vmware-nsx/quantum/manager.py
Gary Kotton b5ea60252f Set default core_plugin to None
Fixes bug 1093989

Change-Id: Ib0b77994b813e6b2ec0621949371c66d66472896
2013-01-02 16:47:54 +00:00

145 lines
5.2 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Nicira Networks, Inc
# All Rights Reserved.
#
# 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.
# @author: Somik Behera, Nicira Networks, Inc.
from quantum.common.exceptions import ClassNotFound
from quantum.openstack.common import cfg
from quantum.openstack.common import importutils
from quantum.openstack.common import log as logging
from quantum.openstack.common import periodic_task
from quantum.plugins.common import constants
LOG = logging.getLogger(__name__)
class Manager(periodic_task.PeriodicTasks):
# Set RPC API version to 1.0 by default.
RPC_API_VERSION = '1.0'
def __init__(self, host=None):
if not host:
host = cfg.CONF.host
self.host = host
super(Manager, self).__init__()
def periodic_tasks(self, context, raise_on_error=False):
self.run_periodic_tasks(context, raise_on_error=raise_on_error)
def init_host(self):
"""Handle initialization if this is a standalone service.
Child classes should override this method.
"""
pass
def after_start(self):
"""Handler post initialization stuff.
Child classes can override this method.
"""
pass
class QuantumManager(object):
"""
Quantum's Manager class is responsible for parsing a config file and
instantiating the correct plugin that concretely implement
quantum_plugin_base class.
The caller should make sure that QuantumManager is a singleton.
"""
_instance = None
def __init__(self, options=None, config_file=None):
# If no options have been provided, create an empty dict
if not options:
options = {}
if cfg.CONF.core_plugin is None:
msg = _('Quantum core_plugin not configured!')
LOG.critical(msg)
raise Exception(msg)
# NOTE(jkoelker) Testing for the subclass with the __subclasshook__
# breaks tach monitoring. It has been removed
# intentianally to allow v2 plugins to be monitored
# for performance metrics.
plugin_provider = cfg.CONF.core_plugin
LOG.debug(_("Plugin location: %s"), plugin_provider)
# If the plugin can't be found let them know gracefully
try:
LOG.info(_("Loading Plugin: %s"), plugin_provider)
plugin_klass = importutils.import_class(plugin_provider)
except ClassNotFound:
LOG.exception(_("Error loading plugin"))
raise Exception(_("Plugin not found. You can install a "
"plugin with: pip install <plugin-name>\n"
"Example: pip install quantum-sample-plugin"))
self.plugin = plugin_klass()
# core plugin as a part of plugin collection simplifies
# checking extensions
# TODO (enikanorov): make core plugin the same as
# the rest of service plugins
self.service_plugins = {constants.CORE: self.plugin}
self._load_service_plugins()
def _load_service_plugins(self):
plugin_providers = cfg.CONF.service_plugins
LOG.debug(_("Loading service plugins: %s"), plugin_providers)
for provider in plugin_providers:
if provider == '':
continue
try:
LOG.info(_("Loading Plugin: %s"), provider)
plugin_class = importutils.import_class(provider)
except ClassNotFound:
LOG.exception(_("Error loading plugin"))
raise Exception(_("Plugin not found."))
plugin_inst = plugin_class()
# only one implementation of svc_type allowed
# specifying more than one plugin
# for the same type is a fatal exception
if plugin_inst.get_plugin_type() in self.service_plugins:
raise Exception(_("Multiple plugins for service "
"%s were configured"),
plugin_inst.get_plugin_type())
self.service_plugins[plugin_inst.get_plugin_type()] = plugin_inst
LOG.debug(_("Successfully loaded %(type)s plugin. "
"Description: %(desc)s"),
{"type": plugin_inst.get_plugin_type(),
"desc": plugin_inst.get_plugin_description()})
@classmethod
def get_instance(cls):
if cls._instance is None:
cls._instance = cls()
return cls._instance
@classmethod
def get_plugin(cls):
return cls.get_instance().plugin
@classmethod
def get_service_plugins(cls):
return cls.get_instance().service_plugins