test/vpp_object.py

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