Introduce L3 agent extension for SNAT logging

This patch introduces SNAT logging extension for Neutron Packet Logging
framework.

Co-Authored-By: Kim Bao Long <longkb@vn.fujitsu.com>
Partial-Bug: #1752290
Change-Id: I882b8e75525f51ef8b5b032fc89843ae904844e7

neutron/agent/l3/extensions/snat_log.py

@@ -0,0 +1,39 @@
+# Copyright (c) 2018 Fujitsu Limited
+# 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_lib.agent import l3_extension
+from oslo_log import log as logging
+
+from neutron.services.logapi.agent.l3 import base
+from neutron.services.logapi.agent import log_extension as log_ext
+from neutron.services.logapi.rpc import agent as agent_rpc
+
+LOG = logging.getLogger(__name__)
+SNAT_LOG_DRIVER = 'snat_log'
+
+
+class SNATLoggingExtension(base.L3LoggingExtensionBase,
+                           l3_extension.L3AgentExtension):
+
+    def initialize(self, connection, driver_type):
+        """Initialize SNAT logging agent extension"""
+
+        snat_log_cls = self._load_driver_cls(
+            log_ext.LOGGING_DRIVERS_NAMESPACE, SNAT_LOG_DRIVER)
+        self.log_driver = snat_log_cls(self.agent_api)
+        self.resource_rpc = agent_rpc.LoggingApiStub()
+        self._register_rpc_consumers()
+        self.log_driver.initialize(self.resource_rpc)
+        LOG.info("Loaded SNAT logging driver")

neutron/tests/unit/agent/l3/extensions/test_snat_log.py

@@ -0,0 +1,50 @@
+# Copyright (c) 2018 Fujitsu Limited
+# 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.
+
+import mock
+from neutron_lib import constants as lib_const
+
+from neutron.agent.l3.extensions import snat_log
+from neutron.api.rpc.callbacks.consumer import registry
+from neutron.api.rpc.callbacks import resources
+from neutron.api.rpc.handlers import resources_rpc
+from neutron.tests.unit.services.logapi.agent.l3 import test_base
+
+
+class SnatLogExtensionInitializeTestCase(test_base.L3LoggingExtBaseTestCase):
+
+    def setUp(self):
+        super(SnatLogExtensionInitializeTestCase, self).setUp()
+        self.snat_log_ext = snat_log.SNATLoggingExtension()
+        self.snat_log_ext.consume_api(self.agent_api)
+
+    @mock.patch.object(registry, 'register')
+    @mock.patch.object(resources_rpc, 'ResourcesPushRpcCallback')
+    def test_initialize_subscribed_to_rpc(self, rpc_mock, subscribe_mock):
+        call_to_patch = 'neutron.common.rpc.Connection'
+        with mock.patch(call_to_patch,
+                        return_value=self.connection) as create_connection:
+            self.snat_log_ext.initialize(
+                self.connection, lib_const.L3_AGENT_MODE)
+            create_connection.assert_has_calls([mock.call()])
+            self.connection.create_consumer.assert_has_calls(
+                [mock.call(
+                     resources_rpc.resource_type_versioned_topic(
+                         resources.LOGGING_RESOURCE),
+                     [rpc_mock()],
+                     fanout=True)]
+            )
+            subscribe_mock.assert_called_with(
+                mock.ANY, resources.LOGGING_RESOURCE)

setup.cfg

@@ -109,6 +109,7 @@ neutron.agent.l2.extensions =
 neutron.agent.l3.extensions =
     fip_qos = neutron.agent.l3.extensions.qos.fip:FipQosAgentExtension
     port_forwarding = neutron.agent.l3.extensions.port_forwarding:PortForwardingAgentExtension
+    snat_log = neutron.agent.l3.extensions.snat_log:SNATLoggingExtension
 neutron.services.logapi.drivers =
     ovs = neutron.services.logapi.drivers.openvswitch.ovs_firewall_log:OVSFirewallLoggingDriver
 neutron.qos.agent_drivers =