deb-ceilometer/ceilometer/collector/dispatcher.py
Julien Danjou 8780157755 Add and use ceilometer own log module
This fixes bug #1004130

Change-Id: I143124ad411d5efefa604e831173dca87548bd7f
Signed-off-by: Julien Danjou <julien.danjou@enovance.com>
2012-06-07 16:24:07 +02:00

76 lines
2.9 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.
"""Given an incoming message, process it through the registered converters
and publish the results.
"""
import pkg_resources
from ceilometer import log
LOG = log.getLogger(__name__)
class NotificationDispatcher(object):
"""Manages invoking plugins to convert notification messages to counters.
"""
def __init__(self, plugin_namespace, publish_func):
self.plugin_namespace = plugin_namespace
self.publish_func = publish_func
self.handlers = {}
self._load_plugins()
def _load_plugins(self):
# Listen for notifications from nova
for ep in pkg_resources.iter_entry_points(self.plugin_namespace):
LOG.info('attempting to load notification handler for %s:%s',
self.plugin_namespace, ep.name)
try:
plugin_class = ep.load()
plugin = plugin_class()
# FIXME(dhellmann): Currently assumes all plugins are
# enabled when they are discovered and
# importable. Need to add check against global
# configuration flag and check that asks the plugin if
# it should be enabled.
for event_type in plugin.get_event_types():
LOG.info('subscribing %s handler to %s events',
ep.name, event_type)
self.handlers.setdefault(event_type, []).append(plugin)
except Exception as err:
LOG.warning('Failed to load notification handler %s: %s',
ep.name, err)
LOG.exception(err)
if not self.handlers:
LOG.warning('Failed to load any notification handlers for %s',
self.plugin_namespace)
def notify(self, body):
"""Dispatch the notification to the appropriate handler
and publish the counters returned.
"""
event_type = body.get('event_type')
LOG.info('NOTIFICATION: %s', event_type)
for handler in self.handlers.get(event_type, []):
for c in handler.process_notification(body):
LOG.info('COUNTER: %s', c)
# FIXME(dhellmann): Spawn green thread?
self.publish_func(c)
return