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 1.7 2005/11/19 21:47:32 swildner Exp $
  29 #
  30 # PROVIDE: initdiskless
  31
  32 . /etc/rc.subr
  33 dummy_rc_command "$1"
  34
  35 # On entry to this script the entire system consists of a read-only root
  36 # mounted via NFS.  We use the contents of /conf to create and populate
  37 # memory filesystems.  The kernel has run BOOTP and configured an interface
  38 # (otherwise it would not have been able to mount the NFS root!)
  39 #
  40 # The following directories are scanned.  Each successive directory overrides
  41 # (is merged into) the previous one.
  42 #
  43 #       /conf/base              universal base
  44 #       /conf/default           modified by a secondary universal base
  45 #       /conf/${ipba}           modified based on the assigned broadcast IP
  46 #       /conf/${ip}             modified based on the machine's assigned IP
  47 #
  48 # Each of these directories may contain any number of subdirectories which
  49 # represent directories in / on the diskless machine.  The existance of
  50 # these subdirectories causes this script to create a MEMORY FILESYSTEM for
  51 # /<sub_directory_name>.  For example, if /conf/base/etc exists then a
  52 # memory filesystem will be created for /etc.
  53 #
  54 # If a subdirectory contains the file 'diskless_remount' the contents of
  55 # the file is used to remount the subdirectory prior to it being copied to
  56 # the memory filesystem.  For example, if /conf/base/etc/diskless_remount
  57 # contains the string 'my.server.com:/etc' then my.server.com:/etc will be
  58 # mounted in place of the subdirectory.  This allows you to avoid making
  59 # duplicates of system directories in /conf.
  60 #
  61 # If a subdirectory contains the file 'md_size', the contents of the
  62 # file is used to determine the size of the memory filesystem, in 512
  63 # byte sectors.  The default is 8192 (4MB).  You only have to specify an
  64 # md_size if the default doesn't work for you (i.e. if it is too big or
  65 # too small).  Note that in -current the default is 4096 (2MB).  For
  66 # example, /conf/base/etc/md_size might contain '16384'.
  67 #
  68 # If /conf/<special_dir>/SUBDIR.cpio.gz exists, the file is cpio'd into
  69 # the specified /SUBDIR (and a memory filesystem is created for /SUBDIR
  70 # if necessary).
  71 #
  72 # If /conf/<special_dir>/SUBDIR.remove exists, the file contains a list
  73 # of paths which are rm -rf'd relative to /SUBDIR.
  74 #
  75 # You will almost universally want to create a /conf/base/etc containing
  76 # a diskless_remount and possibly an md_size file.  You will then almost
  77 # universally want to override rc.conf, rc.local, and fstab by creating
  78 # /conf/default/etc/{rc.conf,rc.local,fstab}.  Your fstab should be sure
  79 # to mount a /usr... typically an NFS readonly /usr.
  80 #
  81 # NOTE!  rc.diskless2 will create /var, /tmp, and /dev.  Those filesystems
  82 # should not be specified in /conf.  At least not yet.
  83
  84 dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null`
  85 [ ${dlv:=0} -eq 0 ] && exit 0
  86
  87 # chkerr:
  88 #
  89 # Routine to check for error
  90 #
  91 #       checks error code and drops into shell on failure.
  92 #       if shell exits, terminates script as well as /etc/rc.
  93 #
  94 chkerr() {
  95         case $1 in
  96         0)
  97         ;;
  98         *)
  99         echo "$2 failed: dropping into /bin/sh"
 100         /bin/sh
 101         # RESUME
 102         ;;
 103         esac
 104 }
 105
 106 # Create a generic memory disk
 107 #
 108 mount_md() {
 109         /sbin/mdmfs -i 4096 -s $1 -M md $2
 110 }
 111
 112 # Create the memory filesystem if it has not already been created
 113 #
 114 create_md() {
 115         if [ "x`eval echo \\$md_created_$1`" = "x" ]; then
 116         if [ "x`eval echo \\$md_size_$1`" = "x" ]; then
 117             md_size=4096
 118         else
 119             md_size=`eval echo \\$md_size_$1`
 120         fi
 121         mount_md $md_size /$1
 122         /bin/chmod 755 /$1
 123         eval md_created_$1=created
 124     fi
 125 }
 126
 127 # DEBUGGING
 128 #
 129 # set -v
 130
 131 # Figure out our interface and IP.
 132 #
 133 bootp_ifc=""
 134 bootp_ipa=""
 135 bootp_ipbca=""
 136 iflist=`ifconfig -l`
 137 for i in ${iflist} ; do
 138         set `ifconfig ${i}`
 139         while [ $# -ge 1 ] ; do
 140                 if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then
 141                         bootp_ifc=${i} ; bootp_ipa=${2} ; shift
 142                 fi
 143                 if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then
 144                         bootp_ipbca=$2; shift
 145                 fi
 146                 shift
 147         done
 148         if [ "${bootp_ifc}" != "" ] ; then
 149                 break
 150         fi
 151 done
 152 echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}"
 153
 154 # Figure out our NFS root path
 155 #
 156 set `mount -t nfs`
 157 while [ $# -ge 1 ] ; do
 158         if [ "$2" = "on" -a "$3" = "/" ]; then
 159                 nfsroot="$1"
 160                 break
 161         fi
 162         shift
 163 done
 164
 165 # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca},
 166 # and /conf/${bootp_ipa}.  For each subdirectory found within these
 167 # directories:
 168 #
 169 # - calculate memory filesystem sizes.  If the subdirectory (prior to
 170 #   NFS remounting) contains the file 'md_size', the contents specified
 171 #   in 512 byte sectors will be used to size the memory filesystem.  Otherwise
 172 #   8192 sectors (4MB) is used.
 173 #
 174 # - handle NFS remounts.  If the subdirectory contains the file
 175 #   diskless_remount, the contents of the file is NFS mounted over
 176 #   the directory.  For example /conf/base/etc/diskless_remount
 177 #   might contain 'myserver:/etc'.  NFS remounts allow you to avoid
 178 #   having to dup your system directories in /conf.  Your server must
 179 #   be sure to export those filesystems -alldirs, however.
 180 #   If the diskless_remount file contains a string beginning with a
 181 #   '/' it is assumed that the local nfsroot should be prepended to
 182 #   it before attemping to the remount.  This allows the root to be
 183 #   relocated without needing to change the remount files.
 184 #
 185 for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
 186         for j in /conf/$i/* ; do
 187         # memory filesystem size specification
 188         #
 189         subdir=${j##*/}
 190         if [ -d $j -a -f $j/md_size ]; then
 191             eval md_size_$subdir=`cat $j/md_size`
 192         fi
 193
 194         # NFS remount
 195         #
 196         if [ -d $j -a -f $j/diskless_remount ]; then
 197                 nfspt=`/bin/cat $j/diskless_remount`
 198                 if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then
 199                 nfspt="${nfsroot}${nfspt}"
 200                 fi
 201                 mount_nfs $nfspt $j
 202                 chkerr $? "mount_nfs $nfspt $j"
 203         fi
 204     done
 205 done
 206
 207 # - Create all required MFS filesystems and populate them from
 208 #   our templates.  Support both a direct template and a dir.cpio.gz
 209 #   archive.  Support dir.remove files containing a list of relative
 210 #   paths to remove.
 211 #
 212 # TODO:
 213 #   + find a way to assign a 'group' identifier to a machine
 214 #       so we can use group-specific configurations;
 215
 216 for i in base default ${bootp_ipbca} ${bootp_ipa} ; do
 217         for j in /conf/$i/* ; do
 218         subdir=${j##*/}
 219         if [ -d $j ]; then
 220                 create_md $subdir
 221                 cp -Rp $j/* /$subdir
 222         fi
 223         done
 224         for j in /conf/$i/*.cpio.gz ; do
 225                 subdir=${j%*.cpio.gz}
 226                 subdir=${subdir##*/}
 227                 if [ -f $j ]; then
 228                         create_md $subdir
 229                         echo "Loading /$subdir from cpio archive $j"
 230                         (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d )
 231                 fi
 232         done
 233         for j in /conf/$i/*.remove ; do
 234                 subdir=${j%*.remove}
 235                 subdir=${subdir##*/}
 236                 if [ -f $j ]; then
 237                         # doubly sure it is a memory disk before rm -rf'ing
 238                         create_md $subdir
 239                         (cd /$subdir; rm -rf `/bin/cat $j`)
 240                 fi
 241         done
 242 done
 243