fix qpid test issue with eventlet monkey patching

Tests now ensure that eventlet monkey patching is enabled before
importing the qpid module, otherwise qpid will hang.

Currently, qpid randomly hangs, depending on the order of the Python
module import, which probably depends on the local file modification
time.

Closes-Bug: #1409899
Change-Id: I516c580faef04f55fcc095d22adbfabcfa001da7

tests/__init__.py

@@ -1 +1,23 @@
+# Copyright 2014 eNovance
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
 
+try:
+    import eventlet
+except ImportError:
+    pass
+else:
+    # Ensure that eventlet monkey patching is enabled before loading the qpid
+    # module, otherwise qpid will hang
+    eventlet.monkey_patch()

tests/drivers/test_impl_zmq.py

@@ -24,12 +24,8 @@ from oslo import messaging
 from oslo.utils import importutils
 from oslo_messaging.tests import utils as test_utils
 
-# NOTE(jamespage) the zmq driver implementation is currently tied
-# to eventlet so we have to monkey_patch to support testing
 # eventlet is not yet py3 compatible, so skip if not installed
 eventlet = importutils.try_import('eventlet')
-if eventlet:
-    eventlet.monkey_patch()
 
 impl_zmq = importutils.try_import('oslo.messaging._drivers.impl_zmq')