openstack/oslo.messaging
Code Issues Proposed changes

Implements notification-dispatcher-filter

Browse Source 
The NotificationFilter class is used to filter notifications that a
notification listerner endpoint will received.

The notification can be filtered on different fields: context,
publisher_id, event_type, metadata, and payload

DocImpact
Implements: blueprint notification-dispatcher-filter
Change-Id: Ic1239422fac9879b113c9d3d6c3f8dccef20d044
This commit is contained in:
Mehdi Abaakouk 2014-03-03 19:35:16 +01:00 committed by gordon chung
parent e55a83e832
commit 3d232a0f38
5 changed files with 197 additions and 3 deletions
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2
oslo_messaging/notify/__init__.py
View File

@ -17,9 +17,11 @@ __all__ = ['Notifier',
'LoggingNotificationHandler',
'get_notification_listener',
'NotificationResult',
'NotificationFilter',
'PublishErrorsHandler',
'LoggingErrorNotificationHandler']
from .filter import NotificationFilter
from .notifier import *
from .listener import *
from .log_handler import *

9
oslo_messaging/notify/dispatcher.py
View File

@ -56,7 +56,9 @@ class NotificationDispatcher(object):
for endpoint, prio in itertools.product(endpoints, PRIORITIES):
if hasattr(endpoint, prio):
method = getattr(endpoint, prio)
self._callbacks_by_priority.setdefault(prio, []).append(method)
screen = getattr(endpoint, 'filter_rule', None)
self._callbacks_by_priority.setdefault(prio, []).append(
(screen, method))
priorities = self._callbacks_by_priority.keys()
self._targets_priorities = set(itertools.product(self.targets,
@ -118,7 +120,10 @@ class NotificationDispatcher(object):
payload = self.serializer.deserialize_entity(ctxt,
message.get('payload'))
for callback in self._callbacks_by_priority.get(priority, []):
for screen, callback in self._callbacks_by_priority.get(priority, []):
if screen and not screen.match(ctxt, publisher_id, event_type,
metadata, payload):
continue
localcontext.set_local_context(ctxt)
try:
if executor_callback:

77
oslo_messaging/notify/filter.py Normal file
View File

@ -0,0 +1,77 @@
#
# Copyright 2013 eNovance
#
# 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 re
class NotificationFilter(object):
"""Filter notification messages
The NotificationFilter class is used to filter notifications that an
endpoint will received.
The notification can be filter on different fields: context,
publisher_id, event_type, metadata and payload.
The filter is done via a regular expression
filter_rule = NotificationFilter(
publisher_id='^compute.*',
context={'tenant_id': '^5f643cfc-664b-4c69-8000-ce2ed7b08216$',
'roles='private'},
event_type='^compute\.instance\..*',
metadata={'timestamp': 'Aug'},
payload={'state': '^active$')
"""
def __init__(self, context=None, publisher_id=None, event_type=None,
metadata=None, payload=None):
self._regex_publisher_id = None
self._regex_event_type = None
if publisher_id is not None:
self._regex_publisher_id = re.compile(publisher_id)
if event_type is not None:
self._regex_event_type = re.compile(event_type)
self._regexs_context = self._build_regex_dict(context)
self._regexs_metadata = self._build_regex_dict(metadata)
self._regexs_payload = self._build_regex_dict(payload)
@staticmethod
def _build_regex_dict(regex_list):
if regex_list is None:
return {}
return dict((k, re.compile(regex_list[k])) for k in regex_list)
@staticmethod
def _check_for_mismatch(data, regex):
if isinstance(regex, dict):
for k in regex:
if (k not in data or not regex[k].match(data[k])):
return True
elif regex is not None and not regex.match(data):
return True
return False
def match(self, context, publisher_id, event_type, metadata, payload):
if (self._check_for_mismatch(publisher_id, self._regex_publisher_id) or
self._check_for_mismatch(event_type, self._regex_event_type) or
self._check_for_mismatch(context, self._regexs_context) or
self._check_for_mismatch(metadata, self._regexs_metadata) or
self._check_for_mismatch(payload, self._regexs_payload)):
return False
return True

8
oslo_messaging/notify/listener.py
View File

@ -44,10 +44,15 @@ A simple example of a notification listener with multiple endpoints might be::
import oslo_messaging
class NotificationEndpoint(object):
filter_rule = NotificationFilter(publisher_id='^compute.*')
def warn(self, ctxt, publisher_id, event_type, payload, metadata):
do_something(payload)
class ErrorEndpoint(object):
filter_rule = NotificationFilter(event_type='^instance\..*\.start$',
context={'ctxt_key': 'regexp'})
def error(self, ctxt, publisher_id, event_type, payload, metadata):
do_something(payload)
@ -69,7 +74,8 @@ A simple example of a notification listener with multiple endpoints might be::
A notifier sends a notification on a topic with a priority, the notification
listener will receive this notification if the topic of this one have been set
in one of the targets and if an endpoint implements the method named like the
priority
priority and if the notification match the NotificationFilter rule set into
the filter_rule attribute of the endpoint.
Parameters to endpoint methods are the request context supplied by the client,
the publisher_id of the notification message, the event_type, the payload and

104
oslo_messaging/tests/notify/test_dispatcher.py
View File

@ -147,3 +147,107 @@ class TestDispatcher(test_utils.BaseTestCase):
callback()
mylog.warning.assert_called_once_with('Unknown priority "%s"',
'what???')
class TestDispatcherFilter(test_utils.BaseTestCase):
scenarios = [
('publisher_id_match',
dict(filter_rule=dict(publisher_id='^compute.*'),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=True)),
('publisher_id_nomatch',
dict(filter_rule=dict(publisher_id='^compute.*'),
publisher_id='network01.manager',
event_type='instance.create.start',
context={},
match=False)),
('event_type_match',
dict(filter_rule=dict(event_type='^instance\.create'),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=True)),
('event_type_nomatch',
dict(filter_rule=dict(event_type='^instance\.delete'),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=False)),
('context_match',
dict(filter_rule=dict(context={'user': '^adm'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={'user': 'admin'},
match=True)),
('context_key_missing',
dict(filter_rule=dict(context={'user': '^adm'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={'project': 'admin'},
metadata={},
match=False)),
('metadata_match',
dict(filter_rule=dict(metadata={'message_id': '^99'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=True)),
('metadata_key_missing',
dict(filter_rule=dict(metadata={'user': '^adm'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=False)),
('payload_match',
dict(filter_rule=dict(payload={'state': '^active$'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=True)),
('payload_no_match',
dict(filter_rule=dict(payload={'state': '^deleted$'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=False)),
('payload_key_missing',
dict(filter_rule=dict(payload={'user': '^adm'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={},
match=False)),
('mix_match',
dict(filter_rule=dict(event_type='^instance\.create',
publisher_id='^compute',
context={'user': '^adm'}),
publisher_id='compute01.manager',
event_type='instance.create.start',
context={'user': 'admin'},
match=True)),
]
def test_filters(self):
notification_filter = oslo_messaging.NotificationFilter(
**self.filter_rule)
endpoint = mock.Mock(spec=['info'], filter_rule=notification_filter)
targets = [oslo_messaging.Target(topic='notifications')]
dispatcher = notify_dispatcher.NotificationDispatcher(
targets, [endpoint], serializer=None, allow_requeue=True)
message = {'payload': {'state': 'active'},
'priority': 'info',
'publisher_id': self.publisher_id,
'event_type': self.event_type,
'timestamp': '2014-03-03 18:21:04.369234',
'message_id': '99863dda-97f0-443a-a0c1-6ed317b7fd45'}
incoming = mock.Mock(ctxt=self.context, message=message)
with dispatcher(incoming) as callback:
callback()
if self.match:
self.assertEqual(1, endpoint.info.call_count)
else:
self.assertEqual(0, endpoint.info.call_count)