aodh/ceilometer/plugin.py
Doug Hellmann 7d8bd50d08 Decouple the nova notifier from ceilometer code
The move to oslo.config introduced a conflict in the nova notifier
because both nova and ceilometer have copies of the
openstack.common.rpc library and define an option for the AMQP
exchange name for the project. This changeset decouples the notifier
plugin in ceilometer from most of the ceilometer code, to remove that
conflict.

The nova notifier is rewritten to emit a new notification message with
event type `compute.instance.delete.samples` instead of making the old
RPC calls directly to the ceilometer collector, and a notification
listener plugin is provided to convert those messages to sample data.

The notifier implementations are split between the one that worked
in folsom and the one that works in grizzly to maintain backwards
compatibility.

get_hypervisor_inspector() is moved to a location where it can be
imported both by the compute agent manager and the notifier
plugin. The definition of `disabled_compute_pollsters` option is also
moved for the same reason.

The tox configuration is changed to run the nova notifier tests
separately from the other tests, since nose cannot import nova and
ceilometer code in the same process.

bug 1130952

Change-Id: I39ba4564c9c14f09dbdd768d7a83f6940e3942ad
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
2013-02-26 14:22:27 -05:00

132 lines
3.9 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
ExchangeTopics = namedtuple('ExchangeTopics', ['exchange', 'topics'])
class PluginBase(object):
"""Base class for all plugins.
"""
def is_enabled(self):
"""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
def is_enabled(self):
return True
@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."""
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(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, instance):
"""Return a sequence of Counter instances from polling the
resources."""
class PublisherBase(PluginBase):
"""Base class for plugins that publish the sampler."""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def publish_counters(self, context, counters, source):
"Publish counters into final conduit."
class TransformerBase(PluginBase):
"""Base class for plugins that transform the counter."""
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def handle_sample(self, context, counter, source):
"""Transform a counter.
:param context: Passed from the data collector.
:param counter: A counter.
:param source: Passed from data collector.
"""
def flush(self, context, source):
"""Flush counters cached previously.
:param context: Passed from the data collector.
:param source: Source of counters that are being published."""
return []
def __init__(self, **kwargs):
"""Setup transformer.
Each time a transformed is involved in a pipeline, a new transformer
instance is created and chained into the pipeline. i.e. transformer
instance is per pipeline. This helps if transformer need keep some
cache and per-pipeline information.
:param kwargs: The parameters that are defined in pipeline config file.
"""
super(TransformerBase, self).__init__()