Fix the topic and server that the listener client uses

This was only working for one heat engine as it was sending
the listener messages to a topic of "engine_id".

Change-Id: Ib542d1ebb85b004f5a67213e678882c5a723dc0e
Closes-bug: 1433821

heat/engine/service.py

@@ -232,7 +232,7 @@ class EngineListener(service.Service):
         super(EngineListener, self).start()
         self.target = messaging.Target(
             server=self.engine_id,
-            topic="heat-engine-listener")
+            topic=rpc_api.LISTENER_TOPIC)
         server = rpc_messaging.get_rpc_server(self.target, self)
         server.start()
 
@@ -863,7 +863,8 @@ class EngineService(service.Service):
         self.cctxt = self._client.prepare(
             version='1.0',
             timeout=timeout,
-            topic=lock_engine_id)
+            topic=rpc_api.LISTENER_TOPIC,
+            server=lock_engine_id)
         try:
             self.cctxt.call(cnxt, call, *args, **kwargs)
         except messaging.MessagingTimeout:

heat/engine/stack_lock.py

@@ -24,7 +24,7 @@ from heat.common.i18n import _LI
 from heat.common.i18n import _LW
 from heat.common import messaging as rpc_messaging
 from heat.objects import stack_lock as stack_lock_object
-
+from heat.rpc import api as rpc_api
 
 cfg.CONF.import_opt('engine_life_check_timeout', 'heat.common.config')
 
@@ -41,7 +41,7 @@ class StackLock(object):
     @staticmethod
     def engine_alive(context, engine_id):
         client = rpc_messaging.get_rpc_client(
-            version='1.0', topic="heat-engine-listener",
+            version='1.0', topic=rpc_api.LISTENER_TOPIC,
             server=engine_id)
         client_context = client.prepare(
             timeout=cfg.CONF.engine_life_check_timeout)

heat/rpc/api.py

@@ -12,6 +12,7 @@
 #    under the License.
 
 ENGINE_TOPIC = 'engine'
+LISTENER_TOPIC = 'heat-engine-listener'
 
 PARAM_KEYS = (
     PARAM_TIMEOUT, PARAM_DISABLE_ROLLBACK, PARAM_ADOPT_STACK_DATA,