test/vpp_object.py

   1 """ abstract vpp object and object registry """
   2
   3 import abc
   4 import six
   5
   6 from six import moves
   7
   8
   9 @six.add_metaclass(abc.ABCMeta)
  10 class VppObject(object):
  11     """ Abstract vpp object """
  12
  13     @abc.abstractmethod
  14     def add_vpp_config(self):
  15         """ Add the configuration for this object to vpp. """
  16         pass
  17
  18     @abc.abstractmethod
  19     def query_vpp_config(self):
  20         """Query the vpp configuration.
  21
  22         :return: True if the object is configured"""
  23         pass
  24
  25     @abc.abstractmethod
  26     def remove_vpp_config(self):
  27         """ Remove the configuration for this object from vpp. """
  28         pass
  29
  30     @abc.abstractmethod
  31     def object_id(self):
  32         """ Return a unique string representing this object. """
  33         pass
  34
  35
  36 class VppObjectRegistry(object):
  37     """ Class which handles automatic configuration cleanup. """
  38     _shared_state = {}
  39
  40     def __init__(self):
  41         self.__dict__ = self._shared_state
  42         if not hasattr(self, "_object_registry"):
  43             self._object_registry = []
  44         if not hasattr(self, "_object_dict"):
  45             self._object_dict = dict()
  46
  47     def register(self, obj, logger):
  48         """ Register an object in the registry. """
  49         if obj.object_id() not in self._object_dict:
  50             self._object_registry.append(obj)
  51             self._object_dict[obj.object_id()] = obj
  52             logger.debug("REG: registering %s" % obj)
  53         else:
  54             logger.debug("REG: duplicate add, ignoring (%s)" % obj)
  55
  56     def unregister_all(self, logger):
  57         """ Remove all object registrations from registry. """
  58         logger.debug("REG: removing all object registrations")
  59         self._object_registry = []
  60         self._object_dict = dict()
  61
  62     def remove_vpp_config(self, logger):
  63         """
  64         Remove configuration (if present) from vpp and then remove all objects
  65         from the registry.
  66         """
  67         if not self._object_registry:
  68             logger.info("REG: No objects registered for auto-cleanup.")
  69             return
  70         logger.info("REG: Removing VPP configuration for registered objects")
  71         # remove the config in reverse order as there might be dependencies
  72         failed = []
  73         for obj in reversed(self._object_registry):
  74             if obj.query_vpp_config():
  75                 logger.info("REG: Removing configuration for %s" % obj)
  76                 obj.remove_vpp_config()
  77                 if obj.query_vpp_config():
  78                     failed.append(obj)
  79             else:
  80                 logger.info(
  81                     "REG: Skipping removal for %s, configuration not present" %
  82                     obj)
  83         self.unregister_all(logger)
  84         if failed:
  85             logger.error("REG: Couldn't remove configuration for object(s):")
  86             for obj in failed:
  87                 logger.error(moves.reprlib.repr(obj))
  88             raise Exception("Couldn't remove configuration for object(s): %s" %
  89                             (", ".join(str(x) for x in failed)))