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

   1 #!/bin/sh
   2
   3 # lxc-watchdog.sh
   4 #
   5 # Dobrica Pavlinusic <dpavlin@rot13.org> 2010-03-15
   6 #
   7 # this script can be used to start/stop Linux containers
   8 # using clever inotify hack to monitor halt/reboot from
   9 # Tony Risinger posted to lxc-users mailing list
  10 #
  11 # http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00074.html
  12
  13
  14 which inotifywait >/dev/null || apt-get install inotify-tools
  15
  16
  17 lxc_exists() {
  18         name=$1
  19
  20         if [ ! -e /var/lib/lxc/$name/config ] ; then
  21                 echo "Usage: $0 name"
  22                 lxc_status
  23                 exit 1
  24         fi
  25 }
  26
  27
  28 lxc_rootfs() {
  29         grep lxc.rootfs "/var/lib/lxc/$1/config" | cut -d= -f2 | sed 's/^ *//'
  30 }
  31
  32
  33 lxc_status() {
  34         lxc-ls -1 | sort -u | xargs -i lxc-info -n {} | sed "s/'//g" | while read name is status ; do
  35                 on_boot="       "
  36                 test -s /var/lib/lxc/$name/on_boot && on_boot="on_boot"
  37                 echo "$name $status $on_boot $(lxc_rootfs $name)"
  38         done
  39 }
  40
  41
  42 cleanup_init_scripts() {
  43         rootfs=$(lxc_rootfs $1)
  44
  45         ls \
  46                 $rootfs/etc/rc?.d/*umountfs \
  47                 $rootfs/etc/rc?.d/*umountroot \
  48                 $rootfs/etc/rc?.d/*hwclock* \
  49         2>/dev/null | xargs -i rm -v {}
  50 }
  51
  52
  53 setup_inittab() {
  54         rootfs=$(lxc_rootfs $1)
  55         remove=$2
  56         add=$3
  57
  58         # let container respond to kill -SIGPWR
  59         inittab=$rootfs/etc/inittab
  60         if ! grep "$add" ${inittab} >/dev/null ; then
  61                 grep -v "$remove" ${inittab} > ${inittab}.new
  62                 echo $add >> ${inittab}.new
  63                 mv ${inittab}.new ${inittab}
  64                 echo "$inittab modified with $add"
  65         fi
  66 }
  67
  68
  69 lxc_kill() {
  70         name=$1
  71         sig=$2
  72
  73         init_pid=`lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
  74         if [ -z "$init_pid" ] ; then
  75                 lxc-info -n $name
  76                 exit 1
  77         fi
  78         echo "$name kill $sig $init_pid"
  79         /bin/kill $sig $init_pid
  80 }
  81
  82 lxc_stop() {
  83         lxc_kill $name -SIGPWR
  84         lxc-wait -n $name -s STOPPED
  85 #       rm -f /var/lib/lxc/${name}/on_boot
  86 }
  87
  88
  89 lxc_start() {
  90         name=$1
  91
  92         if ! lxc-info -n $name | grep RUNNING ; then
  93                 echo "$name start"
  94                 lxc-start -n $name -o /tmp/${name}.log -d
  95                 lxc-wait  -n $name -s RUNNING
  96                 lxc-info  -n $name
  97                 echo $name > /var/lib/lxc/${name}/on_boot
  98         fi
  99 }
 100
 101 lxc_watchdog() {
 102 name=$1
 103 rootfs=$(lxc_rootfs $1)
 104
 105 while true; do
 106         vps_utmp=${rootfs}/var/run/utmp
 107         tasks=`wc -l < /cgroup/${name}/tasks`
 108         test -z "$tasks" && exit 1
 109         if [ "$tasks" -eq 1 ]; then
 110
 111                 runlevel="$(runlevel ${vps_utmp})"
 112                 echo `date +%Y-%m-%dT%H:%M:%S` "$name runlevel $runlevel"
 113
 114                 case $runlevel in
 115                 N*)
 116                         # nothing for new boot state
 117                 ;;
 118                 ??0)
 119                         echo "$name halt"
 120                         lxc-stop -n "${name}"
 121                         lxc-wait -n ${name} -s STOPPED
 122                         break
 123                 ;;
 124                 ??6)
 125                         echo "$name reboot";
 126                         lxc-stop -n ${name}
 127                         lxc-wait -n ${name} -s STOPPED
 128                         lxc-start -d -n ${name} -o /tmp/${name}.log
 129                 ;;
 130                 *)
 131                         # make sure vps is still running
 132                         state="$(lxc-info -n "${name}" | sed -e 's/.* is //')"
 133                         [ "$state" = "RUNNING" ] || break
 134                 ;;
 135                 esac
 136         else
 137                 echo "# $name $tasks tasks"
 138         fi
 139
 140         # time of 5 minutes on it JUST IN CASE...
 141         inotifywait -qqt 300 ${vps_utmp}
 142 done
 143
 144 echo "${name} exited"
 145
 146 }
 147
 148
 149 command_on_lxc() {
 150 command=$1
 151 shift
 152
 153 echo "# $command $1"
 154
 155 case "$command" in
 156
 157 start)
 158         lxc_exists $1
 159         cleanup_init_scripts $1
 160         setup_inittab $1 ::power      "p0::powerfail:/sbin/init 0"
 161         setup_inittab $1 ::ctrlaltdel "p6::ctrlaltdel:/sbin/init 6"
 162         lxc_start $1
 163         ( nohup $0 watchdog $1 >> /tmp/$1.log 2>/dev/null ) &
 164         ;;
 165 stop|halt)
 166         lxc_exists $1
 167         lxc_stop $1
 168         ;;
 169 reload|force-reload|restart|reboot)
 170         lxc_kill $1 -SIGINT
 171         ;;
 172 watchdog)
 173         lxc_watchdog $1
 174         ;;
 175 *)
 176         echo "Usage: $0 {start|stop|restart|status}" >&2
 177         exit 3
 178         ;;
 179
 180 esac
 181
 182 }
 183
 184 command=$1
 185 shift
 186
 187 test "$command" = "status" && lxc_status && exit
 188
 189 if [ -z "$1" ] ; then
 190         ls /var/lib/lxc/*/on_boot | while read path ; do
 191                 name=`echo $path | cut -d/ -f5`
 192                 command_on_lxc $command $name
 193         done
 194 else
 195         while [ ! -z "$1" ] ; do
 196                 command_on_lxc $command $1
 197                 shift
 198         done
 199 fi
 200