allow manila ports to do multiple port binding for ML2

Similar to Nova live migration
(see https://review.opendev.org/c/openstack/neutron/+/414251/74/neutron/plugins/ml2/plugin.py#2005)
Manila wants to do share live migration, and needs to modify its ports in a
similar way: issue port binding upfront to determine the segmentation id in
the target network segment.

Closes-Bug: #2003095
Change-Id: I647d00a30564ade246e704ff199b6aceafdc4c50

neutron/plugins/ml2/common/constants.py

@@ -14,6 +14,9 @@
 from neutron_lib import constants
 
 DEFAULT_DEVICE_OWNER = ''
+# TODO(carthaca): use from neutron-lib once
+# change id I9be781d99a08a6a015c3747eb15f20bc356cf08e has been released
+DEVICE_OWNER_MANILA_PREFIX = "manila:"
 
 # TODO(liuyulong): move to neutron-lib or common constants
 NO_PBLOCKS_TYPES = [

neutron/plugins/ml2/plugin.py

@@ -2611,11 +2611,12 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
             self.mechanism_manager.update_network_postcommit(mech_context)
 
     @staticmethod
-    def _validate_compute_port(port):
-        if not port['device_owner'].startswith(
-                const.DEVICE_OWNER_COMPUTE_PREFIX):
+    def _validate_port_supports_multiple_bindings(port):
+        if not port['device_owner'].startswith((
+                const.DEVICE_OWNER_COMPUTE_PREFIX,
+                ml2_consts.DEVICE_OWNER_MANILA_PREFIX)):
             msg = _('Invalid port %s. Operation only valid on compute '
-                    'ports') % port['id']
+                    'and shared filesystem ports') % port['id']
             raise exc.BadRequest(resource='port', msg=msg)
 
     def _make_port_binding_dict(self, binding, fields=None):
@@ -2655,7 +2656,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         attrs = binding[pbe_ext.RESOURCE_NAME]
         with db_api.CONTEXT_WRITER.using(context):
             port_db = self._get_port(context, port_id)
-            self._validate_compute_port(port_db)
+            self._validate_port_supports_multiple_bindings(port_db)
             if self._get_binding_for_host(port_db.port_bindings,
                                           attrs[pbe_ext.HOST]):
                 raise exc.PortBindingAlreadyExists(
@@ -2703,7 +2704,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         port = ports_obj.Port.get_object(context, id=port_id)
         if not port:
             raise exc.PortNotFound(port_id=port_id)
-        self._validate_compute_port(port)
+        self._validate_port_supports_multiple_bindings(port)
         filters = filters or {}
         pager = base_obj.Pager(sorts, limit, page_reverse, marker)
         bindings = ports_obj.PortBinding.get_objects(
@@ -2718,7 +2719,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         port = ports_obj.Port.get_object(context, id=port_id)
         if not port:
             raise exc.PortNotFound(port_id=port_id)
-        self._validate_compute_port(port)
+        self._validate_port_supports_multiple_bindings(port)
         binding = ports_obj.PortBinding.get_object(context, host=host,
                                                    port_id=port_id)
         if not binding:
@@ -2736,7 +2737,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
         attrs = binding[pbe_ext.RESOURCE_NAME]
         with db_api.CONTEXT_WRITER.using(context):
             port_db = self._get_port(context, port_id)
-            self._validate_compute_port(port_db)
+            self._validate_port_supports_multiple_bindings(port_db)
             original_binding = self._get_binding_for_host(
                 port_db.port_bindings, host)
             if not original_binding:
@@ -2773,7 +2774,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
             if isinstance(port_id, dict):
                 port_id = port_id['port_id']
             port_db = self._get_port(context, port_id)
-            self._validate_compute_port(port_db)
+            self._validate_port_supports_multiple_bindings(port_db)
             active_binding = p_utils.get_port_binding_by_status_and_host(
                 port_db.port_bindings, const.ACTIVE)
             if host == (active_binding and active_binding.host):

neutron/tests/unit/plugins/ml2/test_plugin.py

@@ -2197,6 +2197,25 @@ class TestMl2PluginOnly(Ml2PluginV2TestCase):
                                                          host=host,
                                                          port_id=port_id)
 
+    def test__validate_port_supports_multiple_bindings(self):
+        plugin = directory.get_plugin()
+        device_owner_raises = {
+            'manila:share': False,
+            'compute:host': False,
+            'network:router': True,
+            'fake:device': True,
+        }
+
+        for device_owner, raises in device_owner_raises.items():
+            port = {'id': 'fake_port_id', 'device_owner': device_owner}
+            if raises:
+                self.assertRaises(
+                    exc.BadRequest,
+                    plugin._validate_port_supports_multiple_bindings,
+                    port)
+            else:
+                plugin._validate_port_supports_multiple_bindings(port)
+
 
 class Test_GetNetworkMtu(Ml2PluginV2TestCase):
 

releasenotes/notes/multiple-portbinding-for-manila-5f5232d506fe414e.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Manila owned ports can now have multiple port bindings associated in order
+    to support nondisruptive Manila share server migration across physical
+    networks.