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
  21 which inotifywait >/dev/null || apt-get install inotify-tools
  22
  23
  24 lxc_exists() {
  25         name=$1
  26
  27         if [ ! -e /var/lib/lxc/$name/config ] ; then
  28                 echo "Usage: $0 name"
  29                 lxc_status
  30                 exit 1
  31         fi
  32 }
  33
  34
  35 lxc_rootfs() {
  36         grep lxc.rootfs "/var/lib/lxc/$1/config" | cut -d= -f2 | sed 's/^ *//'
  37 }
  38
  39
  40 lxc_status() {
  41         lxc-ls -1 | sort -u | xargs -i lxc-info -n {} | sed "s/'//g" | while read name is status ; do
  42                 boot="    "
  43                 test -s /var/lib/lxc/$name/on_boot && boot="boot"
  44                 echo "$name $status $boot $(lxc_rootfs $name)"
  45         done
  46 }
  47
  48
  49 cleanup_init_scripts() {
  50         rootfs=$(lxc_rootfs $1)
  51
  52         ls \
  53                 $rootfs/etc/rc?.d/*umountfs \
  54                 $rootfs/etc/rc?.d/*umountroot \
  55                 $rootfs/etc/rc?.d/*hwclock* \
  56         2>/dev/null | xargs -i rm -v {}
  57 }
  58
  59
  60 setup_inittab() {
  61         rootfs=$(lxc_rootfs $1)
  62         remove=$2
  63         add=$3
  64
  65         # let container respond to kill -SIGPWR
  66         inittab=$rootfs/etc/inittab
  67         if ! grep "$add" ${inittab} >/dev/null ; then
  68                 grep -v "$remove" ${inittab} > ${inittab}.new
  69                 echo $add >> ${inittab}.new
  70                 mv ${inittab}.new ${inittab}
  71                 echo "$inittab modified with $add"
  72         fi
  73 }
  74
  75
  76 lxc_log() {
  77         echo `date +%Y-%m-%dT%H:%M:%S` $*
  78 }
  79
  80
  81 lxc_kill() {
  82         name=$1
  83         sig=$2
  84
  85         init_pid=`lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
  86         if [ -z "$init_pid" ] ; then
  87                 lxc-info -n $name
  88                 exit 1
  89         fi
  90         lxc_log "$name kill $sig $init_pid"
  91         /bin/kill $sig $init_pid
  92 }
  93
  94 lxc_stop() {
  95         lxc_log "$name stop"
  96         lxc_kill $name -SIGPWR
  97         lxc-wait -n $name -s STOPPED
  98         lxc_log "$name stoped"
  99 #       rm -f /var/lib/lxc/${name}/on_boot
 100 }
 101
 102
 103 lxc_start() {
 104         name=$1
 105
 106         if ! lxc-info -n $name | grep RUNNING ; then
 107                 lxc_log "$name start"
 108                 lxc-start -n $name -o /tmp/${name}.log -d
 109                 lxc-wait  -n $name -s RUNNING
 110                 lxc-info  -n $name
 111                 test -f /var/lib/lxc/${name}/on_boot || echo $name > /var/lib/lxc/${name}/on_boot
 112         fi
 113 }
 114
 115 lxc_watchdog() {
 116 name=$1
 117 rootfs=$(lxc_rootfs $1)
 118
 119 while true; do
 120         vps_utmp=${rootfs}/var/run/utmp
 121         tasks=`wc -l < /cgroup/${name}/tasks`
 122         test -z "$tasks" && exit 1
 123         if [ "$tasks" -eq 1 ]; then
 124
 125                 runlevel="$(runlevel ${vps_utmp})"
 126                 lxc_log "$name runlevel $runlevel"
 127
 128                 case $runlevel in
 129                 N*)
 130                         # nothing for new boot state
 131                 ;;
 132                 ??0)
 133                         lxc_log "$name halt"
 134                         lxc-stop -n "${name}"
 135                         lxc-wait -n ${name} -s STOPPED
 136                         break
 137                 ;;
 138                 ??6)
 139                         lxc_log "$name reboot";
 140                         lxc-stop -n ${name}
 141                         lxc-wait -n ${name} -s STOPPED
 142                         lxc-start -d -n ${name} -o /tmp/${name}.log
 143                 ;;
 144                 *)
 145                         # make sure vps is still running
 146                         state="$(lxc-info -n "${name}" | sed -e 's/.* is //')"
 147                         [ "$state" = "RUNNING" ] || break
 148                 ;;
 149                 esac
 150         else
 151                 lxc_log "$name $tasks tasks"
 152         fi
 153
 154         # time of 5 minutes on it JUST IN CASE...
 155         inotifywait -qqt 300 ${vps_utmp}
 156 done
 157
 158 lxc_log "$name watchdog exited"
 159
 160 }
 161
 162
 163 command_on_lxc() {
 164 command=$1
 165 shift
 166
 167 echo "# $command $1"
 168
 169 case "$command" in
 170
 171 start)
 172         lxc_exists $1
 173         cleanup_init_scripts $1
 174         setup_inittab $1 ::power      "p0::powerfail:/sbin/init 0"
 175         setup_inittab $1 ::ctrlaltdel "p6::ctrlaltdel:/sbin/init 6"
 176         lxc_start $1
 177         # give container 5 seconds to start more than one process
 178         ( sleep 5 ; nohup $0 watchdog $1 >> /tmp/$1.log 2>/dev/null ) &
 179         ;;
 180 stop|halt)
 181         lxc_exists $1
 182         lxc_stop $1
 183         ;;
 184 reload|force-reload|restart|reboot)
 185         lxc_kill $1 -SIGINT
 186         ;;
 187 watchdog)
 188         lxc_watchdog $1
 189         ;;
 190 boot)
 191         echo $1 > /var/lib/lxc/$1/on_boot
 192         ;;
 193 disable)
 194         echo -n > /var/lib/lxc/$1/on_boot
 195         ;;
 196 *)
 197         echo "Usage: $0 {start|stop|restart|status}" >&2
 198         exit 3
 199         ;;
 200
 201 esac
 202
 203 }
 204
 205 command=$1
 206 shift
 207
 208 test "$command" = "status" && lxc_status && exit
 209
 210 if [ -z "$1" ] ; then
 211         ls /var/lib/lxc/*/on_boot | while read path ; do
 212                 name=`echo $path | cut -d/ -f5`
 213                 if [ "$command" != "start" -o "$command" = "start" -a -s $path ] ; then
 214                         command_on_lxc $command $name
 215                 else
 216                         echo "# skip $command $name"
 217                 fi
 218         done
 219 else
 220         while [ ! -z "$1" ] ; do
 221                 command_on_lxc $command $1
 222                 shift
 223         done
 224 fi
 225