Adds ability to inherit wsgi extensions

Needed for blueprint disable-server-extensions

It is possible to create a wsgi resource that extends another
resource by using the same controller, but any extensions that
have been applied to the original resource will have no affect.

This adds a new parameter to ResourceExtension that allows it
to inherit extensions from another resource. This is necessary
because we are moving key funcionality of the /servers resource
into extensions, and some other resources (like create-server-ext)
extend that functionality. This way we can keep the functionality
of the other extensions.

Change-Id: I21b4c2569c35d59c1f466642355564084a277aea

1 files changed, 24 insertions, 0 deletions

diff --git a/nova/tests/api/openstack/compute/test_extensions.py b/nova/tests/api/openstack/compute/test_extensions.py
index 32533936b..ebecb3ce6 100644
--- a/nova/tests/api/openstack/compute/test_extensions.py
+++ b/nova/tests/api/openstack/compute/test_extensions.py
@@ -109,11 +109,14 @@ class StubExtensionManager(object):
         self.action_ext = action_ext
         self.request_ext = request_ext
         self.controller_ext = controller_ext
+        self.extra_resource_ext = None
 
     def get_resources(self):
         resource_exts = []
         if self.resource_ext:
             resource_exts.append(self.resource_ext)
+        if self.extra_resource_ext:
+            resource_exts.append(self.extra_resource_ext)
         return resource_exts
 
     def get_actions(self):
@@ -511,6 +514,27 @@ class ControllerExtensionTest(ExtensionTestCase):
         self.assertEqual(200, response.status_int)
         self.assertEqual(extension_body, response.body)
 
+    def test_controller_extension_late_inherited_resource(self):
+        # Need a dict for the body to convert to a ResponseObject
+        controller = StubController(dict(foo=response_body))
+        parent_ext = base_extensions.ResourceExtension('tweedles', controller)
+
+        ext_controller = StubLateExtensionController(extension_body)
+        extension = StubControllerExtension()
+        cont_ext = base_extensions.ControllerExtension(extension, 'tweedles',
+                                                       ext_controller)
+
+        manager = StubExtensionManager(resource_ext=parent_ext,
+                                       controller_ext=cont_ext)
+        child_ext = base_extensions.ResourceExtension('beetles', controller,
+                                                      inherits='tweedles')
+        manager.extra_resource_ext = child_ext
+        app = compute.APIRouter(manager)
+        request = webob.Request.blank("/fake/beetles")
+        response = request.get_response(app)
+        self.assertEqual(200, response.status_int)
+        self.assertEqual(extension_body, response.body)
+
     def test_controller_action_extension_early(self):
         controller = StubActionController(response_body)
         actions = dict(action='POST')