Add log_handler to oslo.messaging

Move log_handler from oslo-incubator to oslo.messaging and include
unit tests. This patch also adds an additional test case from the
original version in oslo-incubator. Originally, the test case only
checked to make sure the notification was not sent. Now a positive test
case exists to test both paths.

bp graduate-notifier-log-handler
Co-Authored By: Ben Nemec <bnemec@redhat.com>

Change-Id: I9ea051ec7e3614579341a31d8dc1c13d9514b8a9

oslo/messaging/notify/log_handler.py

@@ -0,0 +1,36 @@
+# 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 logging
+
+from oslo.config import cfg
+from oslo import messaging
+
+
+class PublishErrorsHandler(logging.Handler):
+    def __init__(self, *args, **kwargs):
+        logging.Handler.__init__(self, *args, **kwargs)
+        self._transport = messaging.get_transport(cfg.CONF)
+        self._notifier = messaging.Notifier(self._transport,
+                                            publisher_id='error.publisher')
+
+    def emit(self, record):
+        # NOTE(bnemec): Notifier registers this opt with the transport.
+        if ('log' in self._transport.conf.notification_driver):
+            # NOTE(lbragstad): If we detect that log is one of the
+            # notification drivers, then return. This protects from infinite
+            # recursion where something bad happens, it gets logged, the log
+            # handler sends a notification, and the log_notifier sees the
+            # notification and logs it.
+            return
+        self._notifier.error(None, 'error_notification',
+                             dict(error=record.msg))

tests/test_log_handler.py

@@ -0,0 +1,66 @@
+# 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 logging
+import mock
+
+from oslo import messaging
+from oslo.messaging.notify import log_handler
+from tests import test_notifier
+from tests import utils as test_utils
+
+
+class PublishErrorsHandlerTestCase(test_utils.BaseTestCase):
+    """Tests for log.PublishErrorsHandler"""
+    def setUp(self):
+        super(PublishErrorsHandlerTestCase, self).setUp()
+        self.conf.register_opts(messaging.notify.notifier._notifier_opts)
+        self.publisherrorshandler = (log_handler.
+                                     PublishErrorsHandler(logging.ERROR))
+
+    def test_emit_cfg_log_notifier_in_notifier_drivers(self):
+        drivers = ['messaging', 'log']
+        self.config(notification_driver=drivers)
+        self.stub_flg = True
+
+        transport = test_notifier._FakeTransport(self.conf)
+        notifier = messaging.Notifier(transport)
+
+        def fake_notifier(*args, **kwargs):
+            self.stub_flg = False
+
+        self.stubs.Set(notifier, 'error', fake_notifier)
+
+        logrecord = logging.LogRecord(name='name', level='WARN',
+                                      pathname='/tmp', lineno=1, msg='Message',
+                                      args=None, exc_info=None)
+        self.publisherrorshandler.emit(logrecord)
+        self.assertTrue(self.stub_flg)
+
+    @mock.patch.object(messaging.notify.notifier.Notifier, '_notify')
+    def test_emit_notification(self, mock_notify):
+        logrecord = logging.LogRecord(name='name', level='ERROR',
+                                      pathname='/tmp', lineno=1, msg='Message',
+                                      args=None, exc_info=None)
+        mock_init = mock.Mock(return_value=None)
+        with mock.patch.object(messaging.notify.notifier.Notifier,
+                               '__init__', mock_init):
+            # Recreate the handler so the __init__ mock takes effect.
+            self.publisherrorshandler = (log_handler.
+                                         PublishErrorsHandler(logging.ERROR))
+            self.publisherrorshandler.emit(logrecord)
+            mock_init.assert_called_with(mock.ANY,
+                                         publisher_id='error.publisher')
+            mock_notify.assert_called_with(None,
+                                           'error_notification',
+                                           {'error': 'Message'},
+                                           'ERROR')