recepies/lxc/lxc-watchdog.sh

#!/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

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/^ *//'
}


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 {}
}


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

}


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

}


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 ${vps_utmp}
        tasks=`wc -l < /cgroup/${name}/tasks`
        test -z "$tasks" && exit 1
        if [ "$tasks" -eq 1 ]; then

                runlevel="$(runlevel ${vps_utmp})"
                echo "# $name runlevel $runlevel"

                case $runlevel in
                N*)
                        # nothing for new boot state
                ;;
                ??0)
                        echo "$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
                        lxc-start -d -n ${name} -o /tmp/${name}.log
                ;;
                *)
                        # make sure vps is still running
                        state="$(lxc-info -n "${name}" | sed -e 's/.* is //')"
                        [ "$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

1	dpavlin	181	#!/bin/sh
2	root	175
3	dpavlin	181	# 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	root	175	# http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00074.html
12
13	dpavlin	181
14	dpavlin	177	which inotifywait >/dev/null \|\| apt-get install inotify-tools
15	root	175
16	dpavlin	181	lxc_status() {
17			lxc-ls -1 \| sort -u \| xargs -i lxc-info -n {}
18			}
19	root	175
20	dpavlin	181	lxc_exists() {
21			name=$1
22	root	175
23	dpavlin	181	if [ ! -e /var/lib/lxc/$name/config ] ; then
24			echo "Usage: $0 name"
25			lxc_status
26			exit 1
27			fi
28			}
29	root	175
30	dpavlin	179
31	dpavlin	181	lxc_rootfs() {
32			grep lxc.rootfs "/var/lib/lxc/$1/config" \| cut -d= -f2 \| sed 's/^ *//'
33			}
34	dpavlin	178
35	root	175
36	dpavlin	181	cleanup_init_scripts() {
37			rootfs=$(lxc_rootfs $1)
38	dpavlin	179
39	dpavlin	181	ls \
40			$rootfs/etc/rc?.d/*umountfs \
41			$rootfs/etc/rc?.d/*umountroot \
42			$rootfs/etc/rc?.d/hwclock \
43			2>/dev/null \| xargs -i rm -v {}
44			}
45	dpavlin	179
46	dpavlin	181
47			setup_inittab() {
48			rootfs=$(lxc_rootfs $1)
49
50			# let container respond to kill -SIGPWR
51			inittab=$rootfs/etc/inittab
52			powerfail="pw::powerfail:/sbin/init 0"
53			if ! grep "$powerfail" ${inittab} >/dev/null ; then
54			grep -v ::power ${inittab} > ${inittab}.new
55			echo $powerfail >> ${inittab}.new
56			mv ${inittab}.new ${inittab}
57			echo "$initab modified"
58			fi
59
60			}
61
62
63			lxc_stop() {
64			name=$1
65
66			init_pid=`lxc-ps -C init -o pid \| grep "^$name" \| cut -d" " -f2-`
67			if [ -z "$init_pid" ] ; then
68			lxc-info -n $name
69			exit 1
70			fi
71			echo "$name stop $init_pid"
72			/bin/kill -SIGPWR $init_pid
73	dpavlin	179	lxc-wait -n $name -s STOPPED
74
75	dpavlin	181	}
76	dpavlin	179
77
78	dpavlin	181	lxc_start() {
79			name=$1
80
81			if ! lxc-info -n $name \| grep RUNNING ; then
82			echo "$name start"
83			lxc-start -n $name -o /tmp/${name}.log -d
84			lxc-wait -n $name -s RUNNING
85			lxc-info -n $name
86			fi
87			}
88
89			lxc_watchdog() {
90			name=$1
91			rootfs=$(lxc_rootfs $1)
92
93	root	175	while true; do
94			# time of 5 minutes on it JUST IN CASE...
95			vps_utmp=${rootfs}/var/run/utmp
96			inotifywait -qqt 300 ${vps_utmp}
97	dpavlin	181	tasks=`wc -l < /cgroup/${name}/tasks`
98			test -z "$tasks" && exit 1
99			if [ "$tasks" -eq 1 ]; then
100	root	175
101			runlevel="$(runlevel ${vps_utmp})"
102			echo "# $name runlevel $runlevel"
103
104			case $runlevel in
105			N*)
106			# nothing for new boot state
107			;;
108			??0)
109			echo "$name halt"
110			lxc-stop -n "${name}"
111	dpavlin	181	lxc-wait -n ${name} -s STOPPED
112	root	175	break
113			;;
114			??6)
115			echo "$name reboot";
116			lxc-stop -n ${name}
117			lxc-wait -n ${name} -s STOPPED
118			lxc-start -d -n ${name} -o /tmp/${name}.log
119			;;
120			*)
121			# make sure vps is still running
122			state="$(lxc-info -n "${name}" \| sed -e 's/.* is //')"
123			[ "$state" = "RUNNING" ] \|\| break
124			;;
125			esac
126	dpavlin	181	else
127			echo "# $name $tasks tasks"
128	root	175	fi
129			done
130
131	dpavlin	181	echo "${name} exited"
132
133			}
134
135
136			case "$1" in
137
138			start)
139			lxc_exists $2
140			cleanup_init_scripts $2
141			setup_inittab $2
142			lxc_start $2
143			( nohup $0 watchdog $2 >> /tmp/$2.log ) &
144			;;
145			stop)
146			lxc_exists $2
147			lxc_stop $2
148			;;
149			status)
150			lxc_status
151			;;
152			reload\|force-reload\|restart)
153			lxc_stop $2
154			lxc_start $2
155			;;
156			watchdog)
157			lxc_watchdog $2
158			;;
159			*)
160			echo "Usage: $0 {start\|stop\|restart\|status}" >&2
161			exit 3
162			;;
163
164			esac
165