rewrite into init-like script with start/stop/status name

git-svn-id: svn://svn.rot13.org/sysadmin-cookbook@181 191e9f34-6774-4a6d-acfc-7664dacd4a2a

diff --git a/recepies/lxc/lxc-watchdog.sh b/recepies/lxc/lxc-watchdog.sh
index 7d0b0cd..b616eeb 100755 (executable)
--- a/recepies/lxc/lxc-watchdog.sh
+++ b/recepies/lxc/lxc-watchdog.sh
@@ -1,61 +1,102 @@
-#!/bin/bash
-
-# based on Tony Risinger code from lxc-users
+#!/bin/sh
+
+# lxc-watchdog.sh
+#
+# Dobrica Pavlinusic <dpavlin@rot13.org> 2010-03-15
+#
+# this script can be used to start/stop Linux containers 
+# using clever inotify hack to monitor halt/reboot from
+# Tony Risinger posted to lxc-users mailing list
+#
 # http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00074.html
 
+
 which inotifywait >/dev/null || apt-get install inotify-tools
 
-name=$1
+lxc_status() {
+       lxc-ls -1 | sort -u | xargs -i lxc-info -n {}
+}
+
+lxc_exists() {
+       name=$1
+
+       if [ ! -e /var/lib/lxc/$name/config ] ; then
+               echo "Usage: $0 name"
+               lxc_status
+               exit 1
+       fi
+}
+
+
+lxc_rootfs() {
+       grep lxc.rootfs "/var/lib/lxc/$1/config" | cut -d= -f2 | sed 's/^ *//'
+}
 
-if [ ! -e /var/lib/lxc/$name/config ] ; then
-       echo "Usage: $0 name"
-       ls /var/lib/lxc/*/config | cut -d/ -f5
-       exit 1
-fi
 
-rootfs=`grep lxc.rootfs /var/lib/lxc/$name/config | cut -d= -f2`
-echo "$name rootfs $rootfs"
+cleanup_init_scripts() {
+       rootfs=$(lxc_rootfs $1)
 
+       ls \
+               $rootfs/etc/rc?.d/*umountfs \
+               $rootfs/etc/rc?.d/*umountroot \
+               $rootfs/etc/rc?.d/*hwclock* \
+       2>/dev/null | xargs -i rm -v {}
+}
 
-# cleanup init scripts which don't work in containers
-ls \
-       $rootfs/etc/rc?.d/*umountfs \
-       $rootfs/etc/rc?.d/*umountroot \
-       $rootfs/etc/rc?.d/*hwclock* \
-2>/dev/null | xargs -i rm -v {}
 
+setup_inittab() {
+       rootfs=$(lxc_rootfs $1)
+
+       # let container respond to kill -SIGPWR
+       inittab=$rootfs/etc/inittab
+       powerfail="pw::powerfail:/sbin/init 0"
+       if ! grep "$powerfail" ${inittab} >/dev/null ; then
+               grep -v ::power ${inittab} > ${inittab}.new
+               echo $powerfail >> ${inittab}.new
+               mv ${inittab}.new ${inittab}
+               echo "$initab modified"
+       fi
 
-# let container respond to kill -SIGPWR
-inittab=$rootfs/etc/inittab
-powerfail="pw::powerfail:/sbin/init 0"
-if ! grep "$powerfail" ${inittab} >/dev/null ; then
-       grep -v ::power ${inittab} > ${inittab}.new
-       echo $powerfail >> ${inittab}.new
-       mv ${inittab}.new ${inittab}
-       echo "$initab modified"
-fi
+}
 
 
-if [ "$2" == "stop" ] ; then
-       echo "$name stop"
-       kill -SIGPWR `lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
+lxc_stop() {
+       name=$1
+
+       init_pid=`lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
+       if [ -z "$init_pid" ] ; then
+               lxc-info -n $name
+               exit 1
+       fi
+       echo "$name stop $init_pid"
+       /bin/kill -SIGPWR $init_pid
        lxc-wait -n $name -s STOPPED
-       exit
-fi
+
+}
 
 
-if ! lxc-info -n $name | grep RUNNING ; then
-       echo "$name start"
-       lxc-start -n $name -o /tmp/${name}.log -d
-       lxc-wait  -n $name -s RUNNING
-       lxc-info  -n $name
-fi
+lxc_start() {
+       name=$1
+
+       if ! lxc-info -n $name | grep RUNNING ; then
+               echo "$name start"
+               lxc-start -n $name -o /tmp/${name}.log -d
+               lxc-wait  -n $name -s RUNNING
+               lxc-info  -n $name
+       fi
+}
+
+lxc_watchdog() {
+name=$1
+rootfs=$(lxc_rootfs $1)
 
 while true; do
        # time of 5 minutes on it JUST IN CASE...
        vps_utmp=${rootfs}/var/run/utmp
        inotifywait -qqt 300 ${vps_utmp}
-       if [ $(wc -l < /cgroup/${name}/tasks) -eq 1 ]; then
+       tasks=`wc -l < /cgroup/${name}/tasks`
+       test -z "$tasks" && exit 1
+       if [ "$tasks" -eq 1 ]; then
 
                runlevel="$(runlevel ${vps_utmp})"
                echo "# $name runlevel $runlevel"
@@ -67,13 +108,13 @@ while true; do
                ??0)
                        echo "$name halt"
                        lxc-stop -n "${name}"
+                       lxc-wait -n ${name} -s STOPPED
                        break
                ;;
                ??6)
                        echo "$name reboot";
                        lxc-stop -n ${name}
                        lxc-wait -n ${name} -s STOPPED
-                       mount /mnt/llin -o remount,rw
                        lxc-start -d -n ${name} -o /tmp/${name}.log
                ;;
                *)
@@ -82,6 +123,43 @@ while true; do
                        [ "$state" = "RUNNING" ] || break
                ;;
                esac
+       else
+               echo "# $name $tasks tasks"
        fi
 done
 
+echo "${name} exited"
+
+}
+
+
+case "$1" in
+
+start)
+       lxc_exists $2
+       cleanup_init_scripts $2
+       setup_inittab $2
+       lxc_start $2
+       ( nohup $0 watchdog $2 >> /tmp/$2.log ) &
+       ;;
+stop)
+       lxc_exists $2
+       lxc_stop $2
+       ;;
+status)
+       lxc_status
+       ;;
+reload|force-reload|restart)
+       lxc_stop $2
+       lxc_start $2
+       ;;
+watchdog)
+       lxc_watchdog $2
+       ;;
+*)
+       echo "Usage: $0 {start|stop|restart|status}" >&2
+       exit 3
+       ;;
+
+esac
+