text: # Copyright 2012 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.
  #
  # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  """Manage access to the clients, including authenticating when needed.
  """
  
  import logging
  
  from neutronclient import client
  from neutronclient.neutron import client as neutron_client
  
  
  LOG = logging.getLogger(__name__)
  
  
  class ClientCache(object):
      """Descriptor class for caching created client handles.
      """
  
      def __init__(self, factory):
          self.factory = factory
          self._handle = None
  
      def __get__(self, instance, owner):
          # Tell the ClientManager to login to keystone
          if self._handle is None:
              self._handle = self.factory(instance)
          return self._handle
  
  
  class ClientManager(object):
      """Manages access to API clients, including authentication.
      """
      neutron = ClientCache(neutron_client.make_client)
      # Provide support for old quantum commands (for example
      # in stable versions)
      quantum = neutron
  
      def __init__(self, token=None, url=None,
                   auth_url=None,
                   endpoint_type=None,
                   tenant_name=None, tenant_id=None,
                   username=None, password=None,
                   region_name=None,
                   api_version=None,
                   auth_strategy=None,
                   insecure=False,
                   ca_cert=None,
                   log_credentials=False,
                   ):
          self._token = token
          self._url = url
          self._auth_url = auth_url
          self._endpoint_type = endpoint_type
          self._tenant_name = tenant_name
          self._tenant_id = tenant_id
          self._username = username
          self._password = password
          self._region_name = region_name
          self._api_version = api_version
          self._service_catalog = None
          self._auth_strategy = auth_strategy
          self._insecure = insecure
          self._ca_cert = ca_cert
          self._log_credentials = log_credentials
          return
  
      def initialize(self):
          if not self._url:
              httpclient = client.HTTPClient(
                  username=self._username,
                  tenant_name=self._tenant_name,
                  tenant_id=self._tenant_id,
                  password=self._password,
                  region_name=self._region_name,
                  auth_url=self._auth_url,
                  endpoint_type=self._endpoint_type,
                  insecure=self._insecure,
                  ca_cert=self._ca_cert,
                  log_credentials=self._log_credentials)
              httpclient.authenticate()
              # Populate other password flow attributes
              self._token = httpclient.auth_token
              self._url = httpclient.endpoint_url
  