package/docker-engine: rewrite dockerd init script

This brings the dockerd init script in line with the standard
Buildroot init script pattern.

Reload using SIGHUP is also supported now, note that the Docker
documentation cautions that not all parameters can be changed at
runtime (without a full restart).

Signed-off-by: Fiona Klute (WIWA) <fiona.klute@gmx.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/docker-engine/S60dockerd

@@ -1,38 +1,68 @@
 #!/bin/sh
 
-NAME=dockerd
-DAEMON=/usr/bin/$NAME
-PIDFILE=/var/run/$NAME.pid
-DAEMON_ARGS=""
+DAEMON="dockerd"
+PIDFILE="/var/run/$DAEMON.pid"
 
-[ -r /etc/default/$NAME ] && . /etc/default/$NAME $1
+DOCKERD_ARGS=""
 
-do_start() {
-        echo -n "Starting $NAME: "
-        start-stop-daemon --start --quiet --background --make-pidfile \
-		--pidfile $PIDFILE --exec $DAEMON -- $DAEMON_ARGS \
-                && echo "OK" || echo "FAIL"
+# shellcheck source=/dev/null
+[ -r "/etc/default/$DAEMON" ] && . "/etc/default/$DAEMON"
+
+start() {
+	printf 'Starting %s: ' "$DAEMON"
+	# shellcheck disable=SC2086 # we need word splitting for DOCKERD_ARGS
+	start-stop-daemon --start --background --pidfile "$PIDFILE" \
+		--exec "/usr/bin/$DAEMON" \
+		-- --pidfile "$PIDFILE" $DOCKERD_ARGS
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+	return "$status"
 }
 
-do_stop() {
-        echo -n "Stopping $NAME: "
-        start-stop-daemon --stop --quiet --pidfile $PIDFILE \
-                && echo "OK" || echo "FAIL"
+stop() {
+	printf 'Stopping %s: ' "$DAEMON"
+	start-stop-daemon --stop --pidfile "$PIDFILE" --exec "/usr/bin/$DAEMON"
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+		return "$status"
+	fi
+	while start-stop-daemon --stop --test --quiet --pidfile "$PIDFILE" \
+		--exec "/usr/bin/$DAEMON"; do
+		sleep 0.1
+	done
+	rm -f "$PIDFILE"
+	return "$status"
+}
+
+restart() {
+	stop
+	start
+}
+
+reload() {
+	printf "Reloading %s config: " "$DAEMON"
+	start-stop-daemon --stop --signal HUP -q --pidfile "$PIDFILE" \
+		--exec "/usr/bin/$DAEMON"
+	status=$?
+	if [ "$status" -eq 0 ]; then
+		echo "OK"
+	else
+		echo "FAIL"
+	fi
+	return "$status"
 }
 
 case "$1" in
-        start)
-                do_start
-                ;;
-        stop)
-                do_stop
-                ;;
-        restart)
-                do_stop
-                sleep 1
-                do_start
-                ;;
+	start|stop|restart|reload)
+		"$1";;
 	*)
-                echo "Usage: $0 {start|stop|restart}"
-                exit 1
+		echo "Usage: $0 {start|stop|restart|reload}"
+		exit 1
 esac