Merge "Add a new option to skip loading Trunk extension"

doc/source/admin/config-trunking.rst

@@ -72,6 +72,20 @@ Controller node
      [DEFAULT]
      service_plugins = trunk
 
+Compute node
+------------
+
+* If you are using the ``Open vSwitch`` mechanism driver, then you can
+  verify the value of ``trunk_enabled`` flag in
+  ``/etc/neutron/plugins/ml2/openvswitch_agent.ini`` config file.
+  Note that ``True`` is the default value, but you can overwrite this
+  option like this:
+
+  .. code-block:: ini
+
+     [OVS]
+     trunk_enabled = True
+
 Verify service operation
 ------------------------
 

neutron/conf/plugins/ml2/drivers/ovs_conf.py

@@ -185,6 +185,11 @@ ovs_opts = [
                      "limit features which will add meter kbps rules "
                      "and apply them to the OpenFlow flow table "
                      "BANDWIDTH_RATE_LIMIT for VM ports."),
+    cfg.BoolOpt('trunk_enabled', default=True,
+                help=_('Enable agent side trunk extension. If you do not '
+                       'need the trunk extension, you can safely set '
+                       'config option to False, it will avoid the agent '
+                       'to declare some queues.')),
 ]
 
 agent_opts = [

neutron/services/trunk/drivers/openvswitch/agent/driver.py

@@ -93,13 +93,13 @@ class OVSTrunkSkeleton(agent.TrunkSkeleton):
 
 def init_handler(resource, event, trigger, payload=None):
     """Handler for agent init event."""
-    # Set up agent-side RPC for receiving trunk events; we may want to
-    # make this setup conditional based on server-side capabilities.
     global TRUNK_SKELETON
 
-    manager = trunk_manager.TrunkManager(trigger.int_br)
-    handler = ovsdb_handler.OVSDBHandler(manager)
-    TRUNK_SKELETON = OVSTrunkSkeleton(handler)
+    if cfg.CONF.OVS.trunk_enabled:
+        LOG.info("Registering Trunk extension")
+        manager = trunk_manager.TrunkManager(trigger.int_br)
+        handler = ovsdb_handler.OVSDBHandler(manager)
+        TRUNK_SKELETON = OVSTrunkSkeleton(handler)
 
 
 def unregister():

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

@@ -13,6 +13,7 @@
 
 from unittest import mock
 
+from oslo_config import cfg
 import oslo_messaging
 from oslo_utils import uuidutils
 
@@ -137,3 +138,25 @@ class OvsTrunkSkeletonTest(base.BaseTestCase):
                 self.skeleton.ovsdb_handler, 'unwire_subports_for_trunk'):
             self._test_handle_subports_trunk_on_trunk_update(
                 events.DELETED)
+
+
+class InitHandlerTest(base.BaseTestCase):
+
+    def setUp(self):
+        super().setUp()
+        # Unset the driver to avoid race condition between tests
+        driver.TRUNK_SKELETON = None
+
+    def test_init_handler_plugin_default(self):
+        driver.init_handler(mock.Mock(), mock.Mock(), mock.Mock(), None)
+        self.assertIsInstance(driver.TRUNK_SKELETON, driver.OVSTrunkSkeleton)
+
+    def test_init_handler_plugin_disabled(self):
+        cfg.CONF.set_override('trunk_enabled', False, group='OVS')
+        driver.init_handler(mock.Mock(), mock.Mock(), mock.Mock(), None)
+        self.assertFalse(driver.TRUNK_SKELETON)
+
+    def test_init_handler_plugin_enabled(self):
+        cfg.CONF.set_override('trunk_enabled', True, group='OVS')
+        driver.init_handler(mock.Mock(), mock.Mock(), mock.Mock(), None)
+        self.assertIsInstance(driver.TRUNK_SKELETON, driver.OVSTrunkSkeleton)

releasenotes/notes/skip-Trunk-ovs-extension-option-bbe5ef1a9fb89146.yaml

@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    An new option name ``trunk_enabled`` has been added to
+    ``neutron-openvswitch-agent`` under ``OVS`` group. This new option can be
+    set to ``False`` in order to disable loading the ``trunk`` extension on
+    agent side. The default value for this option is ``True`` to keep backward
+    compatibility with previous deployments. The recommendation is to set this
+    option to ``False`` if you do not use the ``trunk`` extension, so that
+    the number of queues created by the RPCServer will reduce. This can have
+    a very good impact on large-scale scenario using RabbitMQ message broker.