aodh/ceilometer/extension_manager.py
Julien Danjou 51c8a8e55c Update pep8 to 1.3.3
This is needed to update openstack.common

Change-Id: I8410f978f38b3893b71239f97f785086ca5faffe
Signed-off-by: Julien Danjou <julien@danjou.info>
2013-01-15 14:39:29 +01:00

72 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 plugin loader.
"""
from stevedore import enabled
from ceilometer.openstack.common import log
LOG = log.getLogger(__name__)
def should_use_extension(namespace, ext, disabled_names):
"""Return boolean indicating whether the extension
should be used.
Tests the extension against a couple of criteria to see whether it
should be used, logs the reason it is not used if not, and then
returns the result.
"""
if ext.name in disabled_names:
LOG.debug(
'%s extension %r disabled through configuration setting',
namespace, ext.name,
)
return False
if not ext.obj.is_enabled():
LOG.debug(
'%s extension %r reported that it is disabled',
namespace,
ext.name,
)
return False
LOG.debug('using %s extension %r', namespace, ext.name)
return True
class ActivatedExtensionManager(enabled.EnabledExtensionManager):
"""Loads extensions based on a configurable set that should be
disabled and asking each one if it should be active or not.
"""
def __init__(self, namespace, disabled_names, invoke_on_load=True,
invoke_args=(), invoke_kwds={}):
def local_check_func(ext):
return should_use_extension(namespace, ext, disabled_names)
super(ActivatedExtensionManager, self).__init__(
namespace=namespace,
check_func=local_check_func,
invoke_on_load=invoke_on_load,
invoke_args=invoke_args,
invoke_kwds=invoke_kwds,
)