scripts/vunify.sh

   1 #!/bin/sh
   2
   3 # Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
   4 # based on vunify by Jacques Gelinas
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 2, or (at your option)
   9 # any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20 # This scripts is used to unify the disk space used by vservers
  21 # It takes various RPM packages and hard link them together so all
  22 # vservers are sharing the same exact copy of the files.
  23 # After doing so, it set them immutable, so the vserver can't change them
  24
  25 # This has the following advantages:
  26 #       -You save disk space. If you have 100 vservers, each using 500 megs
  27 #        (common linux server installation), you can unify 90% of that
  28 #       -Memory usage. Since the exact same binary are loaded, including
  29 #        the same shared object, you save some memory and this can increase
  30 #        performance, especially the memory cache usage.
  31 #
  32 # On the down side, you are loosing some flexibility. The vserver
  33 # administrators can't upgrade package as they see fit, since the
  34 # files are immutable. On the other end, just unifying glibc is probably
  35 # a win.
  36 : ${UTIL_VSERVER_VARS:=$(dirname $0)/util-vserver-vars}
  37 test -e "$UTIL_VSERVER_VARS" || {
  38     echo "Can not find util-vserver installation; aborting..."
  39     exit 1
  40 }
  41 . "$UTIL_VSERVER_VARS"
  42
  43 if [ $# = 0 ] ; then
  44         echo vunify [ --undo ] ref-vserver vservers -- packages
  45 else
  46         undo=0
  47         if [ "$1" == "--undo" ] ; then
  48                 undo=1
  49                 shift
  50         fi
  51         ref=$1
  52         shift
  53         servers=
  54         while [ "$1" != "" -a "$1" != "--" ]
  55         do
  56                 servers="$servers $1"
  57                 shift
  58         done
  59         if [ "$servers" = "" ] ; then
  60                 echo No vserver specified >&2
  61                 exit 1
  62         elif [ "$1" != "--" ] ; then
  63                 echo Missing -- marker >&2
  64                 exit 1
  65         else
  66                 shift
  67                 if [ $# = 0 ] ; then
  68                         echo No package specified >&2
  69                         exit 1
  70                 else
  71                         if [ ! -d $VROOTDIR/$ref/. ] ; then
  72                                 echo No vserver $ref >&2
  73                                 exit 1
  74                         else
  75                                 #echo ref=$ref
  76                                 #echo servers=$servers
  77                                 #echo packages=$*
  78                                 tmpfile=/var/run/vunifi.$$
  79                                 rm -f $tmpfile
  80                                 echo Extracting list of file to unify in $tmpfile
  81                                 for pkg in $*
  82                                 do
  83                                         $VROOTDIR/$ref/bin/rpm --root $VROOTDIR/$ref -ql --dump $pkg | \
  84                                         while read path size mtime md5 \
  85                                                 mode owner group isconfig isdoc rdev symlink
  86                                         do
  87                                                 if [ "$isconfig" = 0 ] ; then
  88                                                         echo $path >>$tmpfile
  89                                                 fi
  90                                         done
  91                                 done
  92                                 for serv in $servers
  93                                 do
  94                                         if [ "$undo" = 0 ] ; then
  95                                                 echo Unifying server $serv
  96                                                 cat $tmpfile | while read file
  97                                                 do
  98                                                         if [ ! -d $VROOTDIR/$ref/$file -a ! -L $VROOTDIR/$ref/$file ] ; then
  99                                                                 ln -f $VROOTDIR/$ref/$file $VROOTDIR/$serv/$file
 100                                                         fi
 101                                                 done
 102                                                 cat $tmpfile | while read file
 103                                                 do
 104                                                         chattr +i $VROOTDIR/$ref/$file
 105                                                 done
 106                                         else
 107                                                 echo Differencing server $serv
 108                                                 cat $tmpfile | while read file
 109                                                 do
 110                                                         chattr -i $VROOTDIR/$ref/$file
 111                                                         if [ ! -d $VROOTDIR/$ref/$file ] ; then
 112                                                                 rm -f $VROOTDIR/$serv/$file
 113                                                                 cp -a $VROOTDIR/$ref/$file $VROOTDIR/$serv/$file
 114                                                         fi
 115                                                 done
 116                                         fi
 117                                 done
 118                                 rm -f $tmpfile
 119                         fi
 120                 fi
 121         fi
 122 fi
 123