Add agent-side driver scaffolding for trunk functionality

The agent code is enhanced to allow the trunk agent-side counterpart
to be activated seamlessly by means or local registry notifications.
Some integration with the server side is provided by loading the
RPC agent-side skeleton. Basic unit testing provides some coverage.

More effective functional and system coverage will be provided once
everything comes together.

Partially-implements: blueprint vlan-aware-vms

Co-Authored-By: Adolfo Duarte <adolfo.duarte@hpe.com>
Change-Id: Id70553e8980593f99548a4d2b0a78355933f7c2c

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

@@ -0,0 +1,29 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+#
+# 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.callbacks import events
+from neutron.callbacks import registry
+
+
+def notify_init_event(agent_type, agent):
+    """Notify init event for the specified agent."""
+    registry.notify(agent_type, events.AFTER_INIT, agent, agent=agent)
+
+
+def register(callback, agent_type):
+    """Subscribe callback to init event for the specified agent.
+
+    :param agent_type: an agent type as defined in neutron_lib.constants.
+    :param callback: a callback that can process the agent init event.
+    """
+    registry.subscribe(callback, agent_type, events.AFTER_INIT)

neutron/plugins/ml2/drivers/openvswitch/agent/ovs_capabilities.py

@@ -0,0 +1,23 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+#
+# 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_lib import constants
+
+from neutron.plugins.ml2.drivers.agent import capabilities
+from neutron.services.trunk.drivers.openvswitch.agent import driver
+
+
+def register():
+    """Register OVS capabilities."""
+    # Add capabilities to be loaded during agent initialization
+    capabilities.register(driver.init_handler, constants.AGENT_TYPE_OVS)

neutron/plugins/ml2/drivers/openvswitch/agent/ovs_neutron_agent.py

@@ -52,11 +52,14 @@ from neutron import context
 from neutron.extensions import portbindings
 from neutron.plugins.common import constants as p_const
 from neutron.plugins.common import utils as p_utils
+from neutron.plugins.ml2.drivers.agent import capabilities
 from neutron.plugins.ml2.drivers.l2pop.rpc_manager import l2population_rpc
 from neutron.plugins.ml2.drivers.openvswitch.agent.common \
     import constants
 from neutron.plugins.ml2.drivers.openvswitch.agent \
     import ovs_agent_extension_api as ovs_ext_api
+from neutron.plugins.ml2.drivers.openvswitch.agent \
+    import ovs_capabilities
 from neutron.plugins.ml2.drivers.openvswitch.agent \
     import ovs_dvr_neutron_agent
 from neutron.plugins.ml2.drivers.openvswitch.agent import vlanmanager
@@ -2152,10 +2155,12 @@ def prepare_xen_compute():
 
 def main(bridge_classes):
     prepare_xen_compute()
+    ovs_capabilities.register()
     validate_tunnel_config(cfg.CONF.AGENT.tunnel_types, cfg.CONF.OVS.local_ip)
 
     try:
         agent = OVSNeutronAgent(bridge_classes, cfg.CONF)
+        capabilities.notify_init_event(n_const.AGENT_TYPE_OVS, agent)
     except (RuntimeError, ValueError) as e:
         LOG.error(_LE("%s Agent terminated!"), e)
         sys.exit(1)

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

@@ -0,0 +1,46 @@
+# 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.api.rpc.callbacks.consumer import registry
+from neutron.api.rpc.callbacks import resources
+from neutron.services.trunk.rpc import agent
+
+LOG = logging.getLogger(__name__)
+
+TRUNK_SKELETON = None
+
+
+class OVSTrunkSkeleton(agent.TrunkSkeleton):
+
+    def __init__(self):
+        super(OVSTrunkSkeleton, self).__init__()
+        registry.unsubscribe(self.handle_trunks, resources.TRUNK)
+
+    def handle_trunks(self, trunk, event_type):
+        """This method is not required by the OVS Agent driver.
+
+        Trunk notifications are handled via local OVSDB events.
+        """
+        raise NotImplementedError()
+
+    def handle_subports(self, subports, event_type):
+        # TODO(armax): call into TrunkManager to wire the subports
+        LOG.debug("Event %s for subports: %s", event_type, subports)
+
+
+def init_handler(resource, event, trigger, agent=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
+    TRUNK_SKELETON = OVSTrunkSkeleton()

neutron/tests/unit/plugins/ml2/drivers/agent/test_capabilities.py

@@ -0,0 +1,40 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+#
+# 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.
+
+import mock
+
+from neutron.callbacks import events
+from neutron.plugins.ml2.drivers.agent import capabilities
+from neutron.tests import base
+
+
+class CapabilitiesTest(base.BaseTestCase):
+
+    @mock.patch("neutron.callbacks.manager.CallbacksManager.notify")
+    def test_notify_init_event(self, mocked_manager):
+        mock_agent_type = mock.Mock()
+        mock_agent = mock.Mock()
+        capabilities.notify_init_event(mock_agent_type, mock_agent)
+        mocked_manager.assert_called_with(mock_agent_type,
+                                          events.AFTER_INIT,
+                                          mock_agent,
+                                          agent=mock_agent)
+
+    @mock.patch("neutron.callbacks.manager.CallbacksManager.subscribe")
+    def test_register(self, mocked_subscribe):
+        mock_callback = mock.Mock()
+        mock_agent_type = mock.Mock()
+        capabilities.register(mock_callback, mock_agent_type)
+        mocked_subscribe.assert_called_with(mock_callback,
+                                            mock_agent_type,
+                                            events.AFTER_INIT)

neutron/tests/unit/plugins/ml2/drivers/openvswitch/agent/test_ovs_capabilities.py

@@ -0,0 +1,30 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+#
+# 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.
+
+import mock
+
+from neutron.callbacks import events
+from neutron.plugins.ml2.drivers.openvswitch.agent import ovs_capabilities
+from neutron.services.trunk.drivers.openvswitch.agent import driver
+from neutron.tests import base
+from neutron_lib import constants
+
+
+class CapabilitiesTest(base.BaseTestCase):
+
+    @mock.patch("neutron.callbacks.manager.CallbacksManager.subscribe")
+    def test_register(self, mocked_subscribe):
+        ovs_capabilities.register()
+        mocked_subscribe.assert_called_with(driver.init_handler,
+                                            constants.AGENT_TYPE_OVS,
+                                            events.AFTER_INIT)

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

@@ -0,0 +1,28 @@
+# Copyright 2016 Hewlett Packard Enterprise Development LP
+#
+# 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.
+
+import mock
+
+from neutron.api.rpc.callbacks import resources
+from neutron.services.trunk.drivers.openvswitch.agent import driver
+from neutron.tests import base
+
+
+class OvsTrunkSkeletonTest(base.BaseTestCase):
+
+    @mock.patch("neutron.api.rpc.callbacks.resource_manager."
+                "ConsumerResourceCallbacksManager.unregister")
+    def test___init__(self, mocked_unregister):
+        test_obj = driver.OVSTrunkSkeleton()
+        mocked_unregister.assert_called_with(test_obj.handle_trunks,
+                                             resources.TRUNK)