port_forwarding: validate args before invoking db update (cont.)

This is a follow up for https://review.opendev.org/#/c/738145/

During backporting review, it became clear that unit test had a
flaw. It assumed that order of items in dictionary that make up
the exception message did not change. That is not true, based
on the python version used.

This follow up also includes a review feedback that did not make
into the original change: rename function that raises exception
to have "raise" in its name (raise_port_forwarding_update_failed).

Change-Id: I6fcd64e205e584017e6c9022f82a5497ea1cc576
Closes-Bug: #1878299

neutron/services/portforwarding/pf_plugin.py

@@ -471,7 +471,7 @@ class PortForwardingPlugin(fip_pf.PortForwardingPluginBase):
                                      msg=message)
 
     def _check_port_forwarding_update(self, context, pf_obj):
-        def _check_port_forwarding_update_failed(conflict):
+        def _raise_port_forwarding_update_failed(conflict):
             message = _("Another port forwarding entry with the same "
                         "attributes already exists, conflicting "
                         "values are %s") % conflict
@@ -499,7 +499,7 @@ class PortForwardingPlugin(fip_pf.PortForwardingPluginBase):
             # Ensure there are no conflicts on the outside
             if (obj.floating_ip_address == pf_obj.floating_ip_address and
                     obj.external_port == pf_obj.external_port):
-                _check_port_forwarding_update_failed(
+                _raise_port_forwarding_update_failed(
                     {'floating_ip_address': str(obj.floating_ip_address),
                      'external_port': obj.external_port})
             # Ensure there are no conflicts in the inside
@@ -507,7 +507,7 @@ class PortForwardingPlugin(fip_pf.PortForwardingPluginBase):
             if (obj.internal_port_id == pf_obj.internal_port_id and
                     obj.internal_ip_address == pf_obj.internal_ip_address and
                     obj.internal_port == pf_obj.internal_port):
-                _check_port_forwarding_update_failed(
+                _raise_port_forwarding_update_failed(
                     {'internal_port_id': obj.internal_port_id,
                      'internal_ip_address': str(obj.internal_ip_address),
                      'internal_port': obj.internal_port})

neutron/tests/unit/services/portforwarding/test_pf_plugin.py

@@ -246,7 +246,7 @@ class TestPortForwardingPlugin(testlib_api.SqlTestCase):
         mock_pf_get_objects.return_value = [pf_obj, other_pf_obj]
         self.assertRaisesRegex(
             lib_exc.BadRequest,
-            "already exist.*same_fip_addr.*same_ext_port",
+            "already exist.*same_fip_addr",
             self.pf_plugin._check_port_forwarding_update,
             self.ctxt, pf_obj)
         mock_get_port.assert_called_once_with(self.ctxt, mock.ANY)
@@ -269,8 +269,7 @@ class TestPortForwardingPlugin(testlib_api.SqlTestCase):
         mock_pf_get_objects.return_value = [pf_obj, other_pf_obj]
         self.assertRaisesRegex(
             lib_exc.BadRequest,
-            "already exist.*same_int_port_id.*{}.*same_int_port".format(
-                same_internal_ip),
+            "already exist.*{}".format(same_internal_ip),
             self.pf_plugin._check_port_forwarding_update,
             self.ctxt, pf_obj)
         mock_get_port.assert_called_once_with(self.ctxt, 'same_int_port_id')