recepies/lxc/lxc-watchdog.sh

#! /bin/sh
### BEGIN INIT INFO
# Provides:          lxc-watchdog
# Required-Start:    $remote_fs $named $network $time
# Required-Stop:     $remote_fs $named $network
# Required-Start:    
# Required-Stop:     
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Manage Linux Containers startup/shutdown
# Description:       Uses clever inotify hack to monitor container's
#                    halt/reboot events watching /var/run/utmp
### END INIT INFO

# Author: Dobrica Pavlinusic <dpavlin@rot13.org>
#
# based on Tony Risinger post to lxc-users mailing list
# http://www.mail-archive.com/lxc-users@lists.sourceforge.net/msg00074.html
#
# Install with:
# ln -sf /srv/sysadmin-cookbook/recepies/lxc/lxc-watchdog.sh /etc/init.d/lxc-watchdog
# update-rc.d lxc-watchdog defaults


which inotifywait >/dev/null || apt-get install inotify-tools


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/^ *//'
}

lxc_hostname() {
        inside=`cat $(lxc_rootfs $1)/etc/hostname`
        config=`grep lxc.utsname /var/lib/lxc/$name/config | cut -d= -f2`
        echo "$config [$inside]";
}

lxc_ip() {
        ( grep lxc.network.ipv4 /var/lib/lxc/$name/config | cut -d= -f2 || \
        grep address $(lxc_rootfs $name)/etc/network/interfaces | sed 's/.*address //' ) | \
        sed -e 's/ *//g' -e 's/\/.*$//'
}

lxc_status() {
        ( 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
                boot="-"
                test -s /var/lib/lxc/$name/on_boot && boot="boot"
                echo "$name $status $boot $(lxc_rootfs $name) $(lxc_ip $name) $(lxc_hostname $name)"
        done ) | column -t
}


cleanup_init_scripts() {
        rootfs=$(lxc_rootfs $1)

        ls \
                $rootfs/etc/rc?.d/*checkroot* \
                $rootfs/etc/rc?.d/*umountfs \
                $rootfs/etc/rc?.d/*umountroot \
                $rootfs/etc/rc?.d/*hwclock* \
                $rootfs/etc/rc?.d/*udev* \
        2>/dev/null | xargs -i rm -v {}

        echo $1 > $rootfs/etc/hostname
        grep $1 $rootfs/etc/hosts || echo "$(lxc_ip $1) $1" >> $rootfs/etc/hosts
}


setup_inittab() {
        rootfs=$(lxc_rootfs $1)
        remove=$2
        add=$3

        # let container respond to kill -SIGPWR
        inittab=$rootfs/etc/inittab
        if test -e $inittab && ! grep "$add" ${inittab} >/dev/null ; then
                grep -v "$remove" ${inittab} > ${inittab}.new
                echo $add >> ${inittab}.new
                mv ${inittab}.new ${inittab}
                echo "$inittab modified with $add"
        fi
}


lxc_log() {
        echo `date +%Y-%m-%dT%H:%M:%S` $*
}


lxc_kill() {
        name=$1
        sig=$2

        init_pid=`lxc-ps -C init -o pid | grep "^$name" | cut -d" " -f2-`
        if [ -z "$init_pid" ] ; then
                lxc-info -n $name
                exit 1
        fi
        lxc_log "$name kill $sig $init_pid"
        /bin/kill $sig $init_pid
}

lxc_stop() {
        lxc_log "$name stop"
        lxc_kill $name -SIGPWR
        lxc-wait -n $name -s STOPPED
        lxc_log "$name stoped"
#       rm -f /var/lib/lxc/${name}/on_boot
}


lxc_start() {
        name=$1
        rootfs=$(lxc_rootfs $1)

        if [ ! -e $rootfs ] ; then
                echo "ERROR $name rootfs $rootfs not found"
                return
        fi

        if ! lxc-info -n $name | grep RUNNING ; then
                lxc_log "$name start"
                lxc-start -n $name -o /tmp/${name}.log -d
                lxc-wait  -n $name -s RUNNING
                lxc-info  -n $name
                test -f /var/lib/lxc/${name}/on_boot || echo $name > /var/lib/lxc/${name}/on_boot
        fi
}

lxc_watchdog() {
name=$1
rootfs=$(lxc_rootfs $1)

while true; do
        vps_utmp=${rootfs}/var/run/utmp
        tasks=`wc -l < /cgroup/${name}/tasks`
        test -z "$tasks" && exit 1
        if [ "$tasks" -eq 1 ]; then

                runlevel="$(runlevel ${vps_utmp})"
                lxc_log "$name runlevel $runlevel"

                case $runlevel in
                N*)
                        # nothing for new boot state
                ;;
                ??0)
                        lxc_log "$name halt"
                        lxc-stop -n "${name}"
                        lxc-wait -n ${name} -s STOPPED
                        break
                ;;
                ??6)
                        lxc_log "$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 //')"
                        [ "$state" = "RUNNING" ] || break
                ;;
                esac
        else
                lxc_log "$name $tasks tasks"
        fi

        # time of 5 minutes on it JUST IN CASE...
        inotifywait -qqt 300 ${vps_utmp}
done

lxc_log "$name watchdog exited"

}


usage() {
        echo "Usage: $0 {start|stop|restart|status|boot|disable} [name name ... ]" >&2
        exit 3
}

command_on_lxc() {
command=$1
shift

echo "# $command $1"

case "$command" in

start)
        lxc_exists $1
        cleanup_init_scripts $1
        setup_inittab $1 ":respawn:/sbin/getty.*tty1"   "c1:12345:respawn:/sbin/getty 38400 tty1 linux"
        setup_inittab $1 "::power"                      "p0::powerfail:/sbin/init 0"
        setup_inittab $1 "::ctrlaltdel"                 "p6::ctrlaltdel:/sbin/init 6"
        lxc_start $1
        # give container 5 seconds to start more than one process
        ( sleep 5 ; nohup $0 watchdog $1 >> /tmp/$1.log 2>/dev/null ) &
        ;;
stop|halt)
        lxc_exists $1
        lxc_stop $1
        ;;
reload|force-reload|restart|reboot)
        lxc_kill $1 -SIGINT
        ;;
watchdog)
        lxc_watchdog $1
        ;;
boot)
        echo $1 > /var/lib/lxc/$1/on_boot
        ;;
disable)
        echo -n > /var/lib/lxc/$1/on_boot
        ;;
*)
        usage
        ;;

esac

}

command=$1
test -z "$command" && usage
test "$command" = "status" && lxc_status && exit
shift

if [ -z "$1" ] ; then
        ls /var/lib/lxc/*/on_boot | while read path ; do
                name=`echo $path | cut -d/ -f5`
                if [ "$command" != "start" -o "$command" = "start" -a -s $path ] ; then
                        command_on_lxc $command $name
                else
                        echo "# skip $command $name"
                fi
        done
else
        while [ ! -z "$1" ] ; do
                command_on_lxc $command $1
                shift
        done
fi

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