Remove six.add_metaclass

Replace six.add_metaclass with Python 3 style code.

Change-Id: Ifc3f2bcb8fcdd2b555864bd4e22a973a7858c272
Implements: blueprint six-removal
Signed-off-by: Takashi Natsume <takanattie@gmail.com>

nova/api/openstack/wsgi.py

@@ -737,8 +737,7 @@ class ControllerMetaclass(type):
                                                        cls_dict)
 
 
-@six.add_metaclass(ControllerMetaclass)
-class Controller(object):
+class Controller(metaclass=ControllerMetaclass):
     """Default controller."""
 
     _view_builder_class = None

nova/compute/monitors/base.py

@@ -12,13 +12,10 @@
 
 import abc
 
-import six
-
 from nova.objects import fields
 
 
-@six.add_metaclass(abc.ABCMeta)
-class MonitorBase(object):
+class MonitorBase(metaclass=abc.ABCMeta):
     """Base class for all resource monitor plugins.
 
     A monitor is responsible for adding a set of related metrics to

nova/compute/multi_cell_list.py

@@ -15,8 +15,6 @@ import copy
 import heapq
 
 import eventlet
-import six
-
 from oslo_log import log as logging
 
 import nova.conf
@@ -114,8 +112,7 @@ def query_wrapper(ctx, fn, *args, **kwargs):
             return
 
 
-@six.add_metaclass(abc.ABCMeta)
-class CrossCellLister(object):
+class CrossCellLister(metaclass=abc.ABCMeta):
     """An implementation of a cross-cell efficient lister.
 
     This primarily provides a listing implementation for fetching

nova/conductor/tasks/base.py

@@ -14,7 +14,6 @@ import abc
 import functools
 
 from oslo_utils import excutils
-import six
 
 
 def rollback_wrapper(original):
@@ -28,8 +27,7 @@ def rollback_wrapper(original):
     return wrap
 
 
-@six.add_metaclass(abc.ABCMeta)
-class TaskBase(object):
+class TaskBase(metaclass=abc.ABCMeta):
 
     def __init__(self, context, instance):
         self.context = context

nova/console/rfb/auth.py

@@ -15,8 +15,6 @@
 import abc
 import enum
 
-import six
-
 VERSION_LENGTH = 12
 SUBTYPE_LENGTH = 4
 
@@ -40,8 +38,7 @@ class AuthType(enum.IntEnum):
     MSLOGON = 0xfffffffa  # Used by UltraVNC
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RFBAuthScheme(object):
+class RFBAuthScheme(metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def security_type(self):

nova/console/securityproxy/base.py

@@ -15,11 +15,8 @@
 
 import abc
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class SecurityProxy(object):
+class SecurityProxy(metaclass=abc.ABCMeta):
     """A console security Proxy Helper
 
     Console security proxy helpers should subclass

nova/manager.py

@@ -52,7 +52,6 @@ This module provides Manager, a base class for managers.
 """
 
 from oslo_service import periodic_task
-import six
 
 import nova.conf
 from nova.db import base
@@ -87,8 +86,7 @@ class ManagerMeta(profiler.get_traced_meta(), type(PeriodicTasks)):
     """
 
 
-@six.add_metaclass(ManagerMeta)
-class Manager(base.Base, PeriodicTasks):
+class Manager(base.Base, PeriodicTasks, metaclass=ManagerMeta):
     __trace_args__ = {"name": "rpc"}
 
     def __init__(self, host=None, service_name='undefined'):

nova/pci/devspec.py

@@ -31,8 +31,7 @@ ANY = '*'
 REGEX_ANY = '.*'
 
 
-@six.add_metaclass(abc.ABCMeta)
-class PciAddressSpec(object):
+class PciAddressSpec(metaclass=abc.ABCMeta):
     """Abstract class for all PCI address spec styles
 
     This class checks the address fields of the pci.passthrough_whitelist

nova/scheduler/driver.py

@@ -21,15 +21,12 @@ Scheduler base class that all Schedulers should inherit from
 
 import abc
 
-import six
-
 from nova import objects
 from nova.scheduler import host_manager
 from nova import servicegroup
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Scheduler(object):
+class Scheduler(metaclass=abc.ABCMeta):
     """The base class that all Scheduler classes should inherit from."""
 
     # TODO(mriedem): We should remove this flag now so that all scheduler

nova/test.py

@@ -645,8 +645,7 @@ class APICoverage(object):
             testtools.matchers.ContainsAll(api_methods))
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SubclassSignatureTestCase(testtools.TestCase):
+class SubclassSignatureTestCase(testtools.TestCase, metaclass=abc.ABCMeta):
     """Ensure all overridden methods of all subclasses of the class
     under test exactly match the signature of the base class.
 

nova/virt/libvirt/imagebackend.py

@@ -79,8 +79,7 @@ def _update_utime_ignore_eacces(path):
                 ctxt.reraise = False
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Image(object):
+class Image(metaclass=abc.ABCMeta):
 
     SUPPORTS_CLONE = False
 

nova/virt/libvirt/volume/fs.py

@@ -15,16 +15,13 @@
 import abc
 import os
 
-import six
-
 from nova import utils
 from nova.virt.libvirt.volume import mount
 from nova.virt.libvirt.volume import volume as libvirt_volume
 
 
-@six.add_metaclass(abc.ABCMeta)
 class LibvirtBaseFileSystemVolumeDriver(
-    libvirt_volume.LibvirtBaseVolumeDriver):
+    libvirt_volume.LibvirtBaseVolumeDriver, metaclass=abc.ABCMeta):
     """The base class for file system type volume drivers"""
 
     def __init__(self, host):
@@ -96,8 +93,8 @@ class LibvirtBaseFileSystemVolumeDriver(
         return os.path.join(mount_path, connection_info['data']['name'])
 
 
-@six.add_metaclass(abc.ABCMeta)
-class LibvirtMountedFileSystemVolumeDriver(LibvirtBaseFileSystemVolumeDriver):
+class LibvirtMountedFileSystemVolumeDriver(LibvirtBaseFileSystemVolumeDriver,
+                                           metaclass=abc.ABCMeta):
     # NOTE(mdbooth): Hopefully we'll get to the point where everything which
     # previously subclassed LibvirtBaseFileSystemVolumeDriver now subclasses
     # LibvirtMountedFileSystemVolumeDriver. If we get there, we should fold

nova/virt/libvirt/volume/remotefs.py

@@ -107,8 +107,7 @@ class RemoteFilesystem(object):
                               compression=compression)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RemoteFilesystemDriver(object):
+class RemoteFilesystemDriver(metaclass=abc.ABCMeta):
     @abc.abstractmethod
     def create_file(self, host, dst_path, on_execute, on_completion):
         """Create file on the remote system.

nova/virt/powervm/disk/driver.py

@@ -22,7 +22,6 @@ import pypowervm.const as pvm_const
 import pypowervm.tasks.scsi_mapper as tsk_map
 import pypowervm.util as pvm_u
 import pypowervm.wrappers.virtual_io_server as pvm_vios
-import six
 
 from nova import exception
 from nova.virt.powervm import mgmt
@@ -61,8 +60,7 @@ class IterableToFileAdapter(object):
         return return_value
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DiskAdapter(object):
+class DiskAdapter(metaclass=abc.ABCMeta):
 
     capabilities = {
         'shared_storage': False,

nova/virt/powervm/vif.py

@@ -148,8 +148,7 @@ def unplug(adapter, instance, vif, cna_w_list=None):
         _push_vif_event(adapter, 'unplug', vnet_w, instance, vif['type'])
 
 
-@six.add_metaclass(abc.ABCMeta)
-class PvmVifDriver(object):
+class PvmVifDriver(metaclass=abc.ABCMeta):
     """Represents an abstract class for a PowerVM Vif Driver.
 
     A VIF Driver understands a given virtual interface type (network).  It

nova/weights.py

@@ -19,8 +19,6 @@ Pluggable Weighing support
 
 import abc
 
-import six
-
 from nova import loadables
 
 
@@ -63,8 +61,7 @@ class WeighedObject(object):
         return "<WeighedObject '%s': %s>" % (self.obj, self.weight)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseWeigher(object):
+class BaseWeigher(metaclass=abc.ABCMeta):
     """Base class for pluggable weighers.
 
     The attributes maxval and minval can be specified to set up the maximum