Fix handling expected exceptions in rabbit driver

We shouldn't be logging expected exceptions. Add a failing rabbit driver
test to check this and fix it.

Change-Id: I78b758957117be7c11c5826a27dd6d1d4fffe9cb

oslo/messaging/_drivers/amqpdriver.py

@@ -40,7 +40,8 @@ class AMQPIncomingMessage(base.IncomingMessage):
     def _send_reply(self, conn, reply=None, failure=None,
                     ending=False, log_failure=True):
         if failure:
-            failure = rpc_common.serialize_remote_exception(failure)
+            failure = rpc_common.serialize_remote_exception(failure,
+                                                            log_failure)
 
         msg = {'result': reply, 'failure': failure}
         if ending:

tests/test_rabbit.py

@@ -24,6 +24,7 @@ import kombu
 import testscenarios
 
 from oslo import messaging
+from oslo.messaging._drivers import common as driver_common
 from oslo.messaging._drivers import impl_rabbit as rabbit_driver
 from oslo.messaging.openstack.common import jsonutils
 from oslo.messaging import transport as msg_transport
@@ -96,6 +97,14 @@ class TestSendReceive(test_utils.BaseTestCase):
         senders = []
         replies = []
         msgs = []
+        errors = []
+
+        def stub_error(msg, *a, **kw):
+            if (a and len(a) == 1 and isinstance(a[0], dict) and a[0]):
+                a = a[0]
+            errors.append(str(msg) % a)
+
+        self.stubs.Set(driver_common.LOG, 'error', stub_error)
 
         def send_and_wait_for_reply(i):
             try:
@@ -150,6 +159,11 @@ class TestSendReceive(test_utils.BaseTestCase):
             else:
                 self.assertEqual(reply, {'bar': order[i]})
 
+        if not self.timeout and self.failure and not self.expected:
+            self.assertTrue(len(errors) > 0, errors)
+        else:
+            self.assertEqual(len(errors), 0, errors)
+
 
 TestSendReceive.generate_scenarios()