test/vpp_object.py

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