Ensure that manager.py is stopped when keystone restarted

This patch ensures that any running manager.py script is stopped if the
keystone service (either standalone, or run via apache2) is restarted.
The ManagerServer will automatically (re)start the manager.py script
when it is needed.

Change-Id: I4e3dff340cce73b2de7d697f3685d602defb5179
Related-Bug: #1823743

hooks/keystone_hooks.py

@@ -125,6 +125,7 @@ from keystone_utils import (
     pause_unit_helper,
     resume_unit_helper,
     remove_old_packages,
+    stop_manager_instance,
 )
 
 from charmhelpers.contrib.hahelpers.cluster import (
@@ -243,6 +244,7 @@ def config_changed_postupgrade():
             CONFIGS.write(WSGI_KEYSTONE_API_CONF)
         if not is_unit_paused_set():
             restart_pid_check('apache2')
+            stop_manager_instance()
 
     if enable_memcache(release=release):
         # If charm or OpenStack have been upgraded then the list of required
@@ -262,6 +264,7 @@ def config_changed_postupgrade():
 
     if snap_install_requested() and not is_unit_paused_set():
         service_restart('snap.keystone.*')
+        stop_manager_instance()
 
     if (is_db_initialised() and is_elected_leader(CLUSTER_RES) and not
             is_unit_paused_set()):
@@ -670,6 +673,7 @@ def upgrade_charm():
         log("Package purge detected, restarting services", "INFO")
         for s in services():
             service_restart(s)
+        stop_manager_instance()
 
     if is_elected_leader(CLUSTER_RES):
         log('Cluster leader - ensuring endpoint configuration is up to '