Prevent update-status to run unrequired handlers

Before the update-status hook would run handlers that are expected to
run when the configuration changes or relations added/removed.

The update-status hook doesn't hold the machine lock which makes
concurrent hook executions possible and seen in the gate where for
example multiple "apt-get" executions trying to acquire dpkg's lock.

Closes-Bug: #2016893
Change-Id: I63bfd9903057cbea2db8de4f1b612601aacb568d

src/reactive/placement_handlers.py

@@ -34,6 +34,7 @@ charms_openstack.charm.use_defaults(
 )
 
 
+@reactive.when_not('is-update-status-hook')
 @reactive.when('shared-db.available')
 @reactive.when('identity-service.available')
 def render_config(*args):
@@ -60,6 +61,7 @@ def render_config(*args):
     reactive.set_state('config.rendered')
 
 
+@reactive.when_not('is-update-status-hook')
 @reactive.when('config.rendered')
 @reactive.when('placement.available')
 @reactive.when_not('db.synced')
@@ -77,6 +79,7 @@ def init_db():
             reactive.set_state('db.synced')
 
 
+@reactive.when_not('is-update-status-hook')
 @reactive.when('ha.connected')
 def cluster_connected(hacluster):
     """Configure HA resources in corosync"""

unit_tests/test_placement_handlers.py

@@ -40,7 +40,9 @@ class TestRegisteredHooks(test_utils.TestRegisteredHooks):
                 'cluster_connected': ('ha.connected',),
             },
             'when_not': {
-                'init_db': ('db.synced',),
+                'init_db': ('db.synced', 'is-update-status-hook'),
+                'render_config': ('is-update-status-hook', ),
+                'cluster_connected': ('is-update-status-hook', ),
             },
         }
         # test that the hooks were registered via the