Merge "Update metering agent to use stevedore alias for driver"

neutron/services/metering/agents/metering_agent.py

@@ -22,9 +22,9 @@ import oslo_messaging
 from oslo_service import loopingcall
 from oslo_service import periodic_task
 from oslo_service import service
-from oslo_utils import importutils
 from oslo_utils import timeutils
 
+from neutron.services.metering.drivers import utils as driverutils
 from neutron._i18n import _, _LE, _LI, _LW
 from neutron.agent import rpc as agent_rpc
 from neutron.common import config as common_config
@@ -86,8 +86,8 @@ class MeteringAgent(MeteringPluginRpc, manager.Manager):
         LOG.info(_LI("Loading Metering driver %s"), self.conf.driver)
         if not self.conf.driver:
             raise SystemExit(_('A metering driver must be specified'))
-        self.metering_driver = importutils.import_object(
-            self.conf.driver, self, self.conf)
+        self.metering_driver = driverutils.load_metering_driver(self,
+                                                                self.conf)
 
     def _metering_notification(self):
         for label_id, info in self.metering_infos.items():

neutron/services/metering/drivers/utils.py

@@ -0,0 +1,42 @@
+# Copyright 2017 Red Hat, Inc.
+# 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 oslo_log import log as logging
+
+from neutron._i18n import _LE
+from neutron.common import utils as utils
+
+
+LOG = logging.getLogger(__name__)
+
+METERING_NAMESPACE = 'neutron.services.metering_drivers'
+
+
+def load_metering_driver(plugin, conf):
+    """Load metering driver
+
+    :param plugin: the metering plugin
+    :param conf: driver configuration object
+    :raises SystemExit of 1 if driver cannot be loaded
+    """
+
+    try:
+        loaded_class = utils.load_class_by_alias_or_classname(
+                METERING_NAMESPACE, conf.driver)
+        return loaded_class(plugin, conf)
+    except ImportError:
+        LOG.error(_LE("Error loading metering driver '%s'"),
+                  conf.driver)
+        raise SystemExit(1)

neutron/tests/unit/services/metering/agents/test_metering_agent.py

@@ -54,7 +54,7 @@ class TestMeteringOperations(base.BaseTestCase):
 
         self.noop_driver = ('neutron.services.metering.drivers.noop.'
                             'noop_driver.NoopMeteringDriver')
-        cfg.CONF.set_override('driver', self.noop_driver)
+        cfg.CONF.set_override('driver', 'noop')
         cfg.CONF.set_override('measure_interval', 0)
         cfg.CONF.set_override('report_interval', 0)
 
@@ -230,9 +230,7 @@ class TestMeteringDriver(base.BaseTestCase):
         super(TestMeteringDriver, self).setUp()
         metering_agent_config.register_metering_agent_opts()
 
-        self.noop_driver = ('neutron.services.metering.drivers.noop.'
-                            'noop_driver.NoopMeteringDriver')
-        cfg.CONF.set_override('driver', self.noop_driver)
+        cfg.CONF.set_override('driver', 'noop')
 
         self.agent = metering_agent.MeteringAgent('my agent', cfg.CONF)
         self.driver = mock.Mock()
@@ -244,7 +242,7 @@ class TestMeteringDriver(base.BaseTestCase):
         with mock.patch.object(metering_agent, 'LOG') as log:
             self.agent.add_metering_label(None, ROUTERS)
             log.exception.assert_called_with(mock.ANY,
-                                             {'driver': self.noop_driver,
+                                             {'driver': 'noop',
                                               'func': 'add_metering_label'})
 
     def test_add_metering_label_runtime_error(self):
@@ -253,7 +251,7 @@ class TestMeteringDriver(base.BaseTestCase):
         with mock.patch.object(metering_agent, 'LOG') as log:
             self.agent.add_metering_label(None, ROUTERS)
             log.exception.assert_called_with(mock.ANY,
-                                             {'driver': self.noop_driver,
+                                             {'driver': 'noop',
                                               'func':
                                               'add_metering_label'})
 

releasenotes/notes/metering-driver-stevedore-alias-2c4fdb0556205a3a.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - The metering agent driver can now be specified with a stevedore
+    alias in the ``metering_agent.ini`` file. For example,
+    ``driver = iptables`` instead of
+    ``driver = neutron.services.metering.iptables.iptables_driver:IptablesMeteringDriver``.

setup.cfg

@@ -151,6 +151,9 @@ neutron.agent.firewall_drivers =
     iptables = neutron.agent.linux.iptables_firewall:IptablesFirewallDriver
     iptables_hybrid = neutron.agent.linux.iptables_firewall:OVSHybridIptablesFirewallDriver
     openvswitch = neutron.agent.linux.openvswitch_firewall:OVSFirewallDriver
+neutron.services.metering_drivers =
+    noop = neutron.services.metering.drivers.noop.noop_driver:NoopMeteringDriver
+    iptables = neutron.services.metering.iptables.iptables_driver:IptablesMeteringDriver
 tempest.test_plugins =
     neutron_tests = neutron.tests.tempest.plugin:NeutronTempestPlugin