test/vpp_object.py

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