Raise GatewayConflict as BadRequest

neutron GatewayConflictWithAllocationPools exception is raised
as a 500, but it is actually user error, so it should be a 400.
Catch the GatewayConflictWithAllocationPools exception and raise
as a BadRequest with the relevant info.

Change-Id: Id94590c2c8637a64a90f06834c7e3400ea2b6330
JIRA:NCP-1993
Closes-Bug: #1599980

quark/plugin_modules/routes.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import netaddr
+from neutron.common import exceptions as neutron_exc
 from neutron import quota
 from neutron_lib import exceptions as n_exc
 from oslo_config import cfg
@@ -71,7 +72,11 @@ def create_route(context, route):
 
         alloc_pools = allocation_pool.AllocationPools(subnet["cidr"],
                                                       policies=policies)
+        try:
             alloc_pools.validate_gateway_excluded(route["gateway"])
+        except neutron_exc.GatewayConflictWithAllocationPools as e:
+            LOG.exception(str(e))
+            raise n_exc.BadRequest(resource="routes", msg=str(e))
 
         # TODO(anyone): May want to denormalize the cidr values into columns
         #               to achieve single db lookup on conflict check

quark/tests/functional/plugin_modules/test_routes.py

@@ -15,7 +15,6 @@
 
 import contextlib
 import mock
-from neutron.common import exceptions as n_exc_ext
 from neutron_lib import exceptions as n_exc
 from oslo_config import cfg
 from quark import exceptions as q_exc
@@ -102,8 +101,7 @@ class QuarkCreateRoutes(BaseFunctionalTest):
             self.assertIsNotNone(sub)
             self.assertIsNotNone(ipp)
             create_route["subnet_id"] = sub["id"]
-            with self.assertRaises(
+            with self.assertRaises(n_exc.BadRequest):
-                    n_exc_ext.GatewayConflictWithAllocationPools):
                 routes_api.create_route(self.context,
                                         dict(route=create_route))