Notification and CDM partial update

In this changeset, I implemented the notification handling (Rx only)
system for consuming incoming notifications, more especially the Nova
ones. The notifications handlers also contain the logic which
incrementally updates the Compute model.

Change-Id: Ia036a5a2be6caa64b7f180de38821b57c624300c
Partially-implements: blueprint cluster-model-objects-wrapper

watcher/tests/decision_engine/model/notification/test_notifications.py

@@ -0,0 +1,106 @@
+# -*- encoding: utf-8 -*-
+# Copyright (c) 2016 b<>com
+#
+# Authors: Vincent FRANCOISE <vincent.francoise@b-com.com>
+#
+# 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 os
+
+import mock
+from oslo_serialization import jsonutils
+
+from watcher.common import context
+from watcher.common import service as watcher_service
+from watcher.decision_engine.model.notification import base
+from watcher.decision_engine.model.notification import filtering
+from watcher.tests import base as base_test
+from watcher.tests.decision_engine.model.notification import fake_managers
+
+
+class DummyManager(fake_managers.FakeManager):
+
+    def __init__(self):
+        super(DummyManager, self).__init__()
+        self.notification_endpoints = [DummyNotification(self.fake_cdmc)]
+
+
+class DummyNotification(base.NotificationEndpoint):
+
+    @property
+    def filter_rule(self):
+        return filtering.NotificationFilter(
+            publisher_id=r'.*',
+            event_type=r'compute.dummy',
+            payload={'data': {'nested': r'^T.*'}},
+        )
+
+    def info(self, ctxt, publisher_id, event_type, payload, metadata):
+        pass
+
+
+class NotificationTestCase(base_test.TestCase):
+
+    def load_message(self, filename):
+        cwd = os.path.abspath(os.path.dirname(__file__))
+        data_folder = os.path.join(cwd, "data")
+
+        with open(os.path.join(data_folder, filename), 'rb') as json_file:
+            json_data = jsonutils.load(json_file)
+
+        return json_data
+
+
+class TestReceiveNotifications(NotificationTestCase):
+
+    def setUp(self):
+        super(TestReceiveNotifications, self).setUp()
+
+        p_from_dict = mock.patch.object(context.RequestContext, 'from_dict')
+        m_from_dict = p_from_dict.start()
+        m_from_dict.return_value = self.context
+        self.addCleanup(p_from_dict.stop)
+
+    @mock.patch.object(DummyNotification, 'info')
+    def test_receive_dummy_notification(self, m_info):
+        message = {
+            'publisher_id': 'nova-compute',
+            'event_type': 'compute.dummy',
+            'payload': {'data': {'nested': 'TEST'}},
+            'priority': 'INFO',
+        }
+        de_service = watcher_service.Service(DummyManager)
+        incoming = mock.Mock(ctxt=self.context.to_dict(), message=message)
+
+        de_service.notification_handler.dispatcher.dispatch(incoming)
+
+        m_info.assert_called_once_with(
+            self.context, 'nova-compute', 'compute.dummy',
+            {'data': {'nested': 'TEST'}},
+            {'message_id': None, 'timestamp': None})
+
+    @mock.patch.object(DummyNotification, 'info')
+    def test_skip_unwanted_notification(self, m_info):
+        message = {
+            'publisher_id': 'nova-compute',
+            'event_type': 'compute.dummy',
+            'payload': {'data': {'nested': 'unwanted'}},
+            'priority': 'INFO',
+        }
+        de_service = watcher_service.Service(DummyManager)
+        incoming = mock.Mock(ctxt=self.context.to_dict(), message=message)
+
+        de_service.notification_handler.dispatcher.dispatch(incoming)
+
+        self.assertEqual(0, m_info.call_count)