text: # -*- coding: utf-8 -*-
  
  #
  #
  #  Copyright 2013 Netflix, Inc.
  #
  #     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.
  #
  #
  
  """
  aminator.plugins.volume.base
  ============================
  Base class(es) for volume plugins
  """
  import abc
  import logging
  
  from aminator.plugins.base import BasePlugin
  
  
  __all__ = ('BaseVolumePlugin',)
  log = logging.getLogger(__name__)
  
  
  class BaseVolumePlugin(BasePlugin):
      """
      Volume plugins ask blockdevice for an os block device, the cloud for a volume at
      that block device, mount it, and return the mount point for the provisioner. How they go about it
      is up to the implementor.
      The are context managers to ensure they unmount and clean up resources
      """
      __metaclass__ = abc.ABCMeta
      _entry_point = 'aminator.plugins.volume'
  
      @abc.abstractmethod
      def __enter__(self):
          return self
  
      @abc.abstractmethod
      def __exit__(self, exc_type, exc_value, trace):
          if exc_type:
              log.debug('Exception encountered in volume plugin context manager',
                        exc_info=(exc_type, exc_value, trace))
          return False
  
      def __call__(self, cloud, blockdevice):
          self._cloud = cloud
          self._blockdevice = blockdevice
          return self
  