moby/contrib/init/upstart/docker.conf

description "Docker daemon"

start on (filesystem and net-device-up IFACE!=lo)
stop on runlevel [!2345]

limit nofile 524288 1048576

# Having non-zero limits causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
limit nproc unlimited unlimited

respawn

kill timeout 20

pre-start script
	# see also https://github.com/tianon/cgroupfs-mount/blob/master/cgroupfs-mount
	if grep -v '^#' /etc/fstab | grep -q cgroup \
		|| [ ! -e /proc/cgroups ] \
		|| [ ! -d /sys/fs/cgroup ]; then
		exit 0
	fi
	if ! mountpoint -q /sys/fs/cgroup; then
		mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
	fi
	(
		cd /sys/fs/cgroup
		for sys in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
			mkdir -p $sys
			if ! mountpoint -q $sys; then
				if ! mount -n -t cgroup -o $sys cgroup $sys; then
					rmdir $sys || true
				fi
			fi
		done
	)
end script

script
	# modify these in /etc/default/$UPSTART_JOB (/etc/default/docker)
	DOCKERD=/usr/bin/dockerd
	DOCKER_OPTS=
	if [ -f /etc/default/$UPSTART_JOB ]; then
		. /etc/default/$UPSTART_JOB
	fi
	exec "$DOCKERD" $DOCKER_OPTS --raw-logs
end script

# Don't emit "started" event until docker.sock is ready.
# See https://github.com/docker/docker/issues/6647
post-start script
	DOCKER_OPTS=
	DOCKER_SOCKET=
	if [ -f /etc/default/$UPSTART_JOB ]; then
		. /etc/default/$UPSTART_JOB
	fi

	if ! printf "%s" "$DOCKER_OPTS" | grep -qE -e '-H|--host'; then
		DOCKER_SOCKET=/var/run/docker.sock
	else
		DOCKER_SOCKET=$(printf "%s" "$DOCKER_OPTS" | grep -oP -e '(-H|--host)\W*unix://\K(\S+)' | sed 1q)
	fi

	if [ -n "$DOCKER_SOCKET" ]; then
		while ! [ -e "$DOCKER_SOCKET" ]; do
			initctl status $UPSTART_JOB | grep -qE "(stop|respawn)/" && exit 1
			echo "Waiting for $DOCKER_SOCKET"
			sleep 0.1
		done
		echo "$DOCKER_SOCKET is up"
	fi
end script