ConfFixture should work even when zmq/redis is not present

Previous driver and other locations in the code we used
zmq_async.import_zmq() and importutils.try_import() to
not fail fast when pyzmq and redis python packages are
not installed. If we don't do this, we are going to break
Nova/Cinder/Glance etc.

Closes-Bug: #1503499
Change-Id: I1529241b5e1d902b37d6b610646a5a46a18f13b0

oslo_messaging/_drivers/zmq_driver/broker/zmq_broker.py

@@ -18,12 +18,12 @@ import os
 from oslo_utils import excutils
 import six
 from stevedore import driver
-import zmq
 
 from oslo_messaging._drivers.zmq_driver.broker import zmq_queue_proxy
+from oslo_messaging._drivers.zmq_driver import zmq_async
 from oslo_messaging._i18n import _LE, _LI
 
-
+zmq = zmq_async.import_zmq(zmq_concurrency='native')
 LOG = logging.getLogger(__name__)
 
 

oslo_messaging/_drivers/zmq_driver/broker/zmq_queue_proxy.py

@@ -15,7 +15,6 @@
 import logging
 
 import six
-import zmq
 
 from oslo_messaging._drivers.zmq_driver.broker import zmq_base_proxy
 from oslo_messaging._drivers.zmq_driver.client.publishers\
@@ -24,6 +23,7 @@ from oslo_messaging._drivers.zmq_driver import zmq_address
 from oslo_messaging._drivers.zmq_driver import zmq_async
 from oslo_messaging._i18n import _LI
 
+zmq = zmq_async.import_zmq(zmq_concurrency='native')
 LOG = logging.getLogger(__name__)
 
 

oslo_messaging/_drivers/zmq_driver/matchmaker/matchmaker_redis.py

@@ -14,11 +14,11 @@
 import logging
 
 from oslo_config import cfg
-import redis
+from oslo_utils import importutils
 
 from oslo_messaging._drivers.zmq_driver.matchmaker import base
 
-
+redis = importutils.try_import('redis')
 LOG = logging.getLogger(__name__)
 
 

oslo_messaging/_drivers/zmq_driver/poller/threading_poller.py

@@ -16,10 +16,12 @@ import logging
 import threading
 
 from oslo_utils import eventletutils
-import zmq
 
+from oslo_messaging._drivers.zmq_driver import zmq_async
 from oslo_messaging._drivers.zmq_driver import zmq_poller
 
+zmq = zmq_async.import_zmq(zmq_concurrency='native')
+
 LOG = logging.getLogger(__name__)
 
 _threading = threading

oslo_messaging/_drivers/zmq_driver/zmq_async.py

@@ -14,8 +14,6 @@
 
 import logging
 
-from oslo_messaging._drivers.zmq_driver.poller import green_poller
-from oslo_messaging._drivers.zmq_driver.poller import threading_poller
 from oslo_messaging._i18n import _, _LE
 from oslo_utils import importutils
 
@@ -45,7 +43,10 @@ def get_poller(zmq_concurrency='eventlet'):
     _raise_error_if_invalid_config_value(zmq_concurrency)
 
     if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
+        from oslo_messaging._drivers.zmq_driver.poller import green_poller
         return green_poller.GreenPoller()
+
+    from oslo_messaging._drivers.zmq_driver.poller import threading_poller
     return threading_poller.ThreadingPoller()
 
 
@@ -53,7 +54,10 @@ def get_reply_poller(zmq_concurrency='eventlet'):
     _raise_error_if_invalid_config_value(zmq_concurrency)
 
     if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
+        from oslo_messaging._drivers.zmq_driver.poller import green_poller
         return green_poller.HoldReplyPoller()
+
+    from oslo_messaging._drivers.zmq_driver.poller import threading_poller
     return threading_poller.ThreadingPoller()
 
 
@@ -61,7 +65,10 @@ def get_executor(method, zmq_concurrency='eventlet'):
     _raise_error_if_invalid_config_value(zmq_concurrency)
 
     if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
+        from oslo_messaging._drivers.zmq_driver.poller import green_poller
         return green_poller.GreenExecutor(method)
+
+    from oslo_messaging._drivers.zmq_driver.poller import threading_poller
     return threading_poller.ThreadingExecutor(method)