code: def prepare_attached(self, action, a_name, **kwargs):
          
          client = action.client
          config_id = action.config_id
          policy = self._policy
          if action.container_map.use_attached_parent_name:
              v_alias = '{0.config_name}.{0.instance_name}'.format(config_id)
          else:
              v_alias = config_id.instance_name
          user = policy.volume_users[config_id.map_name][v_alias]
          permissions = policy.volume_permissions[config_id.map_name][v_alias]
  
          if not (self.prepare_local and hasattr(client, 'run_cmd')):
              return self._prepare_container(client, action, a_name, v_alias)
          if action.client_config.features['volumes']:
              volume_detail = client.inspect_volume(a_name)
              local_path = volume_detail['Mountpoint']
          else:
              instance_detail = client.inspect_container(a_name)
              volumes = get_instance_volumes(instance_detail, False)
              path = resolve_value(policy.default_volume_paths[config_id.map_name][v_alias])
              local_path = volumes.get(path)
              if not local_path:
                  raise ValueError("Could not locate local path of volume alias '{0}' / "
                                   "path '{1}' in container {2}.".format(action.config_id.instance_name, path, a_name))
          return [
              client.run_cmd(cmd)
              for cmd in get_preparation_cmd(user, permissions, local_path)
          ]
docs: Prepares an attached volume for a container configuration.
  
          :param action: Action configuration.
          :type action: dockermap.map.runner.ActionConfig
          :param a_name: The full name or id of the container sharing the volume.
          :type a_name: unicode | str