etc/rc.d/initdiskless

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 1999  Matt Dillon
   4 # All rights reserved.
   5 #
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions
   8 # are met:
   9 # 1. Redistributions of source code must retain the above copyright
  10 #    notice, this list of conditions and the following disclaimer.
  11 # 2. Redistributions in binary form must reproduce the above copyright
  12 #    notice, this list of conditions and the following disclaimer in the
  13 #    documentation and/or other materials provided with the distribution.
  14 #
  15 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25 # SUCH DAMAGE.
  26 #
  27 # $FreeBSD: src/etc/rc.d/initdiskless,v 1.24 2003/06/30 21:47:06 brooks Exp $
  28 # $DragonFly: src/etc/rc.d/initdiskless,v 1.9 2008/02/19 22:02:47 thomas Exp $
  29 #
  30 # PROVIDE: initdiskless
  31
  32 . /etc/rc.subr
  33 dummy_rc_command "$1"
  34
  35 # On entry to this script the entire system consists of a read-only root
  36 # mounted via NFS.  We use the contents of /conf to create and populate
  37 # memory filesystems.  The kernel has run BOOTP and configured an interface
  38 # (otherwise it would not have been able to mount the NFS root!)
  39 #
  40 # The following directories are scanned.  Each successive directory overrides
  41 # (is merged into) the previous one.
  42 #
  43 #       /conf/base              universal base
  44 #       /conf/default           modified by a secondary universal base
  45 #       /conf/${ipbca}          modified based on the assigned broadcast IP
  46 #       /conf/${ipa}            modified based on the machine's assigned IP
  47 #
  48 # If a directory contains the file 'remount', the contents of the file is
  49 # used to remount the directory. For example, if /conf/base/remount contains
  50 # the string 'my.server.com:/new_conf' then my.server.com:/new_conf will be
  51 # mounted in place of the directory.
  52 #
  53 # Each of these directories may contain any number of subdirectories which
  54 # represent directories in / on the diskless machine.  The existence of
  55 # these subdirectories causes this script to create a MEMORY FILESYSTEM for
  56 # /<sub_directory_name>.  For example, if /conf/base/etc exists then a
  57 # memory filesystem will be created for /etc.
  58 #
  59 # If a subdirectory contains the file 'diskless_remount' the contents of
  60 # the file is used to remount the subdirectory prior to it being copied to
  61 # the memory filesystem.  For example, if /conf/base/etc/diskless_remount
  62 # contains the string 'my.server.com:/etc' then my.server.com:/etc will be
  63 # mounted in place of the subdirectory.  This allows you to avoid making
  64 # duplicates of system directories in /conf.
  65 #
  66 # If a subdirectory contains the file 'md_size', the contents of the
  67 # file is used to determine the size of the memory filesystem, in 512
  68 # byte sectors.  The default is 4096 (2MB).  You only have to specify an
  69 # md_size if the default doesn't work for you (i.e. if it is too big or
  70 # too small).  For example, /conf/base/etc/md_size might contain '16384'.
  71 #
  72 # If /conf/<special_dir>/SUBDIR.cpio.gz exists, the file is cpio'd into
  73 # the specified /SUBDIR (and a memory filesystem is created for /SUBDIR
  74 # if necessary).
  75 #
  76 # If /conf/<special_dir>/SUBDIR.remove exists, the file contains a list
  77 # of paths which are rm -rf'd relative to /SUBDIR.
  78 #
  79 # You will almost universally want to create a /conf/base/etc containing
  80 # a diskless_remount and possibly an md_size file.  You will then almost
  81 # universally want to override rc.conf, rc.local, and fstab by creating
  82 # /conf/default/etc/{rc.conf,rc.local,fstab}.  Your fstab should be sure
  83 # to mount a /usr... typically an NFS readonly /usr.
  84 #
  85 # NOTE!  rc.d/diskless will create /var, /tmp, and /dev.  Those filesystems
  86 # should not be specified in /conf.  At least not yet.
  87
  88 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
  89 [ ${dlv:=0} -eq 0 ] && exit 0
  90
  91 # chkerr:
  92 #
  93 # Routine to check for error
  94 #
  95 #       checks error code and drops into shell on failure.
  96 #       if shell exits, terminates script as well as /etc/rc.
  97 #
  98 chkerr() {
  99         case $1 in
 100         0)
 101         ;;
 102         *)
 103         echo "$2 failed: dropping into /bin/sh"
 104         /bin/sh
 105         # RESUME
 106         ;;
 107         esac
 108 }
 109
 110 # Create a generic memory disk
 111 #
 112 mount_md() {
 113         /sbin/mount_tmpfs -s $1 tmpfs $2
 114 }
 115
 116 # Create the memory filesystem if it has not already been created
 117 #
 118 create_md() {
 119         if [ "x`eval echo \\$md_created_$1`" = "x" ]; then
 120                 if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
 121                         if [ "$1" = "etc" ]; then
 122                                 md_size=12M
 123                         else
 124                                 md_size=2M
 125                         fi
 126                 else
 127                         md_size=`eval echo \\$md_size_$1`
 128
 129                         # for backwards compatibility...
 130                         # if it's a number, then treat it as number of sectors
 131                         #
 132                         if [ "$md_size" = "${md_size%%[!0-9]*}" ]; then
 133                                 md_size=`expr $md_size '*' 512`
 134                         fi
 135                 fi
 136                 mount_md $md_size /$1
 137                 /bin/chmod 755 /$1
 138                 eval md_created_$1=created
 139         fi
 140 }
 141
 142 # DEBUGGING
 143 #
 144 # set -v
 145
 146 # Figure out our interface and IP.
 147 #
 148 bootp_ifc=""
 149 bootp_ipa=""
 150 bootp_ipbca=""
 151 iflist=`ifconfig -l`
 152 for i in ${iflist} ; do
 153         set `ifconfig ${i}`
 154         while [ $# -ge 1 ] ; do
 155                 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
 156                         bootp_ifc=${i} ; bootp_ipa=${2} ; shift
 157                 fi
 158                 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
 159                         bootp_ipbca=$2; shift
 160                 fi
 161                 shift
 162         done
 163         if [ "${bootp_ifc}" != "" ] ; then
 164                 break
 165         fi
 166 done
 167 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}"
 168
 169 # Figure out our NFS root path
 170 #
 171 set `mount -t nfs`
 172 while [ $# -ge 1 ] ; do
 173         if [ "$2" = "on" -a "$3" = "/" ]; then
 174                 nfsroot="$1"
 175                 break
 176         fi
 177         shift
 178 done
 179
 180 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
 181 # and /conf/${bootp_ipa}.  For each subdirectory found within these
 182 # directories:
 183 #
 184 # - calculate memory filesystem sizes.  If the subdirectory (prior to
 185 #   NFS remounting) contains the file 'md_size', the contents specified
 186 #   in 512 byte sectors will be used to size the memory filesystem.
 187 #
 188 # - handle NFS remounts.  If the subdirectory contains the file
 189 #   diskless_remount, the contents of the file is NFS mounted over
 190 #   the directory.  For example /conf/base/etc/diskless_remount
 191 #   might contain 'myserver:/etc'.  NFS remounts allow you to avoid
 192 #   having to dup your system directories in /conf.  Your server must
 193 #   be sure to export those filesystems -alldirs, however.
 194 #   If the diskless_remount file contains a string beginning with a
 195 #   '/' it is assumed that the local nfsroot should be prepended to
 196 #   it before attemping to the remount.  This allows the root to be
 197 #   relocated without needing to change the remount files.
 198 #
 199 for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
 200         if [ -f /conf/$i/remount ]; then
 201                 nfspt=`/bin/cat /conf/$i/remount`
 202                 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then
 203                         nfspt="${nfsroot}${nfspt}"
 204                 fi
 205                 mount_nfs $nfspt /conf/$i
 206                 chkerr $? "mount_nfs $nfspt /conf/$i"
 207         fi
 208
 209         for j in /conf/$i/* ; do
 210                 # memory filesystem size specification
 211                 #
 212                 subdir=${j##*/}
 213                 if [ -d $j -a -f $j/md_size ]; then
 214                         eval md_size_$subdir=`cat $j/md_size`
 215                 fi
 216
 217                 # NFS remount
 218                 #
 219                 if [ -d $j -a -f $j/diskless_remount ]; then
 220                         nfspt=`/bin/cat $j/diskless_remount`
 221                         if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then
 222                                 nfspt="${nfsroot}${nfspt}"
 223                         fi
 224                         mount_nfs $nfspt $j
 225                         chkerr $? "mount_nfs $nfspt $j"
 226                 fi
 227         done
 228 done
 229
 230 # - Create all required TMPFS filesystems and populate them from
 231 #   our templates.  Support both a direct template and a dir.cpio.gz
 232 #   archive.  Support dir.remove files containing a list of relative
 233 #   paths to remove.
 234 #
 235 # TODO:
 236 #   + find a way to assign a 'group' identifier to a machine
 237 #       so we can use group-specific configurations;
 238
 239 for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
 240         for j in /conf/$i/* ; do
 241         subdir=${j##*/}
 242         if [ -d $j ]; then
 243                 create_md $subdir
 244                 cp -Rp $j/* /$subdir
 245         fi
 246         done
 247         for j in /conf/$i/*.cpio.gz ; do
 248                 subdir=${j%*.cpio.gz}
 249                 subdir=${subdir##*/}
 250                 if [ -f $j ]; then
 251                         create_md $subdir
 252                         echo "Loading /$subdir from cpio archive $j"
 253                         (cd /$subdir ; /usr/bin/cpio --extract -d -F $j )
 254                 fi
 255         done
 256         for j in /conf/$i/*.remove ; do
 257                 subdir=${j%*.remove}
 258                 subdir=${subdir##*/}
 259                 if [ -f $j ]; then
 260                         # doubly sure it is a memory disk before rm -rf'ing
 261                         create_md $subdir
 262                         (cd /$subdir; rm -rf `/bin/cat $j`)
 263                 fi
 264         done
 265 done