commit 5f6e37f966a627670480429d153a21631e170c20
Author: Rodolfo Alonso Hernandez <ralonsoh@redhat.com>
Date:   Wed Jul 29 11:49:31 2020 +0000

    Filter ML2Plugin mech driver supported extensions
    
    Each mechanism driver loaded in the ML2Plugin can provide what
    extensions are supported. By default, any mech driver can support
    all extensions.
    
    This extension filtering is done during the plugin initialization.
    If any requested extension is not supported, it will be silently
    removed from the loaded extensions.
    
    Depends-On: https://review.opendev.org/#/c/743519
    Related-Bug: #1888829
    
    Change-Id: Id4809d4f3c4e13a93f9160df3618f8602b57437c

diff --git a/neutron/plugins/ml2/drivers/mech_agent.py b/neutron/plugins/ml2/drivers/mech_agent.py
index b33de46..f5b67be 100644
--- a/neutron/plugins/ml2/drivers/mech_agent.py
+++ b/neutron/plugins/ml2/drivers/mech_agent.py
@@ -49,6 +49,7 @@ class AgentMechanismDriverBase(api.MechanismDriver, metaclass=abc.ABCMeta):
         :param agent_type: Constant identifying agent type in agents_db
         :param supported_vnic_types: The binding:vnic_type values we can bind
         """
+        super(AgentMechanismDriverBase, self).__init__()
         self.agent_type = agent_type
         self.supported_vnic_types = supported_vnic_types
 
diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index bb1b735..9b6f5a7 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -223,7 +223,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
             sg_rpc.disable_security_group_extension_by_config(aliases)
             vlantransparent._disable_extension_by_config(aliases)
             filter_validation._disable_extension_by_config(aliases)
-            self._aliases = aliases
+            self._aliases = self._filter_extensions_by_mech_driver(aliases)
         return self._aliases
 
     def __new__(cls, *args, **kwargs):
@@ -288,6 +288,17 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                         driver=extension_driver, service_plugin=service_plugin
                     )
 
+    def _filter_extensions_by_mech_driver(self, aliases):
+        """Return the supported extensions by the loaded mech drivers"""
+        if not self.mechanism_manager.ordered_mech_drivers:
+            return aliases
+
+        supported_extensions = set([])
+        for mech_driver in self.mechanism_manager.ordered_mech_drivers:
+            supported_extensions |= mech_driver.obj.supported_extensions(
+                set(aliases))
+        return list(supported_extensions)
+
     @registry.receives(resources.PORT,
                        [provisioning_blocks.PROVISIONING_COMPLETE])
     def _port_provisioned(self, rtype, event, trigger, payload=None):
diff --git a/neutron/tests/unit/plugins/ml2/drivers/mechanism_logger.py b/neutron/tests/unit/plugins/ml2/drivers/mechanism_logger.py
index e7d3ba4..2f4a2c0 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/mechanism_logger.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/mechanism_logger.py
@@ -25,6 +25,9 @@ class LoggerMechanismDriver(api.MechanismDriver):
 
     Generally used for testing and debugging.
     """
+    def __init__(self, *args, **kwargs):
+        super(LoggerMechanismDriver, self).__init__(*args, **kwargs)
+        self._supported_extensions = set()
 
     def initialize(self):
         pass
@@ -140,3 +143,8 @@ class LoggerMechanismDriver(api.MechanismDriver):
                  "%(segments)s, candidate hosts %(hosts)s ",
                  {'segments': segments, 'hosts': candidate_hosts})
         return set()
+
+    def supported_extensions(self, extensions):
+        if self._supported_extensions:
+            return extensions & self._supported_extensions
+        return extensions
diff --git a/neutron/tests/unit/plugins/ml2/drivers/mechanism_test.py b/neutron/tests/unit/plugins/ml2/drivers/mechanism_test.py
index a17ed2d..b4ed810 100644
--- a/neutron/tests/unit/plugins/ml2/drivers/mechanism_test.py
+++ b/neutron/tests/unit/plugins/ml2/drivers/mechanism_test.py
@@ -32,6 +32,7 @@ class TestMechanismDriver(api.MechanismDriver):
     def __init__(self, *args, **kwargs):
         super(TestMechanismDriver, self).__init__(*args, **kwargs)
         self._supported_vnic_types = ('test_mechanism_driver_vnic_type', )
+        self._supported_extensions = set([])
 
     def initialize(self):
         self.bound_ports = set()
@@ -267,6 +268,11 @@ class TestMechanismDriver(api.MechanismDriver):
     def get_standard_device_mappings(self, agent):
         return {}
 
+    def supported_extensions(self, extensions):
+        if self._supported_extensions:
+            return extensions & self._supported_extensions
+        return extensions
+
 
 class TestMechanismDriverWithAgent(mech_agent.AgentMechanismDriverBase,
                                    TestMechanismDriver):
diff --git a/neutron/tests/unit/plugins/ml2/test_plugin.py b/neutron/tests/unit/plugins/ml2/test_plugin.py
index a9e00c1..6224474 100644
--- a/neutron/tests/unit/plugins/ml2/test_plugin.py
+++ b/neutron/tests/unit/plugins/ml2/test_plugin.py
@@ -166,6 +166,24 @@ class TestMl2BulkToggleWithoutBulkless(Ml2PluginV2TestCase):
         self.assertFalse(self._skip_native_bulk)
 
 
+class TestMl2FilterExtensions(Ml2PluginV2TestCase):
+
+    _mechanism_drivers = ['logger', 'test']
+
+    def test__filter_extensions_by_mech_driver(self):
+        extension_aliases = ['ext1', 'ext2', 'ext3', 'ext4', 'ext5']
+        supported_aliases = [{'ext0', 'ext1', 'ext2'},
+                             {'ext4', 'ext5', 'ext6'}]
+        for idx, mech_driver in enumerate(
+                self.plugin.mechanism_manager.ordered_mech_drivers):
+            mech_driver.obj._supported_extensions = supported_aliases[idx]
+
+        supported_extensions = sorted(
+            self.plugin._filter_extensions_by_mech_driver(extension_aliases))
+        self.assertEqual(['ext1', 'ext2', 'ext4', 'ext5'],
+                         supported_extensions)
+
+
 class TestMl2BasicGet(test_plugin.TestBasicGet,
                       Ml2PluginV2TestCase):
     pass