Ensure queue is declared durable so messages aren't dropped

Fixes bug lp901375

Ensure that a queue is declared durable so messages aren't dropped before
consumers are started

Change-Id: I9f8dfd6eaf3996be58fecff6ad91508bdcef23f3

nova/rpc/impl_kombu.py

@@ -290,6 +290,27 @@ class FanoutPublisher(Publisher):
                 **options)
 
 
+class NotifyPublisher(TopicPublisher):
+    """Publisher class for 'notify'"""
+
+    def __init__(self, *args, **kwargs):
+        self.durable = kwargs.pop('durable', FLAGS.rabbit_durable_queues)
+        super(NotifyPublisher, self).__init__(*args, **kwargs)
+
+    def reconnect(self, channel):
+        super(NotifyPublisher, self).reconnect(channel)
+
+        # NOTE(jerdfelt): Normally the consumer would create the queue, but
+        # we do this to ensure that messages don't get dropped if the
+        # consumer is started after we do
+        queue = kombu.entity.Queue(channel=channel,
+                exchange=self.exchange,
+                durable=self.durable,
+                name=self.routing_key,
+                routing_key=self.routing_key)
+        queue.declare()
+
+
 class Connection(object):
     """Connection object."""
 
@@ -461,14 +482,18 @@ class Connection(object):
         """Send a 'direct' message"""
         self.publisher_send(DirectPublisher, msg_id, msg)
 
-    def topic_send(self, topic, msg, **kwargs):
+    def topic_send(self, topic, msg):
         """Send a 'topic' message"""
-        self.publisher_send(TopicPublisher, topic, msg, **kwargs)
+        self.publisher_send(TopicPublisher, topic, msg)
 
     def fanout_send(self, topic, msg):
         """Send a 'fanout' message"""
         self.publisher_send(FanoutPublisher, topic, msg)
 
+    def notify_send(self, topic, msg, **kwargs):
+        """Send a notify message on a topic"""
+        self.publisher_send(NotifyPublisher, topic, msg, **kwargs)
+
     def consume(self, limit=None):
         """Consume from all queues/consumers"""
         it = self.iterconsume(limit=limit)
@@ -778,7 +803,7 @@ def notify(context, topic, msg):
     LOG.debug(_('Sending notification on %s...'), topic)
     _pack_context(msg, context)
     with ConnectionContext() as conn:
-        conn.topic_send(topic, msg, durable=True)
+        conn.notify_send(topic, msg, durable=True)
 
 
 def msg_reply(msg_id, reply=None, failure=None, ending=False):