aodh/ceilometer/plugin.py
Julien Danjou 00531f9de0 Unify Counter generation from notifications
This will make sure we don't lose any metadata information from
notifications into the Counter/samples we publish.

This is part of fixing bug #1187833 and bug #1187843

Change-Id: I315581907be1dcec33f43a5d5fd7b7876a7889f6
Signed-off-by: Julien Danjou <julien@danjou.info>
2013-07-05 13:40:25 +02:00

93 lines
2.8 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
import collections
from oslo.config import cfg
# Import this option so every Notification plugin can use it freely.
cfg.CONF.import_opt('notification_topics',
'ceilometer.openstack.common.notifier.rpc_notifier')
ExchangeTopics = collections.namedtuple('ExchangeTopics',
['exchange', 'topics'])
class PluginBase(object):
"""Base class for all plugins.
"""
@staticmethod
def is_enabled():
"""Return boolean indicating whether this plugin should
be enabled and used by the caller.
"""
return True
class NotificationBase(PluginBase):
"""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.
:param conf: Configuration.
"""
@abc.abstractmethod
def process_notification(self, message):
"""Return a sequence of Counter instances for the given message.
:param message: Message to process.
"""
class PollsterBase(PluginBase):
"""Base class for plugins that support the polling API."""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def get_counter_names(self):
"""Return a sequence of Counter names supported by the pollster."""
@abc.abstractmethod
def get_counters(self, manager, cache):
"""Return a sequence of Counter instances from polling the resources.
:param manager: The service manager class invoking the plugin.
:param cache: A dictionary to allow pollsters to pass data
between themselves when recomputing it would be
expensive (e.g., asking another service for a
list of objects).
"""