Added ability to detect import errors in list_notifier if one or more drivers could not be loaded.

Authors

@@ -99,6 +99,7 @@ Scott Moser <smoser@ubuntu.com>
 Soren Hansen <soren.hansen@rackspace.com>
 Stephanie Reese <reese.sm@gmail.com>
 Thierry Carrez <thierry@openstack.org>
+Tim Simpson <tim.simpson@rackspace.com>
 Todd Willey <todd@ansolabs.com>
 Trey Morris <trey.morris@rackspace.com>
 Tushar Patil <tushar.vitthal.patil@gmail.com>

nova/notifier/list_notifier.py

@@ -16,6 +16,7 @@
 from nova import flags
 from nova import log as logging
 from nova import utils
+from nova.exception import ClassNotFound
 
 flags.DEFINE_multistring('list_notifier_drivers',
                          ['nova.notifier.no_op_notifier'],
@@ -27,17 +28,31 @@ LOG = logging.getLogger('nova.notifier.list_notifier')
 
 drivers = None
 
-def __get_drivers():
+
+class ImportFailureNotifier(object):
+
+    def __init__(self, exception):
+        self.exception = exception
+
+    def notify(message):
+        raise self.exception
+
+
+def _get_drivers():
     """Instantiates and returns drivers based on the flag values."""
     global drivers
     if not drivers:
-        drivers = [utils.import_object(notification_driver)
+        drivers = []
-                   for notification_driver in FLAGS.list_notifier_drivers]
+        for notification_driver in FLAGS.list_notifier_drivers:
+            try:
+                drivers.append(utils.import_object(notification_driver))
+            except ClassNotFound as e:
+                drivers.append(ImportFailureNotifier(e))
     return drivers
 
 def notify(message):
     """Passes notification to mulitple notifiers in a list."""
-    for driver in __get_drivers():
+    for driver in _get_drivers():
         try:
             driver.notify(message)
         except Exception as e:

nova/tests/notifier/test_list_notifier.py

@@ -31,10 +31,26 @@ from nova import test
 
 class NotifierListTestCase(test.TestCase):
     """Test case for notifications"""
+
     def setUp(self):
         super(NotifierListTestCase, self).setUp()
         list_notifier._reset_drivers()
         self.stubs = stubout.StubOutForTesting()
+        # Mock log to add one to exception_count when log.exception is called
+        def mock_exception(cls, *args):
+            self.exception_count += 1
+        self.exception_count = 0
+        list_notifier_log = logging.getLogger('nova.notifier.list_notifier')
+        self.stubs.Set(list_notifier_log, "exception", mock_exception)
+        # Mock no_op notifier to add one to notify_count when called.
+        def mock_notify(cls, *args):
+            self.notify_count += 1
+        self.notify_count = 0
+        self.stubs.Set(nova.notifier.no_op_notifier, 'notify', mock_notify)
+        # Mock log_notifier to raise RuntimeError when called.
+        def mock_notify2(cls, *args):
+            raise RuntimeError("Bad notifier.")
+        self.stubs.Set(nova.notifier.log_notifier, 'notify', mock_notify2)
 
     def tearDown(self):
         self.stubs.UnsetAll()
@@ -45,41 +61,25 @@ class NotifierListTestCase(test.TestCase):
         self.flags(notification_driver='nova.notifier.list_notifier',
                    list_notifier_drivers=['nova.notifier.no_op_notifier',
                                           'nova.notifier.no_op_notifier'])
-        self.notify_count = 0
-
-        def mock_notify(cls, *args):
-            self.notify_count += 1
-
-        self.stubs.Set(nova.notifier.no_op_notifier, 'notify',
-                mock_notify)
-
         notify('publisher_id', 'event_type',
                 nova.notifier.api.WARN, dict(a=3))
         self.assertEqual(self.notify_count, 2)
+        self.assertEqual(self.exception_count, 0)
 
     def test_send_notifications_with_errors(self):
-        self.exception_count = 0
-        def mock_exception(cls, *args):
-            self.exception_count += 1
-
-        self.notify_count = 0
-        def mock_notify(cls, *args):
-            self.notify_count += 1
-
-        def mock_notify2(cls, *args):
-            raise RuntimeError("Bad notifier.")
 
         self.flags(notification_driver='nova.notifier.list_notifier',
                    list_notifier_drivers=['nova.notifier.no_op_notifier',
                                           'nova.notifier.log_notifier'])
-
-        list_notifier_log = logging.getLogger('nova.notifier.list_notifier')
-        list_notifier_log.exception
-        self.stubs.Set(list_notifier_log, "exception", mock_exception)
-        self.stubs.Set(nova.notifier.no_op_notifier, 'notify', mock_notify)
-        self.stubs.Set(nova.notifier.log_notifier, 'notify', mock_notify2)
-
         notify('publisher_id', 'event_type', nova.notifier.api.WARN, dict(a=3))
-
         self.assertEqual(self.notify_count, 1)
         self.assertEqual(self.exception_count, 1)
+
+    def test_when_driver_fails_to_import(self):
+        self.flags(notification_driver='nova.notifier.list_notifier',
+                   list_notifier_drivers=['nova.notifier.no_op_notifier',
+                                          'nova.notifier.logo_notifier',
+                                          'fdsjgsdfhjkhgsfkj'])
+        notify('publisher_id', 'event_type', nova.notifier.api.WARN, dict(a=3))
+        self.assertEqual(self.exception_count, 2)
+        self.assertEqual(self.notify_count, 1)