deb-ceilometer/ceilometer/plugin.py
Julien Danjou 6ddde20759 Rework RPC notification mechanism
We allow plugin to specify clearly which exchange and topic there are
interested in, and we call directly the handler process notification without
looking in a dict to be faster.

Change-Id: I867f0b2568d140bfc0dae63163fd02c8c080d8d1
Signed-off-by: Julien Danjou <julien@danjou.info>
2012-10-01 12:51:09 +02:00

70 lines
2.2 KiB
Python

# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.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.
"""Base class for plugins.
"""
import abc
from collections import namedtuple
from ceilometer.openstack.common import cfg
# Import rabbit_notifier to register notification_topics flag so that
# plugins can use it
import ceilometer.openstack.common.notifier.rabbit_notifier
ExchangeTopics = namedtuple('ExchangeTopics', ['exchange', 'topics'])
class NotificationBase(object):
"""Base class for plugins that support the notification API."""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def get_event_types(self):
"""Return a sequence of strings defining the event types to be
given to this plugin."""
@abc.abstractmethod
def get_exchange_topics(self, conf):
"""Return a sequence of ExchangeTopics defining the exchange and
topics to be connected for this plugin."""
@abc.abstractmethod
def process_notification(self, message):
"""Return a sequence of Counter instances for the given message."""
def notification_to_metadata(self, event):
"""Transform a payload dict to a metadata dict."""
metadata = dict([(k, event['payload'].get(k))
for k in self.metadata_keys])
metadata['event_type'] = event['event_type']
metadata['host'] = event['publisher_id']
return metadata
class PollsterBase(object):
"""Base class for plugins that support the polling API."""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def get_counters(self, manager, instance):
"""Return a sequence of Counter instances from polling the
resources."""