git.rot13.org Git - sysadmin-cookbook/blob - recepies/lxc/lxc-watchdog.sh

   1 #! /bin/sh
   2 ### BEGIN INIT INFO
   3 # Provides:          lxc-watchdog
   4 # Required-Start:    $remote_fs $named $network $time
   5 # Required-Stop:     $remote_fs $named $network
   6 # Required-Start:
   7 # Required-Stop:
   8 # Default-Start:     2 3 4 5
   9 # Default-Stop:      0 1 6
  10 # Short-Description: Manage Linux Containers startup/shutdown
  11 # Description:       Uses clever inotify hack to monitor container's
  12 #                    halt/reboot events watching /var/run/utmp
  13 ### END INIT INFO
  14
  15 # Author: Dobrica Pavlinusic <dpavlin@rot13.org>
  16 #
  17 # based on Tony Risinger post to lxc-users mailing list
  18 # http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00074.html
  19 #
  20 # Install with:
  21 # ln -sf /srv/sysadmin-cookbook/recepies/lxc/lxc-watchdog.sh /etc/init.d/lxc-watchdog
  22 # update-rc.d lxc-watchdog defaults
  23
  24
  25 which inotifywait >/dev/null || apt-get install inotify-tools
  26
  27
  28 lxc_exists() {
  29         name=$1
  30
  31         if [ ! -e /var/lib/lxc/$name/config ] ; then
  32                 echo "Usage: $0 name"
  33                 lxc_status
  34                 exit 1
  35         fi
  36 }
  37
  38
  39 lxc_rootfs() {
  40         grep '^ *lxc\.rootfs *=' "/var/lib/lxc/$1/config" | cut -d= -f2 | sed 's/^ *//'
  41 }
  42
  43 lxc_hostname() {
  44         inside=`cat $(lxc_rootfs $1)/etc/hostname`
  45         config=`grep lxc.utsname /var/lib/lxc/$name/config | cut -d= -f2`
  46         echo "$config [$inside]";
  47 }
  48
  49 lxc_ip() {
  50         ( grep lxc.network.ipv4 /var/lib/lxc/$name/config | grep -v '^#' | cut -d= -f2 || \
  51         grep address $(lxc_rootfs $name)/etc/network/interfaces | grep -v '^#' | sed 's/.*address //' ) | \
  52         head -1 | \
  53         sed -e 's/ *//g' -e 's/\/.*$//'
  54 }
  55
  56 lxc_status() {
  57         ( find /var/lib/lxc/ -name "config" | cut -d/ -f5 | sort -u | xargs -i lxc-info -n {} | sed "s/'//g" | while read name is status ; do
  58                 boot="-"
  59                 test -s /var/lib/lxc/$name/on_boot && boot="boot"
  60                 echo "$name $status $boot $(lxc_rootfs $name) $(lxc_ip $name) $(lxc_hostname $name)"
  61         done ) | column -t
  62 }
  63
  64
  65 cleanup_init_scripts() {
  66         rootfs=$(lxc_rootfs $1)
  67
  68         ls \
  69                 $rootfs/etc/rc?.d/*checkroot* \
  70                 $rootfs/etc/rc?.d/*umountfs \
  71                 $rootfs/etc/rc?.d/*umountroot \
  72                 $rootfs/etc/rc?.d/*hwclock* \
  73                 $rootfs/etc/rc?.d/*udev* \
  74         2>/dev/null | xargs -i rm -v {}
  75
  76         echo $1 > $rootfs/etc/hostname
  77         grep $1 $rootfs/etc/hosts || echo "$(lxc_ip $1) $1" >> $rootfs/etc/hosts
  78 }
  79
  80
  81 setup_inittab() {
  82         rootfs=$(lxc_rootfs $1)
  83         remove=$2
  84         add=$3
  85
  86         # let container respond to kill -SIGPWR
  87         inittab=$rootfs/etc/inittab
  88         if test -e $inittab && ! grep "$add" ${inittab} >/dev/null ; then
  89                 grep -v "$remove" ${inittab} > ${inittab}.new
  90                 echo $add >> ${inittab}.new
  91                 mv ${inittab}.new ${inittab}
  92                 echo "$inittab modified with $add"
  93         fi
  94 }
  95
  96
  97 lxc_log() {
  98         echo `date +%Y-%m-%dT%H:%M:%S` $*
  99 }
 100
 101
 102 lxc_kill() {
 103         name=$1
 104         sig=$2
 105
 106         init_pid=`lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
 107         if [ -z "$init_pid" ] ; then
 108                 lxc-info -n $name
 109                 exit 1
 110         fi
 111         lxc_log "$name kill $sig $init_pid"
 112         /bin/kill $sig $init_pid
 113 }
 114
 115 lxc_stop() {
 116         lxc_log "$name stop"
 117         lxc_kill $name -SIGPWR
 118         lxc-wait -n $name -s STOPPED
 119         lxc_log "$name stoped"
 120 #       rm -f /var/lib/lxc/${name}/on_boot
 121 }
 122
 123
 124 lxc_start() {
 125         name=$1
 126         rootfs=$(lxc_rootfs $1)
 127
 128         if [ ! -e $rootfs ] ; then
 129                 echo "ERROR $name rootfs $rootfs not found"
 130                 return
 131         fi
 132
 133         if ! lxc-info -n $name | grep RUNNING ; then
 134                 lxc_log "$name start"
 135                 lxc-start -n $name -o /tmp/${name}.log -d
 136                 lxc-wait  -n $name -s RUNNING
 137                 lxc-info  -n $name
 138                 test -f /var/lib/lxc/${name}/on_boot || echo $name > /var/lib/lxc/${name}/on_boot
 139         fi
 140 }
 141
 142 lxc_watchdog() {
 143 name=$1
 144 rootfs=$(lxc_rootfs $1)
 145
 146 while true; do
 147         vps_utmp=${rootfs}/var/run/utmp
 148         tasks=`wc -l < /cgroup/${name}/tasks`
 149         test -z "$tasks" && exit 1
 150         if [ "$tasks" -eq 1 ]; then
 151
 152                 runlevel="$(runlevel ${vps_utmp})"
 153                 lxc_log "$name runlevel $runlevel"
 154
 155                 case $runlevel in
 156                 N*)
 157                         # nothing for new boot state
 158                 ;;
 159                 ??0)
 160                         lxc_log "$name halt"
 161                         lxc-stop -n "${name}"
 162                         lxc-wait -n ${name} -s STOPPED
 163                         break
 164                 ;;
 165                 ??6)
 166                         lxc_log "$name reboot";
 167                         lxc-stop -n ${name}
 168                         lxc-wait -n ${name} -s STOPPED
 169                         lxc-start -d -n ${name} -o /tmp/${name}.log
 170                 ;;
 171                 *)
 172                         # make sure vps is still running
 173                         state="$(lxc-info -n "${name}" | sed -e 's/.* is //')"
 174                         [ "$state" = "RUNNING" ] || break
 175                 ;;
 176                 esac
 177         else
 178                 lxc_log "$name $tasks tasks"
 179         fi
 180
 181         # time of 5 minutes on it JUST IN CASE...
 182         inotifywait -qqt 300 ${vps_utmp}
 183 done
 184
 185 lxc_log "$name watchdog exited"
 186
 187 }
 188
 189
 190 usage() {
 191         echo "Usage: $0 {start|stop|restart|status|boot|disable} [name name ... ]" >&2
 192         exit 3
 193 }
 194
 195 command_on_lxc() {
 196 command=$1
 197 shift
 198
 199 echo "# $command $1"
 200
 201 case "$command" in
 202
 203 start)
 204         lxc_exists $1
 205         cleanup_init_scripts $1
 206         setup_inittab $1 ":respawn:/sbin/getty.*tty1"   "c1:12345:respawn:/sbin/getty 38400 tty1 linux"
 207         setup_inittab $1 "::power"                      "p0::powerfail:/sbin/init 0"
 208         setup_inittab $1 "::ctrlaltdel"                 "p6::ctrlaltdel:/sbin/init 6"
 209         lxc_start $1
 210         # give container 5 seconds to start more than one process
 211         ( sleep 5 ; nohup $0 watchdog $1 >> /tmp/$1.log 2>/dev/null ) &
 212         ;;
 213 stop|halt)
 214         lxc_exists $1
 215         lxc_stop $1
 216         ;;
 217 reload|force-reload|restart|reboot)
 218         lxc_kill $1 -SIGINT
 219         ;;
 220 watchdog)
 221         lxc_watchdog $1
 222         ;;
 223 boot)
 224         echo $1 > /var/lib/lxc/$1/on_boot
 225         ;;
 226 disable)
 227         echo -n > /var/lib/lxc/$1/on_boot
 228         ;;
 229 *)
 230         usage
 231         ;;
 232
 233 esac
 234
 235 }
 236
 237 command=$1
 238 test -z "$command" && usage
 239 test "$command" = "status" && lxc_status && exit
 240 shift
 241
 242 if [ -z "$1" ] ; then
 243         ls /var/lib/lxc/*/on_boot | while read path ; do
 244                 name=`echo $path | cut -d/ -f5`
 245                 if [ "$command" != "start" -o "$command" = "start" -a -s $path ] ; then
 246                         command_on_lxc $command $name
 247                 else
 248                         echo "# skip $command $name"
 249                 fi
 250         done
 251 else
 252         while [ ! -z "$1" ] ; do
 253                 command_on_lxc $command $1
 254                 shift
 255         done
 256 fi
 257