#!/bin/sh # # Copyright (c) 1999 Matt Dillon # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # # $FreeBSD$ # # PROVIDE: initdiskless # KEYWORD: FreeBSD # On entry to this script the entire system consists of a read-only root # mounted via NFS. We use the contents of /conf to create and populate # memory filesystems. The kernel has run BOOTP and configured an interface # (otherwise it would not have been able to mount the NFS root!) # # The following directories are scanned. Each sucessive directory overrides # (is merged into) the previous one. # # /conf/base universal base # /conf/default modified by a secondary universal base # /conf/${ipba} modified based on the assigned broadcast IP # /conf/${ip} modified based on the machine's assigned IP # # Each of these directories may contain any number of subdirectories which # represent directories in / on the diskless machine. The existance of # these subdirectories causes this script to create a MEMORY FILESYSTEM for # /<sub_directory_name>. For example, if /conf/base/etc exists then a # memory filesystem will be created for /etc. # # If a subdirectory contains the file 'diskless_remount' the contents of # the file is used to remount the subdirectory prior to it being copied to # the memory filesystem. For example, if /conf/base/etc/diskless_remount # contains the string 'my.server.com:/etc' then my.server.com:/etc will be # mounted in place of the subdirectory. This allows you to avoid making # duplicates of system directories in /conf. # # If a subdirectory contains the file 'md_size', the contents of the # file is used to determine the size of the memory filesystem, in 512 # byte sectors. The default is 10240 (5MB). You only have to specify an # md_size if the default doesn't work for you (i.e. if it is too big or # too small). For example, /conf/base/etc/md_size might contain '16384'. # # If /conf/<special_dir>/SUBDIR.cpio.gz exists, the file is cpio'd into # the specified /SUBDIR (and a memory filesystem is created for /SUBDIR # if necessary). # # If /conf/<special_dir>/SUBDIR.remove exists, the file contains a list # of paths which are rm -rf'd relative to /SUBDIR. # # You will almost universally want to create a /conf/base/etc containing # a diskless_remount and possibly an md_size file. You will then almost # universally want to override rc.conf, rc.local, and fstab by creating # /conf/default/etc/{rc.conf,rc.local,fstab}. Your fstab should be sure # to mount a /usr... typically an NFS readonly /usr. # # NOTE! /etc/rc.d/diskless will create /var, /tmp, and /dev. # Those filesystems should not be specified in /conf. At least not yet. dlv=`/sbin/sysctl -n vfs.nfs.diskless_valid 2> /dev/null` [ ${dlv:=0} -eq 0 ] && exit 0 # chkerr: # # Routine to check for error # # checks error code and drops into shell on failure. # if shell exits, terminates script as well as /etc/rc. # chkerr() { case $1 in 0) ;; *) echo "$2 failed: dropping into /bin/sh" /bin/sh # RESUME ;; esac } # Create a generic memory disk # mount_md() { /sbin/mdmfs -i 4096 -s $1 -M md $2 } # Create the memory filesystem if it has not already been created # create_md() { if [ "x`eval echo \\$md_created_$1`" = "x" ]; then if [ "x`eval echo \\$md_size_$1`" = "x" ]; then md_size=10240 else md_size=`eval echo \\$md_size_$1` fi mount_md $md_size /$1 /bin/chmod 755 /$1 eval md_created_$1=created fi } # DEBUGGING # # set -v # Figure out our interface and IP. # bootp_ifc="" bootp_ipa="" bootp_ipbca="" iflist=`ifconfig -l` for i in ${iflist} ; do set `ifconfig ${i}` while [ $# -ge 1 ] ; do if [ "${bootp_ifc}" = "" -a "$1" = "inet" ] ; then bootp_ifc=${i} ; bootp_ipa=${2} ; shift fi if [ "${bootp_ipbca}" = "" -a "$1" = "broadcast" ] ; then bootp_ipbca=$2; shift fi shift done if [ "${bootp_ifc}" != "" ] ; then break fi done echo "Interface ${bootp_ifc} IP-Address ${bootp_ipa} Broadcast ${bootp_ipbca}" # Figure out our NFS root path # set `mount -t nfs` while [ $# -ge 1 ] ; do if [ "$2" = "on" -a "$3" = "/" ]; then nfsroot="$1" break fi shift done # Resolve templates in /conf/base, /conf/default, /conf/${bootp_ipbca}, # and /conf/${bootp_ipa}. For each subdirectory found within these # directories: # # - calculate memory filesystem sizes. If the subdirectory (prior to # NFS remounting) contains the file 'md_size', the contents specified # in 512 byte sectors will be used to size the memory filesystem. Otherwise # 8192 sectors (4MB) is used. # # - handle NFS remounts. If the subdirectory contains the file # diskless_remount, the contents of the file is NFS mounted over # the directory. For example /conf/base/etc/diskless_remount # might contain 'myserver:/etc'. NFS remounts allow you to avoid # having to dup your system directories in /conf. Your server must # be sure to export those filesystems -alldirs, however. # If the diskless_remount file contains a string beginning with a # '/' it is assumed that the local nfsroot should be prepended to # it before attemping to the remount. This allows the root to be # relocated without needing to change the remount files. # for i in base default ${bootp_ipbca} ${bootp_ipa} ; do for j in /conf/$i/* ; do # memory filesystem size specification # subdir=${j##*/} if [ -d $j -a -f $j/md_size ]; then eval md_size_$subdir=`cat $j/md_size` fi # NFS remount # if [ -d $j -a -f $j/diskless_remount ]; then nfspt=`/bin/cat $j/diskless_remount` if [ `expr "$nfspt" : '\(.\)'` = "/" ]; then nfspt="${nfsroot}${nfspt}" fi mount_nfs $nfspt $j chkerr $? "mount_nfs $nfspt $j" fi done done # - Create all required MFS filesystems and populate them from # our templates. Support both a direct template and a dir.cpio.gz # archive. Support dir.remove files containing a list of relative # paths to remove. # # TODO: # + find a way to assign a 'group' identifier to a machine # so we can use group-specific configurations; for i in base default ${bootp_ipbca} ${bootp_ipa} ; do for j in /conf/$i/* ; do subdir=${j##*/} if [ -d $j ]; then create_md $subdir cp -Rp $j/* /$subdir fi done for j in /conf/$i/*.cpio.gz ; do subdir=${j%*.cpio.gz} subdir=${subdir##*/} if [ -f $j ]; then create_md $subdir echo "Loading /$subdir from cpio archive $j" (cd / ; /stand/gzip -d < $j | /stand/cpio --extract -d ) fi done for j in /conf/$i/*.remove ; do subdir=${j%*.remove} subdir=${subdir##*/} if [ -f $j ]; then # doubly sure it is a memory disk before rm -rf'ing create_md $subdir (cd /$subdir; rm -rf `/bin/cat $j`) fi done done