aodh/ceilometer/plugin.py
Lianhao Lu 5de8c6fce5 Added resources support in pollster's interface
1. Change the pollster's interface to support resources:
- Added optional parameter 'resources' to the method get_samples. It
  specifies a list of the endpoints from which the pollster would get
  data.

2. Change the PollingTask to record the resources for each pollster.

3. Pass the resources recorded in PollingTask to the pollsters in
central agent.

This patch only changes the interface of pollsters and PollingTask in
central agent. The existing central agent's pollsters still ignore the
resources passed in by the PollingTask.

Implements: blueprint support-resources-pipeline-item
Change-Id: Ic7a83c63ea291d0527004113bc8d8bb09311d14f
2014-01-20 09:38:18 +08:00

107 lines
3.4 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
import fnmatch
from oslo.config import cfg
import six
# 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.
"""
@six.add_metaclass(abc.ABCMeta)
class NotificationBase(PluginBase):
"""Base class for plugins that support the notification API."""
@abc.abstractproperty
def 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.
"""
@staticmethod
def _handle_event_type(event_type, event_type_to_handle):
"""Check whether event_type should be handled according to
event_type_to_handle.
"""
return any(map(lambda e: fnmatch.fnmatch(event_type, e),
event_type_to_handle))
def to_samples(self, notification):
"""Return samples produced by *process_notification* for the given
notification, if it's handled by this notification handler.
:param notification: The notification to process.
"""
if self._handle_event_type(notification['event_type'],
self.event_types):
return self.process_notification(notification)
return []
@six.add_metaclass(abc.ABCMeta)
class PollsterBase(PluginBase):
"""Base class for plugins that support the polling API."""
@abc.abstractmethod
def get_samples(self, manager, cache, resources=[]):
"""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).
:param resources: A list of the endpoints the pollster will get data
from. It's up to the specific pollster to decide
how to use it.
"""