Remove usage of six.add_metaclass

With python 3.x, classes can use the metaclass= logic
to not require usage of the six library.

One step in removing all of six usage from neutron.

Change-Id: I2f815e412d9a96eb5faf2b3bb3a1e393a9db9309

neutron/agent/firewall.py

@@ -16,8 +16,6 @@
 import abc
 import contextlib
 
-import six
-
 from neutron_lib.api.definitions import port_security as psec
 from neutron_lib import constants as n_const
 from neutron_lib.utils import runtime
@@ -49,8 +47,7 @@ def load_firewall_driver_class(driver):
         'neutron.agent.firewall_drivers', driver)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FirewallDriver(object):
+class FirewallDriver(object, metaclass=abc.ABCMeta):
     """Firewall Driver base class.
 
     Defines methods that any driver providing security groups

neutron/agent/l2/extensions/qos.py

@@ -21,7 +21,6 @@ from neutron_lib import constants
 from neutron_lib.services.qos import constants as qos_consts
 from oslo_concurrency import lockutils
 from oslo_log import log as logging
-import six
 
 from neutron.api.rpc.callbacks.consumer import registry
 from neutron.api.rpc.callbacks import events
@@ -32,8 +31,7 @@ from neutron import manager
 LOG = logging.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class QosAgentDriver(object):
+class QosAgentDriver(object, metaclass=abc.ABCMeta):
     """Defines stable abstract interface for QoS Agent Driver.
 
     QoS Agent driver defines the interface to be implemented by Agent

neutron/agent/l3/router_info.py

@@ -20,7 +20,6 @@ from neutron_lib import constants as lib_constants
 from neutron_lib.exceptions import l3 as l3_exc
 from neutron_lib.utils import helpers
 from oslo_log import log as logging
-import six
 
 from neutron._i18n import _
 from neutron.agent.l3 import namespaces
@@ -42,8 +41,7 @@ ADDRESS_SCOPE_MARK_ID_MAX = 2048
 DEFAULT_ADDRESS_SCOPE = "noscope"
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseRouterInfo(object):
+class BaseRouterInfo(object, metaclass=abc.ABCMeta):
 
     def __init__(self,
                  agent,

neutron/agent/linux/dhcp.py

@@ -161,8 +161,7 @@ class NetModel(DictModel):
         return self._ns_name
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DhcpBase(object):
+class DhcpBase(object, metaclass=abc.ABCMeta):
 
     def __init__(self, conf, network, process_monitor,
                  version=None, plugin=None):
@@ -216,8 +215,7 @@ class DhcpBase(object):
         raise NotImplementedError()
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DhcpLocalProcess(DhcpBase):
+class DhcpLocalProcess(DhcpBase, metaclass=abc.ABCMeta):
     PORTS = []
 
     def __init__(self, conf, network, process_monitor, version=None,

neutron/agent/linux/external_process.py

@@ -22,7 +22,6 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import fileutils
 import psutil
-import six
 
 from neutron.agent.linux import ip_lib
 from neutron.agent.linux import utils
@@ -37,8 +36,7 @@ agent_cfg.register_external_process_opts()
 agent_cfg.register_process_monitor_opts(cfg.CONF)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class MonitoredProcess(object):
+class MonitoredProcess(object, metaclass=abc.ABCMeta):
     @abc.abstractproperty
     def active(self):
         """Boolean representing the running state of the process."""

neutron/agent/linux/interface.py

@@ -22,7 +22,6 @@ from neutron_lib import exceptions
 from oslo_log import log as logging
 from oslo_utils import excutils
 from pyroute2.netlink import exceptions as pyroute2_exc
-import six
 
 from neutron.agent.common import ovs_lib
 from neutron.agent.linux import ip_lib
@@ -36,8 +35,7 @@ def _get_veth(name1, name2, namespace2):
             ip_lib.IPDevice(name2, namespace=namespace2))
 
 
-@six.add_metaclass(abc.ABCMeta)
-class LinuxInterfaceDriver(object):
+class LinuxInterfaceDriver(object, metaclass=abc.ABCMeta):
 
     DEV_NAME_LEN = constants.LINUX_DEV_LEN
     DEV_NAME_PREFIX = constants.TAP_DEVICE_PREFIX

neutron/agent/linux/pd_driver.py

@@ -15,15 +15,12 @@
 
 import abc
 
-import six
-
 from neutron.conf.agent import common as agent_conf
 
 agent_conf.register_pddriver_opts()
 
 
-@six.add_metaclass(abc.ABCMeta)
-class PDDriverBase(object):
+class PDDriverBase(object, metaclass=abc.ABCMeta):
 
     def __init__(self, router_id, subnet_id, ri_ifname):
         self.router_id = router_id

neutron/api/rpc/callbacks/resource_manager.py

@@ -15,7 +15,6 @@ import collections
 
 from neutron_lib.callbacks import exceptions
 from oslo_log import log as logging
-import six
 
 from neutron.api.rpc.callbacks import exceptions as rpc_exc
 from neutron.api.rpc.callbacks import resources
@@ -31,8 +30,7 @@ def _validate_resource_type(resource_type):
         raise exceptions.Invalid(element='resource', value=resource_type)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ResourceCallbacksManager(object):
+class ResourceCallbacksManager(object, metaclass=abc.ABCMeta):
     """A callback system that allows information providers in a loose manner.
     """
 

neutron/cmd/upgrade_checks/base.py

@@ -14,11 +14,8 @@
 
 import abc
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class BaseChecks(object):
+class BaseChecks(object, metaclass=abc.ABCMeta):
 
     """Base class providing upgrade checks.
 

neutron/core_extensions/base.py

@@ -15,8 +15,6 @@
 
 import abc
 
-import six
-
 
 NETWORK = 'network'
 PORT = 'port'
@@ -27,8 +25,7 @@ EVENT_UPDATE = 'update'
 CORE_RESOURCES = [NETWORK, PORT]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class CoreResourceExtension(object):
+class CoreResourceExtension(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def process_fields(self, context, resource_type, event_type,

neutron/extensions/address_scope.py

@@ -17,7 +17,6 @@ import abc
 from neutron_lib.api.definitions import address_scope as apidef
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import directory
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -45,8 +44,7 @@ class Address_scope(api_extensions.APIExtensionDescriptor):
         return [ex]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AddressScopePluginBase(object):
+class AddressScopePluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_address_scope(self, context, address_scope):

neutron/extensions/agent.py

@@ -19,7 +19,6 @@ from neutron_lib.api.definitions import agent as apidef
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib import exceptions
 from neutron_lib.plugins import directory
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -45,8 +44,7 @@ class Agent(api_extensions.APIExtensionDescriptor):
         return [ex]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AgentPluginBase(object):
+class AgentPluginBase(object, metaclass=abc.ABCMeta):
     """REST API to operate the Agent.
 
     All of method must be in an admin context.

neutron/extensions/availability_zone.py

@@ -17,7 +17,6 @@ import abc
 from neutron_lib.api.definitions import availability_zone as az_def
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import directory
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -40,8 +39,7 @@ class Availability_zone(api_extensions.APIExtensionDescriptor):
         return [ex]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AvailabilityZonePluginBase(object):
+class AvailabilityZonePluginBase(object, metaclass=abc.ABCMeta):
     """REST API to operate the Availability Zone."""
 
     @abc.abstractmethod

neutron/extensions/dhcpagentscheduler.py

@@ -22,7 +22,6 @@ from neutron_lib.api import extensions as api_extensions
 from neutron_lib.api import faults
 from neutron_lib.plugins import directory
 from neutron_lib import rpc as n_rpc
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import resource
@@ -100,8 +99,7 @@ class Dhcpagentscheduler(api_extensions.APIExtensionDescriptor):
         return exts
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DhcpAgentSchedulerPluginBase(object):
+class DhcpAgentSchedulerPluginBase(object, metaclass=abc.ABCMeta):
     """REST API to operate the DHCP agent scheduler.
 
     All of method must be in an admin context.

neutron/extensions/dvr.py

@@ -16,7 +16,6 @@ import abc
 
 from neutron_lib.api.definitions import dvr as apidef
 from neutron_lib.api import extensions
-import six
 
 
 class Dvr(extensions.APIExtensionDescriptor):
@@ -25,8 +24,7 @@ class Dvr(extensions.APIExtensionDescriptor):
     api_definition = apidef
 
 
-@six.add_metaclass(abc.ABCMeta)
-class DVRMacAddressPluginBase(object):
+class DVRMacAddressPluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def get_dvr_mac_address_list(self, context):

neutron/extensions/floating_ip_port_forwarding.py

@@ -21,7 +21,6 @@ from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import constants as plugin_consts
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as service_base
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -77,8 +76,8 @@ class Floating_ip_port_forwarding(api_extensions.APIExtensionDescriptor):
         return resources
 
 
-@six.add_metaclass(abc.ABCMeta)
-class PortForwardingPluginBase(service_base.ServicePluginBase):
+class PortForwardingPluginBase(service_base.ServicePluginBase,
+                               metaclass=abc.ABCMeta):
 
     path_prefix = apidef.API_PREFIX
 

neutron/extensions/floatingip_pools.py

@@ -16,7 +16,6 @@ import itertools
 from neutron_lib.api.definitions import floatingip_pools as apidef
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import constants
-import six
 
 from neutron.api.v2 import resource_helper
 
@@ -42,8 +41,7 @@ class Floatingip_pools(api_extensions.APIExtensionDescriptor):
         return resources
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FloatingIPPoolPluginBase(object):
+class FloatingIPPoolPluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def get_floatingip_pools(self, context, filters=None, fields=None,

neutron/extensions/l3.py

@@ -18,7 +18,6 @@ import abc
 from neutron_lib.api.definitions import l3 as l3_apidef
 from neutron_lib.api import extensions
 from neutron_lib.plugins import constants
-import six
 
 from neutron.api.v2 import resource_helper
 from neutron.conf import quota
@@ -42,8 +41,7 @@ class L3(extensions.APIExtensionDescriptor):
             register_quota=True)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RouterPluginBase(object):
+class RouterPluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_router(self, context, router):

neutron/extensions/l3_conntrack_helper.py

@@ -21,7 +21,6 @@ from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import constants as plugin_consts
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as service_base
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -81,8 +80,8 @@ class L3_conntrack_helper(api_extensions.APIExtensionDescriptor):
         return resources
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ConntrackHelperPluginBase(service_base.ServicePluginBase):
+class ConntrackHelperPluginBase(service_base.ServicePluginBase,
+                                metaclass=abc.ABCMeta):
 
     path_prefix = apidef.API_PREFIX
 

neutron/extensions/l3agentscheduler.py

@@ -24,7 +24,6 @@ from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib import rpc as n_rpc
 from oslo_log import log as logging
-import six
 import webob.exc
 
 from neutron._i18n import _
@@ -187,8 +186,7 @@ class RouterDoesntSupportScheduling(exceptions.Conflict):
     message = _("Router %(router_id)s does not support agent scheduling.")
 
 
-@six.add_metaclass(abc.ABCMeta)
-class L3AgentSchedulerPluginBase(object):
+class L3AgentSchedulerPluginBase(object, metaclass=abc.ABCMeta):
     """REST API to operate the l3 agent scheduler.
 
     All of method must be in an admin context.

neutron/extensions/logging.py

@@ -20,7 +20,6 @@ from neutron_lib.api.definitions import logging as apidef
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import constants as plugin_const
 from neutron_lib.services import base as service_base
-import six
 
 from neutron.api.v2 import resource_helper
 
@@ -50,8 +49,7 @@ class Logging(api_extensions.APIExtensionDescriptor):
         return resources
 
 
-@six.add_metaclass(abc.ABCMeta)
-class LoggingPluginBase(service_base.ServicePluginBase):
+class LoggingPluginBase(service_base.ServicePluginBase, metaclass=abc.ABCMeta):
 
     path_prefix = apidef.API_PREFIX
 

neutron/extensions/metering.py

@@ -18,7 +18,6 @@ from neutron_lib.api.definitions import metering as metering_apidef
 from neutron_lib.api import extensions
 from neutron_lib.plugins import constants
 from neutron_lib.services import base as service_base
-import six
 
 from neutron.api.v2 import resource_helper
 
@@ -42,8 +41,8 @@ class Metering(extensions.APIExtensionDescriptor):
             constants.METERING, translate_name=True, allow_bulk=True)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class MeteringPluginBase(service_base.ServicePluginBase):
+class MeteringPluginBase(service_base.ServicePluginBase,
+                         metaclass=abc.ABCMeta):
 
     def get_plugin_description(self):
         return constants.METERING

neutron/extensions/network_availability_zone.py

@@ -16,7 +16,6 @@ import abc
 
 from neutron_lib.api.definitions import network_availability_zone as apidef
 from neutron_lib.api import extensions
-import six
 
 
 class Network_availability_zone(extensions.APIExtensionDescriptor):
@@ -25,8 +24,7 @@ class Network_availability_zone(extensions.APIExtensionDescriptor):
     api_definition = apidef
 
 
-@six.add_metaclass(abc.ABCMeta)
-class NetworkAvailabilityZonePluginBase(object):
+class NetworkAvailabilityZonePluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def get_network_availability_zones(self, network):

neutron/extensions/network_segment_range.py

@@ -20,7 +20,6 @@ from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as service_base
 from oslo_log import log as logging
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -63,8 +62,8 @@ class Network_segment_range(api_extensions.APIExtensionDescriptor):
         return NetworkSegmentRangePluginBase
 
 
-@six.add_metaclass(abc.ABCMeta)
-class NetworkSegmentRangePluginBase(service_base.ServicePluginBase):
+class NetworkSegmentRangePluginBase(service_base.ServicePluginBase,
+                                    metaclass=abc.ABCMeta):
     """REST API to manage network segment ranges.
 
     All methods must be in an admin context.

neutron/extensions/qos.py

@@ -22,7 +22,6 @@ from neutron_lib.api import extensions as api_extensions
 from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from neutron_lib.services import base as service_base
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -80,8 +79,7 @@ class Qos(api_extensions.APIExtensionDescriptor):
         return resources
 
 
-@six.add_metaclass(abc.ABCMeta)
-class QoSPluginBase(service_base.ServicePluginBase):
+class QoSPluginBase(service_base.ServicePluginBase, metaclass=abc.ABCMeta):
 
     path_prefix = apidef.API_PREFIX
 

neutron/extensions/router_availability_zone.py

@@ -16,7 +16,6 @@ import abc
 
 from neutron_lib.api.definitions import router_availability_zone as apidef
 from neutron_lib.api import extensions
-import six
 
 
 class Router_availability_zone(extensions.APIExtensionDescriptor):
@@ -25,8 +24,7 @@ class Router_availability_zone(extensions.APIExtensionDescriptor):
     api_definition = apidef
 
 
-@six.add_metaclass(abc.ABCMeta)
-class RouterAvailabilityZonePluginBase(object):
+class RouterAvailabilityZonePluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def get_router_availability_zones(self, router):

neutron/extensions/securitygroup.py

@@ -355,8 +355,7 @@ class Securitygroup(api_extensions.ExtensionDescriptor):
         return [stdattr_ext.Standardattrdescription.get_alias()]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SecurityGroupPluginBase(object):
+class SecurityGroupPluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_security_group(self, context, security_group):

neutron/extensions/segment.py

@@ -21,7 +21,6 @@ from neutron_lib.api import extensions as api_extensions
 from neutron_lib import constants
 from neutron_lib.db import constants as db_const
 from neutron_lib.plugins import directory
-import six
 
 from neutron.api import extensions
 from neutron.api.v2 import base
@@ -149,8 +148,7 @@ class Segment(api_extensions.ExtensionDescriptor):
                 stdattrseg_apidef.ALIAS]
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SegmentPluginBase(object):
+class SegmentPluginBase(object, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_segment(self, context, segment):

neutron/extensions/tagging.py

@@ -22,7 +22,6 @@ from neutron_lib import exceptions
 from neutron_lib.plugins import directory
 from neutron_lib import rpc as n_rpc
 from neutron_lib.services import base as service_base
-import six
 import webob.exc
 
 from neutron._i18n import _
@@ -226,8 +225,7 @@ class Tagging(api_extensions.ExtensionDescriptor):
         return EXTENDED_ATTRIBUTES_2_0
 
 
-@six.add_metaclass(abc.ABCMeta)
-class TagPluginBase(service_base.ServicePluginBase):
+class TagPluginBase(service_base.ServicePluginBase, metaclass=abc.ABCMeta):
     """REST API to operate the Tag."""
 
     def get_plugin_description(self):

neutron/ipam/driver.py

@@ -13,14 +13,12 @@
 import abc
 
 from oslo_config import cfg
-import six
 
 from neutron.ipam import requests as ipam_req
 from neutron import manager
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Pool(object):
+class Pool(object, metaclass=abc.ABCMeta):
     """Interface definition for an IPAM driver.
 
     There should be an instance of the driver for every subnet pool.
@@ -128,8 +126,7 @@ class Pool(object):
         return True
 
 
-@six.add_metaclass(abc.ABCMeta)
-class Subnet(object):
+class Subnet(object, metaclass=abc.ABCMeta):
     """Interface definition for an IPAM subnet
 
     A subnet would typically be associated with a network but may not be.  It
@@ -167,8 +164,7 @@ class Subnet(object):
         """
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SubnetGroup(object):
+class SubnetGroup(object, metaclass=abc.ABCMeta):
     """Interface definition for a filtered group of IPAM Subnets
 
     Allocates from a group of semantically equivalent subnets.  The list of

neutron/ipam/requests.py

@@ -17,20 +17,17 @@ from neutron_lib.api import validators
 from neutron_lib import constants
 from oslo_utils import netutils
 from oslo_utils import uuidutils
-import six
 
 from neutron._i18n import _
 from neutron.common import utils as common_utils
 from neutron.ipam import exceptions as ipam_exc
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SubnetPool(object):
+class SubnetPool(object, metaclass=abc.ABCMeta):
     """Represents a pool of IPs available inside an address scope."""
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SubnetRequest(object):
+class SubnetRequest(object, metaclass=abc.ABCMeta):
     """Carries the data needed to make a subnet request
 
     The data validated and carried by an instance of this class is the data
@@ -184,8 +181,7 @@ class SpecificSubnetRequest(SubnetRequest):
         return self._subnet_cidr.prefixlen
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AddressRequest(object):
+class AddressRequest(object, metaclass=abc.ABCMeta):
     """Abstract base class for address requests"""
 
 

neutron/manager.py

@@ -24,7 +24,6 @@ import oslo_messaging
 from oslo_service import periodic_task
 from oslo_utils import excutils
 from osprofiler import profiler
-import six
 
 from neutron._i18n import _
 from neutron.common import utils
@@ -40,8 +39,7 @@ class ManagerMeta(profiler.TracedMeta, type(periodic_task.PeriodicTasks)):
     pass
 
 
-@six.add_metaclass(ManagerMeta)
-class Manager(periodic_task.PeriodicTasks):
+class Manager(periodic_task.PeriodicTasks, metaclass=ManagerMeta):
     __trace_args__ = {"name": "rpc"}
 
     # Set RPC API version to 1.0 by default.
@@ -91,8 +89,7 @@ def validate_pre_plugin_load():
         return msg
 
 
-@six.add_metaclass(profiler.TracedMeta)
-class NeutronManager(object):
+class NeutronManager(object, metaclass=profiler.TracedMeta):
     """Neutron's Manager class.
 
     Neutron's Manager class is responsible for parsing a config file and

neutron/neutron_plugin_base_v2.py

@@ -23,11 +23,9 @@ methods that needs to be implemented by a v2 Neutron Plug-in.
 import abc
 
 from neutron_lib.services import base as base_services
-import six
 
 
-@six.add_metaclass(abc.ABCMeta)
-class NeutronPluginBaseV2(base_services.WorkerBase):
+class NeutronPluginBaseV2(base_services.WorkerBase, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_subnet(self, context, subnet):

neutron/objects/base.py

@@ -142,10 +142,10 @@ class NeutronObjectRegistry(obj_base.VersionedObjectRegistry):
         return self
 
 
-@six.add_metaclass(abc.ABCMeta)
 class NeutronObject(obj_base.VersionedObject,
                     obj_base.VersionedObjectDictCompat,
-                    obj_base.ComparableVersionedObject):
+                    obj_base.ComparableVersionedObject,
+                    metaclass=abc.ABCMeta):
 
     synthetic_fields = []
     extra_filter_names = set()
@@ -398,8 +398,7 @@ class DeclarativeObject(abc.ABCMeta):
             raise o_exc.NeutronObjectValidatorException(fields=invalid_fields)
 
 
-@six.add_metaclass(DeclarativeObject)
-class NeutronDbObject(NeutronObject):
+class NeutronDbObject(NeutronObject, metaclass=DeclarativeObject):
 
     # should be overridden for all persistent objects
     db_model = None

neutron/objects/qos/rule.py

@@ -23,7 +23,6 @@ from neutron_lib.utils import helpers
 from oslo_utils import versionutils
 from oslo_versionedobjects import exception
 from oslo_versionedobjects import fields as obj_fields
-import six
 
 from neutron.db.qos import models as qos_db_model
 from neutron.objects import base
@@ -43,8 +42,7 @@ def get_rules(obj_cls, context, qos_policy_id):
     return all_rules
 
 
-@six.add_metaclass(abc.ABCMeta)
-class QosRule(base.NeutronDbObject):
+class QosRule(base.NeutronDbObject, metaclass=abc.ABCMeta):
     # Version 1.0: Initial version, only BandwidthLimitRule
     #         1.1: Added DscpMarkingRule
     #         1.2: Added QosMinimumBandwidthRule

neutron/objects/rbac.py

@@ -17,14 +17,12 @@ import abc
 
 from neutron_lib.objects import common_types
 from oslo_versionedobjects import fields as obj_fields
-from six import add_metaclass
 from sqlalchemy import and_
 
 from neutron.objects import base
 
 
-@add_metaclass(abc.ABCMeta)
-class RBACBaseObject(base.NeutronDbObject):
+class RBACBaseObject(base.NeutronDbObject, metaclass=abc.ABCMeta):
     # Version 1.0: Initial version
 
     VERSION = '1.0'

neutron/objects/rbac_db.py

@@ -19,7 +19,6 @@ from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources
 from neutron_lib import exceptions
-from six import add_metaclass
 from six import with_metaclass
 from sqlalchemy import and_
 
@@ -32,9 +31,9 @@ from neutron.objects import base
 from neutron.objects.db import api as obj_db_api
 
 
-@add_metaclass(abc.ABCMeta)
 class RbacNeutronDbObjectMixin(rbac_db_mixin.RbacPluginMixin,
-                               base.NeutronDbObject):
+                               base.NeutronDbObject,
+                               metaclass=abc.ABCMeta):
 
     rbac_db_cls = None
 

neutron/plugins/ml2/drivers/agent/_agent_manager_base.py

@@ -16,8 +16,6 @@
 
 import abc
 
-import six
-
 
 class NetworkSegment(object):
     """Represents a Neutron network segment"""
@@ -29,8 +27,7 @@ class NetworkSegment(object):
         self.mtu = mtu
 
 
-@six.add_metaclass(abc.ABCMeta)
-class CommonAgentManagerRpcCallBackBase(object):
+class CommonAgentManagerRpcCallBackBase(object, metaclass=abc.ABCMeta):
     """Base class for managers RPC callbacks.
 
     This class must be inherited by a RPC callback class that is used
@@ -81,8 +78,7 @@ class CommonAgentManagerRpcCallBackBase(object):
         return updated_devices
 
 
-@six.add_metaclass(abc.ABCMeta)
-class CommonAgentManagerBase(object):
+class CommonAgentManagerBase(object, metaclass=abc.ABCMeta):
     """Base class for managers that are used with the common agent loop.
 
     This class must be inherited by a manager class that is used

neutron/plugins/ml2/drivers/l2pop/rpc_manager/l2population_rpc.py

@@ -19,14 +19,12 @@ import itertools
 from neutron_lib import constants as n_const
 from oslo_config import cfg
 from oslo_log import helpers as log_helpers
-import six
 
 from neutron.plugins.ml2.drivers.l2pop import rpc as l2pop_rpc
 from neutron.plugins.ml2.drivers.openvswitch.agent import vlanmanager
 
 
-@six.add_metaclass(abc.ABCMeta)
-class L2populationRpcCallBackMixin(object):
+class L2populationRpcCallBackMixin(object, metaclass=abc.ABCMeta):
     '''General mixin class of L2-population RPC call back.
 
     The following methods are called through RPC.
@@ -105,8 +103,8 @@ class L2populationRpcCallBackMixin(object):
         pass
 
 
-@six.add_metaclass(abc.ABCMeta)
-class L2populationRpcCallBackTunnelMixin(L2populationRpcCallBackMixin):
+class L2populationRpcCallBackTunnelMixin(L2populationRpcCallBackMixin,
+                                         metaclass=abc.ABCMeta):
     '''Mixin class of L2-population call back for Tunnel.
 
     The following methods are all used in agents as internal methods.

neutron/plugins/ml2/drivers/mech_agent.py

@@ -22,7 +22,6 @@ from neutron_lib import constants as const
 from neutron_lib.placement import utils as place_utils
 from neutron_lib.plugins.ml2 import api
 from oslo_log import log
-import six
 
 from neutron._i18n import _
 from neutron.db import provisioning_blocks
@@ -30,8 +29,7 @@ from neutron.db import provisioning_blocks
 LOG = log.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class AgentMechanismDriverBase(api.MechanismDriver):
+class AgentMechanismDriverBase(api.MechanismDriver, metaclass=abc.ABCMeta):
     """Base class for drivers that attach to networks using an L2 agent.
 
     The AgentMechanismDriverBase provides common code for mechanism
@@ -236,8 +234,8 @@ class AgentMechanismDriverBase(api.MechanismDriver):
             return False
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SimpleAgentMechanismDriverBase(AgentMechanismDriverBase):
+class SimpleAgentMechanismDriverBase(AgentMechanismDriverBase,
+                                     metaclass=abc.ABCMeta):
     """Base class for simple drivers using an L2 agent.
 
     The SimpleAgentMechanismDriverBase provides common code for

neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/api.py

@@ -15,13 +15,11 @@
 import abc
 
 from ovsdbapp import api
-import six
 
 from neutron.common.ovn import constants as ovn_const
 
 
-@six.add_metaclass(abc.ABCMeta)
-class API(api.API):
+class API(api.API, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def create_lswitch_port(self, lport_name, lswitch_name, may_exist=True,
@@ -627,8 +625,7 @@ class API(api.API):
         """
 
 
-@six.add_metaclass(abc.ABCMeta)
-class SbAPI(api.API):
+class SbAPI(api.API, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def chassis_exists(self, hostname):

neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovn_db_sync.py

@@ -24,7 +24,6 @@ from neutron_lib.plugins import constants as plugin_constants
 from neutron_lib.plugins import directory
 from neutron_lib.utils import helpers
 from oslo_log import log
-import six
 
 from neutron.common.ovn import acl as acl_utils
 from neutron.common.ovn import constants as ovn_const
@@ -41,8 +40,7 @@ SYNC_MODE_LOG = 'log'
 SYNC_MODE_REPAIR = 'repair'
 
 
-@six.add_metaclass(abc.ABCMeta)
-class OvnDbSynchronizer(object):
+class OvnDbSynchronizer(object, metaclass=abc.ABCMeta):
 
     def __init__(self, core_plugin, ovn_api, ovn_driver):
         self.ovn_driver = ovn_driver

neutron/plugins/ml2/drivers/type_tunnel.py

@@ -30,7 +30,6 @@ from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_log import log
 from oslo_utils import uuidutils
-import six
 from six import moves
 from sqlalchemy import or_
 
@@ -54,8 +53,7 @@ def chunks(iterable, chunk_size):
         chunk = list(itertools.islice(iterator, 0, chunk_size))
 
 
-@six.add_metaclass(abc.ABCMeta)
-class _TunnelTypeDriverBase(helpers.SegmentTypeDriver):
+class _TunnelTypeDriverBase(helpers.SegmentTypeDriver, metaclass=abc.ABCMeta):
 
     BULK_SIZE = 100
 
@@ -281,8 +279,7 @@ class _TunnelTypeDriverBase(helpers.SegmentTypeDriver):
         return ranges
 
 
-@six.add_metaclass(abc.ABCMeta)
-class TunnelTypeDriver(_TunnelTypeDriverBase):
+class TunnelTypeDriver(_TunnelTypeDriverBase, metaclass=abc.ABCMeta):
     """Define stable abstract interface for ML2 type drivers.
 
     tunnel type networks rely on tunnel endpoints. This class defines abstract
@@ -354,8 +351,7 @@ class TunnelTypeDriver(_TunnelTypeDriverBase):
                 first())
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ML2TunnelTypeDriver(_TunnelTypeDriverBase):
+class ML2TunnelTypeDriver(_TunnelTypeDriverBase, metaclass=abc.ABCMeta):
     """Define stable abstract interface for ML2 type drivers.
 
     tunnel type networks rely on tunnel endpoints. This class defines abstract

neutron/scheduler/base_resource_filter.py

@@ -16,11 +16,9 @@
 import abc
 
 from neutron_lib.db import api as db_api
-import six
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseResourceFilter(object):
+class BaseResourceFilter(object, metaclass=abc.ABCMeta):
     """Encapsulate logic that is specific to the resource type."""
     @abc.abstractmethod
     def filter_agents(self, plugin, context, resource):

neutron/scheduler/base_scheduler.py

@@ -18,13 +18,11 @@ from operator import attrgetter
 import random
 
 from oslo_log import log as logging
-import six
 
 LOG = logging.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class BaseScheduler(object):
+class BaseScheduler(object, metaclass=abc.ABCMeta):
     """The base scheduler (agnostic to resource type).
        Child classes of BaseScheduler must define the
        self.resource_filter to filter agents of

neutron/scheduler/l3_agent_scheduler.py

@@ -26,7 +26,6 @@ from neutron_lib.exceptions import l3 as l3_exc
 from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_log import log as logging
-import six
 
 from neutron.common import utils
 from neutron.conf.db import l3_hamode_db
@@ -38,8 +37,7 @@ LOG = logging.getLogger(__name__)
 cfg.CONF.register_opts(l3_hamode_db.L3_HA_OPTS)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class L3Scheduler(object):
+class L3Scheduler(object, metaclass=abc.ABCMeta):
 
     def __init__(self):
         self.max_ha_agents = cfg.CONF.max_l3_agents_per_router

neutron/scheduler/l3_ovn_scheduler.py

@@ -17,7 +17,6 @@ import copy
 import random
 
 from oslo_log import log
-import six
 
 from neutron.common.ovn import constants as ovn_const
 from neutron.common.ovn import utils
@@ -30,8 +29,7 @@ OVN_SCHEDULER_CHANCE = 'chance'
 OVN_SCHEDULER_LEAST_LOADED = 'leastloaded'
 
 
-@six.add_metaclass(abc.ABCMeta)
-class OVNGatewayScheduler(object):
+class OVNGatewayScheduler(object, metaclass=abc.ABCMeta):
 
     def __init__(self):
         pass

neutron/services/externaldns/driver.py

@@ -17,15 +17,13 @@ import abc
 
 from oslo_config import cfg
 from oslo_log import log
-import six
 
 from neutron import manager
 
 LOG = log.getLogger(__name__)
 
 
-@six.add_metaclass(abc.ABCMeta)
-class ExternalDNSService(object):
+class ExternalDNSService(object, metaclass=abc.ABCMeta):
     """Interface definition for an external dns service driver."""
 
     def __init__(self):

neutron/services/logapi/agent/log_extension.py

@@ -19,7 +19,6 @@ import contextlib
 from neutron_lib.agent import extension
 from neutron_lib import constants
 from oslo_concurrency import lockutils
-import six
 
 from neutron.api.rpc.callbacks.consumer import registry
 from neutron.api.rpc.callbacks import events
@@ -34,8 +33,7 @@ log_cfg.register_log_driver_opts()
 LOGGING_DRIVERS_NAMESPACE = 'neutron.services.logapi.drivers'
 
 
-@six.add_metaclass(abc.ABCMeta)
-class LoggingDriver(object):
+class LoggingDriver(object, metaclass=abc.ABCMeta):
     """Defines abstract interface for logging driver"""
 
     # specific logging types are supported

neutron/services/metering/drivers/abstract_driver.py

@@ -14,11 +14,8 @@
 
 import abc
 
-import six
 
-
-@six.add_metaclass(abc.ABCMeta)
-class MeteringAbstractDriver(object):
+class MeteringAbstractDriver(object, metaclass=abc.ABCMeta):
     """Abstract Metering driver."""
 
     def __init__(self, plugin, conf):

neutron/tests/base.py

@@ -215,8 +215,7 @@ class _CatchTimeoutMetaclass(abc.ABCMeta):
 # kills the whole worker, with all test cases scheduled to it. This metaclass
 # makes all test cases convert Timeout exceptions into unittest friendly
 # failure mode (self.fail).
-@six.add_metaclass(_CatchTimeoutMetaclass)
-class DietTestCase(base.BaseTestCase):
+class DietTestCase(base.BaseTestCase, metaclass=_CatchTimeoutMetaclass):
     """Same great taste, less filling.
 
     BaseTestCase is responsible for doing lots of plugin-centric setup

neutron/tests/common/net_helpers.py

@@ -32,7 +32,6 @@ from neutron_lib import exceptions as n_exc
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import uuidutils
-import six
 
 from neutron.agent.common import ovs_lib
 from neutron.agent.linux import bridge_lib
@@ -717,8 +716,7 @@ class MacvtapFixture(fixtures.Fixture):
                 pass
 
 
-@six.add_metaclass(abc.ABCMeta)
-class PortFixture(fixtures.Fixture):
+class PortFixture(fixtures.Fixture, metaclass=abc.ABCMeta):
     """Create a port.
 
     :ivar port: created port

neutron/tests/unit/extensions/foxinsocks.py

@@ -18,7 +18,6 @@ import abc
 from neutron_lib.api import extensions as api_extensions
 from neutron_lib.services import base
 from oslo_serialization import jsonutils
-import six
 
 from neutron.api import extensions
 from neutron import wsgi
@@ -30,8 +29,7 @@ class FoxInSocksController(wsgi.Controller):
         return "Try to say this Mr. Knox, sir..."
 
 
-@six.add_metaclass(abc.ABCMeta)
-class FoxInSocksPluginInterface(base.ServicePluginBase):
+class FoxInSocksPluginInterface(base.ServicePluginBase, metaclass=abc.ABCMeta):
 
     @abc.abstractmethod
     def method_to_support_foxnsox_extension(self):