Refactors QosAgentDriver

QosAgentDriver has a method which uses linux specific module, which
is trying to import pyroute2.

Module pyroute2 tries to import a module from socket which does not
exists on windows (socket.inet_pton[1]). This can cause neutron
services to fail to start on windows[2].

[1]: https://docs.python.org/2/library/socket.html#socket.inet_pton
[2]: http://paste.openstack.org/show/593272/

Change-Id: I706368bfcaece380e1357e0c504fd3b9553ba49c
Related-Bug: #1492714

neutron/agent/l2/extensions/qos.py

@@ -23,7 +23,6 @@ import six
 
 from neutron._i18n import _LW, _LI
 from neutron.agent.l2 import l2_agent_extension
-from neutron.agent.linux import tc_lib
 from neutron.api.rpc.callbacks.consumer import registry
 from neutron.api.rpc.callbacks import events
 from neutron.api.rpc.callbacks import resources
@@ -122,15 +121,6 @@ class QosAgentDriver(object):
                 LOG.debug("Port %(port)s excluded from QoS rule %(rule)s",
                           {'port': port, 'rule': rule.id})
 
-    def _get_egress_burst_value(self, rule):
-        """Return burst value used for egress bandwidth limitation.
-
-        Because Egress bw_limit is done on ingress qdisc by LB and ovs drivers
-        so it will return burst_value used by tc on as ingress_qdisc.
-        """
-        return tc_lib.TcCommand.get_ingress_qdisc_burst_value(
-                rule.max_kbps, rule.max_burst_kbps)
-
 
 class PortPolicyMap(object):
     def __init__(self):

neutron/agent/l2/extensions/qos_linux.py

@@ -0,0 +1,29 @@
+# Copyright (c) 2017 Cloudbase Solutions
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from neutron.agent.l2.extensions import qos
+from neutron.agent.linux import tc_lib
+
+
+class QosLinuxAgentDriver(qos.QosAgentDriver):
+
+    def _get_egress_burst_value(self, rule):
+        """Return burst value used for egress bandwidth limitation.
+
+        Because Egress bw_limit is done on ingress qdisc by LB and ovs drivers
+        so it will return burst_value used by tc on as ingress_qdisc.
+        """
+        return tc_lib.TcCommand.get_ingress_qdisc_burst_value(
+            rule.max_kbps, rule.max_burst_kbps)

neutron/plugins/ml2/drivers/linuxbridge/agent/extension_drivers/qos_driver.py

@@ -17,7 +17,7 @@ from oslo_log import helpers as log_helpers
 from oslo_log import log
 
 from neutron._i18n import _LI
-from neutron.agent.l2.extensions import qos
+from neutron.agent.l2.extensions import qos_linux as qos
 from neutron.agent.linux import iptables_manager
 from neutron.agent.linux import tc_lib
 import neutron.common.constants as const
@@ -27,7 +27,7 @@ from neutron.plugins.ml2.drivers.linuxbridge.mech_driver import (
 LOG = log.getLogger(__name__)
 
 
-class QosLinuxbridgeAgentDriver(qos.QosAgentDriver):
+class QosLinuxbridgeAgentDriver(qos.QosLinuxAgentDriver):
 
     SUPPORTED_RULES = (
         mech_linuxbridge.LinuxbridgeMechanismDriver.supported_qos_rule_types

neutron/plugins/ml2/drivers/mech_sriov/agent/extension_drivers/qos_driver.py

@@ -15,7 +15,7 @@
 from oslo_log import log as logging
 
 from neutron._i18n import _LE, _LI
-from neutron.agent.l2.extensions import qos
+from neutron.agent.l2.extensions import qos_linux as qos
 from neutron.plugins.ml2.drivers.mech_sriov.agent.common import (
     exceptions as exc)
 from neutron.plugins.ml2.drivers.mech_sriov.agent import eswitch_manager as esm
@@ -25,7 +25,7 @@ from neutron.plugins.ml2.drivers.mech_sriov.mech_driver import (
 LOG = logging.getLogger(__name__)
 
 
-class QosSRIOVAgentDriver(qos.QosAgentDriver):
+class QosSRIOVAgentDriver(qos.QosLinuxAgentDriver):
 
     SUPPORTED_RULES = (
         mech_driver.SriovNicSwitchMechanismDriver.supported_qos_rule_types)

neutron/plugins/ml2/drivers/openvswitch/agent/extension_drivers/qos_driver.py

@@ -17,7 +17,7 @@ import collections
 from oslo_config import cfg
 from oslo_log import log as logging
 
-from neutron.agent.l2.extensions import qos
+from neutron.agent.l2.extensions import qos_linux as qos
 from neutron.plugins.ml2.drivers.openvswitch.mech_driver import (
     mech_openvswitch)
 from neutron.services.qos import qos_consts
@@ -26,7 +26,7 @@ from neutron.services.qos import qos_consts
 LOG = logging.getLogger(__name__)
 
 
-class QosOVSAgentDriver(qos.QosAgentDriver):
+class QosOVSAgentDriver(qos.QosLinuxAgentDriver):
 
     SUPPORTED_RULES = (
         mech_openvswitch.OpenvswitchMechanismDriver.supported_qos_rule_types)

neutron/tests/unit/agent/l2/extensions/test_qos.py

@@ -18,6 +18,7 @@ from neutron_lib import exceptions
 from oslo_utils import uuidutils
 
 from neutron.agent.l2.extensions import qos
+from neutron.agent.l2.extensions import qos_linux
 from neutron.api.rpc.callbacks.consumer import registry
 from neutron.api.rpc.callbacks import events
 from neutron.api.rpc.callbacks import resources
@@ -55,7 +56,7 @@ FAKE_RULE_ID = uuidutils.generate_uuid()
 REALLY_FAKE_RULE_ID = uuidutils.generate_uuid()
 
 
-class FakeDriver(qos.QosAgentDriver):
+class FakeDriver(qos_linux.QosLinuxAgentDriver):
 
     SUPPORTED_RULES = {qos_consts.RULE_TYPE_BANDWIDTH_LIMIT}
 
@@ -152,7 +153,7 @@ class QosExtensionBaseTestCase(base.BaseTestCase):
         # Don't rely on used driver
         mock.patch(
             'neutron.manager.NeutronManager.load_class_for_provider',
-            return_value=lambda: mock.Mock(spec=qos.QosAgentDriver)
+            return_value=lambda: mock.Mock(spec=qos_linux.QosLinuxAgentDriver)
         ).start()