Add toggle for notifications.Publisher

akanda/rug/main.py

@@ -202,7 +202,7 @@ def register_and_load_opts():
     ceilometer_group = cfg.OptGroup(name='ceilometer',
                                     title='Ceilometer Reporting Options')
     c_enable_reporting = cfg.BoolOpt('enabled', default=False)
-    c_topic = cfg.StrOpt('notification_topic',
+    c_topic = cfg.StrOpt('topic',
                          default='notifications.info',
                          help='The name of the topic queue ceilometer '
                               'consumes events from.')
@@ -271,13 +271,14 @@ def _stop_processing(*args):
     )
     metadata_proc.start()
 
-    if cfg.CONF.ceilometer.enabled:
-        # Set up the notifications publisher
-        publisher = notifications.Publisher(
-            cfg.CONF.amqp_url,
-            exchange_name=cfg.CONF.outgoing_notifications_exchange,
-            topic=cfg.CONF.ceilometer.topic,
-        )
+    # Set up the notifications publisher
+    Publisher = (notifications.Publisher if cfg.CONF.ceilometer.enabled
+                 else notifications.NoopPublisher)
+    publisher = Publisher(
+        cfg.CONF.amqp_url,
+        exchange_name=cfg.CONF.outgoing_notifications_exchange,
+        topic=cfg.CONF.ceilometer.topic,
+    )
 
     # Set up a factory to make Workers that know how many threads to
     # run.

akanda/rug/notifications.py

@@ -431,3 +431,26 @@ def _send(self, ready):
                     sender.send(msg)
                 except Exception:
                     LOG.exception('could not publish notification')
+
+
+class NoopPublisher(Publisher):
+    """A Publisher that doesn't do anything.
+
+    The code that publishes notifications is spread across several
+    classes and cannot be easily disabled in configurations that do
+    not require sending metrics to ceilometer.
+
+    This class is used in place of the Publisher class to disable
+    sending metrics without explicitly checking in various places
+    across the code base.
+
+    """
+
+    def start(self):
+        pass
+
+    def stop(self):
+        pass
+
+    def publish(self, incoming):
+        pass

akanda/rug/test/unit/test_main.py

@@ -19,6 +19,7 @@
 import unittest2 as unittest
 
 from akanda.rug import main
+from akanda.rug import notifications as ak_notifications
 
 
 @mock.patch('akanda.rug.main.cfg')
@@ -65,3 +66,25 @@ def test_ensure_local_service_port(self, shuffle_notifications, health,
         main.main()
         quantum = quantum_api.Quantum.return_value
         quantum.ensure_local_service_port.assert_called_once_with()
+
+    def test_ceilometer_disabled(self, shuffle_notifications, health,
+                                 populate, scheduler, notifications,
+                                 multiprocessing, quantum_api, cfg):
+        cfg.CONF.ceilometer.enabled = False
+        notifications.Publisher = mock.Mock(spec=ak_notifications.Publisher)
+        notifications.NoopPublisher = mock.Mock(
+            spec=ak_notifications.NoopPublisher)
+        main.main()
+        self.assertEqual(len(notifications.Publisher.mock_calls), 0)
+        self.assertEqual(len(notifications.NoopPublisher.mock_calls), 1)
+
+    def test_ceilometer_enabled(self, shuffle_notifications, health,
+                                populate, scheduler, notifications,
+                                multiprocessing, quantum_api, cfg):
+        cfg.CONF.ceilometer.enabled = True
+        notifications.Publisher = mock.Mock(spec=ak_notifications.Publisher)
+        notifications.NoopPublisher = mock.Mock(
+            spec=ak_notifications.NoopPublisher)
+        main.main()
+        self.assertEqual(len(notifications.Publisher.mock_calls), 1)
+        self.assertEqual(len(notifications.NoopPublisher.mock_calls), 0)