Handle deferred stops

The ovs package in kinetic+ (zed+) uses  dh_installsystemd with
--no-start for ovsdb-server, ovs-vswitchd, and ovs-record-hostname.
this results in stop events rather than restart events. This
change updates the restart-services actions for this charm to
handle stop events.

Closes-Bug: #2012553
Change-Id: If1dd5d0e5ca640a91893376366b23e78649d5772

src/actions/restart-services

@@ -1,26 +0,0 @@
-#!/usr/bin/env python3
-# Copyright 2021 Canonical Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#  http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import sys
-
-
-sys.path.append('actions')
-
-
-import os_deferred_event_actions
-
-
-if __name__ == "__main__":
-    sys.exit(os_deferred_event_actions.main(sys.argv))

src/actions/restart-services

@@ -0,0 +1 @@
+restart_services.py

src/actions/restart_services.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+# Copyright 2021 Canonical Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import datetime
+import sys
+
+
+sys.path.append('actions')
+sys.path.append('lib')
+
+from charms.layer import basic
+basic.bootstrap_charm_deps()
+
+import charmhelpers.contrib.openstack.deferred_events as deferred_events
+import charmhelpers.contrib.openstack.utils as os_utils
+import charmhelpers.core.hookenv as hookenv
+import charms_openstack.charm
+
+import os_deferred_event_actions
+
+charms_openstack.bus.discover()
+
+
+def restart_services(args):
+    """Restart services.
+
+    :param args: Unused
+    :type args: List[str]
+    """
+    deferred_only = hookenv.action_get("deferred-only")
+    services = hookenv.action_get("services").split()
+    os_deferred_event_actions.restart_services(args)
+    # Clear deferred stops. If the services start time is after the
+    # requested stop time we can infer the stop has happened. This is
+    # to work around Bug #2012553
+    deferred_stops = [
+        e
+        for e in deferred_events.get_deferred_events()
+        if e.action == 'stop']
+    for event in deferred_stops:
+        start_time = deferred_events.get_service_start_time(event.service)
+        deferred_stop_time = datetime.datetime.fromtimestamp(
+            event.timestamp)
+        if start_time > deferred_stop_time:
+            deferred_events.clear_deferred_events([event.service], 'stop')
+        else:
+            if deferred_only or event.service in services:
+                os_utils.restart_services_action([event.service])
+                deferred_events.clear_deferred_events([event.service], 'stop')
+    with charms_openstack.charm.provide_charm_instance() as charm_instance:
+        charm_instance._assess_status()
+
+
+def main(args):
+    hookenv._run_atstart()
+    try:
+        restart_services(args)
+    except Exception as e:
+        hookenv.action_fail(str(e))
+    hookenv._run_atexit()
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))