Forbid create ndp proxy on same router with same ip address

Create multiple ndp proxies with same ip address within one router
is invalid. The related database constraint was missed in previous
patchsets. The patch add some codes fixed this error.

Additionally, Fixed two typo errors.

Related-Bug: #1877301
Change-Id: Iab24ad78a3d4d9b0ee584cf0986328c9ae2bd16a

neutron/db/migration/alembic_migrations/versions/EXPAND_HEAD

@@ -1 +1 @@
-659cbedf30a1
+21ff98fabab1

neutron/db/migration/alembic_migrations/versions/zed/expand/21ff98fabab1_add_ndp_proxy_constraint.py

@@ -0,0 +1,37 @@
+# Copyright 2022 OpenStack Foundation
+#
+#    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 alembic import op
+
+
+"""add ndp proxy constraint
+
+Revision ID: 21ff98fabab1
+Revises: 659cbedf30a1
+Create Date: 2022-05-22 14:16:24.550155
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '21ff98fabab1'
+down_revision = '659cbedf30a1'
+
+
+def upgrade():
+    op.create_unique_constraint(
+        'uniq_ndp_proxy0router_id0ip_address',
+        'ndp_proxies',
+        ['router_id', 'ip_address']
+    )

neutron/db/models/ndp_proxy.py

@@ -28,6 +28,12 @@ class NDPProxy(standard_attr.HasStandardAttributes,
                model_base.HasProject):
 
     __tablename__ = 'ndp_proxies'
+    __table_args__ = (
+        sa.UniqueConstraint(
+            'router_id', 'ip_address',
+            name='uniq_ndp_proxy0router_id0ip_address'),
+        model_base.BASEV2.__table_args__
+    )
 
     name = sa.Column(sa.String(db_const.NAME_FIELD_SIZE))
     router_id = sa.Column(sa.String(db_const.UUID_FIELD_SIZE),

neutron/services/ndp_proxy/exceptions.py

@@ -37,7 +37,7 @@ class AddressScopeConflict(n_exc.Conflict):
 
 
 class RouterGatewayNotValid(n_exc.Conflict):
-    message = _("Can not enable ndp proxy no "
+    message = _("Can not enable ndp proxy on "
                 "router %(router_id)s, %(reason)s.")
 
 
@@ -62,4 +62,4 @@ class RouterIPv6GatewayInUse(n_exc.Conflict):
 
 
 class NDPProxyNotFound(n_exc.NotFound):
-    message = _("NDP proxy %(id)s could not be found.")
+    message = _("Ndp proxy %(id)s could not be found.")

neutron/tests/unit/extensions/test_l3_ndp_proxy.py

@@ -247,7 +247,7 @@ class L3NDPProxyTestCase(test_address_scope.AddressScopeTestCase,
     def test_enable_ndp_proxy_without_external_gateway(self):
         with self.router() as router:
             router_id = router['router']['id']
-            err_msg = ("Can not enable ndp proxy no router %s, The router has "
+            err_msg = ("Can not enable ndp proxy on router %s, The router has "
                        "no external gateway or the external gateway port has "
                        "no IPv6 address.") % router_id
             self._update_router(router_id, {'enable_ndp_proxy': True},
@@ -260,7 +260,7 @@ class L3NDPProxyTestCase(test_address_scope.AddressScopeTestCase,
             self._update_router(
                 router_id,
                 {'external_gateway_info': {'network_id': self.ext_net_id}})
-            err_msg = ("Can not enable ndp proxy no router %s, The router's "
+            err_msg = ("Can not enable ndp proxy on router %s, The router's "
                        "external gateway will be unset.") % router_id
             self._update_router(
                 router_id,
@@ -516,3 +516,10 @@ class L3NDPProxyTestCase(test_address_scope.AddressScopeTestCase,
             self.assertTrue(router_dict['router']['enable_ndp_proxy'])
             self._create_ndp_proxy(
                 router_id, port_id)
+
+    def test_create_ndp_proxy_with_duplicated(self):
+        with self.port(self.private_subnet) as port1:
+            self._create_ndp_proxy(self.router1_id, port1['port']['id'])
+            self._create_ndp_proxy(
+                self.router1_id, port1['port']['id'],
+                expected_code=exc.HTTPConflict.code)

releasenotes/notes/forbid-duplicate-ndp-proxy-entry-28040bc2afb3c1c7.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Forbid the creation of a duplicate NDP proxy entry on the same router,
+    since the IP address of a router is unique and an IPv6 address only needs
+    one NDP proxy.