13b4fed39c
This class will be used to create proper self.target with appropriate API version once we migrate to oslo.messaging. blueprint oslo-messaging Change-Id: I1fb5eb0aaac0d115fd84630e58b333e695ad4f5f
226 lines
8.0 KiB
Python
226 lines
8.0 KiB
Python
# Copyright 2011 VMware, 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.
|
|
|
|
import weakref
|
|
|
|
from oslo.config import cfg
|
|
|
|
from neutron.common import rpc_compat
|
|
from neutron.common import utils
|
|
from neutron.openstack.common import importutils
|
|
from neutron.openstack.common import log as logging
|
|
from neutron.openstack.common import periodic_task
|
|
from neutron.plugins.common import constants
|
|
|
|
from stevedore import driver
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
class Manager(rpc_compat.RpcCallback, 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
|
|
|
|
|
|
def validate_post_plugin_load():
|
|
"""Checks if the configuration variables are valid.
|
|
|
|
If the configuration is invalid then the method will return an error
|
|
message. If all is OK then it will return None.
|
|
"""
|
|
if ('dhcp_agents_per_network' in cfg.CONF and
|
|
cfg.CONF.dhcp_agents_per_network <= 0):
|
|
msg = _("dhcp_agents_per_network must be >= 1. '%s' "
|
|
"is invalid.") % cfg.CONF.dhcp_agents_per_network
|
|
return msg
|
|
|
|
|
|
def validate_pre_plugin_load():
|
|
"""Checks if the configuration variables are valid.
|
|
|
|
If the configuration is invalid then the method will return an error
|
|
message. If all is OK then it will return None.
|
|
"""
|
|
if cfg.CONF.core_plugin is None:
|
|
msg = _('Neutron core_plugin not configured!')
|
|
return msg
|
|
|
|
|
|
class NeutronManager(object):
|
|
"""Neutron's Manager class.
|
|
|
|
Neutron's Manager class is responsible for parsing a config file and
|
|
instantiating the correct plugin that concretely implements
|
|
neutron_plugin_base class.
|
|
The caller should make sure that NeutronManager 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 = {}
|
|
|
|
msg = validate_pre_plugin_load()
|
|
if msg:
|
|
LOG.critical(msg)
|
|
raise Exception(msg)
|
|
|
|
# NOTE(jkoelker) Testing for the subclass with the __subclasshook__
|
|
# breaks tach monitoring. It has been removed
|
|
# intentionally to allow v2 plugins to be monitored
|
|
# for performance metrics.
|
|
plugin_provider = cfg.CONF.core_plugin
|
|
LOG.info(_("Loading core plugin: %s"), plugin_provider)
|
|
self.plugin = self._get_plugin_instance('neutron.core_plugins',
|
|
plugin_provider)
|
|
msg = validate_post_plugin_load()
|
|
if msg:
|
|
LOG.critical(msg)
|
|
raise Exception(msg)
|
|
|
|
# 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 _get_plugin_instance(self, namespace, plugin_provider):
|
|
try:
|
|
# Try to resolve plugin by name
|
|
mgr = driver.DriverManager(namespace, plugin_provider)
|
|
plugin_class = mgr.driver
|
|
except RuntimeError as e1:
|
|
# fallback to class name
|
|
try:
|
|
plugin_class = importutils.import_class(plugin_provider)
|
|
except ImportError as e2:
|
|
LOG.exception(_("Error loading plugin by name, %s"), e1)
|
|
LOG.exception(_("Error loading plugin by class, %s"), e2)
|
|
raise ImportError(_("Plugin not found."))
|
|
return plugin_class()
|
|
|
|
def _load_services_from_core_plugin(self):
|
|
"""Puts core plugin in service_plugins for supported services."""
|
|
LOG.debug(_("Loading services supported by the core plugin"))
|
|
|
|
# supported service types are derived from supported extensions
|
|
for ext_alias in getattr(self.plugin,
|
|
"supported_extension_aliases", []):
|
|
if ext_alias in constants.EXT_TO_SERVICE_MAPPING:
|
|
service_type = constants.EXT_TO_SERVICE_MAPPING[ext_alias]
|
|
self.service_plugins[service_type] = self.plugin
|
|
LOG.info(_("Service %s is supported by the core plugin"),
|
|
service_type)
|
|
|
|
def _load_service_plugins(self):
|
|
"""Loads service plugins.
|
|
|
|
Starts from the core plugin and checks if it supports
|
|
advanced services then loads classes provided in configuration.
|
|
"""
|
|
# load services from the core plugin first
|
|
self._load_services_from_core_plugin()
|
|
|
|
plugin_providers = cfg.CONF.service_plugins
|
|
LOG.debug(_("Loading service plugins: %s"), plugin_providers)
|
|
for provider in plugin_providers:
|
|
if provider == '':
|
|
continue
|
|
|
|
LOG.info(_("Loading Plugin: %s"), provider)
|
|
plugin_inst = self._get_plugin_instance('neutron.service_plugins',
|
|
provider)
|
|
|
|
# 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 ValueError(_("Multiple plugins for service "
|
|
"%s were configured"),
|
|
plugin_inst.get_plugin_type())
|
|
|
|
self.service_plugins[plugin_inst.get_plugin_type()] = plugin_inst
|
|
|
|
# search for possible agent notifiers declared in service plugin
|
|
# (needed by agent management extension)
|
|
if (hasattr(self.plugin, 'agent_notifiers') and
|
|
hasattr(plugin_inst, 'agent_notifiers')):
|
|
self.plugin.agent_notifiers.update(plugin_inst.agent_notifiers)
|
|
|
|
LOG.debug(_("Successfully loaded %(type)s plugin. "
|
|
"Description: %(desc)s"),
|
|
{"type": plugin_inst.get_plugin_type(),
|
|
"desc": plugin_inst.get_plugin_description()})
|
|
|
|
@classmethod
|
|
@utils.synchronized("manager")
|
|
def _create_instance(cls):
|
|
if not cls.has_instance():
|
|
cls._instance = cls()
|
|
|
|
@classmethod
|
|
def has_instance(cls):
|
|
return cls._instance is not None
|
|
|
|
@classmethod
|
|
def clear_instance(cls):
|
|
cls._instance = None
|
|
|
|
@classmethod
|
|
def get_instance(cls):
|
|
# double checked locking
|
|
if not cls.has_instance():
|
|
cls._create_instance()
|
|
return cls._instance
|
|
|
|
@classmethod
|
|
def get_plugin(cls):
|
|
# Return a weakref to minimize gc-preventing references.
|
|
return weakref.proxy(cls.get_instance().plugin)
|
|
|
|
@classmethod
|
|
def get_service_plugins(cls):
|
|
# Return weakrefs to minimize gc-preventing references.
|
|
return dict((x, weakref.proxy(y))
|
|
for x, y in cls.get_instance().service_plugins.iteritems())
|