Use six.with_metaclass to specify metaclasses

Metaclass specification is incompatible between Python 2 and 3. Use the
six.with_metaclass helper to specify metaclasses.

Reviewed-By: Petr Viktorin <pviktori@redhat.com>

ipapython/install/core.py

@@ -54,8 +54,7 @@ class KnobValueError(ValueError):
         self.name = name
 
 
-class InnerClass(object):
-    __metaclass__ = util.InnerClassMeta
+class InnerClass(six.with_metaclass(util.InnerClassMeta, object)):
     __outer_class__ = None
     __outer_name__ = None
 
@@ -162,15 +161,13 @@ def Knob(type, default=_missing, initializable=_missing, sensitive=_missing,
     return util.InnerClassMeta('Knob', (KnobBase,), class_dict)
 
 
-class Configurable(object):
+class Configurable(six.with_metaclass(abc.ABCMeta, object)):
     """
     Base class of all configurables.
 
     FIXME: details of validate/execute, properties and knobs
     """
 
-    __metaclass__ = abc.ABCMeta
-
     @classmethod
     def knobs(cls):
         """
@@ -382,9 +379,8 @@ class ComponentMeta(util.InnerClassMeta, abc.ABCMeta):
     pass
 
 
-class ComponentBase(InnerClass, Configurable):
-    __metaclass__ = ComponentMeta
-
+class ComponentBase(
+        six.with_metaclass(ComponentMeta, InnerClass, Configurable)):
     _order = None
 
     @classmethod

ipapython/install/util.py

@@ -159,5 +159,6 @@ class InnerClassMeta(type):
             self.__outer_class__ = cls
             self.__outer_name__ = name
             self.__name__ = '.'.join((cls.__name__, name))
+            self.__qualname__ = self.__name__
 
         return cls, name

ipaserver/install/ipa_otptoken_import.py

@@ -31,6 +31,7 @@ import dateutil.parser
 import dateutil.tz
 import nss.nss as nss
 import gssapi
+import six
 from six.moves import xrange
 
 from ipapython import admintool
@@ -147,10 +148,8 @@ def convertEncrypted(value, decryptor=None, pconv=base64.b64decode, econv=lambda
     return None
 
 
-class XMLKeyDerivation(object):
+class XMLKeyDerivation(six.with_metaclass(abc.ABCMeta, object)):
     "Interface for XML Encryption 1.1 key derivation."
-    __metaclass__ = abc.ABCMeta
-
     @abc.abstractmethod
     def __init__(self, enckey):
         "Sets up key derivation parameters from the parent XML entity."