add daemon supervisor

The supervise-daemon process is meant to be a lightweight supervisor
which can monitor and restart a daemon if it crashes.

1 files changed, 49 insertions, 0 deletions

diff --git a/sh/supervise-daemon.sh b/sh/supervise-daemon.sh
new file mode 100644
index 00000000..34e3ef71
--- /dev/null
+++ b/sh/supervise-daemon.sh
@@ -0,0 +1,49 @@
+# start / stop / status functions for supervise-daemon
+
+# Copyright (c) 2016 The OpenRC Authors.
+# See the Authors file at the top-level directory of this distribution and
+# https://github.com/OpenRC/openrc/blob/master/AUTHORS
+#
+# This file is part of OpenRC. It is subject to the license terms in
+# the LICENSE file found in the top-level directory of this
+# distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
+# This file may not be copied, modified, propagated, or distributed
+#    except according to the terms contained in the LICENSE file.
+
+supervise_start()
+{
+	if [ -z "$command" ]; then
+		ewarn "The command variable is undefined."
+		ewarn "There is nothing for ${name:-$RC_SVCNAME} to start."
+		return 1
+	fi
+
+	ebegin "Starting ${name:-$RC_SVCNAME}"
+	eval supervise-daemon --start \
+		${pidfile:+--pidfile} $pidfile \
+		${command_user+--user} $command_user \
+		$supervise_daemon_args \
+		$command \
+		-- $command_args $command_args_foreground
+	rc=$?
+	[ -n "${pidfile}" ] && service_set_value "pidfile" "${pidfile}"
+	eend $rc "failed to start $RC_SVCNAME"
+}
+
+supervise_stop()
+{
+	local startpidfile="$(service_get_value "pidfile")"
+	pidfile="${startpidfile:-$pidfile}"
+	[ -n "$pidfile" ] || return 0
+	ebegin "Stopping ${name:-$RC_SVCNAME}"
+	supervise-daemon --stop \
+		${pidfile:+--pidfile} $pidfile \
+		${stopsig:+--signal} $stopsig
+
+	eend $? "Failed to stop $RC_SVCNAME"
+}
+
+supervise_status()
+{
+	_status
+}