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     def object_id(self):
  31         """ Return a unique string representing this object. """
  32         return "Undefined. for <%s %s>" % (self.__class__.__name__, id(self))
  33
  34     def __str__(self):
  35         return self.object_id()
  36
  37     def __repr__(self):
  38         return '<%s>' % self.object_id()
  39
  40     def __hash__(self):
  41         return hash(self.object_id())
  42
  43     def __eq__(self, other):
  44         if not isinstance(other, self.__class__):
  45             return NotImplemented
  46         if other.object_id() == self.object_id():
  47             return True
  48         return False
  49
  50     # This can be removed when python2 support is dropped.
  51     def __ne__(self, other):
  52         return not self.__eq__(other)
  53
  54
  55 class VppObjectRegistry(object):
  56     """ Class which handles automatic configuration cleanup. """
  57     _shared_state = {}
  58
  59     def __init__(self):
  60         self.__dict__ = self._shared_state
  61         if not hasattr(self, "_object_registry"):
  62             self._object_registry = []
  63         if not hasattr(self, "_object_dict"):
  64             self._object_dict = dict()
  65
  66     def register(self, obj, logger):
  67         """ Register an object in the registry. """
  68         if obj.object_id() not in self._object_dict:
  69             self._object_registry.append(obj)
  70             self._object_dict[obj.object_id()] = obj
  71             logger.debug("REG: registering %s" % obj)
  72         else:
  73             logger.debug("REG: duplicate add, ignoring (%s)" % obj)
  74
  75     def unregister_all(self, logger):
  76         """ Remove all object registrations from registry. """
  77         logger.debug("REG: removing all object registrations")
  78         self._object_registry = []
  79         self._object_dict = dict()
  80
  81     def remove_vpp_config(self, logger):
  82         """
  83         Remove configuration (if present) from vpp and then remove all objects
  84         from the registry.
  85         """
  86         if not self._object_registry:
  87             logger.info("REG: No objects registered for auto-cleanup.")
  88             return
  89         logger.info("REG: Removing VPP configuration for registered objects")
  90         # remove the config in reverse order as there might be dependencies
  91         failed = []
  92         for obj in reversed(self._object_registry):
  93             if obj.query_vpp_config():
  94                 logger.info("REG: Removing configuration for %s" % obj)
  95                 obj.remove_vpp_config()
  96                 if obj.query_vpp_config():
  97                     failed.append(obj)
  98             else:
  99                 logger.info(
 100                     "REG: Skipping removal for %s, configuration not present" %
 101                     obj)
 102         self.unregister_all(logger)
 103         if failed:
 104             logger.error("REG: Couldn't remove configuration for object(s):")
 105             for obj in failed:
 106                 logger.error(repr(obj))
 107             raise Exception("Couldn't remove configuration for object(s): %s" %
 108                             (", ".join(str(x) for x in failed)))