NSX|V: don't throw exception when same vnic is configured

In the event of a nova retry we should not throw an exception for
for a port update

Change-Id: Ic4df033952e3dddd170e0fb7b57499750a6155b0
Closes-bug: #1606809

vmware_nsx/db/vnic_index_db.py

@@ -18,6 +18,7 @@ from sqlalchemy.orm import exc
 from neutron.api.v2 import attributes as attr
 from neutron.db import db_base_plugin_v2
 
+from oslo_db import exception as db_exc
 from oslo_log import log as logging
 
 from vmware_nsx.db import nsxv_models
@@ -47,7 +48,14 @@ class VnicIndexDbMixin(object):
         except exc.NoResultFound:
             LOG.debug("No record in DB for vnic-index of port %s", port_id)
 
-    def _set_port_vnic_index_mapping(self, context, port_id, device_id, index):
+    def _get_mappings_for_device_id(self, context, device_id):
+        session = context.session
+        mappings = (session.query(nsxv_models.NsxvPortIndexMapping).
+                    filter_by(device_id=device_id))
+        return mappings
+
+    def _create_port_vnic_index_mapping(self, context, port_id,
+                                        device_id, index):
         """Save the port vnic-index to DB."""
         session = context.session
         with session.begin(subtransactions=True):
@@ -55,6 +63,38 @@ class VnicIndexDbMixin(object):
                 port_id=port_id, device_id=device_id, index=index)
             session.add(index_mapping_model)
 
+    def _update_port_vnic_index_mapping(self, context, port_id,
+                                        device_id, index):
+        session = context.session
+        # delete original entry
+        query = (session.query(nsxv_models.NsxvPortIndexMapping).
+                 filter_by(device_id=device_id, index=index))
+        query.delete()
+        # create a new one
+        self._create_port_vnic_index_mapping(context, port_id, device_id,
+                                             index)
+
+    def _set_port_vnic_index_mapping(self, context, port_id, device_id, index):
+        """Save the port vnic-index to DB."""
+        try:
+            self._create_port_vnic_index_mapping(context, port_id,
+                                                 device_id, index)
+        except db_exc.DBDuplicateEntry:
+            # A retry for the nova scheduling could result in this error.
+            LOG.debug("Entry already exists for %s %s %s", port_id,
+                      device_id, index)
+            mappings = self._get_mappings_for_device_id(context, device_id)
+            for mapping in mappings:
+                if (mapping['port_id'] != port_id and
+                    mapping['index'] == index):
+                    # a new port is using this device - update!
+                    self._update_port_vnic_index_mapping(context, port_id,
+                                                         device_id, index)
+                    return
+                if (mapping['port_id'] == port_id and
+                    mapping['index'] != index):
+                    raise
+
     def _delete_port_vnic_index_mapping(self, context, port_id):
         """Delete the port vnic-index association."""
         session = context.session

vmware_nsx/tests/unit/extensions/test_vnic_index.py

@@ -93,16 +93,46 @@ class VnicIndexDbTestCase(test_db_plugin.NeutronDbPluginV2TestCase):
             self.assertRaises(d_exc.DBDuplicateEntry,
                               plugin._set_port_vnic_index_mapping,
                               context, port_id, device_id, 1)
-            # Only one Port can be associated with a specific index on a device
-            self.assertRaises(d_exc.DBDuplicateEntry,
-                              plugin._set_port_vnic_index_mapping,
-                              context, _uuid(), device_id, vnic_index)
         # Check that the call for _delete_port_vnic_index remove the row from
         # the table
 
         # TODO(kobis): deletion was removed from port - fix this assert
         # self.assertIsNone(plugin._get_port_vnic_index(context, port_id))
 
+    def test_vnic_index_db_duplicate(self):
+        plugin = manager.NeutronManager.get_plugin()
+        vnic_index = 2
+        device_id = _uuid()
+        context = neutron_context.get_admin_context()
+        with self.port(device_id=device_id,
+                       device_owner='compute:None') as port:
+            port_id = port['port']['id']
+            res = self._port_index_update(port_id, vnic_index)
+            self.assertEqual(res['port'][vnicidx.VNIC_INDEX], vnic_index)
+            plugin._set_port_vnic_index_mapping(context, port_id, device_id,
+                                                vnic_index)
+
+    def test_vnic_index_db_duplicate_new_port(self):
+        plugin = manager.NeutronManager.get_plugin()
+        vnic_index = 2
+        device_id = _uuid()
+        context = neutron_context.get_admin_context()
+        with self.port(device_id=device_id,
+                       device_owner='compute:None') as port:
+            with self.port(device_id=device_id,
+                           device_owner='compute:None') as port1:
+                port_id = port['port']['id']
+                res = self._port_index_update(port_id, vnic_index)
+                self.assertEqual(res['port'][vnicidx.VNIC_INDEX], vnic_index)
+                port_id1 = port1['port']['id']
+                plugin._set_port_vnic_index_mapping(context, port_id1,
+                                                    device_id, 2)
+                self.assertIsNone(plugin._get_port_vnic_index(context,
+                                                              port_id))
+                self.assertEqual(vnic_index,
+                                 plugin._get_port_vnic_index(context,
+                                                             port_id1))
+
 
 class TestVnicIndex(VnicIndexDbTestCase):
     pass