Ensure services shutdown during unit testing

* Use stop() instead of kill() in Service fixture.
* Add reset() methods to each rpcapi, and call them after
  shutting down services, allowing for the above to work.

Change-Id: I90a1d9c40fc7f60864cfbfc7c9e47429405bc32c
Closes-Bug: 1411717

designate/central/rpcapi.py

@@ -26,6 +26,11 @@ LOG = logging.getLogger(__name__)
 CENTRAL_API = None
 
 
+def reset():
+    global CENTRAL_API
+    CENTRAL_API = None
+
+
 @rpc_logging(LOG, 'central')
 class CentralAPI(object):
     """

designate/mdns/rpcapi.py

@@ -25,6 +25,11 @@ LOG = logging.getLogger(__name__)
 MDNS_API = None
 
 
+def reset():
+    global MDNS_API
+    MDNS_API = None
+
+
 @rpc_logging(LOG, 'mdns')
 class MdnsAPI(object):
 

designate/pool_manager/rpcapi.py

@@ -28,6 +28,11 @@ LOG = logging.getLogger(__name__)
 MNGR_API = None
 
 
+def reset():
+    global MNGR_API
+    MNGR_API = None
+
+
 @rpc_logging(LOG, 'pool_manager')
 class PoolManagerAPI(object):
     """

designate/tests/fixtures.py

@@ -74,17 +74,31 @@ class ServiceFixture(fixtures.Fixture):
         cls = importutils.import_class(
             'designate.%s.service.Service' % svc_name)
         self.svc = cls()
+        self.svc_name = svc_name
 
     def setUp(self):
         super(ServiceFixture, self).setUp()
+        LOG.info('Starting service %s (%s)', self.svc_name, id(self.svc))
         self.svc.start()
-        self.addCleanup(self.kill)
+        self.addCleanup(self.stop)
+
+    def stop(self):
+        LOG.info('Stopping service %s (%s)', self.svc_name, id(self.svc))
 
-    def kill(self):
         try:
-            self.svc.kill()
+            self.svc.stop()
+
         except Exception:
-            pass
+            LOG.error('Failed to stop service %s (%s)',
+                      self.svc_name, id(self.svc))
+            raise
+
+        finally:
+            # Always try reset the service's RPCAPI
+            mod = importutils.try_import('designate.%s.rpcapi' % self.svc_name)
+            if hasattr(mod, 'reset'):
+                LOG.info('Resetting service %s RPCAPI', self.svc_name)
+                mod.reset()
 
 
 class PolicyFixture(fixtures.Fixture):

designate/zone_manager/rpcapi.py

@@ -26,6 +26,11 @@ LOG = logging.getLogger(__name__)
 ZONE_MANAGER_API = None
 
 
+def reset():
+    global ZONE_MANAGER_API
+    ZONE_MANAGER_API = None
+
+
 @rpc_logging(LOG, 'zone_manager')
 class ZoneManagerAPI(object):
     """