text: # Copyright 2017 Huawei Technologies Co., Ltd.
  # 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 neutron_lib.plugins.ml2 import api
  from oslo_config import cfg
  from oslo_log import log
  
  from neutron.plugins.ml2.drivers import type_vxlan
  from neutron_lib import constants as q_lib_constants
  from neutron_lib import exceptions as n_exc
  
  from tricircle.common import constants
  import tricircle.common.context as t_context
  import tricircle.db.api as db_api
  
  LOG = log.getLogger(__name__)
  
  
  class VxLANTypeDriver(type_vxlan.VxlanTypeDriver):
      def __init__(self):
          super(VxLANTypeDriver, self).__init__()
  
      def get_type(self):
          return constants.NT_VxLAN
  
      def initialize(self):
          try:
              self._initialize(cfg.CONF.tricircle.vni_ranges)
          except n_exc.NetworkTunnelRangeError:
              LOG.exception("Failed to parse vni_ranges. "
                            "Service terminated!")
              raise SystemExit()
  
      def reserve_provider_segment(self, context, segment):
          res = super(VxLANTypeDriver,
                      self).reserve_provider_segment(context, segment)
          res[api.NETWORK_TYPE] = constants.NT_VxLAN
          return res
  
      def allocate_tenant_segment(self, context):
          res = super(VxLANTypeDriver,
                      self).allocate_tenant_segment(context)
          res[api.NETWORK_TYPE] = constants.NT_VxLAN
          return res
  
      def get_mtu(self, physical_network=None):
          pass
  
      def get_endpoint_by_host(self, host):
          LOG.debug("get_endpoint_by_host() called for host %s", host)
          host_endpoint = {'ip_address': None}
          context = t_context.get_db_context()
          agents = db_api.get_agent_by_host_type(
              context, host, q_lib_constants.AGENT_TYPE_OVS)
          if agents:
              host_endpoint['ip_address'] = agents['tunnel_ip']
          return host_endpoint
  