Use flake8-import-order plugin

In reviews we usually check import grouping but it is boring.
By using flake8-import-order plugin, we can avoid this.
It enforces loose checking so it sounds good to use it.
This flake8 plugin is already used in tempest.

Note that flake8-import-order version is pinned to avoid unexpected
breakage of pep8 job.

Setup for unit tests of hacking rules is tweaked to disable
flake8-import-order checks. This extension assumes an actual file exists
and causes hacking rule unit tests.

Change-Id: Ib51bd97dc4394ef2b46d4dbb7fb36a9aa9f8fe3d

neutron/agent/l3/router_info.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import collections
+
 import netaddr
 from neutron_lib import constants as lib_constants
 from neutron_lib.utils import helpers

neutron/extensions/segment.py

@@ -13,7 +13,6 @@
 #    under the License.
 
 import abc
-import six
 
 from neutron_lib.api import converters
 from neutron_lib.api.definitions import provider_net as providernet
@@ -21,6 +20,7 @@ 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 attributes

neutron/manager.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 from collections import defaultdict
+
 from neutron_lib.plugins import constants as lib_const
 from neutron_lib.plugins import directory
 from oslo_config import cfg

neutron/scheduler/dhcp_agent_scheduler.py

@@ -15,9 +15,9 @@
 
 
 import collections
+from operator import itemgetter
 
 from neutron_lib import constants
-from operator import itemgetter
 from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_log import log as logging

neutron/tests/fullstack/resources/client.py

@@ -13,9 +13,9 @@
 #    under the License.
 #
 import functools
-import netaddr
 
 import fixtures
+import netaddr
 from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants
 from neutronclient.common import exceptions

neutron/tests/fullstack/test_l3_agent.py

@@ -13,10 +13,10 @@
 #    under the License.
 
 import functools
-import netaddr
 import os
 import time
 
+import netaddr
 from oslo_utils import uuidutils
 
 from neutron.agent.l3 import ha_router

neutron/tests/functional/agent/l3/framework.py

@@ -15,6 +15,7 @@
 
 import copy
 import functools
+import textwrap
 
 import mock
 import netaddr
@@ -23,7 +24,6 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import uuidutils
 import testtools
-import textwrap
 
 from neutron.agent.common import ovs_lib
 from neutron.agent.l3 import agent as neutron_l3_agent

neutron/tests/functional/agent/linux/bin/ipt_binname.py

@@ -17,6 +17,7 @@
 #    under the License.
 
 from __future__ import print_function
+
 import sys
 
 import eventlet

neutron/tests/functional/agent/test_l2_ovs_agent.py

@@ -14,9 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import time
 
+import mock
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources

neutron/tests/functional/db/test_migrations.py

@@ -13,10 +13,11 @@
 #    under the License.
 
 import collections
+from contextlib import contextmanager
+import subprocess
 
 from alembic.ddl import base as alembic_ddl
 from alembic import script as alembic_script
-from contextlib import contextmanager
 from oslo_config import cfg
 from oslo_config import fixture as config_fixture
 from oslo_db.sqlalchemy import test_migrations
@@ -25,7 +26,6 @@ import six
 import sqlalchemy
 from sqlalchemy import event  # noqa
 from sqlalchemy.sql import ddl as sqla_ddl
-import subprocess
 
 from neutron.db.migration.alembic_migrations import external
 from neutron.db.migration import cli as migration

neutron/tests/unit/agent/l3/test_dvr_fip_ns.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import copy
+
 import mock
 from oslo_config import cfg
 from oslo_utils import uuidutils

neutron/tests/unit/agent/linux/test_external_process.py

@@ -12,9 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import os.path
 
+import mock
 from oslo_utils import fileutils
 import psutil
 

neutron/tests/unit/agent/linux/test_ip_lib.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import errno
+import socket
 
 import mock
 import netaddr
@@ -21,7 +22,6 @@ from neutron_lib import exceptions
 import pyroute2
 from pyroute2.netlink.rtnl import ndmsg
 from pyroute2 import NetlinkError
-import socket
 import testtools
 
 from neutron.agent.common import utils  # noqa

neutron/tests/unit/agent/linux/test_keepalived.py

@@ -14,12 +14,11 @@
 #
 
 import os
-
-import mock
-import testtools
 import textwrap
 
+import mock
 from neutron_lib import constants as n_consts
+import testtools
 
 from neutron.agent.linux import keepalived
 from neutron.tests import base

neutron/tests/unit/agent/test_rpc.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import datetime
+
 import mock
 from oslo_context import context as oslo_context
 

neutron/tests/unit/api/rpc/agentnotifiers/test_dhcp_rpc_agent_api.py

@@ -14,8 +14,8 @@
 # limitations under the License.
 
 import datetime
-import mock
 
+import mock
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import registry
 from neutron_lib.callbacks import resources

neutron/tests/unit/common/test_ipv6_utils.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import collections
+
 import mock
 from neutron_lib import constants
 

neutron/tests/unit/db/test_agents_db.py

@@ -16,8 +16,8 @@
 
 import copy
 import datetime
-import mock
 
+import mock
 from neutron_lib import constants
 from neutron_lib import context
 from neutron_lib import exceptions as n_exc

neutron/tests/unit/db/test_ipam_pluggable_backend.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import copy
+
 import mock
 import netaddr
 from neutron_lib import constants

neutron/tests/unit/db/test_securitygroups_db.py

@@ -12,6 +12,7 @@
 # limitations under the License.
 
 import copy
+
 import mock
 from neutron_lib.callbacks import events
 from neutron_lib.callbacks import exceptions

neutron/tests/unit/db/test_sqlalchemytypes.py

@@ -11,8 +11,8 @@
 #    under the License.
 
 import abc
-import netaddr
 
+import netaddr
 from neutron_lib import context
 from oslo_db import exception
 from oslo_db.tests.sqlalchemy import base as test_base

neutron/tests/unit/extensions/test_flavors.py

@@ -14,9 +14,9 @@
 
 
 import copy
+
 import fixtures
 import mock
-
 from neutron_lib import context
 from neutron_lib.db import constants as db_const
 from oslo_config import cfg

neutron/tests/unit/extensions/test_segment.py

@@ -13,8 +13,8 @@
 #    under the License.
 
 import copy
-from keystoneauth1 import exceptions as ks_exc
 
+from keystoneauth1 import exceptions as ks_exc
 import mock
 import netaddr
 from neutron_lib.api.definitions import portbindings

neutron/tests/unit/extensions/test_timestamp.py

@@ -13,12 +13,12 @@
 #    under the License.
 
 import datetime
-import six
 
 import mock
 from neutron_lib import context
 from neutron_lib.plugins import directory
 from oslo_utils import timeutils
+import six
 
 from neutron.db import db_base_plugin_v2
 from neutron.db import models_v2

neutron/tests/unit/hacking/test_checks.py

@@ -15,6 +15,7 @@ import re
 from flake8 import engine
 from hacking.tests import test_doctest as hacking_doctest
 import pep8
+import pkg_resources
 import testscenarios
 import testtools
 from testtools import content
@@ -288,10 +289,13 @@ def _get_lines(check):
 
 def load_tests(loader, tests, pattern):
 
-    flake8_style = engine.get_style_guide(parse_argv=False,
-                                          # Ignore H104 otherwise it's
-                                          # raised on doctests.
-                                          ignore=('F', 'H104'))
+    default_checks = [e.name for e
+                      in pkg_resources.iter_entry_points('flake8.extension')]
+    flake8_style = engine.get_style_guide(
+        parse_argv=False,
+        # We are testing neutron-specific hacking rules, so there is no need
+        # to run the checks registered by hacking or other flake8 extensions.
+        ignore=default_checks)
     options = flake8_style.options
 
     for name, check in checks.__dict__.items():

neutron/tests/unit/objects/test_quota.py

@@ -13,6 +13,7 @@
 #    under the License.
 
 import datetime
+
 from oslo_utils import uuidutils
 
 from neutron.objects import quota

neutron/tests/unit/plugins/ml2/drivers/macvtap/test_macvtap_common.py

@@ -15,6 +15,7 @@
 #    under the License.
 
 import hashlib
+
 import mock
 
 from neutron.plugins.ml2.drivers.macvtap import macvtap_common as m_common

neutron/tests/unit/services/trunk/drivers/openvswitch/agent/test_trunk_manager.py

@@ -14,8 +14,8 @@
 #    under the License.
 
 import contextlib
-import mock
 
+import mock
 import testtools
 
 from neutron.services.trunk.drivers.openvswitch.agent import trunk_manager

test-requirements.txt

@@ -5,6 +5,7 @@ hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
+flake8-import-order==0.12 # LGPLv3
 mock>=2.0 # BSD
 python-subunit>=0.0.18 # Apache-2.0/BSD
 sphinx!=1.6.1,>=1.5.1 # BSD

tox.ini

@@ -145,6 +145,7 @@ ignore = E125,E126,E128,E129,E265,H404,H405,N530,N534,N536,N537
 enable-extensions=H106,H203,H904
 show-source = true
 exclude = ./.*,build,dist,doc
+import-order-style = pep8
 
 [hacking]
 import_exceptions = neutron._i18n