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OpenStack Study: manager.py**** CubicPower OpenStack Study ****
# 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. from oslo.config import cfg from neutron.common import legacy 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__)
**** CubicPower OpenStack Study **** class Manager(periodic_task.PeriodicTasks): # Set RPC API version to 1.0 by
**** CubicPower OpenStack Study **** def __init__(self, host=None): if not host: host = cfg.CONF.host self.host = host super(Manager, self).__init__()
**** CubicPower OpenStack Study **** def periodic_tasks(self, context, raise_on_error=False): self.run_periodic_tasks(context, raise_on_error=raise_on_error)
**** CubicPower OpenStack Study **** def init_host(self): """Handle initialization if this is a standalone service. Child classes should override this method. """ pass
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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
**** CubicPower OpenStack Study **** 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 implement neutron_plugin_base class. The caller should make sure that NeutronManager is a singleton. """ _instance = None
**** CubicPower OpenStack Study **** 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) legacy.modernize_quantum_config(cfg.CONF) 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()
**** CubicPower OpenStack Study **** 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()
**** CubicPower OpenStack Study **** 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 if not hasattr(self.plugin, "supported_extension_aliases"): return for ext_alias in 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)
**** CubicPower OpenStack Study **** 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")
**** CubicPower OpenStack Study **** def _create_instance(cls): if cls._instance is None: cls._instance = cls() @classmethod
**** CubicPower OpenStack Study **** def get_instance(cls): # double checked locking if cls._instance is None: cls._create_instance() return cls._instance @classmethod
**** CubicPower OpenStack Study **** def get_plugin(cls): return cls.get_instance().plugin @classmethod
**** CubicPower OpenStack Study **** def get_service_plugins(cls): return cls.get_instance().service_plugins
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