chsys

chsys.sh

#!/bin/sh
test `id -u` -eq 0 || { echo "You have to be root!"; exit 1; }
a="/$0"; a=${a%/*}; a=${a:-.}; a=${a#/}/; BINDIR=$(cd $a; pwd)
PATH=/usr/sbin:$PATH:$BINDIR

basename=${0##*/}

test -d "$1" || {
  echo Directory $1 does not exist.
  exit 1
}

CHROOT=${1:-'/var/tmp/rhel5-x86_64'}
shift
CHROOT=`cd $CHROOT; pwd`

FKILL="fuser -v -k -i -SIGTERM $CHROOT"
test -x /bin/busybox && {
  FKILL="fuser -k -SIGTERM $CHROOT"
}

MFS="/dev /tmp /sys /proc /dev/pts /dev/shm /selinux"

test "$1" = "-k" && { kill=true; shift; }
SHELL=${1:-"/bin/sh"}

MTAB=$CHROOT/etc/mtab
rm $MTAB
# This is needed mainly for Arch Linux's pacman
grep -w / /proc/mounts > $MTAB
unset MTAB

mounty() {
  test -d $1 || return 1
  target="$CHROOT$1"
  test -d $target && {
    grep -q "$target" /proc/mounts || \
      { printf "\t" \
          && echo "Mounting $1 to $target..." \
          && mount -n -o rbind $1 $target; }
  }
}

umounty() {
  mount | grep -w "$1" | while read a b c d
    do echo $c
  done | grep -v "^$1$" | sort -r | while read a
  do
    echo -n "$basename: Umounting $a... "
    umount -l $a && echo ok || echo FAILED
  done
}

echo $basename: Mounting filesystems... &&
  for i in $MFS; do mounty $i; done
  echo $basename: Filesystems mounting done

echo $basename: Changing to $CHROOT
echo HINT: sshd postgres sesame condor cumin qpidd openais

addfile () {
  if
    test "$1" = "-o"
  then
    cp $2 $CHROOT/$2
  else
    test -r $CHROOT/$1 || cp $1 $CHROOT/$1
  fi
}

# Files that are system-dependent
# /etc/resolv.conf
# /etc/hosts, /etc/fstab, /etc/passwd,
# /etc/group, /etc/shadow, /etc/ld.so.conf, /etc/scsi_id.config

test -d $CHROOT/etc/sysconfig && touch $CHROOT/etc/sysconfig/network
addfile -o /etc/hosts
addfile -o /etc/resolv.conf
addfile /etc/krb5.conf

addline () {
  test "$1" = "-f" && { force=1; shift; }
  file="$1"
  pat="$2"
  shift
  shift
  test -w "$file" || return 1
  if [ -n "$force" ]
    then sed -i "\^$pat^d" "$file"
    else grep -q "$pat" "$file" && return 1
  fi
  echo "$@" >> $file
}
export PS1="chsys:${CHROOT##*/}\\\\$ "

addline -f $CHROOT/root/.bashrc /tutti/call \
  'test -r /tmp/tutti/call && . `/tmp/tutti/call`'
addline -f $CHROOT/root/.bashrc "PS1" export PS1=\"$PS1\"

echo "$CHROOT" | grep -q "i386" && SETARCH="setarch i386"

$SETARCH chroot "$CHROOT" /usr/bin/env -i \
  SHELL=$SHELL HOME=/root TERM="$TERM" PS1="$PS1" \
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin \
  DISPLAY=$DISPLAY \
  $SHELL -c "{ cat /proc/mounts >> /etc/mtab; cd; exec $SHELL -il; }"

test "$kill" = "true" && $FKILL

orphans() {
  type busybox || return 0
  PROCS=$(busybox fuser $1)
  RET=$?
  test -n "$PROCS" && {
    echo Following processes are still running under $CHROOT:
    for i in $PROCS
    do
      echo $i $(cat /proc/$i/cmdline | tr '\0' ' ')
    done
  }
  return $RET
}

echo
if ! orphans $CHROOT; then
  umounty $CHROOT && echo $basename: Filesystems successfully umounted
else
  echo
  echo "$basename: Filesystems not umounted (check PIDs above)"
fi