text: # Copyright (c) 2013 OpenStack Foundation.
  # 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 oslo_utils import importutils
  
  from neutron.api.rpc.agentnotifiers import l3_rpc_agent_api
  from neutron.api.rpc.handlers import l3_rpc
  from neutron.common import constants as q_const
  from neutron.common import rpc as n_rpc
  from neutron.common import topics
  from neutron.db import common_db_mixin
  from neutron.db import extraroute_db
  from neutron.db import l3_dvrscheduler_db
  from neutron.db import l3_gwmode_db
  from neutron.db import l3_hamode_db
  from neutron.db import l3_hascheduler_db
  from neutron.plugins.common import constants
  
  
  class L3RouterPlugin(common_db_mixin.CommonDbMixin,
                       extraroute_db.ExtraRoute_db_mixin,
                       l3_hamode_db.L3_HA_NAT_db_mixin,
                       l3_gwmode_db.L3_NAT_db_mixin,
                       l3_dvrscheduler_db.L3_DVRsch_db_mixin,
                       l3_hascheduler_db.L3_HA_scheduler_db_mixin):
  
      """Implementation of the Neutron L3 Router Service Plugin.
  
      This class implements a L3 service plugin that provides
      router and floatingip resources and manages associated
      request/response.
      All DB related work is implemented in classes
      l3_db.L3_NAT_db_mixin, l3_hamode_db.L3_HA_NAT_db_mixin,
      l3_dvr_db.L3_NAT_with_dvr_db_mixin, and extraroute_db.ExtraRoute_db_mixin.
      """
      supported_extension_aliases = ["dvr", "router", "ext-gw-mode",
                                     "extraroute", "l3_agent_scheduler",
                                     "l3-ha"]
  
      def __init__(self):
          self.setup_rpc()
          self.router_scheduler = importutils.import_object(
              cfg.CONF.router_scheduler_driver)
          self.start_periodic_l3_agent_status_check()
          super(L3RouterPlugin, self).__init__()
  
      def setup_rpc(self):
          # RPC support
          self.topic = topics.L3PLUGIN
          self.conn = n_rpc.create_connection(new=True)
          self.agent_notifiers.update(
              {q_const.AGENT_TYPE_L3: l3_rpc_agent_api.L3AgentNotifyAPI()})
          self.endpoints = [l3_rpc.L3RpcCallback()]
          self.conn.create_consumer(self.topic, self.endpoints,
                                    fanout=False)
          self.conn.consume_in_threads()
  
      def get_plugin_type(self):
          return constants.L3_ROUTER_NAT
  
      def get_plugin_description(self):
          """returns string description of the plugin."""
          return ("L3 Router Service Plugin for basic L3 forwarding"
                  " between (L2) Neutron networks and access to external"
                  " networks via a NAT gateway.")
  
      def create_floatingip(self, context, floatingip):
          """Create floating IP.
  
          :param context: Neutron request context
          :param floatingip: data for the floating IP being created
          :returns: A floating IP object on success
  
          As the l3 router plugin asynchronously creates floating IPs
          leveraging the l3 agent, the initial status for the floating
          IP object will be DOWN.
          """
          return super(L3RouterPlugin, self).create_floatingip(
              context, floatingip,
              initial_status=q_const.FLOATINGIP_STATUS_DOWN)
  