RPC callbacks: add hook to register additional resources

This change adds a hook so that additional classes
for OVObjects can be registered beyond the base classes.

The intent is to allow stadium project to register classes
for the OVObjects they use.

Change-Id: Icb6a73aeca0286725c78a3bf403e1df895a34d4e
Needed-By: Ie0f1c9f3f2bd1cf317b921ee1c1691c2816d8832

neutron/api/rpc/callbacks/resources.py

@@ -10,6 +10,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutron._i18n import _
 from neutron.objects.logapi import logging_resource as log_object
 from neutron.objects import network
 from neutron.objects import ports
@@ -61,6 +62,17 @@ def get_resource_type(resource_cls):
     return resource_cls.obj_name()
 
 
+def register_resource_class(resource_cls):
+    resource_type = get_resource_type(resource_cls)
+    if not resource_type:
+        msg = _("cannot find resource type for %s class") % resource_cls
+        raise ValueError(msg)
+    if resource_type not in _TYPE_TO_CLS_MAP:
+        _TYPE_TO_CLS_MAP[resource_type] = resource_cls
+    if resource_type not in LOCAL_RESOURCE_VERSIONS:
+        LOCAL_RESOURCE_VERSIONS[resource_type] = resource_cls.VERSION
+
+
 def is_valid_resource_type(resource_type):
     return resource_type in _TYPE_TO_CLS_MAP
 

neutron/tests/unit/api/rpc/callbacks/test_resources.py

@@ -10,6 +10,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_versionedobjects import base as obj_base
+
 from neutron.api.rpc.callbacks import resources
 from neutron.objects.qos import policy
 from neutron.tests import base
@@ -52,3 +54,23 @@ class GetResourceClsTestCase(base.BaseTestCase):
 
     def test_unknown_type(self):
         self.assertIsNone(resources.get_resource_cls('unknown-resource-type'))
+
+
+class RegisterResourceClass(base.BaseTestCase):
+
+    def test_register_resource_class(self):
+        class DummyOVO(obj_base.VersionedObject):
+            pass
+
+        self.assertFalse(
+            resources.is_valid_resource_type('DummyOVO'))
+        resources.register_resource_class(DummyOVO)
+        self.assertTrue(
+            resources.is_valid_resource_type('DummyOVO'))
+
+    def test_register_bogus_resource_class(self):
+        class DummyOVO(object):
+            pass
+
+        self.assertRaises(ValueError,
+                          resources.register_resource_class, DummyOVO)