Apply six for metaclass

__metaclass__ cannot be used in python3.
six be used in general for python 3 compatibility.

Change-Id: I9fc7a59df3af29b4cc1287c40fa4e883d994a961
Closes-Bug: #1236648

openstack/common/apiclient/auth.py

@@ -23,6 +23,7 @@
 import argparse
 import logging
 import os
+import six
 
 from stevedore import extension
 
@@ -102,15 +103,14 @@ def load_plugin_from_args(args):
     raise exceptions.AuthPluginOptionsMissing(["auth_system"])
 
 
+@six.add_metaclass(abc.ABCMeta)
 class BaseAuthPlugin(object):
     """Base class for authentication plugins.
 
     An authentication plugin needs to override at least the authenticate
     method to be a valid plugin.
     """
 
-    __metaclass__ = abc.ABCMeta
-
     auth_system = None
     opt_names = []
     common_opt_names = [

openstack/common/apiclient/base.py

@@ -26,6 +26,7 @@
 # pylint: disable=E1102
 
 import abc
+import six
 import urllib
 
 from openstack.common.apiclient import exceptions
@@ -201,11 +202,10 @@ def _delete(self, url):
         return self.client.delete(url)
 
 
+@six.add_metaclass(abc.ABCMeta)
 class ManagerWithFind(BaseManager):
     """Manager with additional `find()`/`findall()` methods."""
 
-    __metaclass__ = abc.ABCMeta
-
     @abc.abstractmethod
     def list(self):
         pass

openstack/common/periodic_task.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import datetime
+import six
 import time
 
 from oslo.config import cfg
@@ -150,8 +151,8 @@ def __init__(cls, names, bases, dict_):
                 cls._periodic_last_run[name] = task._periodic_last_run
 
 
+@six.add_metaclass(_PeriodicTasksMeta)
 class PeriodicTasks(object):
-    __metaclass__ = _PeriodicTasksMeta
 
     def run_periodic_tasks(self, context, raise_on_error=False):
         """Tasks to be run at a periodic interval."""

openstack/common/policy.py

@@ -279,11 +279,10 @@ def enforce(self, rule, target, creds, do_raise=False,
         return result
 
 
+@six.add_metaclass(abc.ABCMeta)
 class BaseCheck(object):
     """Abstract base class for Check classes."""
 
-    __metaclass__ = abc.ABCMeta
-
     @abc.abstractmethod
     def __str__(self):
         """String representation of the Check tree rooted at this node."""
@@ -626,6 +625,7 @@ def decorator(func):
     return decorator
 
 
+@six.add_metaclass(ParseStateMeta)
 class ParseState(object):
     """Implement the core of parsing the policy language.
 
@@ -638,8 +638,6 @@ class ParseState(object):
     shouldn't be that big a problem.
     """
 
-    __metaclass__ = ParseStateMeta
-
     def __init__(self):
         """Initialize the ParseState."""
 

openstack/common/rpc/serializer.py

@@ -15,11 +15,12 @@
 """Provides the definition of an RPC serialization handler"""
 
 import abc
+import six
 
 
+@six.add_metaclass(abc.ABCMeta)
 class Serializer(object):
     """Generic (de-)serialization definition base class."""
-    __metaclass__ = abc.ABCMeta
 
     @abc.abstractmethod
     def serialize_entity(self, context, entity):

requirements.txt

@@ -14,7 +14,7 @@ stevedore>=0.10
 sqlalchemy-migrate>=0.7.2
 SQLAlchemy>=0.7.8,<=0.7.99
 qpid-python
-six
+six>=1.4.1
 netaddr
 pycrypto>=2.6
 Babel>=0.9.6

tests/unit/test_periodic.py

@@ -82,7 +82,6 @@ class ManagerMetaTestCase(test.BaseTestCase):
 
     def test_meta(self):
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task
             def foo(self):
@@ -112,7 +111,6 @@ def setUp(self):
 
     def test_periodic_tasks_with_idle(self):
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=200)
             def bar(self):
@@ -128,7 +126,6 @@ def bar(self):
 
     def test_periodic_tasks_constant(self):
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=0)
             def bar(self):
@@ -143,7 +140,6 @@ def test_periodic_tasks_idle_calculation(self):
         timeutils.set_time_override(fake_time)
 
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=10)
             def bar(self, context):
@@ -179,7 +175,6 @@ def test_periodic_tasks_immediate_runs_now(self):
         timeutils.set_time_override(fake_time)
 
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=10, run_immediately=True)
             def bar(self, context):
@@ -214,7 +209,6 @@ def bar(self, context):
 
     def test_periodic_tasks_disabled(self):
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=-1)
             def bar(self):
@@ -228,7 +222,6 @@ def test_external_running_here(self):
         self.config(run_external_periodic_tasks=True)
 
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=200, external_process_ok=True)
             def bar(self):
@@ -241,7 +234,6 @@ def test_external_running_elsewhere(self):
         self.config(run_external_periodic_tasks=False)
 
         class Manager(periodic_task.PeriodicTasks):
-            __metaclass__ = periodic_task._PeriodicTasksMeta
 
             @periodic_task.periodic_task(spacing=200, external_process_ok=True)
             def bar(self):

tests/unit/test_policy.py

@@ -552,8 +552,8 @@ def spam():
         self.assertEqual(spam.reducers, [['d', 'e', 'f'], ['a', 'b', 'c']])
 
     def test_parse_state_meta(self):
+        @six.add_metaclass(policy.ParseStateMeta)
         class FakeState(object):
-            __metaclass__ = policy.ParseStateMeta
 
             @policy.reducer('a', 'b', 'c')
             @policy.reducer('d', 'e', 'f')