text: # Copyright 2013 Netease, LLC.
  # 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.
  
  """The Extended Availability Zone Status API extension."""
  
  from nova.api.openstack import extensions
  from nova.api.openstack import wsgi
  from nova import availability_zones as avail_zone
  
  ALIAS = "os-extended-availability-zone"
  authorize = extensions.os_compute_soft_authorizer(ALIAS)
  PREFIX = "OS-EXT-AZ"
  
  
  class ExtendedAZController(wsgi.Controller):
      def _extend_server(self, context, server, instance):
          key = "%s:availability_zone" % PREFIX
          az = avail_zone.get_instance_availability_zone(context, instance)
          server[key] = az or ''
  
      @wsgi.extends
      def show(self, req, resp_obj, id):
          context = req.environ['nova.context']
          if authorize(context):
              server = resp_obj.obj['server']
              db_instance = req.get_db_instance(server['id'])
              self._extend_server(context, server, db_instance)
  
      @wsgi.extends
      def detail(self, req, resp_obj):
          context = req.environ['nova.context']
          if authorize(context):
              servers = list(resp_obj.obj['servers'])
              for server in servers:
                  db_instance = req.get_db_instance(server['id'])
                  self._extend_server(context, server, db_instance)
  
  
  class ExtendedAvailabilityZone(extensions.V21APIExtensionBase):
      """Extended Availability Zone support."""
  
      name = "ExtendedAvailabilityZone"
      alias = ALIAS
      version = 1
  
      def get_controller_extensions(self):
          controller = ExtendedAZController()
          extension = extensions.ControllerExtension(self, 'servers', controller)
          return [extension]
  
      def get_resources(self):
          return []
  