Add unit tests for zmq_async

Change option from boolean zmq_native to string zmq_concurrency. This
eliminates ambiguity by requiring the user to explicitly name
the mechanism they want to use for concurrency.

Change-Id: I341a3eee73a0449716d3ee0df690bbe6af39bdf0

3 files changed, 210 insertions, 30 deletions

diff --git a/oslo_messaging/_drivers/impl_zmq.py b/oslo_messaging/_drivers/impl_zmq.py
index 064fe7c..18086eb 100644
--- a/oslo_messaging/_drivers/impl_zmq.py
+++ b/oslo_messaging/_drivers/impl_zmq.py
@@ -48,10 +48,8 @@ zmq_opts = [
                 default=True,
                 help='Use REQ/REP pattern for all methods CALL/CAST/FANOUT.'),
 
-    cfg.BoolOpt('rpc_zmq_native',
-                default=False,
-                help='Switches ZeroMQ eventlet/threading way of usage.'
-                     'Affects pollers, executors etc.'),
+    cfg.StrOpt('rpc_zmq_concurrency', default='eventlet',
+               help='Type of concurrency used. Either "native" or "eventlet"'),
 
     # The following port is unassigned by IANA as of 2012-05-21
     cfg.IntOpt('rpc_zmq_port', default=9501,
diff --git a/oslo_messaging/_drivers/zmq_driver/zmq_async.py b/oslo_messaging/_drivers/zmq_driver/zmq_async.py
index 2617463..7f437fd 100644
--- a/oslo_messaging/_drivers/zmq_driver/zmq_async.py
+++ b/oslo_messaging/_drivers/zmq_driver/zmq_async.py
@@ -14,20 +14,25 @@
 
 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
 
-from oslo_messaging._i18n import _LE
-
 LOG = logging.getLogger(__name__)
 
-green_zmq = importutils.try_import('eventlet.green.zmq')
+# Map zmq_concurrency config option names to the actual module name.
+ZMQ_MODULES = {
+    'native': 'zmq',
+    'eventlet': 'eventlet.green.zmq',
+}
+
 
+def import_zmq(zmq_concurrency='eventlet'):
+    _raise_error_if_invalid_config_value(zmq_concurrency)
 
-def import_zmq(native_zmq=False):
-    if native_zmq:
-        imported_zmq = importutils.try_import('zmq')
-    else:
-        imported_zmq = green_zmq or importutils.try_import('zmq')
+    imported_zmq = importutils.try_import(ZMQ_MODULES[zmq_concurrency],
+                                          default='zmq')
 
     if imported_zmq is None:
         errmsg = _LE("ZeroMQ not found!")
@@ -36,28 +41,35 @@ def import_zmq(native_zmq=False):
     return imported_zmq
 
 
-def get_poller(native_zmq=False):
-    if native_zmq or green_zmq is None:
-        from oslo_messaging._drivers.zmq_driver.poller import threading_poller
-        return threading_poller.ThreadingPoller()
-    else:
-        from oslo_messaging._drivers.zmq_driver.poller import green_poller
+def get_poller(zmq_concurrency='eventlet'):
+    _raise_error_if_invalid_config_value(zmq_concurrency)
+
+    if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
         return green_poller.GreenPoller()
+    return threading_poller.ThreadingPoller()
 
 
-def get_reply_poller(native_zmq=False):
-    if native_zmq or green_zmq is None:
-        from oslo_messaging._drivers.zmq_driver.poller import threading_poller
-        return threading_poller.ThreadingPoller()
-    else:
-        from oslo_messaging._drivers.zmq_driver.poller import green_poller
+def get_reply_poller(zmq_concurrency='eventlet'):
+    _raise_error_if_invalid_config_value(zmq_concurrency)
+
+    if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
         return green_poller.HoldReplyPoller()
+    return threading_poller.ThreadingPoller()
+
 
+def get_executor(method, zmq_concurrency='eventlet'):
+    _raise_error_if_invalid_config_value(zmq_concurrency)
 
-def get_executor(method, native_zmq=False):
-    if native_zmq or green_zmq is None:
-        from oslo_messaging._drivers.zmq_driver.poller import threading_poller
-        return threading_poller.ThreadingExecutor(method)
-    else:
-        from oslo_messaging._drivers.zmq_driver.poller import green_poller
+    if zmq_concurrency == 'eventlet' and _is_eventlet_zmq_available():
         return green_poller.GreenExecutor(method)
+    return threading_poller.ThreadingExecutor(method)
+
+
+def _is_eventlet_zmq_available():
+    return importutils.try_import('eventlet.green.zmq')
+
+
+def _raise_error_if_invalid_config_value(zmq_concurrency):
+    if zmq_concurrency not in ZMQ_MODULES:
+        errmsg = _('Invalid zmq_concurrency value: %s')
+        raise ValueError(errmsg % zmq_concurrency)
diff --git a/oslo_messaging/tests/drivers/zmq/test_zmq_async.py b/oslo_messaging/tests/drivers/zmq/test_zmq_async.py
new file mode 100644
index 0000000..28e091a
--- /dev/null
+++ b/oslo_messaging/tests/drivers/zmq/test_zmq_async.py
@@ -0,0 +1,170 @@
+#    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.
+
+import mock
+
+from oslo_messaging._drivers.zmq_driver.poller import green_poller
+from oslo_messaging._drivers.zmq_driver.poller import threading_poller
+from oslo_messaging._drivers.zmq_driver import zmq_async
+from oslo_messaging.tests import utils as test_utils
+
+
+class TestImportZmq(test_utils.BaseTestCase):
+
+    def setUp(self):
+        super(TestImportZmq, self).setUp()
+
+    def test_config_short_names_are_converted_to_correct_module_names(self):
+        mock_try_import = mock.Mock()
+        zmq_async.importutils.try_import = mock_try_import
+
+        zmq_async.importutils.try_import.return_value = 'mock zmq module'
+        self.assertEqual('mock zmq module', zmq_async.import_zmq('native'))
+        mock_try_import.assert_called_with('zmq', default='zmq')
+
+        zmq_async.importutils.try_import.return_value = 'mock eventlet module'
+        self.assertEqual('mock eventlet module',
+                         zmq_async.import_zmq('eventlet'))
+        mock_try_import.assert_called_with('eventlet.green.zmq', default='zmq')
+
+    def test_when_no_args_then_default_zmq_module_is_loaded(self):
+        mock_try_import = mock.Mock()
+        zmq_async.importutils.try_import = mock_try_import
+
+        zmq_async.import_zmq()
+
+        mock_try_import.assert_called_with('eventlet.green.zmq', default='zmq')
+
+    def test_when_import_fails_then_raise_ImportError(self):
+        zmq_async.importutils.try_import = mock.Mock()
+        zmq_async.importutils.try_import.return_value = None
+
+        with self.assertRaisesRegexp(ImportError, "ZeroMQ not found!"):
+            zmq_async.import_zmq('native')
+
+    def test_invalid_config_value_raise_ValueError(self):
+        invalid_opt = 'x'
+
+        errmsg = 'Invalid zmq_concurrency value: x'
+        with self.assertRaisesRegexp(ValueError, errmsg):
+            zmq_async.import_zmq(invalid_opt)
+
+
+class TestGetPoller(test_utils.BaseTestCase):
+
+    def setUp(self):
+        super(TestGetPoller, self).setUp()
+
+    def test_when_no_arg_to_get_poller_then_return_default_poller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        actual = zmq_async.get_poller()
+
+        self.assertTrue(isinstance(actual, green_poller.GreenPoller))
+
+    def test_when_native_poller_requested_then_return_ThreadingPoller(self):
+        actual = zmq_async.get_poller('native')
+
+        self.assertTrue(isinstance(actual, threading_poller.ThreadingPoller))
+
+    def test_when_eventlet_is_unavailable_then_return_ThreadingPoller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: False
+
+        actual = zmq_async.get_poller('eventlet')
+
+        self.assertTrue(isinstance(actual, threading_poller.ThreadingPoller))
+
+    def test_when_eventlet_is_available_then_return_GreenPoller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        actual = zmq_async.get_poller('eventlet')
+
+        self.assertTrue(isinstance(actual, green_poller.GreenPoller))
+
+    def test_invalid_config_value_raise_ValueError(self):
+        invalid_opt = 'x'
+
+        errmsg = 'Invalid zmq_concurrency value: x'
+        with self.assertRaisesRegexp(ValueError, errmsg):
+            zmq_async.get_poller(invalid_opt)
+
+
+class TestGetReplyPoller(test_utils.BaseTestCase):
+
+    def setUp(self):
+        super(TestGetReplyPoller, self).setUp()
+
+    def test_default_reply_poller_is_HoldReplyPoller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        actual = zmq_async.get_reply_poller()
+
+        self.assertTrue(isinstance(actual, green_poller.HoldReplyPoller))
+
+    def test_when_eventlet_is_available_then_return_HoldReplyPoller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        actual = zmq_async.get_reply_poller('eventlet')
+
+        self.assertTrue(isinstance(actual, green_poller.HoldReplyPoller))
+
+    def test_when_eventlet_is_unavailable_then_return_ThreadingPoller(self):
+        zmq_async._is_eventlet_zmq_available = lambda: False
+
+        actual = zmq_async.get_reply_poller('eventlet')
+
+        self.assertTrue(isinstance(actual, threading_poller.ThreadingPoller))
+
+    def test_invalid_config_value_raise_ValueError(self):
+        invalid_opt = 'x'
+
+        errmsg = 'Invalid zmq_concurrency value: x'
+        with self.assertRaisesRegexp(ValueError, errmsg):
+            zmq_async.get_reply_poller(invalid_opt)
+
+
+class TestGetExecutor(test_utils.BaseTestCase):
+
+    def setUp(self):
+        super(TestGetExecutor, self).setUp()
+
+    def test_default_executor_is_GreenExecutor(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        executor = zmq_async.get_executor('any method')
+
+        self.assertTrue(isinstance(executor, green_poller.GreenExecutor))
+        self.assertEqual('any method', executor._method)
+
+    def test_when_eventlet_module_is_available_then_return_GreenExecutor(self):
+        zmq_async._is_eventlet_zmq_available = lambda: True
+
+        executor = zmq_async.get_executor('any method', 'eventlet')
+
+        self.assertTrue(isinstance(executor, green_poller.GreenExecutor))
+        self.assertEqual('any method', executor._method)
+
+    def test_when_eventlet_is_unavailable_then_return_ThreadingExecutor(self):
+        zmq_async._is_eventlet_zmq_available = lambda: False
+
+        executor = zmq_async.get_executor('any method', 'eventlet')
+
+        self.assertTrue(isinstance(executor,
+                                   threading_poller.ThreadingExecutor))
+        self.assertEqual('any method', executor._method)
+
+    def test_invalid_config_value_raise_ValueError(self):
+        invalid_opt = 'x'
+
+        errmsg = 'Invalid zmq_concurrency value: x'
+        with self.assertRaisesRegexp(ValueError, errmsg):
+            zmq_async.get_executor('any method', invalid_opt)