to clients when they connect.
16294 @item @code{server-password} (default: @code{""})
16295 Password the clients have to enter in order to connect.
16297 @item @code{max-users} (default: @code{100})
16298 Maximum of users that can be connected to the server at once.
16300 @item @code{max-user-bandwidth} (default: @code{#f})
16301 Maximum voice traffic a user can send per second.
16303 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
16304 File name of the sqlite database.
16305 The service's user will become the owner of the directory.
16307 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
16308 File name of the log file.
16309 The service's user will become the owner of the directory.
16311 @item @code{autoban-attempts} (default: @code{10})
16312 Maximum number of logins a user can make in @code{autoban-timeframe}
16313 without getting auto banned for @code{autoban-time}.
16315 @item @code{autoban-timeframe} (default: @code{120})
16316 Timeframe for autoban in seconds.
16318 @item @code{autoban-time} (default: @code{300})
16319 Amount of time in seconds for which a client gets banned
16320 when violating the autoban limits.
16322 @item @code{opus-threshold} (default: @code{100})
16323 Percentage of clients that need to support opus
16324 before switching over to opus audio codec.
16326 @item @code{channel-nesting-limit} (default: @code{10})
16327 How deep channels can be nested at maximum.
16329 @item @code{channelname-regex} (default: @code{#f})
16330 A string in form of a Qt regular expression that channel names must conform to.
16332 @item @code{username-regex} (default: @code{#f})
16333 A string in form of a Qt regular expression that user names must conform to.
16335 @item @code{text-message-length} (default: @code{5000})
16336 Maximum size in bytes that a user can send in one text chat message.
16338 @item @code{image-message-length} (default: @code{(* 128 1024)})
16339 Maximum size in bytes that a user can send in one image message.
16341 @item @code{cert-required?} (default: @code{#f})
16342 If it is set to @code{#t} clients that use weak password authentification
16343 will not be accepted. Users must have completed the certificate wizard to join.
16345 @item @code{remember-channel?} (default: @code{#f})
16346 Should murmur remember the last channel each user was in when they disconnected
16347 and put them into the remembered channel when they rejoin.
16349 @item @code{allow-html?} (default: @code{#f})
16350 Should html be allowed in text messages, user comments, and channel descriptions.
16352 @item @code{allow-ping?} (default: @code{#f})
16353 Setting to true exposes the current user count, the maximum user count, and
16354 the server's maximum bandwidth per client to unauthenticated users. In the
16355 Mumble client, this information is shown in the Connect dialog.
16357 Disabling this setting will prevent public listing of the server.
16359 @item @code{bonjour?} (default: @code{#f})
16360 Should the server advertise itself in the local network through the bonjour protocol.
16362 @item @code{send-version?} (default: @code{#f})
16363 Should the murmur server version be exposed in ping requests.
16365 @item @code{log-days} (default: @code{31})
16366 Murmur also stores logs in the database, which are accessible via RPC.
16367 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
16368 or -1 to disable logging to the database.
16370 @item @code{obfuscate-ips?} (default: @code{#t})
16371 Should logged ips be obfuscated to protect the privacy of users.
16373 @item @code{ssl-cert} (default: @code{#f})
16374 File name of the SSL/TLS certificate used for encrypted connections.
16377 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
16379 @item @code{ssl-key} (default: @code{#f})
16380 Filepath to the ssl private key used for encrypted connections.
16382 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
16385 @item @code{ssl-dh-params} (default: @code{#f})
16386 File name of a PEM-encoded file with Diffie-Hellman parameters
16387 for the SSL/TLS encryption. Alternatively you set it to
16388 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
16389 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
16391 @item @code{ssl-ciphers} (default: @code{#f})
16392 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
16395 This option is specified using
16396 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
16397 OpenSSL cipher list notation}.
16399 It is recommended that you try your cipher string using 'openssl ciphers <string>'
16400 before setting it here, to get a feel for which cipher suites you will get.
16401 After setting this option, it is recommend that you inspect your Murmur log
16402 to ensure that Murmur is using the cipher suites that you expected it to.
16404 Note: Changing this option may impact the backwards compatibility of your
16405 Murmur server, and can remove the ability for older Mumble clients to be able
16408 @item @code{public-registration} (default: @code{#f})
16409 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
16411 You can optionally register your server in the public server list that the
16412 @code{mumble} client shows on startup.
16413 You cannot register your server if you have set a @code{server-password},
16414 or set @code{allow-ping} to @code{#f}.
16416 It might take a few hours until it shows up in the public list.
16418 @item @code{file} (default: @code{#f})
16419 Optional alternative override for this configuration.
16423 @deftp {Data Type} murmur-public-registration-configuration
16424 Configuration for public registration of a murmur service.
16428 This is a display name for your server. Not to be confused with the hostname.
16430 @item @code{password}
16431 A password to identify your registration.
16432 Subsequent updates will need the same password. Don't lose your password.
16435 This should be a @code{http://} or @code{https://} link to your web
16438 @item @code{hostname} (default: @code{#f})
16439 By default your server will be listed by its IP address.
16440 If it is set your server will be linked by this host name instead.
16446 @node Monitoring Services
16447 @subsubsection Monitoring Services
16449 @subsubheading Tailon Service
16451 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
16452 viewing and searching log files.
16454 The following example will configure the service with default values.
16455 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
16458 (service tailon-service-type)
16461 The following example customises more of the Tailon configuration,
16462 adding @command{sed} to the list of allowed commands.
16465 (service tailon-service-type
16466 (tailon-configuration
16468 (tailon-configuration-file
16469 (allowed-commands '("tail" "grep" "awk" "sed"))))))
16473 @deftp {Data Type} tailon-configuration
16474 Data type representing the configuration of Tailon.
16475 This type has the following parameters:
16478 @item @code{config-file} (default: @code{(tailon-configuration-file)})
16479 The configuration file to use for Tailon. This can be set to a
16480 @dfn{tailon-configuration-file} record value, or any gexp
16481 (@pxref{G-Expressions}).
16483 For example, to instead use a local file, the @code{local-file} function
16487 (service tailon-service-type
16488 (tailon-configuration
16489 (config-file (local-file "./my-tailon.conf"))))
16492 @item @code{package} (default: @code{tailon})
16493 The tailon package to use.
16498 @deftp {Data Type} tailon-configuration-file
16499 Data type representing the configuration options for Tailon.
16500 This type has the following parameters:
16503 @item @code{files} (default: @code{(list "/var/log")})
16504 List of files to display. The list can include strings for a single file
16505 or directory, or a list, where the first item is the name of a
16506 subsection, and the remaining items are the files or directories in that
16509 @item @code{bind} (default: @code{"localhost:8080"})
16510 Address and port to which Tailon should bind on.
16512 @item @code{relative-root} (default: @code{#f})
16513 URL path to use for Tailon, set to @code{#f} to not use a path.
16515 @item @code{allow-transfers?} (default: @code{#t})
16516 Allow downloading the log files in the web interface.
16518 @item @code{follow-names?} (default: @code{#t})
16519 Allow tailing of not-yet existent files.
16521 @item @code{tail-lines} (default: @code{200})
16522 Number of lines to read initially from each file.
16524 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
16525 Commands to allow running. By default, @code{sed} is disabled.
16527 @item @code{debug?} (default: @code{#f})
16528 Set @code{debug?} to @code{#t} to show debug messages.
16530 @item @code{wrap-lines} (default: @code{#t})
16531 Initial line wrapping state in the web interface. Set to @code{#t} to
16532 initially wrap lines (the default), or to @code{#f} to initially not
16535 @item @code{http-auth} (default: @code{#f})
16536 HTTP authentication type to use. Set to @code{#f} to disable
16537 authentication (the default). Supported values are @code{"digest"} or
16540 @item @code{users} (default: @code{#f})
16541 If HTTP authentication is enabled (see @code{http-auth}), access will be
16542 restricted to the credentials provided here. To configure users, use a
16543 list of pairs, where the first element of the pair is the username, and
16544 the 2nd element of the pair is the password.
16547 (tailon-configuration-file
16548 (http-auth "basic")
16549 (users '(("user1" . "password1")
16550 ("user2" . "password2"))))
16557 @subsubheading Darkstat Service
16559 Darkstat is a packet sniffer that captures network traffic, calculates
16560 statistics about usage, and serves reports over HTTP.
16562 @defvar {Scheme Variable} darkstat-service-type
16563 This is the service type for the
16564 @uref{https://unix4lyfe.org/darkstat/, darkstat}
16565 service, its value must be a @code{darkstat-configuration} record as in
16569 (service darkstat-service-type
16570 (darkstat-configuration
16571 (interface "eno1")))
16575 @deftp {Data Type} darkstat-configuration
16576 Data type representing the configuration of @command{darkstat}.
16579 @item @code{package} (default: @code{darkstat})
16580 The darkstat package to use.
16582 @item @code{interface}
16583 Capture traffic on the specified network interface.
16585 @item @code{port} (default: @code{"667"})
16586 Bind the web interface to the specified port.
16588 @item @code{bind-address} (default: @code{"127.0.0.1"})
16589 Bind the web interface to the specified address.
16591 @item @code{base} (default: @code{"/"})
16592 Specify the path of the base URL. This can be useful if
16593 @command{darkstat} is accessed via a reverse proxy.
16598 @subsubheading Prometheus Node Exporter Service
16600 @cindex prometheus-node-exporter
16601 The Prometheus ``node exporter'' makes hardware and operating system statistics
16602 provided by the Linux kernel available for the Prometheus monitoring system.
16603 This service should be deployed on all physical nodes and virtual machines,
16604 where monitoring these statistics is desirable.
16606 @defvar {Scheme variable} prometheus-node-exporter-service-type
16607 This is the service type for the
16608 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
16609 service, its value must be a @code{prometheus-node-exporter-configuration}
16610 record as in this example:
16613 (service prometheus-node-exporter-service-type
16614 (prometheus-node-exporter-configuration
16615 (web-listen-address ":9100")))
16619 @deftp {Data Type} prometheus-node-exporter-configuration
16620 Data type representing the configuration of @command{node_exporter}.
16623 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
16624 The prometheus-node-exporter package to use.
16626 @item @code{web-listen-address} (default: @code{":9100"})
16627 Bind the web interface to the specified address.
16632 @node Kerberos Services
16633 @subsubsection Kerberos Services
16636 The @code{(gnu services kerberos)} module provides services relating to
16637 the authentication protocol @dfn{Kerberos}.
16639 @subsubheading Krb5 Service
16641 Programs using a Kerberos client library normally
16642 expect a configuration file in @file{/etc/krb5.conf}.
16643 This service generates such a file from a definition provided in the
16644 operating system declaration.
16645 It does not cause any daemon to be started.
16647 No ``keytab'' files are provided by this service---you must explicitly create them.
16648 This service is known to work with the MIT client library, @code{mit-krb5}.
16649 Other implementations have not been tested.
16651 @defvr {Scheme Variable} krb5-service-type
16652 A service type for Kerberos 5 clients.
16656 Here is an example of its use:
16658 (service krb5-service-type
16659 (krb5-configuration
16660 (default-realm "EXAMPLE.COM")
16661 (allow-weak-crypto? #t)
16664 (name "EXAMPLE.COM")
16665 (admin-server "groucho.example.com")
16666 (kdc "karl.example.com"))
16669 (admin-server "kerb-admin.argrx.edu")
16670 (kdc "keys.argrx.edu"))))))
16674 This example provides a Kerberos@tie{}5 client configuration which:
16676 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
16677 of which have distinct administration servers and key distribution centers;
16678 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
16679 specified by clients;
16680 @item Accepts services which only support encryption types known to be weak.
16683 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
16684 Only the most commonly used ones are described here.
16685 For a full list, and more detailed explanation of each, see the MIT
16686 @uref{http://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
16690 @deftp {Data Type} krb5-realm
16691 @cindex realm, kerberos
16694 This field is a string identifying the name of the realm.
16695 A common convention is to use the fully qualified DNS name of your organization,
16696 converted to upper case.
16698 @item @code{admin-server}
16699 This field is a string identifying the host where the administration server is
16703 This field is a string identifying the key distribution center
16708 @deftp {Data Type} krb5-configuration
16711 @item @code{allow-weak-crypto?} (default: @code{#f})
16712 If this flag is @code{#t} then services which only offer encryption algorithms
16713 known to be weak will be accepted.
16715 @item @code{default-realm} (default: @code{#f})
16716 This field should be a string identifying the default Kerberos
16717 realm for the client.
16718 You should set this field to the name of your Kerberos realm.
16719 If this value is @code{#f}
16720 then a realm must be specified with every Kerberos principal when invoking programs
16721 such as @command{kinit}.
16723 @item @code{realms}
16724 This should be a non-empty list of @code{krb5-realm} objects, which clients may
16726 Normally, one of them will have a @code{name} field matching the @code{default-realm}
16732 @subsubheading PAM krb5 Service
16735 The @code{pam-krb5} service allows for login authentication and password
16736 management via Kerberos.
16737 You will need this service if you want PAM enabled applications to authenticate
16738 users using Kerberos.
16740 @defvr {Scheme Variable} pam-krb5-service-type
16741 A service type for the Kerberos 5 PAM module.
16744 @deftp {Data Type} pam-krb5-configuration
16745 Data type representing the configuration of the Kerberos 5 PAM module
16746 This type has the following parameters:
16748 @item @code{pam-krb5} (default: @code{pam-krb5})
16749 The pam-krb5 package to use.
16751 @item @code{minimum-uid} (default: @code{1000})
16752 The smallest user ID for which Kerberos authentications should be attempted.
16753 Local accounts with lower values will silently fail to authenticate.
16759 @subsubsection Web Services
16764 The @code{(gnu services web)} module provides the Apache HTTP Server,
16765 the nginx web server, and also a fastcgi wrapper daemon.
16767 @subsubheading Apache HTTP Server
16769 @deffn {Scheme Variable} httpd-service-type
16770 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
16771 (@dfn{httpd}). The value for this service type is a
16772 @code{httpd-configuration} record.
16774 A simple example configuration is given below.
16777 (service httpd-service-type
16778 (httpd-configuration
16781 (server-name "www.example.com")
16782 (document-root "/srv/http/www.example.com")))))
16785 Other services can also extend the @code{httpd-service-type} to add to
16789 (simple-service 'my-extra-server httpd-service-type
16793 (list (string-append
16794 "ServerName "www.example.com
16795 DocumentRoot \"/srv/http/www.example.com\"")))))
16799 The details for the @code{httpd-configuration}, @code{httpd-module},
16800 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
16803 @deffn {Data Type} httpd-configuration
16804 This data type represents the configuration for the httpd service.
16807 @item @code{package} (default: @code{httpd})
16808 The httpd package to use.
16810 @item @code{pid-file} (default: @code{"/var/run/httpd"})
16811 The pid file used by the shepherd-service.
16813 @item @code{config} (default: @code{(httpd-config-file)})
16814 The configuration file to use with the httpd service. The default value
16815 is a @code{httpd-config-file} record, but this can also be a different
16816 G-expression that generates a file, for example a @code{plain-file}. A
16817 file outside of the store can also be specified through a string.
16822 @deffn {Data Type} httpd-module
16823 This data type represents a module for the httpd service.
16827 The name of the module.
16830 The file for the module. This can be relative to the httpd package being
16831 used, the absolute location of a file, or a G-expression for a file
16832 within the store, for example @code{(file-append mod-wsgi
16833 "/modules/mod_wsgi.so")}.
16838 @defvr {Scheme Variable} %default-httpd-modules
16839 A default list of @code{httpd-module} objects.
16842 @deffn {Data Type} httpd-config-file
16843 This data type represents a configuration file for the httpd service.
16846 @item @code{modules} (default: @code{%default-httpd-modules})
16847 The modules to load. Additional modules can be added here, or loaded by
16848 additional configuration.
16850 For example, in order to handle requests for PHP files, you can use Apache’s
16851 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
16854 (service httpd-service-type
16855 (httpd-configuration
16860 (name "proxy_module")
16861 (file "modules/mod_proxy.so"))
16863 (name "proxy_fcgi_module")
16864 (file "modules/mod_proxy_fcgi.so"))
16865 %default-httpd-modules))
16866 (extra-config (list "\
16867 <FilesMatch \\.php$>
16868 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
16869 </FilesMatch>"))))))
16870 (service php-fpm-service-type
16871 (php-fpm-configuration
16872 (socket "/var/run/php-fpm.sock")
16873 (socket-group "httpd")))
16876 @item @code{server-root} (default: @code{httpd})
16877 The @code{ServerRoot} in the configuration file, defaults to the httpd
16878 package. Directives including @code{Include} and @code{LoadModule} are
16879 taken as relative to the server root.
16881 @item @code{server-name} (default: @code{#f})
16882 The @code{ServerName} in the configuration file, used to specify the
16883 request scheme, hostname and port that the server uses to identify
16886 This doesn't need to be set in the server config, and can be specifyed
16887 in virtual hosts. The default is @code{#f} to not specify a
16890 @item @code{document-root} (default: @code{"/srv/http"})
16891 The @code{DocumentRoot} from which files will be served.
16893 @item @code{listen} (default: @code{'("80")})
16894 The list of values for the @code{Listen} directives in the config
16895 file. The value should be a list of strings, when each string can
16896 specify the port number to listen on, and optionally the IP address and
16899 @item @code{pid-file} (default: @code{"/var/run/httpd"})
16900 The @code{PidFile} to use. This should match the @code{pid-file} set in
16901 the @code{httpd-configuration} so that the Shepherd service is
16902 configured correctly.
16904 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
16905 The @code{ErrorLog} to which the server will log errors.
16907 @item @code{user} (default: @code{"httpd"})
16908 The @code{User} which the server will answer requests as.
16910 @item @code{group} (default: @code{"httpd"})
16911 The @code{Group} which the server will answer requests as.
16913 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
16914 A flat list of strings and G-expressions which will be added to the end
16915 of the configuration file.
16917 Any values which the service is extended with will be appended to this
16923 @deffn {Data Type} httpd-virtualhost
16924 This data type represents a virtualhost configuration block for the httpd service.
16926 These should be added to the extra-config for the httpd-service.
16929 (simple-service 'my-extra-server httpd-service-type
16933 (list (string-append
16934 "ServerName "www.example.com
16935 DocumentRoot \"/srv/http/www.example.com\"")))))
16939 @item @code{addresses-and-ports}
16940 The addresses and ports for the @code{VirtualHost} directive.
16942 @item @code{contents}
16943 The contents of the @code{VirtualHost} directive, this should be a list
16944 of strings and G-expressions.
16949 @subsubheading NGINX
16951 @deffn {Scheme Variable} nginx-service-type
16952 Service type for the @uref{https://nginx.org/,NGinx} web server. The
16953 value for this service type is a @code{<nginx-configuration>} record.
16955 A simple example configuration is given below.
16958 (service nginx-service-type
16959 (nginx-configuration
16961 (list (nginx-server-configuration
16962 (server-name '("www.example.com"))
16963 (root "/srv/http/www.example.com"))))))
16966 In addition to adding server blocks to the service configuration
16967 directly, this service can be extended by other services to add server
16968 blocks, as in this example:
16971 (simple-service 'my-extra-server nginx-service-type
16972 (list (nginx-server-configuration
16973 (root "/srv/http/extra-website")
16974 (try-files (list "$uri" "$uri/index.html")))))
16978 At startup, @command{nginx} has not yet read its configuration file, so
16979 it uses a default file to log error messages. If it fails to load its
16980 configuration file, that is where error messages are logged. After the
16981 configuration file is loaded, the default error log file changes as per
16982 configuration. In our case, startup error messages can be found in
16983 @file{/var/run/nginx/logs/error.log}, and after configuration in
16984 @file{/var/log/nginx/error.log}. The second location can be changed
16985 with the @var{log-directory} configuration option.
16987 @deffn {Data Type} nginx-configuration
16988 This data type represents the configuration for NGinx. Some
16989 configuration can be done through this and the other provided record
16990 types, or alternatively, a config file can be provided.
16993 @item @code{nginx} (default: @code{nginx})
16994 The nginx package to use.
16996 @item @code{log-directory} (default: @code{"/var/log/nginx"})
16997 The directory to which NGinx will write log files.
16999 @item @code{run-directory} (default: @code{"/var/run/nginx"})
17000 The directory in which NGinx will create a pid file, and write temporary
17003 @item @code{server-blocks} (default: @code{'()})
17004 A list of @dfn{server blocks} to create in the generated configuration
17005 file, the elements should be of type
17006 @code{<nginx-server-configuration>}.
17008 The following example would setup NGinx to serve @code{www.example.com}
17009 from the @code{/srv/http/www.example.com} directory, without using
17012 (service nginx-service-type
17013 (nginx-configuration
17015 (list (nginx-server-configuration
17016 (server-name '("www.example.com"))
17017 (root "/srv/http/www.example.com"))))))
17020 @item @code{upstream-blocks} (default: @code{'()})
17021 A list of @dfn{upstream blocks} to create in the generated configuration
17022 file, the elements should be of type
17023 @code{<nginx-upstream-configuration>}.
17025 Configuring upstreams through the @code{upstream-blocks} can be useful
17026 when combined with @code{locations} in the
17027 @code{<nginx-server-configuration>} records. The following example
17028 creates a server configuration with one location configuration, that
17029 will proxy requests to a upstream configuration, which will handle
17030 requests with two servers.
17035 (nginx-configuration
17037 (list (nginx-server-configuration
17038 (server-name '("www.example.com"))
17039 (root "/srv/http/www.example.com")
17042 (nginx-location-configuration
17044 (body '("proxy_pass http://server-proxy;"))))))))
17046 (list (nginx-upstream-configuration
17047 (name "server-proxy")
17048 (servers (list "server1.example.com"
17049 "server2.example.com")))))))
17052 @item @code{file} (default: @code{#f})
17053 If a configuration @var{file} is provided, this will be used, rather than
17054 generating a configuration file from the provided @code{log-directory},
17055 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
17056 proper operation, these arguments should match what is in @var{file} to ensure
17057 that the directories are created when the service is activated.
17059 This can be useful if you have an existing configuration file, or it's
17060 not possible to do what is required through the other parts of the
17061 nginx-configuration record.
17063 @item @code{server-names-hash-bucket-size} (default: @code{#f})
17064 Bucket size for the server names hash tables, defaults to @code{#f} to
17065 use the size of the processors cache line.
17067 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
17068 Maximum bucket size for the server names hash tables.
17070 @item @code{extra-content} (default: @code{""})
17071 Extra content for the @code{http} block. Should be string or a string
17072 valued G-expression.
17077 @deftp {Data Type} nginx-server-configuration
17078 Data type representing the configuration of an nginx server block.
17079 This type has the following parameters:
17082 @item @code{listen} (default: @code{'("80" "443 ssl")})
17083 Each @code{listen} directive sets the address and port for IP, or the
17084 path for a UNIX-domain socket on which the server will accept requests.
17085 Both address and port, or only address or only port can be specified.
17086 An address may also be a hostname, for example:
17089 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
17092 @item @code{server-name} (default: @code{(list 'default)})
17093 A list of server names this server represents. @code{'default} represents the
17094 default server for connections matching no other server.
17096 @item @code{root} (default: @code{"/srv/http"})
17097 Root of the website nginx will serve.
17099 @item @code{locations} (default: @code{'()})
17100 A list of @dfn{nginx-location-configuration} or
17101 @dfn{nginx-named-location-configuration} records to use within this
17104 @item @code{index} (default: @code{(list "index.html")})
17105 Index files to look for when clients ask for a directory. If it cannot be found,
17106 Nginx will send the list of files in the directory.
17108 @item @code{try-files} (default: @code{'()})
17109 A list of files whose existence is checked in the specified order.
17110 @code{nginx} will use the first file it finds to process the request.
17112 @item @code{ssl-certificate} (default: @code{#f})
17113 Where to find the certificate for secure connections. Set it to @code{#f} if
17114 you don't have a certificate or you don't want to use HTTPS.
17116 @item @code{ssl-certificate-key} (default: @code{#f})
17117 Where to find the private key for secure connections. Set it to @code{#f} if
17118 you don't have a key or you don't want to use HTTPS.
17120 @item @code{server-tokens?} (default: @code{#f})
17121 Whether the server should add its configuration to response.
17123 @item @code{raw-content} (default: @code{'()})
17124 A list of raw lines added to the server block.
17129 @deftp {Data Type} nginx-upstream-configuration
17130 Data type representing the configuration of an nginx @code{upstream}
17131 block. This type has the following parameters:
17135 Name for this group of servers.
17137 @item @code{servers}
17138 Specify the addresses of the servers in the group. The address can be
17139 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
17140 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
17141 prefix @samp{unix:}. For addresses using an IP address or domain name,
17142 the default port is 80, and a different port can be specified
17148 @deftp {Data Type} nginx-location-configuration
17149 Data type representing the configuration of an nginx @code{location}
17150 block. This type has the following parameters:
17154 URI which this location block matches.
17156 @anchor{nginx-location-configuration body}
17158 Body of the location block, specified as a list of strings. This can contain
17160 configuration directives. For example, to pass requests to a upstream
17161 server group defined using an @code{nginx-upstream-configuration} block,
17162 the following directive would be specified in the body @samp{(list "proxy_pass
17163 http://upstream-name;")}.
17168 @deftp {Data Type} nginx-named-location-configuration
17169 Data type representing the configuration of an nginx named location
17170 block. Named location blocks are used for request redirection, and not
17171 used for regular request processing. This type has the following
17176 Name to identify this location block.
17179 @xref{nginx-location-configuration body}, as the body for named location
17180 blocks can be used in a similar way to the
17181 @code{nginx-location-configuration body}. One restriction is that the
17182 body of a named location block cannot contain location blocks.
17187 @subsubheading Varnish Cache
17189 Varnish is a fast cache server that sits in between web applications
17190 and end users. It proxies requests from clients and caches the
17191 accessed URLs such that multiple requests for the same resource only
17192 creates one request to the back-end.
17194 @defvr {Scheme Variable} varnish-service-type
17195 Service type for the Varnish daemon.
17198 @deftp {Data Type} varnish-configuration
17199 Data type representing the @code{varnish} service configuration.
17200 This type has the following parameters:
17203 @item @code{package} (default: @code{varnish})
17204 The Varnish package to use.
17206 @item @code{name} (default: @code{"default"})
17207 A name for this Varnish instance. Varnish will create a directory in
17208 @file{/var/varnish/} with this name and keep temporary files there. If
17209 the name starts with a forward slash, it is interpreted as an absolute
17212 Pass the @code{-n} argument to other Varnish programs to connect to the
17213 named instance, e.g.@: @command{varnishncsa -n default}.
17215 @item @code{backend} (default: @code{"localhost:8080"})
17216 The backend to use. This option has no effect if @code{vcl} is set.
17218 @item @code{vcl} (default: #f)
17219 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
17220 is @code{#f}, Varnish will proxy @code{backend} using the default
17221 configuration. Otherwise this must be a file-like object with valid
17224 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
17225 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
17226 can do something along these lines:
17229 (define %gnu-mirror
17233 backend gnu @{ .host = "www.gnu.org"; @}"))
17237 (services (cons (service varnish-service-type
17238 (varnish-configuration
17240 (vcl %gnu-mirror)))
17244 The configuration of an already running Varnish instance can be inspected
17245 and changed using the @command{varnishadm} program.
17247 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
17248 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
17249 comprehensive documentation on Varnish and its configuration language.
17251 @item @code{listen} (default: @code{'("localhost:80")})
17252 List of addresses Varnish will listen on.
17254 @item @code{storage} (default: @code{'("malloc,128m")})
17255 List of storage backends that will be available in VCL.
17257 @item @code{parameters} (default: @code{'()})
17258 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
17260 @item @code{extra-options} (default: @code{'()})
17261 Additional arguments to pass to the @command{varnishd} process.
17266 @subsubheading FastCGI
17269 FastCGI is an interface between the front-end and the back-end of a web
17270 service. It is a somewhat legacy facility; new web services should
17271 generally just talk HTTP between the front-end and the back-end.
17272 However there are a number of back-end services such as PHP or the
17273 optimized HTTP Git repository access that use FastCGI, so we have
17274 support for it in Guix.
17276 To use FastCGI, you configure the front-end web server (e.g., nginx) to
17277 dispatch some subset of its requests to the fastcgi backend, which
17278 listens on a local TCP or UNIX socket. There is an intermediary
17279 @code{fcgiwrap} program that sits between the actual backend process and
17280 the web server. The front-end indicates which backend program to run,
17281 passing that information to the @code{fcgiwrap} process.
17283 @defvr {Scheme Variable} fcgiwrap-service-type
17284 A service type for the @code{fcgiwrap} FastCGI proxy.
17287 @deftp {Data Type} fcgiwrap-configuration
17288 Data type representing the configuration of the @code{fcgiwrap} serice.
17289 This type has the following parameters:
17291 @item @code{package} (default: @code{fcgiwrap})
17292 The fcgiwrap package to use.
17294 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
17295 The socket on which the @code{fcgiwrap} process should listen, as a
17296 string. Valid @var{socket} values include
17297 @code{unix:@var{/path/to/unix/socket}},
17298 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
17299 @code{tcp6:[@var{ipv6_addr}]:port}.
17301 @item @code{user} (default: @code{fcgiwrap})
17302 @itemx @code{group} (default: @code{fcgiwrap})
17303 The user and group names, as strings, under which to run the
17304 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
17305 the user asks for the specific user or group names @code{fcgiwrap} that
17306 the corresponding user and/or group is present on the system.
17308 It is possible to configure a FastCGI-backed web service to pass HTTP
17309 authentication information from the front-end to the back-end, and to
17310 allow @code{fcgiwrap} to run the back-end process as a corresponding
17311 local user. To enable this capability on the back-end., run
17312 @code{fcgiwrap} as the @code{root} user and group. Note that this
17313 capability also has to be configured on the front-end as well.
17318 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
17319 with some additional features useful for sites of any size.
17321 These features include:
17323 @item Adaptive process spawning
17324 @item Basic statistics (similar to Apache's mod_status)
17325 @item Advanced process management with graceful stop/start
17326 @item Ability to start workers with different uid/gid/chroot/environment
17327 and different php.ini (replaces safe_mode)
17328 @item Stdout & stderr logging
17329 @item Emergency restart in case of accidental opcode cache destruction
17330 @item Accelerated upload support
17331 @item Support for a "slowlog"
17332 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
17333 a special function to finish request & flush all data while continuing to do
17334 something time-consuming (video converting, stats processing, etc.)
17336 ...@: and much more.
17338 @defvr {Scheme Variable} php-fpm-service-type
17339 A Service type for @code{php-fpm}.
17342 @deftp {Data Type} php-fpm-configuration
17343 Data Type for php-fpm service configuration.
17345 @item @code{php} (default: @code{php})
17346 The php package to use.
17347 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
17348 The address on which to accept FastCGI requests. Valid syntaxes are:
17350 @item @code{"ip.add.re.ss:port"}
17351 Listen on a TCP socket to a specific address on a specific port.
17352 @item @code{"port"}
17353 Listen on a TCP socket to all addresses on a specific port.
17354 @item @code{"/path/to/unix/socket"}
17355 Listen on a unix socket.
17358 @item @code{user} (default: @code{php-fpm})
17359 User who will own the php worker processes.
17360 @item @code{group} (default: @code{php-fpm})
17361 Group of the worker processes.
17362 @item @code{socket-user} (default: @code{php-fpm})
17363 User who can speak to the php-fpm socket.
17364 @item @code{socket-group} (default: @code{php-fpm})
17365 Group that can speak to the php-fpm socket.
17366 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
17367 The process id of the php-fpm process is written to this file
17368 once the service has started.
17369 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
17370 Log for the php-fpm master process.
17371 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
17372 Detailed settings for the php-fpm process manager.
17375 @item @code{<php-fpm-dynamic-process-manager-configuration>}
17376 @item @code{<php-fpm-static-process-manager-configuration>}
17377 @item @code{<php-fpm-on-demand-process-manager-configuration>}
17379 @item @code{display-errors} (default @code{#f})
17380 Determines whether php errors and warning should be sent to clients
17381 and displayed in their browsers.
17382 This is useful for local php development, but a security risk for public sites,
17383 as error messages can reveal passwords and personal data.
17384 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
17385 This file will log the @code{stderr} outputs of php worker processes.
17386 Can be set to @code{#f} to disable logging.
17387 @item @code{file} (default @code{#f})
17388 An optional override of the whole configuration.
17389 You can use the @code{mixed-text-file} function or an absolute filepath for it.
17393 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
17394 Data Type for the @code{dynamic} php-fpm process manager. With the
17395 @code{dynamic} process manager, spare worker processes are kept around
17396 based on it's configured limits.
17398 @item @code{max-children} (default: @code{5})
17399 Maximum of worker processes.
17400 @item @code{start-servers} (default: @code{2})
17401 How many worker processes should be started on start-up.
17402 @item @code{min-spare-servers} (default: @code{1})
17403 How many spare worker processes should be kept around at minimum.
17404 @item @code{max-spare-servers} (default: @code{3})
17405 How many spare worker processes should be kept around at maximum.
17409 @deftp {Data type} php-fpm-static-process-manager-configuration
17410 Data Type for the @code{static} php-fpm process manager. With the
17411 @code{static} process manager, an unchanging number of worker processes
17414 @item @code{max-children} (default: @code{5})
17415 Maximum of worker processes.
17419 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
17420 Data Type for the @code{on-demand} php-fpm process manager. With the
17421 @code{on-demand} process manager, worker processes are only created as
17424 @item @code{max-children} (default: @code{5})
17425 Maximum of worker processes.
17426 @item @code{process-idle-timeout} (default: @code{10})
17427 The time in seconds after which a process with no requests is killed.
17432 @deffn {Scheme Procedure} nginx-php-fpm-location @
17433 [#:nginx-package nginx] @
17434 [socket (string-append "/var/run/php" @
17435 (version-major (package-version php)) @
17437 A helper function to quickly add php to an @code{nginx-server-configuration}.
17440 A simple services setup for nginx with php can look like this:
17442 (services (cons* (service dhcp-client-service-type)
17443 (service php-fpm-service-type)
17444 (service nginx-service-type
17445 (nginx-server-configuration
17446 (server-name '("example.com"))
17447 (root "/srv/http/")
17449 (list (nginx-php-location)))
17451 (ssl-certificate #f)
17452 (ssl-certificate-key #f)))
17456 @cindex cat-avatar-generator
17457 The cat avatar generator is a simple service to demonstrate the use of php-fpm
17458 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
17459 the hash of a user's email address.
17461 @deffn {Scheme Procedure} cat-avatar-generator-serice @
17462 [#:cache-dir "/var/cache/cat-avatar-generator"] @
17463 [#:package cat-avatar-generator] @
17464 [#:configuration (nginx-server-configuration)]
17465 Returns an nginx-server-configuration that inherits @code{configuration}. It
17466 extends the nginx configuration to add a server block that serves @code{package},
17467 a version of cat-avatar-generator. During execution, cat-avatar-generator will
17468 be able to use @code{cache-dir} as its cache directory.
17471 A simple setup for cat-avatar-generator can look like this:
17473 (services (cons* (cat-avatar-generator-service
17475 (nginx-server-configuration
17476 (server-name '("example.com"))))
17481 @subsubheading Hpcguix-web
17483 @cindex hpcguix-web
17484 The @uref{hpcguix-web, https://github.com/UMCUGenetics/hpcguix-web/}
17485 program is a customizable web interface to browse Guix packages,
17486 initially designed for users of high-performance computing (HPC)
17489 @defvr {Scheme Variable} hpcguix-web-service-type
17490 The service type for @code{hpcguix-web}.
17493 @deftp {Data Type} hpcguix-web-configuration
17494 Data type for the hpcguix-web service configuration.
17498 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
17499 configuration. The main items available in this spec are:
17502 @item @code{title-prefix} (default: @code{"hpcguix | "})
17503 The page title prefix.
17505 @item @code{guix-command} (default: @code{"guix"})
17506 The @command{guix} command.
17508 @item @code{package-filter-proc} (default: @code{(const #t)})
17509 A procedure specifying how to filter packages that are displayed.
17511 @item @code{package-page-extension-proc} (default: @code{(const '())})
17512 Extension package for @code{hpcguix-web}.
17514 @item @code{menu} (default: @code{'()})
17515 Additional entry in page @code{menu}.
17517 @item @code{channels} (default: @code{%default-channels})
17518 List of channels from which the package list is built (@pxref{Channels}).
17520 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
17521 The expiration time, in seconds, after which the package list is rebuilt from
17522 the latest instances of the given channels.
17525 See the hpcguix-web repository for a
17526 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
17529 @item @code{package} (default: @code{hpcguix-web})
17530 The hpcguix-web package to use.
17534 A typical hpcguix-web service declaration looks like this:
17537 (service hpcguix-web-service-type
17538 (hpcguix-web-configuration
17540 #~(define site-config
17541 (hpcweb-configuration
17542 (title-prefix "Guix-HPC - ")
17543 (menu '(("/about" "ABOUT"))))))))
17547 The hpcguix-web service periodically updates the package list it publishes by
17548 pulling channels from Git. To that end, it needs to access X.509 certificates
17549 so that it can authenticate Git servers when communicating over HTTPS, and it
17550 assumes that @file{/etc/ssl/certs} contains those certificates.
17552 Thus, make sure to add @code{nss-certs} or another certificate package to the
17553 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
17554 more information on X.509 certificates.
17557 @node Certificate Services
17558 @subsubsection Certificate Services
17561 @cindex HTTP, HTTPS
17562 @cindex Let's Encrypt
17563 @cindex TLS certificates
17564 The @code{(gnu services certbot)} module provides a service to
17565 automatically obtain a valid TLS certificate from the Let's Encrypt
17566 certificate authority. These certificates can then be used to serve
17567 content securely over HTTPS or other TLS-based protocols, with the
17568 knowledge that the client will be able to verify the server's
17571 @url{https://letsencrypt.org/, Let's Encrypt} provides the
17572 @code{certbot} tool to automate the certification process. This tool
17573 first securely generates a key on the server. It then makes a request
17574 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
17575 checks that the request originates from the host in question by using a
17576 challenge-response protocol, requiring the server to provide its
17577 response over HTTP. If that protocol completes successfully, the CA
17578 signs the key, resulting in a certificate. That certificate is valid
17579 for a limited period of time, and therefore to continue to provide TLS
17580 services, the server needs to periodically ask the CA to renew its
17583 The certbot service automates this process: the initial key
17584 generation, the initial certification request to the Let's Encrypt
17585 service, the web server challenge/response integration, writing the
17586 certificate to disk, the automated periodic renewals, and the deployment
17587 tasks associated with the renewal (e.g.@: reloading services, copying keys
17588 with different permissions).
17590 Certbot is run twice a day, at a random minute within the hour. It
17591 won't do anything until your certificates are due for renewal or
17592 revoked, but running it regularly would give your service a chance of
17593 staying online in case a Let's Encrypt-initiated revocation happened for
17596 By using this service, you agree to the ACME Subscriber Agreement, which
17597 can be found there:
17598 @url{https://acme-v01.api.letsencrypt.org/directory}.
17600 @defvr {Scheme Variable} certbot-service-type
17601 A service type for the @code{certbot} Let's Encrypt client. Its value
17602 must be a @code{certbot-configuration} record as in this example:
17605 (define %nginx-deploy-hook
17607 "nginx-deploy-hook"
17608 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
17609 (kill pid SIGHUP))))
17611 (service certbot-service-type
17612 (certbot-configuration
17613 (email "foo@@example.net")
17616 (certificate-configuration
17617 (domains '("example.net" "www.example.net"))
17618 (deploy-hook %nginx-deploy-hook))
17619 (certificate-configuration
17620 (domains '("bar.example.net")))))))
17623 See below for details about @code{certbot-configuration}.
17626 @deftp {Data Type} certbot-configuration
17627 Data type representing the configuration of the @code{certbot} service.
17628 This type has the following parameters:
17631 @item @code{package} (default: @code{certbot})
17632 The certbot package to use.
17634 @item @code{webroot} (default: @code{/var/www})
17635 The directory from which to serve the Let's Encrypt challenge/response
17638 @item @code{certificates} (default: @code{()})
17639 A list of @code{certificates-configuration}s for which to generate
17640 certificates and request signatures. Each certificate has a @code{name}
17641 and several @code{domains}.
17644 Mandatory email used for registration, recovery contact, and important
17645 account notifications.
17647 @item @code{rsa-key-size} (default: @code{2048})
17648 Size of the RSA key.
17650 @item @code{default-location} (default: @i{see below})
17651 The default @code{nginx-location-configuration}. Because @code{certbot}
17652 needs to be able to serve challenges and responses, it needs to be able
17653 to run a web server. It does so by extending the @code{nginx} web
17654 service with an @code{nginx-server-configuration} listening on the
17655 @var{domains} on port 80, and which has a
17656 @code{nginx-location-configuration} for the @code{/.well-known/} URI
17657 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
17658 these nginx configuration data types.
17660 Requests to other URL paths will be matched by the
17661 @code{default-location}, which if present is added to all
17662 @code{nginx-server-configuration}s.
17664 By default, the @code{default-location} will issue a redirect from
17665 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
17666 you to define what to serve on your site via @code{https}.
17668 Pass @code{#f} to not issue a default location.
17672 @deftp {Data Type} certificate-configuration
17673 Data type representing the configuration of a certificate.
17674 This type has the following parameters:
17677 @item @code{name} (default: @i{see below})
17678 This name is used by Certbot for housekeeping and in file paths; it
17679 doesn't affect the content of the certificate itself. To see
17680 certificate names, run @code{certbot certificates}.
17682 Its default is the first provided domain.
17684 @item @code{domains} (default: @code{()})
17685 The first domain provided will be the subject CN of the certificate, and
17686 all domains will be Subject Alternative Names on the certificate.
17688 @item @code{deploy-hook} (default: @code{#f})
17689 Command to be run in a shell once for each successfully issued
17690 certificate. For this command, the shell variable
17691 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
17692 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
17693 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
17694 contain a space-delimited list of renewed certificate domains (for
17695 example, @samp{"example.com www.example.com"}.
17700 For each @code{certificate-configuration}, the certificate is saved to
17701 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
17702 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
17704 @subsubsection DNS Services
17705 @cindex DNS (domain name system)
17706 @cindex domain name system (DNS)
17708 The @code{(gnu services dns)} module provides services related to the
17709 @dfn{domain name system} (DNS). It provides a server service for hosting
17710 an @emph{authoritative} DNS server for multiple zones, slave or master.
17711 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
17712 caching and forwarding DNS server for the LAN, which uses
17713 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
17715 @subsubheading Knot Service
17717 An example configuration of an authoritative server for two zones, one master
17721 (define-zone-entries example.org.zone
17722 ;; Name TTL Class Type Data
17723 ("@@" "" "IN" "A" "127.0.0.1")
17724 ("@@" "" "IN" "NS" "ns")
17725 ("ns" "" "IN" "A" "127.0.0.1"))
17727 (define master-zone
17728 (knot-zone-configuration
17729 (domain "example.org")
17731 (origin "example.org")
17732 (entries example.org.zone)))))
17735 (knot-zone-configuration
17736 (domain "plop.org")
17737 (dnssec-policy "default")
17738 (master (list "plop-master"))))
17740 (define plop-master
17741 (knot-remote-configuration
17743 (address (list "208.76.58.171"))))
17747 (services (cons* (service knot-service-type
17748 (knot-configuration
17749 (remotes (list plop-master))
17750 (zones (list master-zone slave-zone))))
17755 @deffn {Scheme Variable} knot-service-type
17756 This is the type for the Knot DNS server.
17758 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
17759 zones, that is to say domain names you would buy from a registrar. This server
17760 is not a resolver, meaning that it can only resolve names for which it is
17761 authoritative. This server can be configured to serve zones as a master server
17762 or a slave server as a per-zone basis. Slave zones will get their data from
17763 masters, and will serve it as an authoritative server. From the point of view
17764 of a resolver, there is no difference between master and slave.
17766 The following data types are used to configure the Knot DNS server:
17769 @deftp {Data Type} knot-key-configuration
17770 Data type representing a key.
17771 This type has the following parameters:
17774 @item @code{id} (default: @code{""})
17775 An identifier for other configuration fields to refer to this key. IDs must
17776 be unique and must not be empty.
17778 @item @code{algorithm} (default: @code{#f})
17779 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
17780 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
17781 and @code{'hmac-sha512}.
17783 @item @code{secret} (default: @code{""})
17784 The secret key itself.
17789 @deftp {Data Type} knot-acl-configuration
17790 Data type representing an Access Control List (ACL) configuration.
17791 This type has the following parameters:
17794 @item @code{id} (default: @code{""})
17795 An identifier for ether configuration fields to refer to this key. IDs must be
17796 unique and must not be empty.
17798 @item @code{address} (default: @code{'()})
17799 An ordered list of IP addresses, network subnets, or network ranges represented
17800 with strings. The query must match one of them. Empty value means that
17801 address match is not required.
17803 @item @code{key} (default: @code{'()})
17804 An ordered list of references to keys represented with strings. The string
17805 must match a key ID defined in a @code{knot-key-configuration}. No key means
17806 that a key is not require to match that ACL.
17808 @item @code{action} (default: @code{'()})
17809 An ordered list of actions that are permitted or forbidden by this ACL. Possible
17810 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
17811 and @code{'update}.
17813 @item @code{deny?} (default: @code{#f})
17814 When true, the ACL defines restrictions. Listed actions are forbidden. When
17815 false, listed actions are allowed.
17820 @deftp {Data Type} zone-entry
17821 Data type represnting a record entry in a zone file.
17822 This type has the following parameters:
17825 @item @code{name} (default: @code{"@@"})
17826 The name of the record. @code{"@@"} refers to the origin of the zone. Names
17827 are relative to the origin of the zone. For example, in the @code{example.org}
17828 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
17829 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
17830 refers to @code{ns.example.org}.
17832 @item @code{ttl} (default: @code{""})
17833 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
17835 @item @code{class} (default: @code{"IN"})
17836 The class of the record. Knot currently supports only @code{"IN"} and
17837 partially @code{"CH"}.
17839 @item @code{type} (default: @code{"A"})
17840 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
17841 address), NS (Name Server) and MX (Mail eXchange). Many other types are
17844 @item @code{data} (default: @code{""})
17845 The data contained in the record. For instance an IP address associated with
17846 an A record, or a domain name associated with an NS record. Remember that
17847 domain names are relative to the origin unless they end with a dot.
17852 @deftp {Data Type} zone-file
17853 Data type representing the content of a zone file.
17854 This type has the following parameters:
17857 @item @code{entries} (default: @code{'()})
17858 The list of entries. The SOA record is taken care of, so you don't need to
17859 put it in the list of entries. This list should probably contain an entry
17860 for your primary authoritative DNS server. Other than using a list of entries
17861 directly, you can use @code{define-zone-entries} to define a object containing
17862 the list of entries more easily, that you can later pass to the @code{entries}
17863 field of the @code{zone-file}.
17865 @item @code{origin} (default: @code{""})
17866 The name of your zone. This parameter cannot be empty.
17868 @item @code{ns} (default: @code{"ns"})
17869 The domain of your primary authoritative DNS server. The name is relative to
17870 the origin, unless it ends with a dot. It is mandatory that this primary
17871 DNS server corresponds to an NS record in the zone and that it is associated
17872 to an IP address in the list of entries.
17874 @item @code{mail} (default: @code{"hostmaster"})
17875 An email address people can contact you at, as the owner of the zone. This
17876 is translated as @code{<mail>@@<origin>}.
17878 @item @code{serial} (default: @code{1})
17879 The serial number of the zone. As this is used to keep track of changes by
17880 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
17881 Always increment it when you make a change in your zone.
17883 @item @code{refresh} (default: @code{(* 2 24 3600)})
17884 The frequency at which slaves will do a zone transfer. This value is a number
17885 of seconds. It can be computed by multiplications or with
17886 @code{(string->duration)}.
17888 @item @code{retry} (default: @code{(* 15 60)})
17889 The period after which a slave will retry to contact its master when it fails
17890 to do so a first time.
17892 @item @code{expiry} (default: @code{(* 14 24 3600)})
17893 Default TTL of records. Existing records are considered correct for at most
17894 this amount of time. After this period, resolvers will invalidate their cache
17895 and check again that it still exists.
17897 @item @code{nx} (default: @code{3600})
17898 Default TTL of inexistant records. This delay is usually short because you want
17899 your new domains to reach everyone quickly.
17904 @deftp {Data Type} knot-remote-configuration
17905 Data type representing a remote configuration.
17906 This type has the following parameters:
17909 @item @code{id} (default: @code{""})
17910 An identifier for other configuration fields to refer to this remote. IDs must
17911 be unique and must not be empty.
17913 @item @code{address} (default: @code{'()})
17914 An ordered list of destination IP addresses. Addresses are tried in sequence.
17915 An optional port can be given with the @@ separator. For instance:
17916 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
17918 @item @code{via} (default: @code{'()})
17919 An ordered list of source IP addresses. An empty list will have Knot choose
17920 an appropriate source IP. An optional port can be given with the @@ separator.
17921 The default is to choose at random.
17923 @item @code{key} (default: @code{#f})
17924 A reference to a key, that is a string containing the identifier of a key
17925 defined in a @code{knot-key-configuration} field.
17930 @deftp {Data Type} knot-keystore-configuration
17931 Data type representing a keystore to hold dnssec keys.
17932 This type has the following parameters:
17935 @item @code{id} (default: @code{""})
17936 The id of the keystore. It must not be empty.
17938 @item @code{backend} (default: @code{'pem})
17939 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
17941 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
17942 The configuration string of the backend. An example for the PKCS#11 is:
17943 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
17944 For the pem backend, the string reprensents a path in the file system.
17949 @deftp {Data Type} knot-policy-configuration
17950 Data type representing a dnssec policy. Knot DNS is able to automatically
17951 sign your zones. It can either generate and manage your keys automatically or
17952 use keys that you generate.
17954 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
17955 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
17956 zone. In order to be trusted, the KSK needs to be present in the parent zone
17957 (usually a top-level domain). If your registrar supports dnssec, you will
17958 have to send them your KSK's hash so they can add a DS record in their zone.
17959 This is not automated and need to be done each time you change your KSK.
17961 The policy also defines the lifetime of keys. Usually, ZSK can be changed
17962 easily and use weaker cryptographic functions (they use lower parameters) in
17963 order to sign records quickly, so they are changed often. The KSK however
17964 requires manual interaction with the registrar, so they are changed less often
17965 and use stronger parameters because they sign only one record.
17967 This type has the following parameters:
17970 @item @code{id} (default: @code{""})
17971 The id of the policy. It must not be empty.
17973 @item @code{keystore} (default: @code{"default"})
17974 A reference to a keystore, that is a string containing the identifier of a
17975 keystore defined in a @code{knot-keystore-configuration} field. The
17976 @code{"default"} identifier means the default keystore (a kasp database that
17977 was setup by this service).
17979 @item @code{manual?} (default: @code{#f})
17980 Whether the key management is manual or automatic.
17982 @item @code{single-type-signing?} (default: @code{#f})
17983 When @code{#t}, use the Single-Type Signing Scheme.
17985 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
17986 An algorithm of signing keys and issued signatures.
17988 @item @code{ksk-size} (default: @code{256})
17989 The length of the KSK. Note that this value is correct for the default
17990 algorithm, but would be unsecure for other algorithms.
17992 @item @code{zsk-size} (default: @code{256})
17993 The length of the ZSK. Note that this value is correct for the default
17994 algorithm, but would be unsecure for other algorithms.
17996 @item @code{dnskey-ttl} (default: @code{'default})
17997 The TTL value for DNSKEY records added into zone apex. The special
17998 @code{'default} value means same as the zone SOA TTL.
18000 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
18001 The period between ZSK publication and the next rollover initiation.
18003 @item @code{propagation-delay} (default: @code{(* 24 3600)})
18004 An extra delay added for each key rollover step. This value should be high
18005 enough to cover propagation of data from the master server to all slaves.
18007 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
18008 A validity period of newly issued signatures.
18010 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
18011 A period how long before a signature expiration the signature will be refreshed.
18013 @item @code{nsec3?} (default: @code{#f})
18014 When @code{#t}, NSEC3 will be used instead of NSEC.
18016 @item @code{nsec3-iterations} (default: @code{5})
18017 The number of additional times the hashing is performed.
18019 @item @code{nsec3-salt-length} (default: @code{8})
18020 The length of a salt field in octets, which is appended to the original owner
18021 name before hashing.
18023 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
18024 The validity period of newly issued salt field.
18029 @deftp {Data Type} knot-zone-configuration
18030 Data type representing a zone served by Knot.
18031 This type has the following parameters:
18034 @item @code{domain} (default: @code{""})
18035 The domain served by this configuration. It must not be empty.
18037 @item @code{file} (default: @code{""})
18038 The file where this zone is saved. This parameter is ignored by master zones.
18039 Empty means default location that depends on the domain name.
18041 @item @code{zone} (default: @code{(zone-file)})
18042 The content of the zone file. This parameter is ignored by slave zones. It
18043 must contain a zone-file record.
18045 @item @code{master} (default: @code{'()})
18046 A list of master remotes. When empty, this zone is a master. When set, this
18047 zone is a slave. This is a list of remotes identifiers.
18049 @item @code{ddns-master} (default: @code{#f})
18050 The main master. When empty, it defaults to the first master in the list of
18053 @item @code{notify} (default: @code{'()})
18054 A list of slave remote identifiers.
18056 @item @code{acl} (default: @code{'()})
18057 A list of acl identifiers.
18059 @item @code{semantic-checks?} (default: @code{#f})
18060 When set, this adds more semantic checks to the zone.
18062 @item @code{disable-any?} (default: @code{#f})
18063 When set, this forbids queries of the ANY type.
18065 @item @code{zonefile-sync} (default: @code{0})
18066 The delay between a modification in memory and on disk. 0 means immediate
18069 @item @code{serial-policy} (default: @code{'increment})
18070 A policy between @code{'increment} and @code{'unixtime}.
18075 @deftp {Data Type} knot-configuration
18076 Data type representing the Knot configuration.
18077 This type has the following parameters:
18080 @item @code{knot} (default: @code{knot})
18083 @item @code{run-directory} (default: @code{"/var/run/knot"})
18084 The run directory. This directory will be used for pid file and sockets.
18086 @item @code{listen-v4} (default: @code{"0.0.0.0"})
18087 An ip address on which to listen.
18089 @item @code{listen-v6} (default: @code{"::"})
18090 An ip address on which to listen.
18092 @item @code{listen-port} (default: @code{53})
18093 A port on which to listen.
18095 @item @code{keys} (default: @code{'()})
18096 The list of knot-key-configuration used by this configuration.
18098 @item @code{acls} (default: @code{'()})
18099 The list of knot-acl-configuration used by this configuration.
18101 @item @code{remotes} (default: @code{'()})
18102 The list of knot-remote-configuration used by this configuration.
18104 @item @code{zones} (default: @code{'()})
18105 The list of knot-zone-configuration used by this configuration.
18110 @subsubheading Dnsmasq Service
18112 @deffn {Scheme Variable} dnsmasq-service-type
18113 This is the type of the dnsmasq service, whose value should be an
18114 @code{dnsmasq-configuration} object as in this example:
18117 (service dnsmasq-service-type
18118 (dnsmasq-configuration
18120 (servers '("192.168.1.1"))))
18124 @deftp {Data Type} dnsmasq-configuration
18125 Data type representing the configuration of dnsmasq.
18128 @item @code{package} (default: @var{dnsmasq})
18129 Package object of the dnsmasq server.
18131 @item @code{no-hosts?} (default: @code{#f})
18132 When true, don't read the hostnames in /etc/hosts.
18134 @item @code{port} (default: @code{53})
18135 The port to listen on. Setting this to zero completely disables DNS
18136 responses, leaving only DHCP and/or TFTP functions.
18138 @item @code{local-service?} (default: @code{#t})
18139 Accept DNS queries only from hosts whose address is on a local subnet,
18140 ie a subnet for which an interface exists on the server.
18142 @item @code{listen-addresses} (default: @code{'()})
18143 Listen on the given IP addresses.
18145 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
18146 The file to read the IP address of the upstream nameservers from.
18148 @item @code{no-resolv?} (default: @code{#f})
18149 When true, don't read @var{resolv-file}.
18151 @item @code{servers} (default: @code{'()})
18152 Specify IP address of upstream servers directly.
18154 @item @code{cache-size} (default: @code{150})
18155 Set the size of dnsmasq's cache. Setting the cache size to zero
18158 @item @code{negative-cache?} (default: @code{#t})
18159 When false, disable negative caching.
18164 @subsubheading ddclient Service
18167 The ddclient service described below runs the ddclient daemon, which takes
18168 care of automatically updating DNS entries for service providers such as
18169 @uref{https://dyn.com/dns/, Dyn}.
18171 The following example show instantiates the service with its default
18175 (service ddclient-service-type)
18178 Note that ddclient needs to access credentials that are stored in a
18179 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
18180 @code{secret-file} below.) You are expected to create this file manually, in
18181 an ``out-of-band'' fashion (you @emph{could} make this file part of the
18182 service configuration, for instance by using @code{plain-file}, but it will be
18183 world-readable @i{via} @file{/gnu/store}.) See the examples in the
18184 @file{share/ddclient} directory of the @code{ddclient} package.
18186 @c %start of fragment
18188 Available @code{ddclient-configuration} fields are:
18190 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
18191 The ddclient package.
18195 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
18196 The period after which ddclient will retry to check IP and domain name.
18198 Defaults to @samp{300}.
18202 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
18203 Use syslog for the output.
18205 Defaults to @samp{#t}.
18209 @deftypevr {@code{ddclient-configuration} parameter} string mail
18212 Defaults to @samp{"root"}.
18216 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
18217 Mail failed update to user.
18219 Defaults to @samp{"root"}.
18223 @deftypevr {@code{ddclient-configuration} parameter} string pid
18224 The ddclient PID file.
18226 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
18230 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
18231 Enable SSL support.
18233 Defaults to @samp{#t}.
18237 @deftypevr {@code{ddclient-configuration} parameter} string user
18238 Specifies the user name or ID that is used when running ddclient
18241 Defaults to @samp{"ddclient"}.
18245 @deftypevr {@code{ddclient-configuration} parameter} string group
18246 Group of the user who will run the ddclient program.
18248 Defaults to @samp{"ddclient"}.
18252 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
18253 Secret file which will be appended to @file{ddclient.conf} file. This
18254 file contains credentials for use by ddclient. You are expected to
18255 create it manually.
18257 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
18261 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
18262 Extra options will be appended to @file{ddclient.conf} file.
18264 Defaults to @samp{()}.
18269 @c %end of fragment
18273 @subsubsection VPN Services
18274 @cindex VPN (virtual private network)
18275 @cindex virtual private network (VPN)
18277 The @code{(gnu services vpn)} module provides services related to
18278 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
18279 your machine to connect to a VPN, and a @emph{servire} service for your machine
18280 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
18282 @deffn {Scheme Procedure} openvpn-client-service @
18283 [#:config (openvpn-client-configuration)]
18285 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
18288 @deffn {Scheme Procedure} openvpn-server-service @
18289 [#:config (openvpn-server-configuration)]
18291 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
18293 Both can be run simultaneously.
18296 @c %automatically generated documentation
18298 Available @code{openvpn-client-configuration} fields are:
18300 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
18301 The OpenVPN package.
18305 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
18306 The OpenVPN pid file.
18308 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18312 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
18313 The protocol (UDP or TCP) used to open a channel between clients and
18316 Defaults to @samp{udp}.
18320 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
18321 The device type used to represent the VPN connection.
18323 Defaults to @samp{tun}.
18327 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
18328 The certificate authority to check connections against.
18330 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18334 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
18335 The certificate of the machine the daemon is running on. It should be
18336 signed by the authority given in @code{ca}.
18338 Defaults to @samp{"/etc/openvpn/client.crt"}.
18342 @deftypevr {@code{openvpn-client-configuration} parameter} string key
18343 The key of the machine the daemon is running on. It must be the key whose
18344 certificate is @code{cert}.
18346 Defaults to @samp{"/etc/openvpn/client.key"}.
18350 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
18351 Whether to use the lzo compression algorithm.
18353 Defaults to @samp{#t}.
18357 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
18358 Don't re-read key files across SIGUSR1 or --ping-restart.
18360 Defaults to @samp{#t}.
18364 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
18365 Don't close and reopen TUN/TAP device or run up/down scripts across
18366 SIGUSR1 or --ping-restart restarts.
18368 Defaults to @samp{#t}.
18372 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
18375 Defaults to @samp{3}.
18379 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
18380 Add an additional layer of HMAC authentication on top of the TLS control
18381 channel to protect against DoS attacks.
18383 Defaults to @samp{#f}.
18387 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
18388 Whether to check the server certificate has server usage extension.
18390 Defaults to @samp{#t}.
18394 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
18395 Bind to a specific local port number.
18397 Defaults to @samp{#f}.
18401 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
18402 Retry resolving server address.
18404 Defaults to @samp{#t}.
18408 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
18409 A list of remote servers to connect to.
18411 Defaults to @samp{()}.
18413 Available @code{openvpn-remote-configuration} fields are:
18415 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
18418 Defaults to @samp{"my-server"}.
18422 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
18423 Port number the server listens to.
18425 Defaults to @samp{1194}.
18430 @c %end of automatic openvpn-client documentation
18432 @c %automatically generated documentation
18434 Available @code{openvpn-server-configuration} fields are:
18436 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
18437 The OpenVPN package.
18441 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
18442 The OpenVPN pid file.
18444 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
18448 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
18449 The protocol (UDP or TCP) used to open a channel between clients and
18452 Defaults to @samp{udp}.
18456 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
18457 The device type used to represent the VPN connection.
18459 Defaults to @samp{tun}.
18463 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
18464 The certificate authority to check connections against.
18466 Defaults to @samp{"/etc/openvpn/ca.crt"}.
18470 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
18471 The certificate of the machine the daemon is running on. It should be
18472 signed by the authority given in @code{ca}.
18474 Defaults to @samp{"/etc/openvpn/client.crt"}.
18478 @deftypevr {@code{openvpn-server-configuration} parameter} string key
18479 The key of the machine the daemon is running on. It must be the key whose
18480 certificate is @code{cert}.
18482 Defaults to @samp{"/etc/openvpn/client.key"}.
18486 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
18487 Whether to use the lzo compression algorithm.
18489 Defaults to @samp{#t}.
18493 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
18494 Don't re-read key files across SIGUSR1 or --ping-restart.
18496 Defaults to @samp{#t}.
18500 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
18501 Don't close and reopen TUN/TAP device or run up/down scripts across
18502 SIGUSR1 or --ping-restart restarts.
18504 Defaults to @samp{#t}.
18508 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
18511 Defaults to @samp{3}.
18515 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
18516 Add an additional layer of HMAC authentication on top of the TLS control
18517 channel to protect against DoS attacks.
18519 Defaults to @samp{#f}.
18523 @deftypevr {@code{openvpn-server-configuration} parameter} number port
18524 Specifies the port number on which the server listens.
18526 Defaults to @samp{1194}.
18530 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
18531 An ip and mask specifying the subnet inside the virtual network.
18533 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
18537 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
18538 A CIDR notation specifying the IPv6 subnet inside the virtual network.
18540 Defaults to @samp{#f}.
18544 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
18545 The Diffie-Hellman parameters file.
18547 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
18551 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
18552 The file that records client IPs.
18554 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
18558 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
18559 When true, the server will act as a gateway for its clients.
18561 Defaults to @samp{#f}.
18565 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
18566 When true, clients are allowed to talk to each other inside the VPN.
18568 Defaults to @samp{#f}.
18572 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
18573 Causes ping-like messages to be sent back and forth over the link so
18574 that each side knows when the other side has gone down. @code{keepalive}
18575 requires a pair. The first element is the period of the ping sending,
18576 and the second element is the timeout before considering the other side
18581 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
18582 The maximum number of clients.
18584 Defaults to @samp{100}.
18588 @deftypevr {@code{openvpn-server-configuration} parameter} string status
18589 The status file. This file shows a small report on current connection.
18590 It is truncated and rewritten every minute.
18592 Defaults to @samp{"/var/run/openvpn/status"}.
18596 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
18597 The list of configuration for some clients.
18599 Defaults to @samp{()}.
18601 Available @code{openvpn-ccd-configuration} fields are:
18603 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
18606 Defaults to @samp{"client"}.
18610 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
18613 Defaults to @samp{#f}.
18617 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
18620 Defaults to @samp{#f}.
18627 @c %end of automatic openvpn-server documentation
18630 @node Network File System
18631 @subsubsection Network File System
18634 The @code{(gnu services nfs)} module provides the following services,
18635 which are most commonly used in relation to mounting or exporting
18636 directory trees as @dfn{network file systems} (NFS).
18638 @subsubheading RPC Bind Service
18641 The RPC Bind service provides a facility to map program numbers into
18642 universal addresses.
18643 Many NFS related services use this facility. Hence it is automatically
18644 started when a dependent service starts.
18646 @defvr {Scheme Variable} rpcbind-service-type
18647 A service type for the RPC portmapper daemon.
18651 @deftp {Data Type} rpcbind-configuration
18652 Data type representing the configuration of the RPC Bind Service.
18653 This type has the following parameters:
18655 @item @code{rpcbind} (default: @code{rpcbind})
18656 The rpcbind package to use.
18658 @item @code{warm-start?} (default: @code{#t})
18659 If this parameter is @code{#t}, then the daemon will read a
18660 state file on startup thus reloading state information saved by a previous
18666 @subsubheading Pipefs Pseudo File System
18670 The pipefs file system is used to transfer NFS related data
18671 between the kernel and user space programs.
18673 @defvr {Scheme Variable} pipefs-service-type
18674 A service type for the pipefs pseudo file system.
18677 @deftp {Data Type} pipefs-configuration
18678 Data type representing the configuration of the pipefs pseudo file system service.
18679 This type has the following parameters:
18681 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18682 The directory to which the file system is to be attached.
18687 @subsubheading GSS Daemon Service
18690 @cindex global security system
18692 The @dfn{global security system} (GSS) daemon provides strong security for RPC
18694 Before exchanging RPC requests an RPC client must establish a security
18695 context. Typically this is done using the Kerberos command @command{kinit}
18696 or automatically at login time using PAM services (@pxref{Kerberos Services}).
18698 @defvr {Scheme Variable} gss-service-type
18699 A service type for the Global Security System (GSS) daemon.
18702 @deftp {Data Type} gss-configuration
18703 Data type representing the configuration of the GSS daemon service.
18704 This type has the following parameters:
18706 @item @code{nfs-utils} (default: @code{nfs-utils})
18707 The package in which the @command{rpc.gssd} command is to be found.
18709 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18710 The directory where the pipefs file system is mounted.
18716 @subsubheading IDMAP Daemon Service
18718 @cindex name mapper
18720 The idmap daemon service provides mapping between user IDs and user names.
18721 Typically it is required in order to access file systems mounted via NFSv4.
18723 @defvr {Scheme Variable} idmap-service-type
18724 A service type for the Identity Mapper (IDMAP) daemon.
18727 @deftp {Data Type} idmap-configuration
18728 Data type representing the configuration of the IDMAP daemon service.
18729 This type has the following parameters:
18731 @item @code{nfs-utils} (default: @code{nfs-utils})
18732 The package in which the @command{rpc.idmapd} command is to be found.
18734 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
18735 The directory where the pipefs file system is mounted.
18737 @item @code{domain} (default: @code{#f})
18738 The local NFSv4 domain name.
18739 This must be a string or @code{#f}.
18740 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
18745 @node Continuous Integration
18746 @subsubsection Continuous Integration
18748 @cindex continuous integration
18749 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
18750 continuous integration tool for Guix. It can be used both for development and
18751 for providing substitutes to others (@pxref{Substitutes}).
18753 The @code{(gnu services cuirass)} module provides the following service.
18755 @defvr {Scheme Procedure} cuirass-service-type
18756 The type of the Cuirass service. Its value must be a
18757 @code{cuirass-configuration} object, as described below.
18760 To add build jobs, you have to set the @code{specifications} field of the
18761 configuration. Here is an example of a service that polls the Guix repository
18762 and builds the packages from a manifest. Some of the packages are defined in
18763 the @code{"custom-packages"} input, which is the equivalent of
18764 @code{GUIX_PACKAGE_PATH}.
18767 (define %cuirass-specs
18769 '((#:name . "my-manifest")
18770 (#:load-path-inputs . ("guix"))
18771 (#:package-path-inputs . ("custom-packages"))
18772 (#:proc-input . "guix")
18773 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
18774 (#:proc . cuirass-jobs)
18775 (#:proc-args . ((subset . "manifests")
18776 (systems . ("x86_64-linux"))
18777 (manifests . (("config" . "guix/manifest.scm")))))
18778 (#:inputs . (((#:name . "guix")
18779 (#:url . "git://git.savannah.gnu.org/guix.git")
18780 (#:load-path . ".")
18781 (#:branch . "master")
18782 (#:no-compile? . #t))
18783 ((#:name . "config")
18784 (#:url . "git://git.example.org/config.git")
18785 (#:load-path . ".")
18786 (#:branch . "master")
18787 (#:no-compile? . #t))
18788 ((#:name . "custom-packages")
18789 (#:url . "git://git.example.org/custom-packages.git")
18790 (#:load-path . ".")
18791 (#:branch . "master")
18792 (#:no-compile? . #t)))))))
18794 (service cuirass-service-type
18795 (cuirass-configuration
18796 (specifications %cuirass-specs)))
18799 While information related to build jobs is located directly in the
18800 specifications, global settings for the @command{cuirass} process are
18801 accessible in other @code{cuirass-configuration} fields.
18803 @deftp {Data Type} cuirass-configuration
18804 Data type representing the configuration of Cuirass.
18807 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
18808 Location of the log file.
18810 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
18811 Location of the repository cache.
18813 @item @code{user} (default: @code{"cuirass"})
18814 Owner of the @code{cuirass} process.
18816 @item @code{group} (default: @code{"cuirass"})
18817 Owner's group of the @code{cuirass} process.
18819 @item @code{interval} (default: @code{60})
18820 Number of seconds between the poll of the repositories followed by the
18823 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
18824 Location of sqlite database which contains the build results and previously
18825 added specifications.
18827 @item @code{ttl} (default: @code{(* 30 24 3600)})
18828 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
18829 are registered for build results. This means that build results are protected
18830 from garbage collection for at least @var{ttl} seconds.
18832 @item @code{port} (default: @code{8081})
18833 Port number used by the HTTP server.
18835 @item --listen=@var{host}
18836 Listen on the network interface for @var{host}. The default is to
18837 accept connections from localhost.
18839 @item @code{specifications} (default: @code{#~'()})
18840 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
18841 where a specification is an association list
18842 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
18843 keys are keywords (@code{#:keyword-example}) as shown in the example
18846 @item @code{use-substitutes?} (default: @code{#f})
18847 This allows using substitutes to avoid building every dependencies of a job
18850 @item @code{one-shot?} (default: @code{#f})
18851 Only evaluate specifications and build derivations once.
18853 @item @code{fallback?} (default: @code{#f})
18854 When substituting a pre-built binary fails, fall back to building
18857 @item @code{cuirass} (default: @code{cuirass})
18858 The Cuirass package to use.
18862 @node Power Management Services
18863 @subsubsection Power Management Services
18866 @cindex power management with TLP
18867 @subsubheading TLP daemon
18869 The @code{(gnu services pm)} module provides a Guix service definition
18870 for the Linux power management tool TLP.
18872 TLP enables various powersaving modes in userspace and kernel.
18873 Contrary to @code{upower-service}, it is not a passive,
18874 monitoring tool, as it will apply custom settings each time a new power
18875 source is detected. More information can be found at
18876 @uref{http://linrunner.de/en/tlp/tlp.html, TLP home page}.
18878 @deffn {Scheme Variable} tlp-service-type
18879 The service type for the TLP tool. Its value should be a valid
18880 TLP configuration (see below). To use the default settings, simply
18883 (service tlp-service-type)
18887 By default TLP does not need much configuration but most TLP parameters
18888 can be tweaked using @code{tlp-configuration}.
18890 Each parameter definition is preceded by its type; for example,
18891 @samp{boolean foo} indicates that the @code{foo} parameter
18892 should be specified as a boolean. Types starting with
18893 @code{maybe-} denote parameters that won't show up in TLP config file
18894 when their value is @code{'disabled}.
18896 @c The following documentation was initially generated by
18897 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
18898 @c documentation is better, so we shouldn't hesitate to edit below as
18899 @c needed. However if the change you want to make to this documentation
18900 @c can be done in an automated way, it's probably easier to change
18901 @c (generate-documentation) than to make it below and have to deal with
18902 @c the churn as TLP updates.
18904 Available @code{tlp-configuration} fields are:
18906 @deftypevr {@code{tlp-configuration} parameter} package tlp
18911 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
18912 Set to true if you wish to enable TLP.
18914 Defaults to @samp{#t}.
18918 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
18919 Default mode when no power supply can be detected. Alternatives are AC
18922 Defaults to @samp{"AC"}.
18926 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
18927 Number of seconds Linux kernel has to wait after the disk goes idle,
18928 before syncing on AC.
18930 Defaults to @samp{0}.
18934 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
18935 Same as @code{disk-idle-ac} but on BAT mode.
18937 Defaults to @samp{2}.
18941 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
18942 Dirty pages flushing periodicity, expressed in seconds.
18944 Defaults to @samp{15}.
18948 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
18949 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
18951 Defaults to @samp{60}.
18955 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
18956 CPU frequency scaling governor on AC mode. With intel_pstate driver,
18957 alternatives are powersave and performance. With acpi-cpufreq driver,
18958 alternatives are ondemand, powersave, performance and conservative.
18960 Defaults to @samp{disabled}.
18964 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
18965 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
18967 Defaults to @samp{disabled}.
18971 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
18972 Set the min available frequency for the scaling governor on AC.
18974 Defaults to @samp{disabled}.
18978 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
18979 Set the max available frequency for the scaling governor on AC.
18981 Defaults to @samp{disabled}.
18985 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
18986 Set the min available frequency for the scaling governor on BAT.
18988 Defaults to @samp{disabled}.
18992 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
18993 Set the max available frequency for the scaling governor on BAT.
18995 Defaults to @samp{disabled}.
18999 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
19000 Limit the min P-state to control the power dissipation of the CPU, in AC
19001 mode. Values are stated as a percentage of the available performance.
19003 Defaults to @samp{disabled}.
19007 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
19008 Limit the max P-state to control the power dissipation of the CPU, in AC
19009 mode. Values are stated as a percentage of the available performance.
19011 Defaults to @samp{disabled}.
19015 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
19016 Same as @code{cpu-min-perf-on-ac} on BAT mode.
19018 Defaults to @samp{disabled}.
19022 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
19023 Same as @code{cpu-max-perf-on-ac} on BAT mode.
19025 Defaults to @samp{disabled}.
19029 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
19030 Enable CPU turbo boost feature on AC mode.
19032 Defaults to @samp{disabled}.
19036 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
19037 Same as @code{cpu-boost-on-ac?} on BAT mode.
19039 Defaults to @samp{disabled}.
19043 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
19044 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
19045 used under light load conditions.
19047 Defaults to @samp{#f}.
19051 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
19052 Same as @code{sched-powersave-on-ac?} but on BAT mode.
19054 Defaults to @samp{#t}.
19058 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
19059 Enable Linux kernel NMI watchdog.
19061 Defaults to @samp{#f}.
19065 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
19066 For Linux kernels with PHC patch applied, change CPU voltages. An
19067 example value would be @samp{"F:V F:V F:V F:V"}.
19069 Defaults to @samp{disabled}.
19073 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
19074 Set CPU performance versus energy saving policy on AC. Alternatives are
19075 performance, normal, powersave.
19077 Defaults to @samp{"performance"}.
19081 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
19082 Same as @code{energy-perf-policy-ac} but on BAT mode.
19084 Defaults to @samp{"powersave"}.
19088 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
19093 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
19094 Hard disk advanced power management level.
19098 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
19099 Same as @code{disk-apm-bat} but on BAT mode.
19103 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
19104 Hard disk spin down timeout. One value has to be specified for each
19105 declared hard disk.
19107 Defaults to @samp{disabled}.
19111 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
19112 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
19114 Defaults to @samp{disabled}.
19118 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
19119 Select IO scheduler for disk devices. One value has to be specified for
19120 each declared hard disk. Example alternatives are cfq, deadline and
19123 Defaults to @samp{disabled}.
19127 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
19128 SATA aggressive link power management (ALPM) level. Alternatives are
19129 min_power, medium_power, max_performance.
19131 Defaults to @samp{"max_performance"}.
19135 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
19136 Same as @code{sata-linkpwr-ac} but on BAT mode.
19138 Defaults to @samp{"min_power"}.
19142 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
19143 Exclude specified SATA host devices for link power management.
19145 Defaults to @samp{disabled}.
19149 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
19150 Enable Runtime Power Management for AHCI controller and disks on AC
19153 Defaults to @samp{disabled}.
19157 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
19158 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
19160 Defaults to @samp{disabled}.
19164 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
19165 Seconds of inactivity before disk is suspended.
19167 Defaults to @samp{15}.
19171 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
19172 PCI Express Active State Power Management level. Alternatives are
19173 default, performance, powersave.
19175 Defaults to @samp{"performance"}.
19179 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
19180 Same as @code{pcie-aspm-ac} but on BAT mode.
19182 Defaults to @samp{"powersave"}.
19186 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
19187 Radeon graphics clock speed level. Alternatives are low, mid, high,
19190 Defaults to @samp{"high"}.
19194 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
19195 Same as @code{radeon-power-ac} but on BAT mode.
19197 Defaults to @samp{"low"}.
19201 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
19202 Radeon dynamic power management method (DPM). Alternatives are battery,
19205 Defaults to @samp{"performance"}.
19209 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
19210 Same as @code{radeon-dpm-state-ac} but on BAT mode.
19212 Defaults to @samp{"battery"}.
19216 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
19217 Radeon DPM performance level. Alternatives are auto, low, high.
19219 Defaults to @samp{"auto"}.
19223 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
19224 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
19226 Defaults to @samp{"auto"}.
19230 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
19231 Wifi power saving mode.
19233 Defaults to @samp{#f}.
19237 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
19238 Same as @code{wifi-power-ac?} but on BAT mode.
19240 Defaults to @samp{#t}.
19244 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
19245 Disable wake on LAN.
19247 Defaults to @samp{#t}.
19251 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
19252 Timeout duration in seconds before activating audio power saving on
19253 Intel HDA and AC97 devices. A value of 0 disables power saving.
19255 Defaults to @samp{0}.
19259 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
19260 Same as @code{sound-powersave-ac} but on BAT mode.
19262 Defaults to @samp{1}.
19266 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
19267 Disable controller in powersaving mode on Intel HDA devices.
19269 Defaults to @samp{#t}.
19273 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
19274 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
19275 powered on again by releasing (and reinserting) the eject lever or by
19276 pressing the disc eject button on newer models.
19278 Defaults to @samp{#f}.
19282 @deftypevr {@code{tlp-configuration} parameter} string bay-device
19283 Name of the optical drive device to power off.
19285 Defaults to @samp{"sr0"}.
19289 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
19290 Runtime Power Management for PCI(e) bus devices. Alternatives are on
19293 Defaults to @samp{"on"}.
19297 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
19298 Same as @code{runtime-pm-ac} but on BAT mode.
19300 Defaults to @samp{"auto"}.
19304 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
19305 Runtime Power Management for all PCI(e) bus devices, except blacklisted
19308 Defaults to @samp{#t}.
19312 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
19313 Exclude specified PCI(e) device addresses from Runtime Power Management.
19315 Defaults to @samp{disabled}.
19319 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
19320 Exclude PCI(e) devices assigned to the specified drivers from Runtime
19325 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
19326 Enable USB autosuspend feature.
19328 Defaults to @samp{#t}.
19332 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
19333 Exclude specified devices from USB autosuspend.
19335 Defaults to @samp{disabled}.
19339 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
19340 Exclude WWAN devices from USB autosuspend.
19342 Defaults to @samp{#t}.
19346 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
19347 Include specified devices into USB autosuspend, even if they are already
19348 excluded by the driver or via @code{usb-blacklist-wwan?}.
19350 Defaults to @samp{disabled}.
19354 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
19355 Enable USB autosuspend before shutdown.
19357 Defaults to @samp{disabled}.
19361 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
19362 Restore radio device state (bluetooth, wifi, wwan) from previous
19363 shutdown on system startup.
19365 Defaults to @samp{#f}.
19370 @cindex CPU frequency scaling with thermald
19371 @subsubheading Thermald daemon
19373 The @code{(gnu services pm)} module provides an interface to
19374 thermald, a CPU frequency scaling service which helps prevent overheating.
19376 @defvr {Scheme Variable} thermald-service-type
19377 This is the service type for
19378 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
19379 Thermal Daemon, which is responsible for controlling the thermal state
19380 of processors and preventing overheating.
19383 @deftp {Data Type} thermald-configuration
19384 Data type representing the configuration of @code{thermald-service-type}.
19387 @item @code{ignore-cpuid-check?} (default: @code{#f})
19388 Ignore cpuid check for supported CPU models.
19390 @item @code{thermald} (default: @var{thermald})
19391 Package object of thermald.
19396 @node Audio Services
19397 @subsubsection Audio Services
19399 The @code{(gnu services audio)} module provides a service to start MPD
19400 (the Music Player Daemon).
19403 @subsubheading Music Player Daemon
19405 The Music Player Daemon (MPD) is a service that can play music while
19406 being controlled from the local machine or over the network by a variety
19409 The following example shows how one might run @code{mpd} as user
19410 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
19413 (service mpd-service-type
19419 @defvr {Scheme Variable} mpd-service-type
19420 The service type for @command{mpd}
19423 @deftp {Data Type} mpd-configuration
19424 Data type representing the configuration of @command{mpd}.
19427 @item @code{user} (default: @code{"mpd"})
19428 The user to run mpd as.
19430 @item @code{music-dir} (default: @code{"~/Music"})
19431 The directory to scan for music files.
19433 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
19434 The directory to store playlists.
19436 @item @code{port} (default: @code{"6600"})
19437 The port to run mpd on.
19439 @item @code{address} (default: @code{"any"})
19440 The address that mpd will bind to. To use a Unix domain socket,
19441 an absolute path can be specified here.
19446 @node Virtualization Services
19447 @subsubsection Virtualization services
19449 The @code{(gnu services virtualization)} module provides services for
19450 the libvirt and virtlog daemons, as well as other virtualization-related
19453 @subsubheading Libvirt daemon
19454 @code{libvirtd} is the server side daemon component of the libvirt
19455 virtualization management system. This daemon runs on host servers
19456 and performs required management tasks for virtualized guests.
19458 @deffn {Scheme Variable} libvirt-service-type
19459 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
19460 Its value must be a @code{libvirt-configuration}.
19463 (service libvirt-service-type
19464 (libvirt-configuration
19465 (unix-sock-group "libvirt")
19466 (tls-port "16555")))
19470 @c Auto-generated with (generate-libvirt-documentation)
19471 Available @code{libvirt-configuration} fields are:
19473 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
19478 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
19479 Flag listening for secure TLS connections on the public TCP/IP port.
19480 must set @code{listen} for this to have any effect.
19482 It is necessary to setup a CA and issue server certificates before using
19485 Defaults to @samp{#t}.
19489 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
19490 Listen for unencrypted TCP connections on the public TCP/IP port. must
19491 set @code{listen} for this to have any effect.
19493 Using the TCP socket requires SASL authentication by default. Only SASL
19494 mechanisms which support data encryption are allowed. This is
19495 DIGEST_MD5 and GSSAPI (Kerberos5)
19497 Defaults to @samp{#f}.
19501 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
19502 Port for accepting secure TLS connections This can be a port number, or
19505 Defaults to @samp{"16514"}.
19509 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
19510 Port for accepting insecure TCP connections This can be a port number,
19513 Defaults to @samp{"16509"}.
19517 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
19518 IP address or hostname used for client connections.
19520 Defaults to @samp{"0.0.0.0"}.
19524 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
19525 Flag toggling mDNS advertisement of the libvirt service.
19527 Alternatively can disable for all services on a host by stopping the
19530 Defaults to @samp{#f}.
19534 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
19535 Default mDNS advertisement name. This must be unique on the immediate
19538 Defaults to @samp{"Virtualization Host <hostname>"}.
19542 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
19543 UNIX domain socket group ownership. This can be used to allow a
19544 'trusted' set of users access to management capabilities without
19547 Defaults to @samp{"root"}.
19551 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
19552 UNIX socket permissions for the R/O socket. This is used for monitoring
19555 Defaults to @samp{"0777"}.
19559 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
19560 UNIX socket permissions for the R/W socket. Default allows only root.
19561 If PolicyKit is enabled on the socket, the default will change to allow
19562 everyone (eg, 0777)
19564 Defaults to @samp{"0770"}.
19568 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
19569 UNIX socket permissions for the admin socket. Default allows only owner
19570 (root), do not change it unless you are sure to whom you are exposing
19573 Defaults to @samp{"0777"}.
19577 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
19578 The directory in which sockets will be found/created.
19580 Defaults to @samp{"/var/run/libvirt"}.
19584 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
19585 Authentication scheme for UNIX read-only sockets. By default socket
19586 permissions allow anyone to connect
19588 Defaults to @samp{"polkit"}.
19592 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
19593 Authentication scheme for UNIX read-write sockets. By default socket
19594 permissions only allow root. If PolicyKit support was compiled into
19595 libvirt, the default will be to use 'polkit' auth.
19597 Defaults to @samp{"polkit"}.
19601 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
19602 Authentication scheme for TCP sockets. If you don't enable SASL, then
19603 all TCP traffic is cleartext. Don't do this outside of a dev/test
19606 Defaults to @samp{"sasl"}.
19610 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
19611 Authentication scheme for TLS sockets. TLS sockets already have
19612 encryption provided by the TLS layer, and limited authentication is done
19615 It is possible to make use of any SASL authentication mechanism as well,
19616 by using 'sasl' for this option
19618 Defaults to @samp{"none"}.
19622 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
19623 API access control scheme.
19625 By default an authenticated user is allowed access to all APIs. Access
19626 drivers can place restrictions on this.
19628 Defaults to @samp{()}.
19632 @deftypevr {@code{libvirt-configuration} parameter} string key-file
19633 Server key file path. If set to an empty string, then no private key is
19636 Defaults to @samp{""}.
19640 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
19641 Server key file path. If set to an empty string, then no certificate is
19644 Defaults to @samp{""}.
19648 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
19649 Server key file path. If set to an empty string, then no CA certificate
19652 Defaults to @samp{""}.
19656 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
19657 Certificate revocation list path. If set to an empty string, then no
19660 Defaults to @samp{""}.
19664 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
19665 Disable verification of our own server certificates.
19667 When libvirtd starts it performs some sanity checks against its own
19670 Defaults to @samp{#f}.
19674 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
19675 Disable verification of client certificates.
19677 Client certificate verification is the primary authentication mechanism.
19678 Any client which does not present a certificate signed by the CA will be
19681 Defaults to @samp{#f}.
19685 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
19686 Whitelist of allowed x509 Distinguished Name.
19688 Defaults to @samp{()}.
19692 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
19693 Whitelist of allowed SASL usernames. The format for username depends on
19694 the SASL authentication mechanism.
19696 Defaults to @samp{()}.
19700 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
19701 Override the compile time default TLS priority string. The default is
19702 usually "NORMAL" unless overridden at build time. Only set this is it
19703 is desired for libvirt to deviate from the global default settings.
19705 Defaults to @samp{"NORMAL"}.
19709 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
19710 Maximum number of concurrent client connections to allow over all
19713 Defaults to @samp{5000}.
19717 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
19718 Maximum length of queue of connections waiting to be accepted by the
19719 daemon. Note, that some protocols supporting retransmission may obey
19720 this so that a later reattempt at connection succeeds.
19722 Defaults to @samp{1000}.
19726 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
19727 Maximum length of queue of accepted but not yet authenticated clients.
19728 Set this to zero to turn this feature off
19730 Defaults to @samp{20}.
19734 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
19735 Number of workers to start up initially.
19737 Defaults to @samp{5}.
19741 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
19742 Maximum number of worker threads.
19744 If the number of active clients exceeds @code{min-workers}, then more
19745 threads are spawned, up to max_workers limit. Typically you'd want
19746 max_workers to equal maximum number of clients allowed.
19748 Defaults to @samp{20}.
19752 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
19753 Number of priority workers. If all workers from above pool are stuck,
19754 some calls marked as high priority (notably domainDestroy) can be
19755 executed in this pool.
19757 Defaults to @samp{5}.
19761 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
19762 Total global limit on concurrent RPC calls.
19764 Defaults to @samp{20}.
19768 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
19769 Limit on concurrent requests from a single client connection. To avoid
19770 one client monopolizing the server this should be a small fraction of
19771 the global max_requests and max_workers parameter.
19773 Defaults to @samp{5}.
19777 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
19778 Same as @code{min-workers} but for the admin interface.
19780 Defaults to @samp{1}.
19784 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
19785 Same as @code{max-workers} but for the admin interface.
19787 Defaults to @samp{5}.
19791 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
19792 Same as @code{max-clients} but for the admin interface.
19794 Defaults to @samp{5}.
19798 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
19799 Same as @code{max-queued-clients} but for the admin interface.
19801 Defaults to @samp{5}.
19805 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
19806 Same as @code{max-client-requests} but for the admin interface.
19808 Defaults to @samp{5}.
19812 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
19813 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
19815 Defaults to @samp{3}.
19819 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
19822 A filter allows to select a different logging level for a given category
19823 of logs The format for a filter is one of:
19834 where @code{name} is a string which is matched against the category
19835 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
19836 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
19837 be a substring of the full category name, in order to match multiple
19838 similar categories), the optional "+" prefix tells libvirt to log stack
19839 trace for each message matching name, and @code{x} is the minimal level
19840 where matching messages should be logged:
19857 Multiple filters can be defined in a single filters statement, they just
19858 need to be separated by spaces.
19860 Defaults to @samp{"3:remote 4:event"}.
19864 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
19867 An output is one of the places to save logging information The format
19868 for an output can be:
19872 output goes to stderr
19874 @item x:syslog:name
19875 use syslog for the output and use the given name as the ident
19877 @item x:file:file_path
19878 output to a file, with the given filepath
19881 output to journald logging system
19885 In all case the x prefix is the minimal level, acting as a filter
19902 Multiple outputs can be defined, they just need to be separated by
19905 Defaults to @samp{"3:stderr"}.
19909 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
19910 Allows usage of the auditing subsystem to be altered
19914 0: disable all auditing
19917 1: enable auditing, only if enabled on host
19920 2: enable auditing, and exit if disabled on host.
19924 Defaults to @samp{1}.
19928 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
19929 Send audit messages via libvirt logging infrastructure.
19931 Defaults to @samp{#f}.
19935 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
19936 Host UUID. UUID must not have all digits be the same.
19938 Defaults to @samp{""}.
19942 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
19943 Source to read host UUID.
19947 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
19950 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
19954 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
19957 Defaults to @samp{"smbios"}.
19961 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
19962 A keepalive message is sent to a client after @code{keepalive_interval}
19963 seconds of inactivity to check if the client is still responding. If
19964 set to -1, libvirtd will never send keepalive requests; however clients
19965 can still send them and the daemon will send responses.
19967 Defaults to @samp{5}.
19971 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
19972 Maximum number of keepalive messages that are allowed to be sent to the
19973 client without getting any response before the connection is considered
19976 In other words, the connection is automatically closed approximately
19977 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
19978 the last message received from the client. When @code{keepalive-count}
19979 is set to 0, connections will be automatically closed after
19980 @code{keepalive-interval} seconds of inactivity without sending any
19981 keepalive messages.
19983 Defaults to @samp{5}.
19987 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
19988 Same as above but for admin interface.
19990 Defaults to @samp{5}.
19994 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
19995 Same as above but for admin interface.
19997 Defaults to @samp{5}.
20001 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
20002 Timeout for Open vSwitch calls.
20004 The @code{ovs-vsctl} utility is used for the configuration and its
20005 timeout option is set by default to 5 seconds to avoid potential
20006 infinite waits blocking libvirt.
20008 Defaults to @samp{5}.
20012 @c %end of autogenerated docs
20014 @subsubheading Virtlog daemon
20015 The virtlogd service is a server side daemon component of libvirt that is
20016 used to manage logs from virtual machine consoles.
20018 This daemon is not used directly by libvirt client applications, rather it
20019 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
20020 standalone daemon, the main @code{libvirtd} daemon can be restarted without
20021 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
20022 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
20024 @deffn {Scheme Variable} virtlog-service-type
20025 This is the type of the virtlog daemon.
20026 Its value must be a @code{virtlog-configuration}.
20029 (service virtlog-service-type
20030 (virtlog-configuration
20031 (max-clients 1000)))
20035 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
20036 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
20038 Defaults to @samp{3}.
20042 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
20045 A filter allows to select a different logging level for a given category
20046 of logs The format for a filter is one of:
20057 where @code{name} is a string which is matched against the category
20058 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
20059 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
20060 be a substring of the full category name, in order to match multiple
20061 similar categories), the optional "+" prefix tells libvirt to log stack
20062 trace for each message matching name, and @code{x} is the minimal level
20063 where matching messages should be logged:
20080 Multiple filters can be defined in a single filters statement, they just
20081 need to be separated by spaces.
20083 Defaults to @samp{"3:remote 4:event"}.
20087 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
20090 An output is one of the places to save logging information The format
20091 for an output can be:
20095 output goes to stderr
20097 @item x:syslog:name
20098 use syslog for the output and use the given name as the ident
20100 @item x:file:file_path
20101 output to a file, with the given filepath
20104 output to journald logging system
20108 In all case the x prefix is the minimal level, acting as a filter
20125 Multiple outputs can be defined, they just need to be separated by
20128 Defaults to @samp{"3:stderr"}.
20132 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
20133 Maximum number of concurrent client connections to allow over all
20136 Defaults to @samp{1024}.
20140 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
20141 Maximum file size before rolling over.
20143 Defaults to @samp{2MB}
20147 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
20148 Maximum number of backup files to keep.
20150 Defaults to @samp{3}
20154 @subsubheading Transparent Emulation with QEMU
20157 @cindex @code{binfmt_misc}
20158 @code{qemu-binfmt-service-type} provides support for transparent
20159 emulation of program binaries built for different architectures---e.g.,
20160 it allows you to transparently execute an ARMv7 program on an x86_64
20161 machine. It achieves this by combining the @uref{https://www.qemu.org,
20162 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
20164 @defvr {Scheme Variable} qemu-binfmt-service-type
20165 This is the type of the QEMU/binfmt service for transparent emulation.
20166 Its value must be a @code{qemu-binfmt-configuration} object, which
20167 specifies the QEMU package to use as well as the architecture we want to
20171 (service qemu-binfmt-service-type
20172 (qemu-binfmt-configuration
20173 (platforms (lookup-qemu-platforms "arm" "aarch64" "ppc"))))
20176 In this example, we enable transparent emulation for the ARM and aarch64
20177 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
20178 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
20179 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
20182 @deftp {Data Type} qemu-binfmt-configuration
20183 This is the configuration for the @code{qemu-binfmt} service.
20186 @item @code{platforms} (default: @code{'()})
20187 The list of emulated QEMU platforms. Each item must be a @dfn{platform
20188 object} as returned by @code{lookup-qemu-platforms} (see below).
20190 @item @code{guix-support?} (default: @code{#f})
20191 When it is true, QEMU and all its dependencies are added to the build
20192 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
20193 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
20194 handlers to be used within the build environment, which in turn means
20195 that you can transparently build programs for another architecture.
20197 For example, let's suppose you're on an x86_64 machine and you have this
20201 (service qemu-binfmt-service-type
20202 (qemu-binfmt-configuration
20203 (platforms (lookup-qemu-platforms "arm"))
20204 (guix-support? #t)))
20210 guix build -s armhf-linux inkscape
20214 and it will build Inkscape for ARMv7 @emph{as if it were a native
20215 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
20216 if you'd like to test a package build for an architecture you don't have
20219 @item @code{qemu} (default: @code{qemu})
20220 The QEMU package to use.
20224 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
20225 Return the list of QEMU platform objects corresponding to
20226 @var{platforms}@dots{}. @var{platforms} must be a list of strings
20227 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
20228 @code{"mips64el"}, and so on.
20231 @deffn {Scheme Procedure} qemu-platform? @var{obj}
20232 Return true if @var{obj} is a platform object.
20235 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
20236 Return the name of @var{platform}---a string such as @code{"arm"}.
20239 @node Version Control Services
20240 @subsubsection Version Control Services
20242 The @code{(gnu services version-control)} module provides a service to
20243 allow remote access to local Git repositories. There are three options:
20244 the @code{git-daemon-service}, which provides access to repositories via
20245 the @code{git://} unsecured TCP-based protocol, extending the
20246 @code{nginx} web server to proxy some requests to
20247 @code{git-http-backend}, or providing a web interface with
20248 @code{cgit-service-type}.
20250 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
20252 Return a service that runs @command{git daemon}, a simple TCP server to
20253 expose repositories over the Git protocol for anonymous access.
20255 The optional @var{config} argument should be a
20256 @code{<git-daemon-configuration>} object, by default it allows read-only
20257 access to exported@footnote{By creating the magic file
20258 "git-daemon-export-ok" in the repository directory.} repositories under
20263 @deftp {Data Type} git-daemon-configuration
20264 Data type representing the configuration for @code{git-daemon-service}.
20267 @item @code{package} (default: @var{git})
20268 Package object of the Git distributed version control system.
20270 @item @code{export-all?} (default: @var{#f})
20271 Whether to allow access for all Git repositories, even if they do not
20272 have the @file{git-daemon-export-ok} file.
20274 @item @code{base-path} (default: @file{/srv/git})
20275 Whether to remap all the path requests as relative to the given path.
20276 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
20277 then if you later try to pull @code{git://example.com/hello.git}, git
20278 daemon will interpret the path as @code{/srv/git/hello.git}.
20280 @item @code{user-path} (default: @var{#f})
20281 Whether to allow @code{~user} notation to be used in requests. When
20282 specified with empty string, requests to @code{git://host/~alice/foo} is
20283 taken as a request to access @code{foo} repository in the home directory
20284 of user @code{alice}. If @var{(user-path "path")} is specified, the
20285 same request is taken as a request to access @code{path/foo} repository
20286 in the home directory of user @code{alice}.
20288 @item @code{listen} (default: @var{'()})
20289 Whether to listen on specific IP addresses or hostnames, defaults to
20292 @item @code{port} (default: @var{#f})
20293 Whether to listen on an alternative port, which defaults to 9418.
20295 @item @code{whitelist} (default: @var{'()})
20296 If not empty, only allow access to this list of directories.
20298 @item @code{extra-options} (default: @var{'()})
20299 Extra options will be passed to @code{git daemon}, please run
20300 @command{man git-daemon} for more information.
20305 The @code{git://} protocol lacks authentication. When you pull from a
20306 repository fetched via @code{git://}, you don't know that the data you
20307 receive was modified is really coming from the specified host, and you
20308 have your connection is subject to eavesdropping. It's better to use an
20309 authenticated and encrypted transport, such as @code{https}. Although Git allows you
20310 to serve repositories using unsophisticated file-based web servers,
20311 there is a faster protocol implemented by the @code{git-http-backend}
20312 program. This program is the back-end of a proper Git web service. It
20313 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
20314 on running the necessary @code{fcgiwrap} daemon.
20316 Guix has a separate configuration data type for serving Git repositories
20319 @deftp {Data Type} git-http-configuration
20320 Data type representing the configuration for @code{git-http-service}.
20323 @item @code{package} (default: @var{git})
20324 Package object of the Git distributed version control system.
20326 @item @code{git-root} (default: @file{/srv/git})
20327 Directory containing the Git repositories to expose to the world.
20329 @item @code{export-all?} (default: @var{#f})
20330 Whether to expose access for all Git repositories in @var{git-root},
20331 even if they do not have the @file{git-daemon-export-ok} file.
20333 @item @code{uri-path} (default: @file{/git/})
20334 Path prefix for Git access. With the default @code{/git/} prefix, this
20335 will map @code{http://@var{server}/git/@var{repo}.git} to
20336 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
20337 with this prefix are not passed on to this Git instance.
20339 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
20340 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
20345 There is no @code{git-http-service-type}, currently; instead you can
20346 create an @code{nginx-location-configuration} from a
20347 @code{git-http-configuration} and then add that location to a web
20350 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
20351 [config=(git-http-configuration)]
20352 Compute an @code{nginx-location-configuration} that corresponds to the
20353 given Git http configuration. An example nginx service definition to
20354 serve the default @file{/srv/git} over HTTPS might be:
20357 (service nginx-service-type
20358 (nginx-configuration
20361 (nginx-server-configuration
20362 (listen '("443 ssl"))
20363 (server-name "git.my-host.org")
20365 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
20366 (ssl-certificate-key
20367 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
20370 (git-http-nginx-location-configuration
20371 (git-http-configuration (uri-path "/"))))))))))
20374 This example assumes that you are using Let's Encrypt to get your TLS
20375 certificate. @xref{Certificate Services}. The default @code{certbot}
20376 service will redirect all HTTP traffic on @code{git.my-host.org} to
20377 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
20378 system services. @xref{Web Services}.
20381 @subsubheading Cgit Service
20383 @cindex Cgit service
20384 @cindex Git, web interface
20385 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
20386 repositories written in C.
20388 The following example will configure the service with default values.
20389 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
20392 (service cgit-service-type)
20395 The @code{file-object} type designates either a file-like object
20396 (@pxref{G-Expressions, file-like objects}) or a string.
20398 @c %start of fragment
20400 Available @code{cgit-configuration} fields are:
20402 @deftypevr {@code{cgit-configuration} parameter} package package
20407 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
20408 NGINX configuration.
20412 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
20413 Specifies a command which will be invoked to format the content of about
20414 pages (both top-level and for each repository).
20416 Defaults to @samp{""}.
20420 @deftypevr {@code{cgit-configuration} parameter} string agefile
20421 Specifies a path, relative to each repository path, which can be used to
20422 specify the date and time of the youngest commit in the repository.
20424 Defaults to @samp{""}.
20428 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
20429 Specifies a command that will be invoked for authenticating repository
20432 Defaults to @samp{""}.
20436 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
20437 Flag which, when set to @samp{age}, enables date ordering in the branch
20438 ref list, and when set @samp{name} enables ordering by branch name.
20440 Defaults to @samp{"name"}.
20444 @deftypevr {@code{cgit-configuration} parameter} string cache-root
20445 Path used to store the cgit cache entries.
20447 Defaults to @samp{"/var/cache/cgit"}.
20451 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
20452 Number which specifies the time-to-live, in minutes, for the cached
20453 version of repository pages accessed with a fixed SHA1.
20455 Defaults to @samp{-1}.
20459 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
20460 Number which specifies the time-to-live, in minutes, for the cached
20461 version of repository pages accessed without a fixed SHA1.
20463 Defaults to @samp{5}.
20467 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
20468 Number which specifies the time-to-live, in minutes, for the cached
20469 version of the repository summary page.
20471 Defaults to @samp{5}.
20475 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
20476 Number which specifies the time-to-live, in minutes, for the cached
20477 version of the repository index page.
20479 Defaults to @samp{5}.
20483 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
20484 Number which specifies the time-to-live, in minutes, for the result of
20485 scanning a path for Git repositories.
20487 Defaults to @samp{15}.
20491 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
20492 Number which specifies the time-to-live, in minutes, for the cached
20493 version of the repository about page.
20495 Defaults to @samp{15}.
20499 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
20500 Number which specifies the time-to-live, in minutes, for the cached
20501 version of snapshots.
20503 Defaults to @samp{5}.
20507 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
20508 The maximum number of entries in the cgit cache. When set to @samp{0},
20509 caching is disabled.
20511 Defaults to @samp{0}.
20515 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
20516 Sort items in the repo list case sensitively.
20518 Defaults to @samp{#t}.
20522 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
20523 List of common prefixes which, when combined with a repository URL,
20524 generates valid clone URLs for the repository.
20526 Defaults to @samp{()}.
20530 @deftypevr {@code{cgit-configuration} parameter} list clone-url
20531 List of @code{clone-url} templates.
20533 Defaults to @samp{()}.
20537 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
20538 Command which will be invoked to format commit messages.
20540 Defaults to @samp{""}.
20544 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
20545 Flag which, when set to @samp{date}, enables strict date ordering in the
20546 commit log, and when set to @samp{topo} enables strict topological
20549 Defaults to @samp{"git log"}.
20553 @deftypevr {@code{cgit-configuration} parameter} file-object css
20554 URL which specifies the css document to include in all cgit pages.
20556 Defaults to @samp{"/share/cgit/cgit.css"}.
20560 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
20561 Specifies a command which will be invoked to format names and email
20562 address of committers, authors, and taggers, as represented in various
20563 places throughout the cgit interface.
20565 Defaults to @samp{""}.
20569 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
20570 Flag which, when set to @samp{#t}, will make cgit generate a HTML
20571 fragment suitable for embedding in other HTML pages.
20573 Defaults to @samp{#f}.
20577 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
20578 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
20579 commit history graph to the left of the commit messages in the
20580 repository log page.
20582 Defaults to @samp{#f}.
20586 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
20587 Flag which, when set to @samp{#t}, allows all filter settings to be
20588 overridden in repository-specific cgitrc files.
20590 Defaults to @samp{#f}.
20594 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
20595 Flag which, when set to @samp{#t}, allows users to follow a file in the
20598 Defaults to @samp{#f}.
20602 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
20603 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
20606 Defaults to @samp{#t}.
20610 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
20611 Flag which, when set to @samp{#t}, will make cgit generate extra links
20612 "summary", "commit", "tree" for each repo in the repository index.
20614 Defaults to @samp{#f}.
20618 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
20619 Flag which, when set to @samp{#t}, will make cgit display the owner of
20620 each repo in the repository index.
20622 Defaults to @samp{#t}.
20626 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
20627 Flag which, when set to @samp{#t}, will make cgit print the number of
20628 modified files for each commit on the repository log page.
20630 Defaults to @samp{#f}.
20634 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
20635 Flag which, when set to @samp{#t}, will make cgit print the number of
20636 added and removed lines for each commit on the repository log page.
20638 Defaults to @samp{#f}.
20642 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
20643 Flag which, when set to @code{#t}, will make cgit display remote
20644 branches in the summary and refs views.
20646 Defaults to @samp{#f}.
20650 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
20651 Flag which, when set to @code{1}, will make cgit use the subject of the
20652 parent commit as link text when generating links to parent commits in
20655 Defaults to @samp{#f}.
20659 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
20660 Flag which, when set to @samp{#t}, will make cgit use the subject of the
20661 parent commit as link text when generating links to parent commits in
20664 Defaults to @samp{#f}.
20668 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
20669 Flag which, when set to @samp{#t}, will make cgit generate linenumber
20670 links for plaintext blobs printed in the tree view.
20672 Defaults to @samp{#t}.
20676 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
20677 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
20678 set any repo specific settings.
20680 Defaults to @samp{#f}.
20684 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
20685 URL used as link to a shortcut icon for cgit.
20687 Defaults to @samp{"/favicon.ico"}.
20691 @deftypevr {@code{cgit-configuration} parameter} string footer
20692 The content of the file specified with this option will be included
20693 verbatim at the bottom of all pages (i.e.@: it replaces the standard
20694 "generated by..."@: message).
20696 Defaults to @samp{""}.
20700 @deftypevr {@code{cgit-configuration} parameter} string head-include
20701 The content of the file specified with this option will be included
20702 verbatim in the HTML HEAD section on all pages.
20704 Defaults to @samp{""}.
20708 @deftypevr {@code{cgit-configuration} parameter} string header
20709 The content of the file specified with this option will be included
20710 verbatim at the top of all pages.
20712 Defaults to @samp{""}.
20716 @deftypevr {@code{cgit-configuration} parameter} file-object include
20717 Name of a configfile to include before the rest of the current config-
20720 Defaults to @samp{""}.
20724 @deftypevr {@code{cgit-configuration} parameter} string index-header
20725 The content of the file specified with this option will be included
20726 verbatim above the repository index.
20728 Defaults to @samp{""}.
20732 @deftypevr {@code{cgit-configuration} parameter} string index-info
20733 The content of the file specified with this option will be included
20734 verbatim below the heading on the repository index page.
20736 Defaults to @samp{""}.
20740 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
20741 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
20742 in the servers timezone.
20744 Defaults to @samp{#f}.
20748 @deftypevr {@code{cgit-configuration} parameter} file-object logo
20749 URL which specifies the source of an image which will be used as a logo
20752 Defaults to @samp{"/share/cgit/cgit.png"}.
20756 @deftypevr {@code{cgit-configuration} parameter} string logo-link
20757 URL loaded when clicking on the cgit logo image.
20759 Defaults to @samp{""}.
20763 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
20764 Command which will be invoked to format the Owner column of the main
20767 Defaults to @samp{""}.
20771 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
20772 Number of items to display in atom feeds view.
20774 Defaults to @samp{10}.
20778 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
20779 Number of entries to list per page in "log" view.
20781 Defaults to @samp{50}.
20785 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
20786 Number of commit message characters to display in "log" view.
20788 Defaults to @samp{80}.
20792 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
20793 Specifies the number of entries to list per page on the repository index
20796 Defaults to @samp{50}.
20800 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
20801 Specifies the maximum number of repo description characters to display
20802 on the repository index page.
20804 Defaults to @samp{80}.
20808 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
20809 Specifies the maximum size of a blob to display HTML for in KBytes.
20811 Defaults to @samp{0}.
20815 @deftypevr {@code{cgit-configuration} parameter} string max-stats
20816 Maximum statistics period. Valid values are @samp{week},@samp{month},
20817 @samp{quarter} and @samp{year}.
20819 Defaults to @samp{""}.
20823 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
20824 Mimetype for the specified filename extension.
20826 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
20827 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
20828 "image/png") (svg "image/svg+xml"))}.
20832 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
20833 Specifies the file to use for automatic mimetype lookup.
20835 Defaults to @samp{""}.
20839 @deftypevr {@code{cgit-configuration} parameter} string module-link
20840 Text which will be used as the formatstring for a hyperlink when a
20841 submodule is printed in a directory listing.
20843 Defaults to @samp{""}.
20847 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
20848 If set to the value @samp{#t} caching will be disabled.
20850 Defaults to @samp{#f}.
20854 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
20855 If set to @samp{#t} showing full author email addresses will be
20858 Defaults to @samp{#f}.
20862 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
20863 Flag which, when set to @samp{#t}, will make cgit omit the standard
20864 header on all pages.
20866 Defaults to @samp{#f}.
20870 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
20871 A list of subdirectories inside of @code{repository-directory}, relative
20872 to it, that should loaded as Git repositories. An empty list means that
20873 all subdirectories will be loaded.
20875 Defaults to @samp{()}.
20879 @deftypevr {@code{cgit-configuration} parameter} file-object readme
20880 Text which will be used as default value for @code{cgit-repo-readme}.
20882 Defaults to @samp{""}.
20886 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
20887 If set to @code{#t} and @code{repository-directory} is enabled, if any
20888 repositories are found with a suffix of @code{.git}, this suffix will be
20889 removed for the URL and name.
20891 Defaults to @samp{#f}.
20895 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
20896 Maximum number of files to consider when detecting renames.
20898 Defaults to @samp{-1}.
20902 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
20903 The way in which repositories in each section are sorted.
20905 Defaults to @samp{""}.
20909 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
20910 Text used as content for the @code{robots} meta-tag.
20912 Defaults to @samp{("noindex" "nofollow")}.
20916 @deftypevr {@code{cgit-configuration} parameter} string root-desc
20917 Text printed below the heading on the repository index page.
20919 Defaults to @samp{"a fast webinterface for the git dscm"}.
20923 @deftypevr {@code{cgit-configuration} parameter} string root-readme
20924 The content of the file specified with this option will be included
20925 verbatim below thef "about" link on the repository index page.
20927 Defaults to @samp{""}.
20931 @deftypevr {@code{cgit-configuration} parameter} string root-title
20932 Text printed as heading on the repository index page.
20934 Defaults to @samp{""}.
20938 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
20939 If set to @samp{#t} and repository-directory is enabled,
20940 repository-directory will recurse into directories whose name starts
20941 with a period. Otherwise, repository-directory will stay away from such
20942 directories, considered as "hidden". Note that this does not apply to
20943 the ".git" directory in non-bare repos.
20945 Defaults to @samp{#f}.
20949 @deftypevr {@code{cgit-configuration} parameter} list snapshots
20950 Text which specifies the default set of snapshot formats that cgit
20951 generates links for.
20953 Defaults to @samp{()}.
20957 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
20958 Name of the directory to scan for repositories (represents
20961 Defaults to @samp{"/srv/git"}.
20965 @deftypevr {@code{cgit-configuration} parameter} string section
20966 The name of the current repository section - all repositories defined
20967 after this option will inherit the current section name.
20969 Defaults to @samp{""}.
20973 @deftypevr {@code{cgit-configuration} parameter} string section-sort
20974 Flag which, when set to @samp{1}, will sort the sections on the
20975 repository listing by name.
20977 Defaults to @samp{""}.
20981 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
20982 A number which, if defined prior to repository-directory, specifies how
20983 many path elements from each repo path to use as a default section name.
20985 Defaults to @samp{0}.
20989 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
20990 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
20993 Defaults to @samp{#f}.
20997 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
20998 Specifies a command which will be invoked to format plaintext blobs in
21001 Defaults to @samp{""}.
21005 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
21006 Specifies the number of branches to display in the repository "summary"
21009 Defaults to @samp{10}.
21013 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
21014 Specifies the number of log entries to display in the repository
21017 Defaults to @samp{10}.
21021 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
21022 Specifies the number of tags to display in the repository "summary"
21025 Defaults to @samp{10}.
21029 @deftypevr {@code{cgit-configuration} parameter} string strict-export
21030 Filename which, if specified, needs to be present within the repository
21031 for cgit to allow access to that repository.
21033 Defaults to @samp{""}.
21037 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
21038 URL which, if specified, will be used as root for all cgit links.
21040 Defaults to @samp{"/"}.
21044 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
21045 A list of @dfn{cgit-repo} records to use with config.
21047 Defaults to @samp{()}.
21049 Available @code{repository-cgit-configuration} fields are:
21051 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
21052 A mask of snapshot formats for this repo that cgit generates links for,
21053 restricted by the global @code{snapshots} setting.
21055 Defaults to @samp{()}.
21059 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
21060 Override the default @code{source-filter}.
21062 Defaults to @samp{""}.
21066 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
21067 The relative URL used to access the repository.
21069 Defaults to @samp{""}.
21073 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
21074 Override the default @code{about-filter}.
21076 Defaults to @samp{""}.
21080 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
21081 Flag which, when set to @samp{age}, enables date ordering in the branch
21082 ref list, and when set to @samp{name} enables ordering by branch name.
21084 Defaults to @samp{""}.
21088 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
21089 A list of URLs which can be used to clone repo.
21091 Defaults to @samp{()}.
21095 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
21096 Override the default @code{commit-filter}.
21098 Defaults to @samp{""}.
21102 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
21103 Flag which, when set to @samp{date}, enables strict date ordering in the
21104 commit log, and when set to @samp{topo} enables strict topological
21107 Defaults to @samp{""}.
21111 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
21112 The name of the default branch for this repository. If no such branch
21113 exists in the repository, the first branch name (when sorted) is used as
21114 default instead. By default branch pointed to by HEAD, or "master" if
21115 there is no suitable HEAD.
21117 Defaults to @samp{""}.
21121 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
21122 The value to show as repository description.
21124 Defaults to @samp{""}.
21128 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
21129 The value to show as repository homepage.
21131 Defaults to @samp{""}.
21135 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
21136 Override the default @code{email-filter}.
21138 Defaults to @samp{""}.
21142 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
21143 A flag which can be used to disable the global setting
21144 @code{enable-commit-graph?}.
21146 Defaults to @samp{disabled}.
21150 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
21151 A flag which can be used to disable the global setting
21152 @code{enable-log-filecount?}.
21154 Defaults to @samp{disabled}.
21158 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
21159 A flag which can be used to disable the global setting
21160 @code{enable-log-linecount?}.
21162 Defaults to @samp{disabled}.
21166 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
21167 Flag which, when set to @code{#t}, will make cgit display remote
21168 branches in the summary and refs views.
21170 Defaults to @samp{disabled}.
21174 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
21175 A flag which can be used to override the global setting
21176 @code{enable-subject-links?}.
21178 Defaults to @samp{disabled}.
21182 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
21183 A flag which can be used to override the global setting
21184 @code{enable-html-serving?}.
21186 Defaults to @samp{disabled}.
21190 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
21191 Flag which, when set to @code{#t}, hides the repository from the
21194 Defaults to @samp{#f}.
21198 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
21199 Flag which, when set to @samp{#t}, ignores the repository.
21201 Defaults to @samp{#f}.
21205 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
21206 URL which specifies the source of an image which will be used as a logo
21207 on this repo’s pages.
21209 Defaults to @samp{""}.
21213 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
21214 URL loaded when clicking on the cgit logo image.
21216 Defaults to @samp{""}.
21220 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
21221 Override the default @code{owner-filter}.
21223 Defaults to @samp{""}.
21227 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
21228 Text which will be used as the formatstring for a hyperlink when a
21229 submodule is printed in a directory listing. The arguments for the
21230 formatstring are the path and SHA1 of the submodule commit.
21232 Defaults to @samp{""}.
21236 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
21237 Text which will be used as the formatstring for a hyperlink when a
21238 submodule with the specified subdirectory path is printed in a directory
21241 Defaults to @samp{()}.
21245 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
21246 Override the default maximum statistics period.
21248 Defaults to @samp{""}.
21252 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
21253 The value to show as repository name.
21255 Defaults to @samp{""}.
21259 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
21260 A value used to identify the owner of the repository.
21262 Defaults to @samp{""}.
21266 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
21267 An absolute path to the repository directory.
21269 Defaults to @samp{""}.
21273 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
21274 A path (relative to repo) which specifies a file to include verbatim as
21275 the "About" page for this repo.
21277 Defaults to @samp{""}.
21281 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
21282 The name of the current repository section - all repositories defined
21283 after this option will inherit the current section name.
21285 Defaults to @samp{""}.
21289 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
21290 Extra options will be appended to cgitrc file.
21292 Defaults to @samp{()}.
21298 @deftypevr {@code{cgit-configuration} parameter} list extra-options
21299 Extra options will be appended to cgitrc file.
21301 Defaults to @samp{()}.
21306 @c %end of fragment
21308 However, it could be that you just want to get a @code{cgitrc} up and
21309 running. In that case, you can pass an @code{opaque-cgit-configuration}
21310 as a record to @code{cgit-service-type}. As its name indicates, an
21311 opaque configuration does not have easy reflective capabilities.
21313 Available @code{opaque-cgit-configuration} fields are:
21315 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
21319 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
21320 The contents of the @code{cgitrc}, as a string.
21323 For example, if your @code{cgitrc} is just the empty string, you
21324 could instantiate a cgit service like this:
21327 (service cgit-service-type
21328 (opaque-cgit-configuration
21332 @subsubheading Gitolite Service
21334 @cindex Gitolite service
21335 @cindex Git, hosting
21336 @uref{http://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
21337 repositories on a central server.
21339 Gitolite can handle multiple repositories and users, and supports flexible
21340 configuration of the permissions for the users on the repositories.
21342 The following example will configure Gitolite using the default @code{git}
21343 user, and the provided SSH public key.
21346 (service gitolite-service-type
21347 (gitolite-configuration
21348 (admin-pubkey (plain-file
21350 "ssh-rsa AAAA... guix@@example.com"))))
21353 Gitolite is configured through a special admin repository which you can clone,
21354 for example, if you setup Gitolite on @code{example.com}, you would run the
21355 following command to clone the admin repository.
21358 git clone git@@example.com:gitolite-admin
21361 When the Gitolite service is activated, the provided @code{admin-pubkey} will
21362 be inserted in to the @file{keydir} directory in the gitolite-admin
21363 repository. If this results in a change in the repository, it will be
21364 committed using the message ``gitolite setup by GNU Guix''.
21366 @deftp {Data Type} gitolite-configuration
21367 Data type representing the configuration for @code{gitolite-service-type}.
21370 @item @code{package} (default: @var{gitolite})
21371 Gitolite package to use.
21373 @item @code{user} (default: @var{git})
21374 User to use for Gitolite. This will be user that you use when accessing
21377 @item @code{group} (default: @var{git})
21378 Group to use for Gitolite.
21380 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
21381 Directory in which to store the Gitolite configuration and repositories.
21383 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
21384 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
21385 representing the configuration for Gitolite.
21387 @item @code{admin-pubkey} (default: @var{#f})
21388 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
21389 setup Gitolite. This will be inserted in to the @file{keydir} directory
21390 within the gitolite-admin repository.
21392 To specify the SSH key as a string, use the @code{plain-file} function.
21395 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
21401 @deftp {Data Type} gitolite-rc-file
21402 Data type representing the Gitolite RC file.
21405 @item @code{umask} (default: @code{#o0077})
21406 This controls the permissions Gitolite sets on the repositories and their
21409 A value like @code{#o0027} will give read access to the group used by Gitolite
21410 (by default: @code{git}). This is necessary when using Gitolite with software
21411 like cgit or gitweb.
21413 @item @code{git-config-keys} (default: @code{""})
21414 Gitolite allows you to set git config values using the "config" keyword. This
21415 setting allows control over the config keys to accept.
21417 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
21418 Set the role names allowed to be used by users running the perms command.
21420 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
21421 This setting controls the commands and features to enable within Gitolite.
21427 @node Game Services
21428 @subsubsection Game Services
21430 @subsubheading The Battle for Wesnoth Service
21432 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
21433 based tactical strategy game, with several single player campaigns, and
21434 multiplayer games (both networked and local).
21436 @defvar {Scheme Variable} wesnothd-service-type
21437 Service type for the wesnothd service. Its value must be a
21438 @code{wesnothd-configuration} object. To run wesnothd in the default
21439 configuration, instantiate it as:
21442 (service wesnothd-service-type)
21446 @deftp {Data Type} wesnothd-configuration
21447 Data type representing the configuration of @command{wesnothd}.
21450 @item @code{package} (default: @code{wesnoth-server})
21451 The wesnoth server package to use.
21453 @item @code{port} (default: @code{15000})
21454 The port to bind the server to.
21458 @node Miscellaneous Services
21459 @subsubsection Miscellaneous Services
21461 @cindex fingerprint
21462 @subsubheading Fingerprint Service
21464 The @code{(gnu services fingerprint)} module provides a DBus service to
21465 read and identify fingerprints via a fingerprint sensor.
21467 @defvr {Scheme Variable} fprintd-service-type
21468 The service type for @command{fprintd}, which provides the fingerprint
21469 reading capability.
21472 (service fprintd-service-type)
21477 @subsubheading System Control Service
21479 The @code{(gnu services sysctl)} provides a service to configure kernel
21480 parameters at boot.
21482 @defvr {Scheme Variable} sysctl-service-type
21483 The service type for @command{sysctl}, which modifies kernel parameters
21484 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
21488 (service sysctl-service-type
21489 (sysctl-configuration
21490 (settings '(("net.ipv4.ip_forward" . "1")))))
21494 @deftp {Data Type} sysctl-configuration
21495 The data type representing the configuration of @command{sysctl}.
21498 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
21499 The @command{sysctl} executable to use.
21501 @item @code{settings} (default: @code{'()})
21502 An association list specifies kernel parameters and their values.
21507 @subsubheading PC/SC Smart Card Daemon Service
21509 The @code{(gnu services security-token)} module provides the following service
21510 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
21511 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
21512 manager that coordinates communications with smart card readers, smart cards
21513 and cryptographic tokens that are connected to the system.
21515 @defvr {Scheme Variable} pcscd-service-type
21516 Service type for the @command{pcscd} service. Its value must be a
21517 @code{pcscd-configuration} object. To run pcscd in the default
21518 configuration, instantiate it as:
21521 (service pcscd-service-type)
21525 @deftp {Data Type} pcscd-configuration
21526 The data type representing the configuration of @command{pcscd}.
21529 @item @code{pcsc-lite} (default: @code{pcsc-lite})
21530 The pcsc-lite package that provides pcscd.
21531 @item @code{usb-drivers} (default: @code{(list ccid)})
21532 List of packages that provide USB drivers to pcscd. Drivers are expected to be
21533 under @file{pcsc/drivers} in the store directory of the package.
21538 @subsubheading Lirc Service
21540 The @code{(gnu services lirc)} module provides the following service.
21542 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
21543 [#:device #f] [#:driver #f] [#:config-file #f] @
21544 [#:extra-options '()]
21545 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
21546 decodes infrared signals from remote controls.
21548 Optionally, @var{device}, @var{driver} and @var{config-file}
21549 (configuration file name) may be specified. See @command{lircd} manual
21552 Finally, @var{extra-options} is a list of additional command-line options
21553 passed to @command{lircd}.
21557 @subsubheading Spice Service
21559 The @code{(gnu services spice)} module provides the following service.
21561 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
21562 Returns a service that runs @url{http://www.spice-space.org,VDAGENT}, a daemon
21563 that enables sharing the clipboard with a vm and setting the guest display
21564 resolution when the graphical console window resizes.
21567 @subsubsection Dictionary Services
21569 The @code{(gnu services dict)} module provides the following service:
21571 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
21572 Return a service that runs the @command{dicod} daemon, an implementation
21573 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
21575 The optional @var{config} argument specifies the configuration for
21576 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
21577 default it serves the GNU Collaborative International Dictonary of English.
21579 You can add @command{open localhost} to your @file{~/.dico} file to make
21580 @code{localhost} the default server for @command{dico} client
21581 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
21584 @deftp {Data Type} dicod-configuration
21585 Data type representing the configuration of dicod.
21588 @item @code{dico} (default: @var{dico})
21589 Package object of the GNU Dico dictionary server.
21591 @item @code{interfaces} (default: @var{'("localhost")})
21592 This is the list of IP addresses and ports and possibly socket file
21593 names to listen to (@pxref{Server Settings, @code{listen} directive,,
21594 dico, GNU Dico Manual}).
21596 @item @code{handlers} (default: @var{'()})
21597 List of @code{<dicod-handler>} objects denoting handlers (module instances).
21599 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
21600 List of @code{<dicod-database>} objects denoting dictionaries to be served.
21604 @deftp {Data Type} dicod-handler
21605 Data type representing a dictionary handler (module instance).
21609 Name of the handler (module instance).
21611 @item @code{module} (default: @var{#f})
21612 Name of the dicod module of the handler (instance). If it is @code{#f},
21613 the module has the same name as the handler.
21614 (@pxref{Modules,,, dico, GNU Dico Manual}).
21616 @item @code{options}
21617 List of strings or gexps representing the arguments for the module handler
21621 @deftp {Data Type} dicod-database
21622 Data type representing a dictionary database.
21626 Name of the database, will be used in DICT commands.
21628 @item @code{handler}
21629 Name of the dicod handler (module instance) used by this database
21630 (@pxref{Handlers,,, dico, GNU Dico Manual}).
21632 @item @code{complex?} (default: @var{#f})
21633 Whether the database configuration complex. The complex configuration
21634 will need a corresponding @code{<dicod-handler>} object, otherwise not.
21636 @item @code{options}
21637 List of strings or gexps representing the arguments for the database
21638 (@pxref{Databases,,, dico, GNU Dico Manual}).
21642 @defvr {Scheme Variable} %dicod-database:gcide
21643 A @code{<dicod-database>} object serving the GNU Collaborative International
21644 Dictionary of English using the @code{gcide} package.
21647 The following is an example @code{dicod-service} configuration.
21650 (dicod-service #:config
21651 (dicod-configuration
21652 (handlers (list (dicod-handler
21656 (list #~(string-append "dbdir=" #$wordnet))))))
21657 (databases (list (dicod-database
21660 (handler "wordnet")
21661 (options '("database=wn")))
21662 %dicod-database:gcide))))
21665 @node Setuid Programs
21666 @subsection Setuid Programs
21668 @cindex setuid programs
21669 Some programs need to run with ``root'' privileges, even when they are
21670 launched by unprivileged users. A notorious example is the
21671 @command{passwd} program, which users can run to change their
21672 password, and which needs to access the @file{/etc/passwd} and
21673 @file{/etc/shadow} files---something normally restricted to root, for
21674 obvious security reasons. To address that, these executables are
21675 @dfn{setuid-root}, meaning that they always run with root privileges
21676 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
21677 for more info about the setuid mechanism.)
21679 The store itself @emph{cannot} contain setuid programs: that would be a
21680 security issue since any user on the system can write derivations that
21681 populate the store (@pxref{The Store}). Thus, a different mechanism is
21682 used: instead of changing the setuid bit directly on files that are in
21683 the store, we let the system administrator @emph{declare} which programs
21684 should be setuid root.
21686 The @code{setuid-programs} field of an @code{operating-system}
21687 declaration contains a list of G-expressions denoting the names of
21688 programs to be setuid-root (@pxref{Using the Configuration System}).
21689 For instance, the @command{passwd} program, which is part of the Shadow
21690 package, can be designated by this G-expression (@pxref{G-Expressions}):
21693 #~(string-append #$shadow "/bin/passwd")
21696 A default set of setuid programs is defined by the
21697 @code{%setuid-programs} variable of the @code{(gnu system)} module.
21699 @defvr {Scheme Variable} %setuid-programs
21700 A list of G-expressions denoting common programs that are setuid-root.
21702 The list includes commands such as @command{passwd}, @command{ping},
21703 @command{su}, and @command{sudo}.
21706 Under the hood, the actual setuid programs are created in the
21707 @file{/run/setuid-programs} directory at system activation time. The
21708 files in this directory refer to the ``real'' binaries, which are in the
21711 @node X.509 Certificates
21712 @subsection X.509 Certificates
21714 @cindex HTTPS, certificates
21715 @cindex X.509 certificates
21717 Web servers available over HTTPS (that is, HTTP over the transport-layer
21718 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
21719 that the client can then use to @emph{authenticate} the server. To do
21720 that, clients verify that the server's certificate is signed by a
21721 so-called @dfn{certificate authority} (CA). But to verify the CA's
21722 signature, clients must have first acquired the CA's certificate.
21724 Web browsers such as GNU@tie{}IceCat include their own set of CA
21725 certificates, such that they are able to verify CA signatures
21728 However, most other programs that can talk HTTPS---@command{wget},
21729 @command{git}, @command{w3m}, etc.---need to be told where CA
21730 certificates can be found.
21732 @cindex @code{nss-certs}
21733 In GuixSD, this is done by adding a package that provides certificates
21734 to the @code{packages} field of the @code{operating-system} declaration
21735 (@pxref{operating-system Reference}). GuixSD includes one such package,
21736 @code{nss-certs}, which is a set of CA certificates provided as part of
21737 Mozilla's Network Security Services.
21739 Note that it is @emph{not} part of @var{%base-packages}, so you need to
21740 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
21741 most applications and libraries look for certificates by default, points
21742 to the certificates installed globally.
21744 Unprivileged users, including users of Guix on a foreign distro,
21745 can also install their own certificate package in
21746 their profile. A number of environment variables need to be defined so
21747 that applications and libraries know where to find them. Namely, the
21748 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
21749 variables. Some applications add their own environment variables; for
21750 instance, the Git version control system honors the certificate bundle
21751 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
21752 would typically run something like:
21755 $ guix package -i nss-certs
21756 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
21757 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
21758 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
21761 As another example, R requires the @code{CURL_CA_BUNDLE} environment
21762 variable to point to a certificate bundle, so you would have to run
21763 something like this:
21766 $ guix package -i nss-certs
21767 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
21770 For other applications you may want to look up the required environment
21771 variable in the relevant documentation.
21774 @node Name Service Switch
21775 @subsection Name Service Switch
21777 @cindex name service switch
21779 The @code{(gnu system nss)} module provides bindings to the
21780 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
21781 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
21782 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
21783 extended with new ``name'' lookup methods for system databases, which
21784 includes host names, service names, user accounts, and more (@pxref{Name
21785 Service Switch, System Databases and Name Service Switch,, libc, The GNU
21786 C Library Reference Manual}).
21788 The NSS configuration specifies, for each system database, which lookup
21789 method is to be used, and how the various methods are chained
21790 together---for instance, under which circumstances NSS should try the
21791 next method in the list. The NSS configuration is given in the
21792 @code{name-service-switch} field of @code{operating-system} declarations
21793 (@pxref{operating-system Reference, @code{name-service-switch}}).
21796 @cindex .local, host name lookup
21797 As an example, the declaration below configures the NSS to use the
21798 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
21799 back-end}, which supports host name lookups over multicast DNS (mDNS)
21800 for host names ending in @code{.local}:
21803 (name-service-switch
21804 (hosts (list %files ;first, check /etc/hosts
21806 ;; If the above did not succeed, try
21807 ;; with 'mdns_minimal'.
21809 (name "mdns_minimal")
21811 ;; 'mdns_minimal' is authoritative for
21812 ;; '.local'. When it returns "not found",
21813 ;; no need to try the next methods.
21814 (reaction (lookup-specification
21815 (not-found => return))))
21817 ;; Then fall back to DNS.
21821 ;; Finally, try with the "full" 'mdns'.
21826 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
21827 contains this configuration, so you will not have to type it if all you
21828 want is to have @code{.local} host lookup working.
21830 Note that, in this case, in addition to setting the
21831 @code{name-service-switch} of the @code{operating-system} declaration,
21832 you also need to use @code{avahi-service} (@pxref{Networking Services,
21833 @code{avahi-service}}), or @var{%desktop-services}, which includes it
21834 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
21835 to the name service cache daemon (@pxref{Base Services,
21836 @code{nscd-service}}).
21838 For convenience, the following variables provide typical NSS
21841 @defvr {Scheme Variable} %default-nss
21842 This is the default name service switch configuration, a
21843 @code{name-service-switch} object.
21846 @defvr {Scheme Variable} %mdns-host-lookup-nss
21847 This is the name service switch configuration with support for host name
21848 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
21851 The reference for name service switch configuration is given below. It
21852 is a direct mapping of the configuration file format of the C library , so
21853 please refer to the C library manual for more information (@pxref{NSS
21854 Configuration File,,, libc, The GNU C Library Reference Manual}).
21855 Compared to the configuration file format of libc NSS, it has the advantage
21856 not only of adding this warm parenthetic feel that we like, but also
21857 static checks: you will know about syntax errors and typos as soon as you
21858 run @command{guix system}.
21860 @deftp {Data Type} name-service-switch
21862 This is the data type representation the configuration of libc's name
21863 service switch (NSS). Each field below represents one of the supported
21880 The system databases handled by the NSS. Each of these fields must be a
21881 list of @code{<name-service>} objects (see below).
21885 @deftp {Data Type} name-service
21887 This is the data type representing an actual name service and the
21888 associated lookup action.
21892 A string denoting the name service (@pxref{Services in the NSS
21893 configuration,,, libc, The GNU C Library Reference Manual}).
21895 Note that name services listed here must be visible to nscd. This is
21896 achieved by passing the @code{#:name-services} argument to
21897 @code{nscd-service} the list of packages providing the needed name
21898 services (@pxref{Base Services, @code{nscd-service}}).
21901 An action specified using the @code{lookup-specification} macro
21902 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
21903 Reference Manual}). For example:
21906 (lookup-specification (unavailable => continue)
21907 (success => return))
21912 @node Initial RAM Disk
21913 @subsection Initial RAM Disk
21916 @cindex initial RAM disk
21917 For bootstrapping purposes, the Linux-Libre kernel is passed an
21918 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
21919 root file system as well as an initialization script. The latter is
21920 responsible for mounting the real root file system, and for loading any
21921 kernel modules that may be needed to achieve that.
21923 The @code{initrd-modules} field of an @code{operating-system}
21924 declaration allows you to specify Linux-libre kernel modules that must
21925 be available in the initrd. In particular, this is where you would list
21926 modules needed to actually drive the hard disk where your root partition
21927 is---although the default value of @code{initrd-modules} should cover
21928 most use cases. For example, assuming you need the @code{megaraid_sas}
21929 module in addition to the default modules to be able to access your root
21930 file system, you would write:
21935 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
21938 @defvr {Scheme Variable} %base-initrd-modules
21939 This is the list of kernel modules included in the initrd by default.
21942 Furthermore, if you need lower-level customization, the @code{initrd}
21943 field of an @code{operating-system} declaration allows
21944 you to specify which initrd you would like to use. The @code{(gnu
21945 system linux-initrd)} module provides three ways to build an initrd: the
21946 high-level @code{base-initrd} procedure and the low-level
21947 @code{raw-initrd} and @code{expression->initrd} procedures.
21949 The @code{base-initrd} procedure is intended to cover most common uses.
21950 For example, if you want to add a bunch of kernel modules to be loaded
21951 at boot time, you can define the @code{initrd} field of the operating
21952 system declaration like this:
21955 (initrd (lambda (file-systems . rest)
21956 ;; Create a standard initrd but set up networking
21957 ;; with the parameters QEMU expects by default.
21958 (apply base-initrd file-systems
21959 #:qemu-networking? #t
21963 The @code{base-initrd} procedure also handles common use cases that
21964 involves using the system as a QEMU guest, or as a ``live'' system with
21965 volatile root file system.
21967 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
21968 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
21969 such as trying to guess which kernel modules and packages should be included
21970 to the initrd. An example use of @code{raw-initrd} is when a user has
21971 a custom Linux kernel configuration and default kernel modules included by
21972 @code{base-initrd} are not available.
21974 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
21975 honors several options passed on the Linux kernel command line
21976 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
21977 @code{-append} option of QEMU), notably:
21980 @item --load=@var{boot}
21981 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
21982 program, once it has mounted the root file system.
21984 GuixSD uses this option to yield control to a boot program that runs the
21985 service activation programs and then spawns the GNU@tie{}Shepherd, the
21986 initialization system.
21988 @item --root=@var{root}
21989 Mount @var{root} as the root file system. @var{root} can be a
21990 device name like @code{/dev/sda1}, a file system label, or a file system
21993 @item --system=@var{system}
21994 Have @file{/run/booted-system} and @file{/run/current-system} point to
21997 @item modprobe.blacklist=@var{modules}@dots{}
21998 @cindex module, black-listing
21999 @cindex black list, of kernel modules
22000 Instruct the initial RAM disk as well as the @command{modprobe} command
22001 (from the kmod package) to refuse to load @var{modules}. @var{modules}
22002 must be a comma-separated list of module names---e.g.,
22003 @code{usbkbd,9pnet}.
22006 Start a read-eval-print loop (REPL) from the initial RAM disk before it
22007 tries to load kernel modules and to mount the root file system. Our
22008 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
22009 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
22010 Manual}, for more information on Guile's REPL.
22014 Now that you know all the features that initial RAM disks produced by
22015 @code{base-initrd} and @code{raw-initrd} provide,
22016 here is how to use it and customize it further.
22019 @cindex initial RAM disk
22020 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
22021 [#:linux-modules '()] [#:mapped-devices '()] @
22022 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
22023 Return a derivation that builds a raw initrd. @var{file-systems} is
22024 a list of file systems to be mounted by the initrd, possibly in addition to
22025 the root file system specified on the kernel command line via @code{--root}.
22026 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
22027 @var{mapped-devices} is a list of device mappings to realize before
22028 @var{file-systems} are mounted (@pxref{Mapped Devices}).
22029 @var{helper-packages} is a list of packages to be copied in the initrd. It may
22030 include @code{e2fsck/static} or other packages needed by the initrd to check
22031 the root file system.
22033 When @var{qemu-networking?} is true, set up networking with the standard QEMU
22034 parameters. When @var{virtio?} is true, load additional modules so that the
22035 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
22037 When @var{volatile-root?} is true, the root file system is writable but any changes
22041 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
22042 [#:mapped-devices '()] [#:qemu-networking? #f] [#:volatile-root? #f]@
22043 [#:linux-modules '()]
22044 Return as a file-like object a generic initrd, with kernel
22045 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
22046 mounted by the initrd, possibly in addition to the root file system specified
22047 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
22048 mappings to realize before @var{file-systems} are mounted.
22050 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
22052 The initrd is automatically populated with all the kernel modules necessary
22053 for @var{file-systems} and for the given options. Additional kernel
22054 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
22055 loaded at boot time in the order in which they appear.
22058 Needless to say, the initrds we produce and use embed a
22059 statically-linked Guile, and the initialization program is a Guile
22060 program. That gives a lot of flexibility. The
22061 @code{expression->initrd} procedure builds such an initrd, given the
22062 program to run in that initrd.
22064 @deffn {Scheme Procedure} expression->initrd @var{exp} @
22065 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
22066 Return as a file-like object a Linux initrd (a gzipped cpio archive)
22067 containing @var{guile} and that evaluates @var{exp}, a G-expression,
22068 upon booting. All the derivations referenced by @var{exp} are
22069 automatically copied to the initrd.
22072 @node Bootloader Configuration
22073 @subsection Bootloader Configuration
22076 @cindex boot loader
22078 The operating system supports multiple bootloaders. The bootloader is
22079 configured using @code{bootloader-configuration} declaration. All the
22080 fields of this structure are bootloader agnostic except for one field,
22081 @code{bootloader} that indicates the bootloader to be configured and
22084 Some of the bootloaders do not honor every field of
22085 @code{bootloader-configuration}. For instance, the extlinux
22086 bootloader does not support themes and thus ignores the @code{theme}
22089 @deftp {Data Type} bootloader-configuration
22090 The type of a bootloader configuration declaration.
22094 @item @code{bootloader}
22095 @cindex EFI, bootloader
22096 @cindex UEFI, bootloader
22097 @cindex BIOS, bootloader
22098 The bootloader to use, as a @code{bootloader} object. For now
22099 @code{grub-bootloader}, @code{grub-efi-bootloader},
22100 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
22102 @vindex grub-efi-bootloader
22103 @code{grub-efi-bootloader} allows to boot on modern systems using the
22104 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
22105 use if the installation image contains a @file{/sys/firmware/efi} directory
22106 when you boot it on your system.
22108 @vindex grub-bootloader
22109 @code{grub-bootloader} allows you to boot in particular Intel-based machines
22110 in ``legacy'' BIOS mode.
22112 @cindex ARM, bootloaders
22113 @cindex AArch64, bootloaders
22114 Available bootloaders are described in @code{(gnu bootloader @dots{})}
22115 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
22116 of bootloaders for a wide range of ARM and AArch64 systems, using the
22117 @uref{http://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
22119 @item @code{target}
22120 This is a string denoting the target onto which to install the
22123 The interpretation depends on the bootloader in question. For
22124 @code{grub-bootloader}, for example, it should be a device name understood by
22125 the bootloader @command{installer} command, such as @code{/dev/sda} or
22126 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
22127 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
22128 system, usually @file{/boot/efi}.
22130 @item @code{menu-entries} (default: @code{()})
22131 A possibly empty list of @code{menu-entry} objects (see below), denoting
22132 entries to appear in the bootloader menu, in addition to the current
22133 system entry and the entry pointing to previous system generations.
22135 @item @code{default-entry} (default: @code{0})
22136 The index of the default boot menu entry. Index 0 is for the entry of the
22139 @item @code{timeout} (default: @code{5})
22140 The number of seconds to wait for keyboard input before booting. Set to
22141 0 to boot immediately, and to -1 to wait indefinitely.
22143 @item @code{theme} (default: @var{#f})
22144 The bootloader theme object describing the theme to use. If no theme
22145 is provided, some bootloaders might use a default theme, that's true
22148 @item @code{terminal-outputs} (default: @code{'gfxterm})
22149 The output terminals used for the bootloader boot menu, as a list of
22150 symbols. GRUB accepts the values: @code{console}, @code{serial},
22151 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
22152 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
22153 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
22154 configuration,,, grub,GNU GRUB manual}).
22156 @item @code{terminal-inputs} (default: @code{'()})
22157 The input terminals used for the bootloader boot menu, as a list of
22158 symbols. For GRUB, the default is the native platform terminal as
22159 determined at run-time. GRUB accepts the values: @code{console},
22160 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
22161 @code{usb_keyboard}. This field corresponds to the GRUB variable
22162 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
22165 @item @code{serial-unit} (default: @code{#f})
22166 The serial unit used by the bootloader, as an integer from 0 to 3.
22167 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
22168 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22170 @item @code{serial-speed} (default: @code{#f})
22171 The speed of the serial interface, as an integer. For GRUB, the
22172 default value is chosen at run-time; currently GRUB chooses
22173 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
22180 Should you want to list additional boot menu entries @i{via} the
22181 @code{menu-entries} field above, you will need to create them with the
22182 @code{menu-entry} form. For example, imagine you want to be able to
22183 boot another distro (hard to imagine!), you can define a menu entry
22188 (label "The Other Distro")
22189 (linux "/boot/old/vmlinux-2.6.32")
22190 (linux-arguments '("root=/dev/sda2"))
22191 (initrd "/boot/old/initrd"))
22196 @deftp {Data Type} menu-entry
22197 The type of an entry in the bootloader menu.
22202 The label to show in the menu---e.g., @code{"GNU"}.
22205 The Linux kernel image to boot, for example:
22208 (file-append linux-libre "/bzImage")
22211 For GRUB, it is also possible to specify a device explicitly in the
22212 file path using GRUB's device naming convention (@pxref{Naming
22213 convention,,, grub, GNU GRUB manual}), for example:
22216 "(hd0,msdos1)/boot/vmlinuz"
22219 If the device is specified explicitly as above, then the @code{device}
22220 field is ignored entirely.
22222 @item @code{linux-arguments} (default: @code{()})
22223 The list of extra Linux kernel command-line arguments---e.g.,
22224 @code{("console=ttyS0")}.
22226 @item @code{initrd}
22227 A G-Expression or string denoting the file name of the initial RAM disk
22228 to use (@pxref{G-Expressions}).
22229 @item @code{device} (default: @code{#f})
22230 The device where the kernel and initrd are to be found---i.e., for GRUB,
22231 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
22233 This may be a file system label (a string), a file system UUID (a
22234 bytevector, @pxref{File Systems}), or @code{#f}, in which case
22235 the bootloader will search the device containing the file specified by
22236 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
22237 must @emph{not} be an OS device name such as @file{/dev/sda1}.
22242 @c FIXME: Write documentation once it's stable.
22243 Fow now only GRUB has theme support. GRUB themes are created using
22244 the @code{grub-theme} form, which is not documented yet.
22246 @defvr {Scheme Variable} %default-theme
22247 This is the default GRUB theme used by the operating system if no
22248 @code{theme} field is specified in @code{bootloader-configuration}
22251 It comes with a fancy background image displaying the GNU and Guix
22256 @node Invoking guix system
22257 @subsection Invoking @code{guix system}
22259 Once you have written an operating system declaration as seen in the
22260 previous section, it can be @dfn{instantiated} using the @command{guix
22261 system} command. The synopsis is:
22264 guix system @var{options}@dots{} @var{action} @var{file}
22267 @var{file} must be the name of a file containing an
22268 @code{operating-system} declaration. @var{action} specifies how the
22269 operating system is instantiated. Currently the following values are
22274 Display available service type definitions that match the given regular
22275 expressions, sorted by relevance:
22278 $ guix system search console font
22279 name: console-fonts
22280 location: gnu/services/base.scm:729:2
22281 extends: shepherd-root
22282 description: Install the given fonts on the specified ttys (fonts are
22283 + per virtual console on GNU/Linux). The value of this service is a list
22284 + of tty/font pairs like:
22286 + '(("tty1" . "LatGrkCyr-8x16"))
22290 location: gnu/services/base.scm:1048:2
22291 extends: shepherd-root
22292 description: Provide console login using the `mingetty' program.
22296 location: gnu/services/base.scm:775:2
22298 description: Provide a console log-in service as specified by its
22299 + configuration value, a `login-configuration' object.
22305 As for @command{guix package --search}, the result is written in
22306 @code{recutils} format, which makes it easy to filter the output
22307 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
22310 Build the operating system described in @var{file}, activate it, and
22311 switch to it@footnote{This action (and the related actions
22312 @code{switch-generation} and @code{roll-back}) are usable only on
22313 systems already running GuixSD.}.
22315 This effects all the configuration specified in @var{file}: user
22316 accounts, system services, global package list, setuid programs, etc.
22317 The command starts system services specified in @var{file} that are not
22318 currently running; if a service is currently running this command will
22319 arrange for it to be upgraded the next time it is stopped (e.g.@: by
22320 @code{herd stop X} or @code{herd restart X}).
22322 This command creates a new generation whose number is one greater than
22323 the current generation (as reported by @command{guix system
22324 list-generations}). If that generation already exists, it will be
22325 overwritten. This behavior mirrors that of @command{guix package}
22326 (@pxref{Invoking guix package}).
22328 It also adds a bootloader menu entry for the new OS configuration,
22329 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
22330 entries for older configurations to a submenu, allowing you to choose
22331 an older system generation at boot time should you need it.
22334 @c The paragraph below refers to the problem discussed at
22335 @c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
22336 It is highly recommended to run @command{guix pull} once before you run
22337 @command{guix system reconfigure} for the first time (@pxref{Invoking
22338 guix pull}). Failing to do that you would see an older version of Guix
22339 once @command{reconfigure} has completed.
22342 @item switch-generation
22343 @cindex generations
22344 Switch to an existing system generation. This action atomically
22345 switches the system profile to the specified system generation. It
22346 also rearranges the system's existing bootloader menu entries. It
22347 makes the menu entry for the specified system generation the default,
22348 and it moves the entries for the other generatiors to a submenu, if
22349 supported by the bootloader being used. The next time the system
22350 boots, it will use the specified system generation.
22352 The bootloader itself is not being reinstalled when using this
22353 command. Thus, the installed bootloader is used with an updated
22354 configuration file.
22356 The target generation can be specified explicitly by its generation
22357 number. For example, the following invocation would switch to system
22361 guix system switch-generation 7
22364 The target generation can also be specified relative to the current
22365 generation with the form @code{+N} or @code{-N}, where @code{+3} means
22366 ``3 generations ahead of the current generation,'' and @code{-1} means
22367 ``1 generation prior to the current generation.'' When specifying a
22368 negative value such as @code{-1}, you must precede it with @code{--} to
22369 prevent it from being parsed as an option. For example:
22372 guix system switch-generation -- -1
22375 Currently, the effect of invoking this action is @emph{only} to switch
22376 the system profile to an existing generation and rearrange the
22377 bootloader menu entries. To actually start using the target system
22378 generation, you must reboot after running this action. In the future,
22379 it will be updated to do the same things as @command{reconfigure},
22380 like activating and deactivating services.
22382 This action will fail if the specified generation does not exist.
22385 @cindex rolling back
22386 Switch to the preceding system generation. The next time the system
22387 boots, it will use the preceding system generation. This is the inverse
22388 of @command{reconfigure}, and it is exactly the same as invoking
22389 @command{switch-generation} with an argument of @code{-1}.
22391 Currently, as with @command{switch-generation}, you must reboot after
22392 running this action to actually start using the preceding system
22396 Build the derivation of the operating system, which includes all the
22397 configuration files and programs needed to boot and run the system.
22398 This action does not actually install anything.
22401 Populate the given directory with all the files necessary to run the
22402 operating system specified in @var{file}. This is useful for first-time
22403 installations of GuixSD. For instance:
22406 guix system init my-os-config.scm /mnt
22409 copies to @file{/mnt} all the store items required by the configuration
22410 specified in @file{my-os-config.scm}. This includes configuration
22411 files, packages, and so on. It also creates other essential files
22412 needed for the system to operate correctly---e.g., the @file{/etc},
22413 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
22415 This command also installs bootloader on the target specified in
22416 @file{my-os-config}, unless the @option{--no-bootloader} option was
22420 @cindex virtual machine
22422 @anchor{guix system vm}
22423 Build a virtual machine that contains the operating system declared in
22424 @var{file}, and return a script to run that virtual machine (VM).
22425 Arguments given to the script are passed to QEMU as in the example
22426 below, which enables networking and requests 1@tie{}GiB of RAM for the
22430 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
22433 The VM shares its store with the host system.
22435 Additional file systems can be shared between the host and the VM using
22436 the @code{--share} and @code{--expose} command-line options: the former
22437 specifies a directory to be shared with write access, while the latter
22438 provides read-only access to the shared directory.
22440 The example below creates a VM in which the user's home directory is
22441 accessible read-only, and where the @file{/exchange} directory is a
22442 read-write mapping of @file{$HOME/tmp} on the host:
22445 guix system vm my-config.scm \
22446 --expose=$HOME --share=$HOME/tmp=/exchange
22449 On GNU/Linux, the default is to boot directly to the kernel; this has
22450 the advantage of requiring only a very tiny root disk image since the
22451 store of the host can then be mounted.
22453 The @code{--full-boot} option forces a complete boot sequence, starting
22454 with the bootloader. This requires more disk space since a root image
22455 containing at least the kernel, initrd, and bootloader data files must
22456 be created. The @code{--image-size} option can be used to specify the
22459 @cindex System images, creation in various formats
22460 @cindex Creating system images in various formats
22463 @itemx docker-image
22464 Return a virtual machine, disk image, or Docker image of the operating
22465 system declared in @var{file} that stands alone. By default,
22466 @command{guix system} estimates the size of the image needed to store
22467 the system, but you can use the @option{--image-size} option to specify
22468 a value. Docker images are built to contain exactly what they need, so
22469 the @option{--image-size} option is ignored in the case of
22470 @code{docker-image}.
22472 You can specify the root file system type by using the
22473 @option{--file-system-type} option. It defaults to @code{ext4}.
22475 When using @code{vm-image}, the returned image is in qcow2 format, which
22476 the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
22477 for more information on how to run the image in a virtual machine.
22479 When using @code{disk-image}, a raw disk image is produced; it can be
22480 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
22481 the device corresponding to a USB stick, one can copy the image to it
22482 using the following command:
22485 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
22488 When using @code{docker-image}, a Docker image is produced. Guix builds
22489 the image from scratch, not from a pre-existing Docker base image. As a
22490 result, it contains @emph{exactly} what you define in the operating
22491 system configuration file. You can then load the image and launch a
22492 Docker container using commands like the following:
22495 image_id="$(docker load < guixsd-docker-image.tar.gz)"
22496 docker run -e GUIX_NEW_SYSTEM=/var/guix/profiles/system \\
22497 --entrypoint /var/guix/profiles/system/profile/bin/guile \\
22498 $image_id /var/guix/profiles/system/boot
22501 This command starts a new Docker container from the specified image. It
22502 will boot the GuixSD system in the usual manner, which means it will
22503 start any services you have defined in the operating system
22504 configuration. Depending on what you run in the Docker container, it
22505 may be necessary to give the container additional permissions. For
22506 example, if you intend to build software using Guix inside of the Docker
22507 container, you may need to pass the @option{--privileged} option to
22511 Return a script to run the operating system declared in @var{file}
22512 within a container. Containers are a set of lightweight isolation
22513 mechanisms provided by the kernel Linux-libre. Containers are
22514 substantially less resource-demanding than full virtual machines since
22515 the kernel, shared objects, and other resources can be shared with the
22516 host system; this also means they provide thinner isolation.
22518 Currently, the script must be run as root in order to support more than
22519 a single user and group. The container shares its store with the host
22522 As with the @code{vm} action (@pxref{guix system vm}), additional file
22523 systems to be shared between the host and container can be specified
22524 using the @option{--share} and @option{--expose} options:
22527 guix system container my-config.scm \
22528 --expose=$HOME --share=$HOME/tmp=/exchange
22532 This option requires Linux-libre 3.19 or newer.
22537 @var{options} can contain any of the common build options (@pxref{Common
22538 Build Options}). In addition, @var{options} can contain one of the
22542 @item --expression=@var{expr}
22543 @itemx -e @var{expr}
22544 Consider the operating-system @var{expr} evaluates to.
22545 This is an alternative to specifying a file which evaluates to an
22547 This is used to generate the GuixSD installer @pxref{Building the
22548 Installation Image}).
22550 @item --system=@var{system}
22551 @itemx -s @var{system}
22552 Attempt to build for @var{system} instead of the host system type.
22553 This works as per @command{guix build} (@pxref{Invoking guix build}).
22557 Return the derivation file name of the given operating system without
22560 @item --file-system-type=@var{type}
22561 @itemx -t @var{type}
22562 For the @code{disk-image} action, create a file system of the given
22563 @var{type} on the image.
22565 When this option is omitted, @command{guix system} uses @code{ext4}.
22567 @cindex ISO-9660 format
22568 @cindex CD image format
22569 @cindex DVD image format
22570 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
22571 for burning on CDs and DVDs.
22573 @item --image-size=@var{size}
22574 For the @code{vm-image} and @code{disk-image} actions, create an image
22575 of the given @var{size}. @var{size} may be a number of bytes, or it may
22576 include a unit as a suffix (@pxref{Block size, size specifications,,
22577 coreutils, GNU Coreutils}).
22579 When this option is omitted, @command{guix system} computes an estimate
22580 of the image size as a function of the size of the system declared in
22583 @item --root=@var{file}
22584 @itemx -r @var{file}
22585 Make @var{file} a symlink to the result, and register it as a garbage
22588 @item --skip-checks
22589 Skip pre-installation safety checks.
22591 By default, @command{guix system init} and @command{guix system
22592 reconfigure} perform safety checks: they make sure the file systems that
22593 appear in the @code{operating-system} declaration actually exist
22594 (@pxref{File Systems}), and that any Linux kernel modules that may be
22595 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
22596 RAM Disk}). Passing this option skips these tests altogether.
22598 @item --on-error=@var{strategy}
22599 Apply @var{strategy} when an error occurs when reading @var{file}.
22600 @var{strategy} may be one of the following:
22603 @item nothing-special
22604 Report the error concisely and exit. This is the default strategy.
22607 Likewise, but also display a backtrace.
22610 Report the error and enter Guile's debugger. From there, you can run
22611 commands such as @code{,bt} to get a backtrace, @code{,locals} to
22612 display local variable values, and more generally inspect the state of the
22613 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
22614 a list of available debugging commands.
22619 All the actions above, except @code{build} and @code{init},
22620 can use KVM support in the Linux-libre kernel. Specifically, if the
22621 machine has hardware virtualization support, the corresponding
22622 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
22623 must exist and be readable and writable by the user and by the
22624 build users of the daemon (@pxref{Build Environment Setup}).
22627 Once you have built, configured, re-configured, and re-re-configured
22628 your GuixSD installation, you may find it useful to list the operating
22629 system generations available on disk---and that you can choose from the
22630 bootloader boot menu:
22634 @item list-generations
22635 List a summary of each generation of the operating system available on
22636 disk, in a human-readable way. This is similar to the
22637 @option{--list-generations} option of @command{guix package}
22638 (@pxref{Invoking guix package}).
22640 Optionally, one can specify a pattern, with the same syntax that is used
22641 in @command{guix package --list-generations}, to restrict the list of
22642 generations displayed. For instance, the following command displays
22643 generations that are up to 10 days old:
22646 $ guix system list-generations 10d
22651 The @command{guix system} command has even more to offer! The following
22652 sub-commands allow you to visualize how your system services relate to
22655 @anchor{system-extension-graph}
22658 @item extension-graph
22659 Emit in Dot/Graphviz format to standard output the @dfn{service
22660 extension graph} of the operating system defined in @var{file}
22661 (@pxref{Service Composition}, for more information on service
22667 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
22670 produces a PDF file showing the extension relations among services.
22672 @anchor{system-shepherd-graph}
22673 @item shepherd-graph
22674 Emit in Dot/Graphviz format to standard output the @dfn{dependency
22675 graph} of shepherd services of the operating system defined in
22676 @var{file}. @xref{Shepherd Services}, for more information and for an
22681 @node Running GuixSD in a VM
22682 @subsection Running GuixSD in a Virtual Machine
22684 @cindex virtual machine
22685 To run GuixSD in a virtual machine (VM), one can either use the
22686 pre-built GuixSD VM image distributed at
22687 @indicateurl{https://alpha.gnu.org/gnu/guix/guixsd-vm-image-@value{VERSION}.@var{system}.xz}
22688 , or build their own virtual machine image using @command{guix system
22689 vm-image} (@pxref{Invoking guix system}). The returned image is in
22690 qcow2 format, which the @uref{http://qemu.org/, QEMU emulator} can
22694 If you built your own image, you must copy it out of the store
22695 (@pxref{The Store}) and give yourself permission to write to the copy
22696 before you can use it. When invoking QEMU, you must choose a system
22697 emulator that is suitable for your hardware platform. Here is a minimal
22698 QEMU invocation that will boot the result of @command{guix system
22699 vm-image} on x86_64 hardware:
22702 $ qemu-system-x86_64 \
22703 -net user -net nic,model=virtio \
22704 -enable-kvm -m 256 /tmp/qemu-image
22707 Here is what each of these options means:
22710 @item qemu-system-x86_64
22711 This specifies the hardware platform to emulate. This should match the
22715 Enable the unprivileged user-mode network stack. The guest OS can
22716 access the host but not vice versa. This is the simplest way to get the
22719 @item -net nic,model=virtio
22720 You must create a network interface of a given model. If you do not
22721 create a NIC, the boot will fail. Assuming your hardware platform is
22722 x86_64, you can get a list of available NIC models by running
22723 @command{qemu-system-x86_64 -net nic,model=help}.
22726 If your system has hardware virtualization extensions, enabling the
22727 virtual machine support (KVM) of the Linux kernel will make things run
22731 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
22732 which may be insufficient for some operations.
22734 @item /tmp/qemu-image
22735 The file name of the qcow2 image.
22738 The default @command{run-vm.sh} script that is returned by an invocation of
22739 @command{guix system vm} does not add a @command{-net user} flag by default.
22740 To get network access from within the vm add the @code{(dhcp-client-service)}
22741 to your system definition and start the VM using
22742 @command{`guix system vm config.scm` -net user}. An important caveat of using
22743 @command{-net user} for networking is that @command{ping} will not work, because
22744 it uses the ICMP protocol. You'll have to use a different command to check for
22745 network connectivity, for example @command{guix download}.
22747 @subsubsection Connecting Through SSH
22751 To enable SSH inside a VM you need to add a SSH server like @code{(dropbear-service)}
22752 or @code{(lsh-service)} to your VM. The @code{(lsh-service}) doesn't currently
22753 boot unsupervised. It requires you to type some characters to initialize the
22754 randomness generator. In addition you need to forward the SSH port, 22 by
22755 default, to the host. You can do this with
22758 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
22761 To connect to the VM you can run
22764 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
22767 The @command{-p} tells @command{ssh} the port you want to connect to.
22768 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
22769 every time you modify your @command{config.scm} file and the
22770 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
22771 connection to an unknown host every time you connect.
22773 @subsubsection Using @command{virt-viewer} with Spice
22775 As an alternative to the default @command{qemu} graphical client you can
22776 use the @command{remote-viewer} from the @command{virt-viewer} package. To
22777 connect pass the @command{-spice port=5930,disable-ticketing} flag to
22778 @command{qemu}. See previous section for further information on how to do this.
22780 Spice also allows you to do some nice stuff like share your clipboard with your
22781 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
22784 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
22785 -chardev spicevmc,name=vdagent,id=vdagent
22786 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
22787 name=com.redhat.spice.0
22790 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
22792 @node Defining Services
22793 @subsection Defining Services
22795 The previous sections show the available services and how one can combine
22796 them in an @code{operating-system} declaration. But how do we define
22797 them in the first place? And what is a service anyway?
22800 * Service Composition:: The model for composing services.
22801 * Service Types and Services:: Types and services.
22802 * Service Reference:: API reference.
22803 * Shepherd Services:: A particular type of service.
22806 @node Service Composition
22807 @subsubsection Service Composition
22811 Here we define a @dfn{service} as, broadly, something that extends the
22812 functionality of the operating system. Often a service is a process---a
22813 @dfn{daemon}---started when the system boots: a secure shell server, a
22814 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
22815 whose execution can be triggered by another daemon---e.g., an FTP server
22816 started by @command{inetd} or a D-Bus service activated by
22817 @command{dbus-daemon}. Occasionally, a service does not map to a
22818 daemon. For instance, the ``account'' service collects user accounts
22819 and makes sure they exist when the system runs; the ``udev'' service
22820 collects device management rules and makes them available to the eudev
22821 daemon; the @file{/etc} service populates the @file{/etc} directory
22824 @cindex service extensions
22825 GuixSD services are connected by @dfn{extensions}. For instance, the
22826 secure shell service @emph{extends} the Shepherd---the GuixSD
22827 initialization system, running as PID@tie{}1---by giving it the command
22828 lines to start and stop the secure shell daemon (@pxref{Networking
22829 Services, @code{lsh-service}}); the UPower service extends the D-Bus
22830 service by passing it its @file{.service} specification, and extends the
22831 udev service by passing it device management rules (@pxref{Desktop
22832 Services, @code{upower-service}}); the Guix daemon service extends the
22833 Shepherd by passing it the command lines to start and stop the daemon,
22834 and extends the account service by passing it a list of required build
22835 user accounts (@pxref{Base Services}).
22837 All in all, services and their ``extends'' relations form a directed
22838 acyclic graph (DAG). If we represent services as boxes and extensions
22839 as arrows, a typical system might provide something like this:
22841 @image{images/service-graph,,5in,Typical service extension graph.}
22843 @cindex system service
22844 At the bottom, we see the @dfn{system service}, which produces the
22845 directory containing everything to run and boot the system, as returned
22846 by the @command{guix system build} command. @xref{Service Reference},
22847 to learn about the other service types shown here.
22848 @xref{system-extension-graph, the @command{guix system extension-graph}
22849 command}, for information on how to generate this representation for a
22850 particular operating system definition.
22852 @cindex service types
22853 Technically, developers can define @dfn{service types} to express these
22854 relations. There can be any number of services of a given type on the
22855 system---for instance, a system running two instances of the GNU secure
22856 shell server (lsh) has two instances of @var{lsh-service-type}, with
22857 different parameters.
22859 The following section describes the programming interface for service
22860 types and services.
22862 @node Service Types and Services
22863 @subsubsection Service Types and Services
22865 A @dfn{service type} is a node in the DAG described above. Let us start
22866 with a simple example, the service type for the Guix build daemon
22867 (@pxref{Invoking guix-daemon}):
22870 (define guix-service-type
22874 (list (service-extension shepherd-root-service-type guix-shepherd-service)
22875 (service-extension account-service-type guix-accounts)
22876 (service-extension activation-service-type guix-activation)))
22877 (default-value (guix-configuration))))
22881 It defines three things:
22885 A name, whose sole purpose is to make inspection and debugging easier.
22888 A list of @dfn{service extensions}, where each extension designates the
22889 target service type and a procedure that, given the parameters of the
22890 service, returns a list of objects to extend the service of that type.
22892 Every service type has at least one service extension. The only
22893 exception is the @dfn{boot service type}, which is the ultimate service.
22896 Optionally, a default value for instances of this type.
22899 In this example, @var{guix-service-type} extends three services:
22902 @item shepherd-root-service-type
22903 The @var{guix-shepherd-service} procedure defines how the Shepherd
22904 service is extended. Namely, it returns a @code{<shepherd-service>}
22905 object that defines how @command{guix-daemon} is started and stopped
22906 (@pxref{Shepherd Services}).
22908 @item account-service-type
22909 This extension for this service is computed by @var{guix-accounts},
22910 which returns a list of @code{user-group} and @code{user-account}
22911 objects representing the build user accounts (@pxref{Invoking
22914 @item activation-service-type
22915 Here @var{guix-activation} is a procedure that returns a gexp, which is
22916 a code snippet to run at ``activation time''---e.g., when the service is
22920 A service of this type is instantiated like this:
22923 (service guix-service-type
22924 (guix-configuration
22926 (use-substitutes? #f)))
22929 The second argument to the @code{service} form is a value representing
22930 the parameters of this specific service instance.
22931 @xref{guix-configuration-type, @code{guix-configuration}}, for
22932 information about the @code{guix-configuration} data type. When the
22933 value is omitted, the default value specified by
22934 @code{guix-service-type} is used:
22937 (service guix-service-type)
22940 @var{guix-service-type} is quite simple because it extends other
22941 services but is not extensible itself.
22943 @c @subsubsubsection Extensible Service Types
22945 The service type for an @emph{extensible} service looks like this:
22948 (define udev-service-type
22949 (service-type (name 'udev)
22951 (list (service-extension shepherd-root-service-type
22952 udev-shepherd-service)))
22954 (compose concatenate) ;concatenate the list of rules
22955 (extend (lambda (config rules)
22957 (($ <udev-configuration> udev initial-rules)
22958 (udev-configuration
22959 (udev udev) ;the udev package to use
22960 (rules (append initial-rules rules)))))))))
22963 This is the service type for the
22964 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
22965 management daemon}. Compared to the previous example, in addition to an
22966 extension of @var{shepherd-root-service-type}, we see two new fields:
22970 This is the procedure to @dfn{compose} the list of extensions to
22971 services of this type.
22973 Services can extend the udev service by passing it lists of rules; we
22974 compose those extensions simply by concatenating them.
22977 This procedure defines how the value of the service is @dfn{extended} with
22978 the composition of the extensions.
22980 Udev extensions are composed into a list of rules, but the udev service
22981 value is itself a @code{<udev-configuration>} record. So here, we
22982 extend that record by appending the list of rules it contains to the
22983 list of contributed rules.
22986 This is a string giving an overview of the service type. The string can
22987 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
22988 @command{guix system search} command searches these strings and displays
22989 them (@pxref{Invoking guix system}).
22992 There can be only one instance of an extensible service type such as
22993 @var{udev-service-type}. If there were more, the
22994 @code{service-extension} specifications would be ambiguous.
22996 Still here? The next section provides a reference of the programming
22997 interface for services.
22999 @node Service Reference
23000 @subsubsection Service Reference
23002 We have seen an overview of service types (@pxref{Service Types and
23003 Services}). This section provides a reference on how to manipulate
23004 services and service types. This interface is provided by the
23005 @code{(gnu services)} module.
23007 @deffn {Scheme Procedure} service @var{type} [@var{value}]
23008 Return a new service of @var{type}, a @code{<service-type>} object (see
23009 below.) @var{value} can be any object; it represents the parameters of
23010 this particular service instance.
23012 When @var{value} is omitted, the default value specified by @var{type}
23013 is used; if @var{type} does not specify a default value, an error is
23016 For instance, this:
23019 (service openssh-service-type)
23023 is equivalent to this:
23026 (service openssh-service-type
23027 (openssh-configuration))
23030 In both cases the result is an instance of @code{openssh-service-type}
23031 with the default configuration.
23034 @deffn {Scheme Procedure} service? @var{obj}
23035 Return true if @var{obj} is a service.
23038 @deffn {Scheme Procedure} service-kind @var{service}
23039 Return the type of @var{service}---i.e., a @code{<service-type>} object.
23042 @deffn {Scheme Procedure} service-value @var{service}
23043 Return the value associated with @var{service}. It represents its
23047 Here is an example of how a service is created and manipulated:
23051 (service nginx-service-type
23052 (nginx-configuration
23054 (log-directory log-directory)
23055 (run-directory run-directory)
23056 (file config-file))))
23061 (eq? (service-kind s) nginx-service-type)
23065 The @code{modify-services} form provides a handy way to change the
23066 parameters of some of the services of a list such as
23067 @var{%base-services} (@pxref{Base Services, @code{%base-services}}). It
23068 evaluates to a list of services. Of course, you could always use
23069 standard list combinators such as @code{map} and @code{fold} to do that
23070 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
23071 @code{modify-services} simply provides a more concise form for this
23074 @deffn {Scheme Syntax} modify-services @var{services} @
23075 (@var{type} @var{variable} => @var{body}) @dots{}
23077 Modify the services listed in @var{services} according to the given
23078 clauses. Each clause has the form:
23081 (@var{type} @var{variable} => @var{body})
23084 where @var{type} is a service type---e.g.,
23085 @code{guix-service-type}---and @var{variable} is an identifier that is
23086 bound within the @var{body} to the service parameters---e.g., a
23087 @code{guix-configuration} instance---of the original service of that
23090 The @var{body} should evaluate to the new service parameters, which will
23091 be used to configure the new service. This new service will replace the
23092 original in the resulting list. Because a service's service parameters
23093 are created using @code{define-record-type*}, you can write a succinct
23094 @var{body} that evaluates to the new service parameters by using the
23095 @code{inherit} feature that @code{define-record-type*} provides.
23097 @xref{Using the Configuration System}, for example usage.
23101 Next comes the programming interface for service types. This is
23102 something you want to know when writing new service definitions, but not
23103 necessarily when simply looking for ways to customize your
23104 @code{operating-system} declaration.
23106 @deftp {Data Type} service-type
23107 @cindex service type
23108 This is the representation of a @dfn{service type} (@pxref{Service Types
23113 This is a symbol, used only to simplify inspection and debugging.
23115 @item @code{extensions}
23116 A non-empty list of @code{<service-extension>} objects (see below).
23118 @item @code{compose} (default: @code{#f})
23119 If this is @code{#f}, then the service type denotes services that cannot
23120 be extended---i.e., services that do not receive ``values'' from other
23123 Otherwise, it must be a one-argument procedure. The procedure is called
23124 by @code{fold-services} and is passed a list of values collected from
23125 extensions. It may return any single value.
23127 @item @code{extend} (default: @code{#f})
23128 If this is @code{#f}, services of this type cannot be extended.
23130 Otherwise, it must be a two-argument procedure: @code{fold-services}
23131 calls it, passing it the initial value of the service as the first
23132 argument and the result of applying @code{compose} to the extension
23133 values as the second argument. It must return a value that is a valid
23134 parameter value for the service instance.
23137 @xref{Service Types and Services}, for examples.
23140 @deffn {Scheme Procedure} service-extension @var{target-type} @
23142 Return a new extension for services of type @var{target-type}.
23143 @var{compute} must be a one-argument procedure: @code{fold-services}
23144 calls it, passing it the value associated with the service that provides
23145 the extension; it must return a valid value for the target service.
23148 @deffn {Scheme Procedure} service-extension? @var{obj}
23149 Return true if @var{obj} is a service extension.
23152 Occasionally, you might want to simply extend an existing service. This
23153 involves creating a new service type and specifying the extension of
23154 interest, which can be verbose; the @code{simple-service} procedure
23155 provides a shorthand for this.
23157 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
23158 Return a service that extends @var{target} with @var{value}. This works
23159 by creating a singleton service type @var{name}, of which the returned
23160 service is an instance.
23162 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
23166 (simple-service 'my-mcron-job mcron-service-type
23167 #~(job '(next-hour (3)) "guix gc -F 2G"))
23171 At the core of the service abstraction lies the @code{fold-services}
23172 procedure, which is responsible for ``compiling'' a list of services
23173 down to a single directory that contains everything needed to boot and
23174 run the system---the directory shown by the @command{guix system build}
23175 command (@pxref{Invoking guix system}). In essence, it propagates
23176 service extensions down the service graph, updating each node parameters
23177 on the way, until it reaches the root node.
23179 @deffn {Scheme Procedure} fold-services @var{services} @
23180 [#:target-type @var{system-service-type}]
23181 Fold @var{services} by propagating their extensions down to the root of
23182 type @var{target-type}; return the root service adjusted accordingly.
23185 Lastly, the @code{(gnu services)} module also defines several essential
23186 service types, some of which are listed below.
23188 @defvr {Scheme Variable} system-service-type
23189 This is the root of the service graph. It produces the system directory
23190 as returned by the @command{guix system build} command.
23193 @defvr {Scheme Variable} boot-service-type
23194 The type of the ``boot service'', which produces the @dfn{boot script}.
23195 The boot script is what the initial RAM disk runs when booting.
23198 @defvr {Scheme Variable} etc-service-type
23199 The type of the @file{/etc} service. This service is used to create
23200 files under @file{/etc} and can be extended by
23201 passing it name/file tuples such as:
23204 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
23207 In this example, the effect would be to add an @file{/etc/issue} file
23208 pointing to the given file.
23211 @defvr {Scheme Variable} setuid-program-service-type
23212 Type for the ``setuid-program service''. This service collects lists of
23213 executable file names, passed as gexps, and adds them to the set of
23214 setuid-root programs on the system (@pxref{Setuid Programs}).
23217 @defvr {Scheme Variable} profile-service-type
23218 Type of the service that populates the @dfn{system profile}---i.e., the
23219 programs under @file{/run/current-system/profile}. Other services can
23220 extend it by passing it lists of packages to add to the system profile.
23224 @node Shepherd Services
23225 @subsubsection Shepherd Services
23227 @cindex shepherd services
23229 @cindex init system
23230 The @code{(gnu services shepherd)} module provides a way to define
23231 services managed by the GNU@tie{}Shepherd, which is the GuixSD
23232 initialization system---the first process that is started when the
23233 system boots, also known as PID@tie{}1
23234 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
23236 Services in the Shepherd can depend on each other. For instance, the
23237 SSH daemon may need to be started after the syslog daemon has been
23238 started, which in turn can only happen once all the file systems have
23239 been mounted. The simple operating system defined earlier (@pxref{Using
23240 the Configuration System}) results in a service graph like this:
23242 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
23244 You can actually generate such a graph for any operating system
23245 definition using the @command{guix system shepherd-graph} command
23246 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
23248 The @var{%shepherd-root-service} is a service object representing
23249 PID@tie{}1, of type @var{shepherd-root-service-type}; it can be extended
23250 by passing it lists of @code{<shepherd-service>} objects.
23252 @deftp {Data Type} shepherd-service
23253 The data type representing a service managed by the Shepherd.
23256 @item @code{provision}
23257 This is a list of symbols denoting what the service provides.
23259 These are the names that may be passed to @command{herd start},
23260 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
23261 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
23262 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
23264 @item @code{requirements} (default: @code{'()})
23265 List of symbols denoting the Shepherd services this one depends on.
23267 @item @code{respawn?} (default: @code{#t})
23268 Whether to restart the service when it stops, for instance when the
23269 underlying process dies.
23272 @itemx @code{stop} (default: @code{#~(const #f)})
23273 The @code{start} and @code{stop} fields refer to the Shepherd's
23274 facilities to start and stop processes (@pxref{Service De- and
23275 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
23276 G-expressions that get expanded in the Shepherd configuration file
23277 (@pxref{G-Expressions}).
23279 @item @code{actions} (default: @code{'()})
23280 @cindex actions, of Shepherd services
23281 This is a list of @code{shepherd-action} objects (see below) defining
23282 @dfn{actions} supported by the service, in addition to the standard
23283 @code{start} and @code{stop} actions. Actions listed here become available as
23284 @command{herd} sub-commands:
23287 herd @var{action} @var{service} [@var{arguments}@dots{}]
23290 @item @code{documentation}
23291 A documentation string, as shown when running:
23294 herd doc @var{service-name}
23297 where @var{service-name} is one of the symbols in @var{provision}
23298 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
23300 @item @code{modules} (default: @var{%default-modules})
23301 This is the list of modules that must be in scope when @code{start} and
23302 @code{stop} are evaluated.
23307 @deftp {Data Type} shepherd-action
23308 This is the data type that defines additional actions implemented by a
23309 Shepherd service (see above).
23313 Symbol naming the action.
23315 @item documentation
23316 This is a documentation string for the action. It can be viewed by running:
23319 herd doc @var{service} action @var{action}
23323 This should be a gexp that evaluates to a procedure of at least one argument,
23324 which is the ``running value'' of the service (@pxref{Slots of services,,,
23325 shepherd, The GNU Shepherd Manual}).
23328 The following example defines an action called @code{say-hello} that kindly
23334 (documentation "Say hi!")
23335 (procedure #~(lambda (running . args)
23336 (format #t "Hello, friend! arguments: ~s\n"
23341 Assuming this action is added to the @code{example} service, then you can do:
23344 # herd say-hello example
23345 Hello, friend! arguments: ()
23346 # herd say-hello example a b c
23347 Hello, friend! arguments: ("a" "b" "c")
23350 This, as you can see, is a fairly sophisticated way to say hello.
23351 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
23355 @defvr {Scheme Variable} shepherd-root-service-type
23356 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
23358 This is the service type that extensions target when they want to create
23359 shepherd services (@pxref{Service Types and Services}, for an example).
23360 Each extension must pass a list of @code{<shepherd-service>}.
23363 @defvr {Scheme Variable} %shepherd-root-service
23364 This service represents PID@tie{}1.
23368 @node Documentation
23369 @section Documentation
23371 @cindex documentation, searching for
23372 @cindex searching for documentation
23373 @cindex Info, documentation format
23375 @cindex manual pages
23376 In most cases packages installed with Guix come with documentation.
23377 There are two main documentation formats: ``Info'', a browseable
23378 hypertext format used for GNU software, and ``manual pages'' (or ``man
23379 pages''), the linear documentation format traditionally found on Unix.
23380 Info manuals are accessed with the @command{info} command or with Emacs,
23381 and man pages are accessed using @command{man}.
23383 You can look for documentation of software installed on your system by
23384 keyword. For example, the following command searches for information
23385 about ``TLS'' in Info manuals:
23389 "(emacs)Network Security" -- STARTTLS
23390 "(emacs)Network Security" -- TLS
23391 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
23392 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
23397 The command below searches for the same keyword in man pages:
23401 SSL (7) - OpenSSL SSL/TLS library
23402 certtool (1) - GnuTLS certificate tool
23406 These searches are purely local to your computer so you have the
23407 guarantee that documentation you find corresponds to what you have
23408 actually installed, you can access it off-line, and your privacy is
23411 Once you have these results, you can view the relevant documentation by
23415 $ info "(gnutls)Core TLS API"
23425 Info manuals contain sections and indices as well as hyperlinks like
23426 those found in Web pages. The @command{info} reader (@pxref{Top, Info
23427 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
23428 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
23429 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
23430 Introduction}, for an introduction to Info navigation.
23432 @node Installing Debugging Files
23433 @section Installing Debugging Files
23435 @cindex debugging files
23436 Program binaries, as produced by the GCC compilers for instance, are
23437 typically written in the ELF format, with a section containing
23438 @dfn{debugging information}. Debugging information is what allows the
23439 debugger, GDB, to map binary code to source code; it is required to
23440 debug a compiled program in good conditions.
23442 The problem with debugging information is that is takes up a fair amount
23443 of disk space. For example, debugging information for the GNU C Library
23444 weighs in at more than 60 MiB. Thus, as a user, keeping all the
23445 debugging info of all the installed programs is usually not an option.
23446 Yet, space savings should not come at the cost of an impediment to
23447 debugging---especially in the GNU system, which should make it easier
23448 for users to exert their computing freedom (@pxref{GNU Distribution}).
23450 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
23451 mechanism that allows users to get the best of both worlds: debugging
23452 information can be stripped from the binaries and stored in separate
23453 files. GDB is then able to load debugging information from those files,
23454 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
23457 The GNU distribution takes advantage of this by storing debugging
23458 information in the @code{lib/debug} sub-directory of a separate package
23459 output unimaginatively called @code{debug} (@pxref{Packages with
23460 Multiple Outputs}). Users can choose to install the @code{debug} output
23461 of a package when they need it. For instance, the following command
23462 installs the debugging information for the GNU C Library and for GNU
23466 guix package -i glibc:debug guile:debug
23469 GDB must then be told to look for debug files in the user's profile, by
23470 setting the @code{debug-file-directory} variable (consider setting it
23471 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
23475 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
23478 From there on, GDB will pick up debugging information from the
23479 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
23481 In addition, you will most likely want GDB to be able to show the source
23482 code being debugged. To do that, you will have to unpack the source
23483 code of the package of interest (obtained with @code{guix build
23484 --source}, @pxref{Invoking guix build}), and to point GDB to that source
23485 directory using the @code{directory} command (@pxref{Source Path,
23486 @code{directory},, gdb, Debugging with GDB}).
23488 @c XXX: keep me up-to-date
23489 The @code{debug} output mechanism in Guix is implemented by the
23490 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
23491 opt-in---debugging information is available only for the packages
23492 with definitions explicitly declaring a @code{debug} output. This may be
23493 changed to opt-out in the future if our build farm servers can handle
23494 the load. To check whether a package has a @code{debug} output, use
23495 @command{guix package --list-available} (@pxref{Invoking guix package}).
23498 @node Security Updates
23499 @section Security Updates
23501 @cindex security updates
23502 @cindex security vulnerabilities
23503 Occasionally, important security vulnerabilities are discovered in software
23504 packages and must be patched. Guix developers try hard to keep track of
23505 known vulnerabilities and to apply fixes as soon as possible in the
23506 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
23507 containing only security updates.) The @command{guix lint} tool helps
23508 developers find out about vulnerable versions of software packages in the
23513 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
23514 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
23515 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
23519 @xref{Invoking guix lint}, for more information.
23522 As of version @value{VERSION}, the feature described below is considered
23526 Guix follows a functional
23527 package management discipline (@pxref{Introduction}), which implies
23528 that, when a package is changed, @emph{every package that depends on it}
23529 must be rebuilt. This can significantly slow down the deployment of
23530 fixes in core packages such as libc or Bash, since basically the whole
23531 distribution would need to be rebuilt. Using pre-built binaries helps
23532 (@pxref{Substitutes}), but deployment may still take more time than
23536 To address this, Guix implements @dfn{grafts}, a mechanism that allows
23537 for fast deployment of critical updates without the costs associated
23538 with a whole-distribution rebuild. The idea is to rebuild only the
23539 package that needs to be patched, and then to ``graft'' it onto packages
23540 explicitly installed by the user and that were previously referring to
23541 the original package. The cost of grafting is typically very low, and
23542 order of magnitudes lower than a full rebuild of the dependency chain.
23544 @cindex replacements of packages, for grafts
23545 For instance, suppose a security update needs to be applied to Bash.
23546 Guix developers will provide a package definition for the ``fixed''
23547 Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
23548 Packages}). Then, the original package definition is augmented with a
23549 @code{replacement} field pointing to the package containing the bug fix:
23556 (replacement bash-fixed)))
23559 From there on, any package depending directly or indirectly on Bash---as
23560 reported by @command{guix gc --requisites} (@pxref{Invoking guix
23561 gc})---that is installed is automatically ``rewritten'' to refer to
23562 @var{bash-fixed} instead of @var{bash}. This grafting process takes
23563 time proportional to the size of the package, usually less than a
23564 minute for an ``average'' package on a recent machine. Grafting is
23565 recursive: when an indirect dependency requires grafting, then grafting
23566 ``propagates'' up to the package that the user is installing.
23568 Currently, the length of the name and version of the graft and that of
23569 the package it replaces (@var{bash-fixed} and @var{bash} in the example
23570 above) must be equal. This restriction mostly comes from the fact that
23571 grafting works by patching files, including binary files, directly.
23572 Other restrictions may apply: for instance, when adding a graft to a
23573 package providing a shared library, the original shared library and its
23574 replacement must have the same @code{SONAME} and be binary-compatible.
23576 The @option{--no-grafts} command-line option allows you to forcefully
23577 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
23581 guix build bash --no-grafts
23585 returns the store file name of the original Bash, whereas:
23592 returns the store file name of the ``fixed'', replacement Bash. This
23593 allows you to distinguish between the two variants of Bash.
23595 To verify which Bash your whole profile refers to, you can run
23596 (@pxref{Invoking guix gc}):
23599 guix gc -R `readlink -f ~/.guix-profile` | grep bash
23603 @dots{} and compare the store file names that you get with those above.
23604 Likewise for a complete GuixSD system generation:
23607 guix gc -R `guix system build my-config.scm` | grep bash
23610 Lastly, to check which Bash running processes are using, you can use the
23611 @command{lsof} command:
23614 lsof | grep /gnu/store/.*bash
23618 @node Package Modules
23619 @section Package Modules
23621 From a programming viewpoint, the package definitions of the
23622 GNU distribution are provided by Guile modules in the @code{(gnu packages
23623 @dots{})} name space@footnote{Note that packages under the @code{(gnu
23624 packages @dots{})} module name space are not necessarily ``GNU
23625 packages''. This module naming scheme follows the usual Guile module
23626 naming convention: @code{gnu} means that these modules are distributed
23627 as part of the GNU system, and @code{packages} identifies modules that
23628 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
23629 Reference Manual}). For instance, the @code{(gnu packages emacs)}
23630 module exports a variable named @code{emacs}, which is bound to a
23631 @code{<package>} object (@pxref{Defining Packages}).
23633 The @code{(gnu packages @dots{})} module name space is
23634 automatically scanned for packages by the command-line tools. For
23635 instance, when running @code{guix package -i emacs}, all the @code{(gnu
23636 packages @dots{})} modules are scanned until one that exports a package
23637 object whose name is @code{emacs} is found. This package search
23638 facility is implemented in the @code{(gnu packages)} module.
23640 @cindex customization, of packages
23641 @cindex package module search path
23642 Users can store package definitions in modules with different
23643 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
23644 name and module name must match. For instance, the @code{(my-packages
23645 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
23646 relative to the load path specified with @option{--load-path} or
23647 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
23648 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
23649 these package definitions visible to the user interfaces:
23653 By adding the directory containing your package modules to the search path
23654 with the @code{-L} flag of @command{guix package} and other commands
23655 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
23656 environment variable described below.
23659 By defining a @dfn{channel} and configuring @command{guix pull} so that it
23660 pulls from it. A channel is essentially a Git repository containing package
23661 modules. @xref{Channels}, for more information on how to define and use
23665 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
23667 @defvr {Environment Variable} GUIX_PACKAGE_PATH
23668 This is a colon-separated list of directories to search for additional
23669 package modules. Directories listed in this variable take precedence
23670 over the own modules of the distribution.
23673 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
23674 each package is built based solely on other packages in the
23675 distribution. The root of this dependency graph is a small set of
23676 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
23677 bootstrap)} module. For more information on bootstrapping,
23678 @pxref{Bootstrapping}.
23680 @node Packaging Guidelines
23681 @section Packaging Guidelines
23683 @cindex packages, creating
23684 The GNU distribution is nascent and may well lack some of your favorite
23685 packages. This section describes how you can help make the distribution
23686 grow. @xref{Contributing}, for additional information on how you can
23689 Free software packages are usually distributed in the form of
23690 @dfn{source code tarballs}---typically @file{tar.gz} files that contain
23691 all the source files. Adding a package to the distribution means
23692 essentially two things: adding a @dfn{recipe} that describes how to
23693 build the package, including a list of other packages required to build
23694 it, and adding @dfn{package metadata} along with that recipe, such as a
23695 description and licensing information.
23697 In Guix all this information is embodied in @dfn{package definitions}.
23698 Package definitions provide a high-level view of the package. They are
23699 written using the syntax of the Scheme programming language; in fact,
23700 for each package we define a variable bound to the package definition,
23701 and export that variable from a module (@pxref{Package Modules}).
23702 However, in-depth Scheme knowledge is @emph{not} a prerequisite for
23703 creating packages. For more information on package definitions,
23704 @pxref{Defining Packages}.
23706 Once a package definition is in place, stored in a file in the Guix
23707 source tree, it can be tested using the @command{guix build} command
23708 (@pxref{Invoking guix build}). For example, assuming the new package is
23709 called @code{gnew}, you may run this command from the Guix build tree
23710 (@pxref{Running Guix Before It Is Installed}):
23713 ./pre-inst-env guix build gnew --keep-failed
23716 Using @code{--keep-failed} makes it easier to debug build failures since
23717 it provides access to the failed build tree. Another useful
23718 command-line option when debugging is @code{--log-file}, to access the
23721 If the package is unknown to the @command{guix} command, it may be that
23722 the source file contains a syntax error, or lacks a @code{define-public}
23723 clause to export the package variable. To figure it out, you may load
23724 the module from Guile to get more information about the actual error:
23727 ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
23730 Once your package builds correctly, please send us a patch
23731 (@pxref{Contributing}). Well, if you need help, we will be happy to
23732 help you too. Once the patch is committed in the Guix repository, the
23733 new package automatically gets built on the supported platforms by
23734 @url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
23737 @cindex substituter
23738 Users can obtain the new package definition simply by running
23739 @command{guix pull} (@pxref{Invoking guix pull}). When
23740 @code{@value{SUBSTITUTE-SERVER}} is done building the package, installing the
23741 package automatically downloads binaries from there
23742 (@pxref{Substitutes}). The only place where human intervention is
23743 needed is to review and apply the patch.
23747 * Software Freedom:: What may go into the distribution.
23748 * Package Naming:: What's in a name?
23749 * Version Numbers:: When the name is not enough.
23750 * Synopses and Descriptions:: Helping users find the right package.
23751 * Python Modules:: A touch of British comedy.
23752 * Perl Modules:: Little pearls.
23753 * Java Packages:: Coffee break.
23754 * Fonts:: Fond of fonts.
23757 @node Software Freedom
23758 @subsection Software Freedom
23760 @c Adapted from http://www.gnu.org/philosophy/philosophy.html.
23761 @cindex free software
23762 The GNU operating system has been developed so that users can have
23763 freedom in their computing. GNU is @dfn{free software}, meaning that
23764 users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
23765 essential freedoms}: to run the program, to study and change the program
23766 in source code form, to redistribute exact copies, and to distribute
23767 modified versions. Packages found in the GNU distribution provide only
23768 software that conveys these four freedoms.
23770 In addition, the GNU distribution follow the
23771 @url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
23772 software distribution guidelines}. Among other things, these guidelines
23773 reject non-free firmware, recommendations of non-free software, and
23774 discuss ways to deal with trademarks and patents.
23776 Some otherwise free upstream package sources contain a small and optional
23777 subset that violates the above guidelines, for instance because this subset
23778 is itself non-free code. When that happens, the offending items are removed
23779 with appropriate patches or code snippets in the @code{origin} form of the
23780 package (@pxref{Defining Packages}). This way, @code{guix
23781 build --source} returns the ``freed'' source rather than the unmodified
23785 @node Package Naming
23786 @subsection Package Naming
23788 @cindex package name
23789 A package has actually two names associated with it:
23790 First, there is the name of the @emph{Scheme variable}, the one following
23791 @code{define-public}. By this name, the package can be made known in the
23792 Scheme code, for instance as input to another package. Second, there is
23793 the string in the @code{name} field of a package definition. This name
23794 is used by package management commands such as
23795 @command{guix package} and @command{guix build}.
23797 Both are usually the same and correspond to the lowercase conversion of
23798 the project name chosen upstream, with underscores replaced with
23799 hyphens. For instance, GNUnet is available as @code{gnunet}, and
23800 SDL_net as @code{sdl-net}.
23802 We do not add @code{lib} prefixes for library packages, unless these are
23803 already part of the official project name. But @pxref{Python
23804 Modules} and @ref{Perl Modules} for special rules concerning modules for
23805 the Python and Perl languages.
23807 Font package names are handled differently, @pxref{Fonts}.
23810 @node Version Numbers
23811 @subsection Version Numbers
23813 @cindex package version
23814 We usually package only the latest version of a given free software
23815 project. But sometimes, for instance for incompatible library versions,
23816 two (or more) versions of the same package are needed. These require
23817 different Scheme variable names. We use the name as defined
23818 in @ref{Package Naming}
23819 for the most recent version; previous versions use the same name, suffixed
23820 by @code{-} and the smallest prefix of the version number that may
23821 distinguish the two versions.
23823 The name inside the package definition is the same for all versions of a
23824 package and does not contain any version number.
23826 For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
23829 (define-public gtk+
23834 (define-public gtk+-2
23837 (version "2.24.20")
23840 If we also wanted GTK+ 3.8.2, this would be packaged as
23842 (define-public gtk+-3.8
23849 @c See <https://lists.gnu.org/archive/html/guix-devel/2016-01/msg00425.html>,
23850 @c for a discussion of what follows.
23851 @cindex version number, for VCS snapshots
23852 Occasionally, we package snapshots of upstream's version control system
23853 (VCS) instead of formal releases. This should remain exceptional,
23854 because it is up to upstream developers to clarify what the stable
23855 release is. Yet, it is sometimes necessary. So, what should we put in
23856 the @code{version} field?
23858 Clearly, we need to make the commit identifier of the VCS snapshot
23859 visible in the version string, but we also need to make sure that the
23860 version string is monotonically increasing so that @command{guix package
23861 --upgrade} can determine which version is newer. Since commit
23862 identifiers, notably with Git, are not monotonically increasing, we add
23863 a revision number that we increase each time we upgrade to a newer
23864 snapshot. The resulting version string looks like this:
23869 | | `-- upstream commit ID
23871 | `--- Guix package revision
23873 latest upstream version
23876 It is a good idea to strip commit identifiers in the @code{version}
23877 field to, say, 7 digits. It avoids an aesthetic annoyance (assuming
23878 aesthetics have a role to play here) as well as problems related to OS
23879 limits such as the maximum shebang length (127 bytes for the Linux
23880 kernel.) It is best to use the full commit identifiers in
23881 @code{origin}s, though, to avoid ambiguities. A typical package
23882 definition may look like this:
23886 (let ((commit "c3f29bc928d5900971f65965feaae59e1272a3f7")
23887 (revision "1")) ;Guix package revision
23889 (version (git-version "0.9" revision commit))
23892 (uri (git-reference
23893 (url "git://example.org/my-package.git")
23895 (sha256 (base32 "1mbikn@dots{}"))
23896 (file-name (git-file-name name version))))
23901 @node Synopses and Descriptions
23902 @subsection Synopses and Descriptions
23904 @cindex package description
23905 @cindex package synopsis
23906 As we have seen before, each package in GNU@tie{}Guix includes a
23907 synopsis and a description (@pxref{Defining Packages}). Synopses and
23908 descriptions are important: They are what @command{guix package
23909 --search} searches, and a crucial piece of information to help users
23910 determine whether a given package suits their needs. Consequently,
23911 packagers should pay attention to what goes into them.
23913 Synopses must start with a capital letter and must not end with a
23914 period. They must not start with ``a'' or ``the'', which usually does
23915 not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
23916 tool that frobs files''. The synopsis should say what the package
23917 is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
23918 used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
23919 matching a pattern''.
23921 Keep in mind that the synopsis must be meaningful for a very wide
23922 audience. For example, ``Manipulate alignments in the SAM format''
23923 might make sense for a seasoned bioinformatics researcher, but might be
23924 fairly unhelpful or even misleading to a non-specialized audience. It
23925 is a good idea to come up with a synopsis that gives an idea of the
23926 application domain of the package. In this example, this might give
23927 something like ``Manipulate nucleotide sequence alignments'', which
23928 hopefully gives the user a better idea of whether this is what they are
23931 Descriptions should take between five and ten lines. Use full
23932 sentences, and avoid using acronyms without first introducing them.
23933 Please avoid marketing phrases such as ``world-leading'',
23934 ``industrial-strength'', and ``next-generation'', and avoid superlatives
23935 like ``the most advanced''---they are not helpful to users looking for a
23936 package and may even sound suspicious. Instead, try to be factual,
23937 mentioning use cases and features.
23939 @cindex Texinfo markup, in package descriptions
23940 Descriptions can include Texinfo markup, which is useful to introduce
23941 ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
23942 hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
23943 should be careful when using some characters for example @samp{@@} and
23944 curly braces which are the basic special characters in Texinfo
23945 (@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
23946 such as @command{guix package --show} take care of rendering it
23949 Synopses and descriptions are translated by volunteers
23950 @uref{http://translationproject.org/domain/guix-packages.html, at the
23951 Translation Project} so that as many users as possible can read them in
23952 their native language. User interfaces search them and display them in
23953 the language specified by the current locale.
23955 To allow @command{xgettext} to extract them as translatable strings,
23956 synopses and descriptions @emph{must be literal strings}. This means
23957 that you cannot use @code{string-append} or @code{format} to construct
23963 (synopsis "This is translatable")
23964 (description (string-append "This is " "*not*" " translatable.")))
23967 Translation is a lot of work so, as a packager, please pay even more
23968 attention to your synopses and descriptions as every change may entail
23969 additional work for translators. In order to help them, it is possible
23970 to make recommendations or instructions visible to them by inserting
23971 special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
23975 ;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
23976 (description "ARandR is designed to provide a simple visual front end
23977 for the X11 resize-and-rotate (RandR) extension. @dots{}")
23981 @node Python Modules
23982 @subsection Python Modules
23985 We currently package Python 2 and Python 3, under the Scheme variable names
23986 @code{python-2} and @code{python} as explained in @ref{Version Numbers}.
23987 To avoid confusion and naming clashes with other programming languages, it
23988 seems desirable that the name of a package for a Python module contains
23989 the word @code{python}.
23991 Some modules are compatible with only one version of Python, others with both.
23992 If the package Foo compiles only with Python 3, we name it
23993 @code{python-foo}; if it compiles only with Python 2, we name it
23994 @code{python2-foo}. If it is compatible with both versions, we create two
23995 packages with the corresponding names.
23997 If a project already contains the word @code{python}, we drop this;
23998 for instance, the module python-dateutil is packaged under the names
23999 @code{python-dateutil} and @code{python2-dateutil}. If the project name
24000 starts with @code{py} (e.g.@: @code{pytz}), we keep it and prefix it as
24003 @subsubsection Specifying Dependencies
24004 @cindex inputs, for Python packages
24006 Dependency information for Python packages is usually available in the
24007 package source tree, with varying degrees of accuracy: in the
24008 @file{setup.py} file, in @file{requirements.txt}, or in @file{tox.ini}.
24010 Your mission, when writing a recipe for a Python package, is to map
24011 these dependencies to the appropriate type of ``input'' (@pxref{package
24012 Reference, inputs}). Although the @code{pypi} importer normally does a
24013 good job (@pxref{Invoking guix import}), you may want to check the
24014 following check list to determine which dependency goes where.
24019 We currently package Python 2 with @code{setuptools} and @code{pip}
24020 installed like Python 3.4 has per default. Thus you don't need to
24021 specify either of these as an input. @command{guix lint} will warn you
24025 Python dependencies required at run time go into
24026 @code{propagated-inputs}. They are typically defined with the
24027 @code{install_requires} keyword in @file{setup.py}, or in the
24028 @file{requirements.txt} file.
24031 Python packages required only at build time---e.g., those listed with
24032 the @code{setup_requires} keyword in @file{setup.py}---or only for
24033 testing---e.g., those in @code{tests_require}---go into
24034 @code{native-inputs}. The rationale is that (1) they do not need to be
24035 propagated because they are not needed at run time, and (2) in a
24036 cross-compilation context, it's the ``native'' input that we'd want.
24038 Examples are the @code{pytest}, @code{mock}, and @code{nose} test
24039 frameworks. Of course if any of these packages is also required at
24040 run-time, it needs to go to @code{propagated-inputs}.
24043 Anything that does not fall in the previous categories goes to
24044 @code{inputs}, for example programs or C libraries required for building
24045 Python packages containing C extensions.
24048 If a Python package has optional dependencies (@code{extras_require}),
24049 it is up to you to decide whether to add them or not, based on their
24050 usefulness/overhead ratio (@pxref{Submitting Patches, @command{guix
24057 @subsection Perl Modules
24060 Perl programs standing for themselves are named as any other package,
24061 using the lowercase upstream name.
24062 For Perl packages containing a single class, we use the lowercase class name,
24063 replace all occurrences of @code{::} by dashes and prepend the prefix
24065 So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
24066 Modules containing several classes keep their lowercase upstream name and
24067 are also prepended by @code{perl-}. Such modules tend to have the word
24068 @code{perl} somewhere in their name, which gets dropped in favor of the
24069 prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
24072 @node Java Packages
24073 @subsection Java Packages
24076 Java programs standing for themselves are named as any other package,
24077 using the lowercase upstream name.
24079 To avoid confusion and naming clashes with other programming languages,
24080 it is desirable that the name of a package for a Java package is
24081 prefixed with @code{java-}. If a project already contains the word
24082 @code{java}, we drop this; for instance, the package @code{ngsjava} is
24083 packaged under the name @code{java-ngs}.
24085 For Java packages containing a single class or a small class hierarchy,
24086 we use the lowercase class name, replace all occurrences of @code{.} by
24087 dashes and prepend the prefix @code{java-}. So the class
24088 @code{apache.commons.cli} becomes package
24089 @code{java-apache-commons-cli}.
24096 For fonts that are in general not installed by a user for typesetting
24097 purposes, or that are distributed as part of a larger software package,
24098 we rely on the general packaging rules for software; for instance, this
24099 applies to the fonts delivered as part of the X.Org system or fonts that
24100 are part of TeX Live.
24102 To make it easier for a user to search for fonts, names for other packages
24103 containing only fonts are constructed as follows, independently of the
24104 upstream package name.
24106 The name of a package containing only one font family starts with
24107 @code{font-}; it is followed by the foundry name and a dash @code{-}
24108 if the foundry is known, and the font family name, in which spaces are
24109 replaced by dashes (and as usual, all upper case letters are transformed
24111 For example, the Gentium font family by SIL is packaged under the name
24112 @code{font-sil-gentium}.
24114 For a package containing several font families, the name of the collection
24115 is used in the place of the font family name.
24116 For instance, the Liberation fonts consist of three families,
24117 Liberation Sans, Liberation Serif and Liberation Mono.
24118 These could be packaged separately under the names
24119 @code{font-liberation-sans} and so on; but as they are distributed together
24120 under a common name, we prefer to package them together as
24121 @code{font-liberation}.
24123 In the case where several formats of the same font family or font collection
24124 are packaged separately, a short form of the format, prepended by a dash,
24125 is added to the package name. We use @code{-ttf} for TrueType fonts,
24126 @code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
24131 @node Bootstrapping
24132 @section Bootstrapping
24134 @c Adapted from the ELS 2013 paper.
24136 @cindex bootstrapping
24138 Bootstrapping in our context refers to how the distribution gets built
24139 ``from nothing''. Remember that the build environment of a derivation
24140 contains nothing but its declared inputs (@pxref{Introduction}). So
24141 there's an obvious chicken-and-egg problem: how does the first package
24142 get built? How does the first compiler get compiled? Note that this is
24143 a question of interest only to the curious hacker, not to the regular
24144 user, so you can shamelessly skip this section if you consider yourself
24145 a ``regular user''.
24147 @cindex bootstrap binaries
24148 The GNU system is primarily made of C code, with libc at its core. The
24149 GNU build system itself assumes the availability of a Bourne shell and
24150 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
24151 `grep'. Furthermore, build programs---programs that run
24152 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
24153 (@pxref{Derivations}). Consequently, to be able to build anything at
24154 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
24155 Binutils, libc, and the other packages mentioned above---the
24156 @dfn{bootstrap binaries}.
24158 These bootstrap binaries are ``taken for granted'', though we can also
24159 re-create them if needed (more on that later).
24161 @unnumberedsubsec Preparing to Use the Bootstrap Binaries
24163 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
24164 @c large image, it's hard to scroll. Oh well.
24165 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
24167 The figure above shows the very beginning of the dependency graph of the
24168 distribution, corresponding to the package definitions of the @code{(gnu
24169 packages bootstrap)} module. A similar figure can be generated with
24170 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
24173 guix graph -t derivation \
24174 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
24178 At this level of detail, things are
24179 slightly complex. First, Guile itself consists of an ELF executable,
24180 along with many source and compiled Scheme files that are dynamically
24181 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
24182 tarball shown in this graph. This tarball is part of Guix's ``source''
24183 distribution, and gets inserted into the store with @code{add-to-store}
24184 (@pxref{The Store}).
24186 But how do we write a derivation that unpacks this tarball and adds it
24187 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
24188 derivation---the first one that gets built---uses @code{bash} as its
24189 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
24190 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
24191 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
24192 the Guix source distribution, whose sole purpose is to allow the Guile
24193 tarball to be unpacked.
24195 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
24196 Guile that can be used to run subsequent build programs. Its first task
24197 is to download tarballs containing the other pre-built binaries---this
24198 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
24199 @code{ftp-client.scm} are used for this purpose. The
24200 @code{module-import.drv} derivations import those modules in a directory
24201 in the store, using the original layout. The
24202 @code{module-import-compiled.drv} derivations compile those modules, and
24203 write them in an output directory with the right layout. This
24204 corresponds to the @code{#:modules} argument of
24205 @code{build-expression->derivation} (@pxref{Derivations}).
24207 Finally, the various tarballs are unpacked by the
24208 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
24209 etc., at which point we have a working C tool chain.
24212 @unnumberedsubsec Building the Build Tools
24214 Bootstrapping is complete when we have a full tool chain that does not
24215 depend on the pre-built bootstrap tools discussed above. This
24216 no-dependency requirement is verified by checking whether the files of
24217 the final tool chain contain references to the @file{/gnu/store}
24218 directories of the bootstrap inputs. The process that leads to this
24219 ``final'' tool chain is described by the package definitions found in
24220 the @code{(gnu packages commencement)} module.
24222 The @command{guix graph} command allows us to ``zoom out'' compared to
24223 the graph above, by looking at the level of package objects instead of
24224 individual derivations---remember that a package may translate to
24225 several derivations, typically one derivation to download its source,
24226 one to build the Guile modules it needs, and one to actually build the
24227 package from source. The command:
24230 guix graph -t bag \
24231 -e '(@@@@ (gnu packages commencement)
24232 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
24236 produces the dependency graph leading to the ``final'' C
24237 library@footnote{You may notice the @code{glibc-intermediate} label,
24238 suggesting that it is not @emph{quite} final, but as a good
24239 approximation, we will consider it final.}, depicted below.
24241 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
24243 @c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
24244 The first tool that gets built with the bootstrap binaries is
24245 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
24246 for all the following packages. From there Findutils and Diffutils get
24249 Then come the first-stage Binutils and GCC, built as pseudo cross
24250 tools---i.e., with @code{--target} equal to @code{--host}. They are
24251 used to build libc. Thanks to this cross-build trick, this libc is
24252 guaranteed not to hold any reference to the initial tool chain.
24254 From there the final Binutils and GCC (not shown above) are built.
24256 from the final Binutils, and links programs against the just-built libc.
24257 This tool chain is used to build the other packages used by Guix and by
24258 the GNU Build System: Guile, Bash, Coreutils, etc.
24260 And voilà! At this point we have the complete set of build tools that
24261 the GNU Build System expects. These are in the @code{%final-inputs}
24262 variable of the @code{(gnu packages commencement)} module, and are
24263 implicitly used by any package that uses @code{gnu-build-system}
24264 (@pxref{Build Systems, @code{gnu-build-system}}).
24267 @unnumberedsubsec Building the Bootstrap Binaries
24269 @cindex bootstrap binaries
24270 Because the final tool chain does not depend on the bootstrap binaries,
24271 those rarely need to be updated. Nevertheless, it is useful to have an
24272 automated way to produce them, should an update occur, and this is what
24273 the @code{(gnu packages make-bootstrap)} module provides.
24275 The following command builds the tarballs containing the bootstrap
24276 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
24277 of Coreutils and other basic command-line tools):
24280 guix build bootstrap-tarballs
24283 The generated tarballs are those that should be referred to in the
24284 @code{(gnu packages bootstrap)} module mentioned at the beginning of
24287 Still here? Then perhaps by now you've started to wonder: when do we
24288 reach a fixed point? That is an interesting question! The answer is
24289 unknown, but if you would like to investigate further (and have
24290 significant computational and storage resources to do so), then let us
24293 @unnumberedsubsec Reducing the Set of Bootstrap Binaries
24295 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
24296 of binary code! Why is that a problem? It's a problem because these
24297 big chunks of binary code are practically non-auditable, which makes it
24298 hard to establish what source code produced them. Every unauditable
24299 binary also leaves us vulnerable to compiler backdoors as described by
24300 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
24302 This is mitigated by the fact that our bootstrap binaries were generated
24303 from an earlier Guix revision. Nevertheless it lacks the level of
24304 transparency that we get in the rest of the package dependency graph,
24305 where Guix always gives us a source-to-binary mapping. Thus, our goal
24306 is to reduce the set of bootstrap binaries to the bare minimum.
24308 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
24309 on-going projects to do that. One of these is about replacing the
24310 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
24311 of increasing complexity, which could be built from source starting from
24312 a simple and auditable assembler. Your help is welcome!
24316 @section Porting to a New Platform
24318 As discussed above, the GNU distribution is self-contained, and
24319 self-containment is achieved by relying on pre-built ``bootstrap
24320 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
24321 operating system kernel, CPU architecture, and application binary
24322 interface (ABI). Thus, to port the distribution to a platform that is
24323 not yet supported, one must build those bootstrap binaries, and update
24324 the @code{(gnu packages bootstrap)} module to use them on that platform.
24326 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
24327 When everything goes well, and assuming the GNU tool chain supports the
24328 target platform, this can be as simple as running a command like this
24332 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
24335 For this to work, the @code{glibc-dynamic-linker} procedure in
24336 @code{(gnu packages bootstrap)} must be augmented to return the right
24337 file name for libc's dynamic linker on that platform; likewise,
24338 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
24339 taught about the new platform.
24341 Once these are built, the @code{(gnu packages bootstrap)} module needs
24342 to be updated to refer to these binaries on the target platform. That
24343 is, the hashes and URLs of the bootstrap tarballs for the new platform
24344 must be added alongside those of the currently supported platforms. The
24345 bootstrap Guile tarball is treated specially: it is expected to be
24346 available locally, and @file{gnu/local.mk} has rules to download it for
24347 the supported architectures; a rule for the new platform must be added
24350 In practice, there may be some complications. First, it may be that the
24351 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
24352 above) is not recognized by all the GNU tools. Typically, glibc
24353 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
24354 configure flag (see @code{gcc.scm} for examples of how to handle this).
24355 Second, some of the required packages could fail to build for that
24356 platform. Lastly, the generated binaries could be broken for some
24359 @c *********************************************************************
24360 @include contributing.texi
24362 @c *********************************************************************
24363 @node Acknowledgments
24364 @chapter Acknowledgments
24366 Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
24367 which was designed and
24368 implemented by Eelco Dolstra, with contributions from other people (see
24369 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
24370 management, and promoted unprecedented features, such as transactional
24371 package upgrades and rollbacks, per-user profiles, and referentially
24372 transparent build processes. Without this work, Guix would not exist.
24374 The Nix-based software distributions, Nixpkgs and NixOS, have also been
24375 an inspiration for Guix.
24377 GNU@tie{}Guix itself is a collective work with contributions from a
24378 number of people. See the @file{AUTHORS} file in Guix for more
24379 information on these fine people. The @file{THANKS} file lists people
24380 who have helped by reporting bugs, taking care of the infrastructure,
24381 providing artwork and themes, making suggestions, and more---thank you!
24384 @c *********************************************************************
24385 @node GNU Free Documentation License
24386 @appendix GNU Free Documentation License
24387 @cindex license, GNU Free Documentation License
24388 @include fdl-1.3.texi
24390 @c *********************************************************************
24391 @node Concept Index
24392 @unnumbered Concept Index
24395 @node Programming Index
24396 @unnumbered Programming Index
24397 @syncodeindex tp fn
24398 @syncodeindex vr fn
24403 @c Local Variables:
24404 @c ispell-local-dictionary: "american";