functional: Move single-use function to its caller

The '_check_api_endpoint' function only had a single caller and was far
more complicated that necessary. Move it to that caller and simplify.

Change-Id: I535886dbac4e41677285a14c010ec45a54e77c79
Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

nova/tests/functional/integrated_helpers.py

@@ -1045,21 +1045,6 @@ def _setup_services(self):
             if not self.ADMIN_API:
                 self.admin_api.microversion = self.microversion
 
-    def _check_api_endpoint(self, endpoint, expected_middleware):
-        app = self.api_fixture.app().get((None, '/v2'))
-
-        while getattr(app, 'application', False):
-            for middleware in expected_middleware:
-                if isinstance(app.application, middleware):
-                    expected_middleware.remove(middleware)
-                    break
-            app = app.application
-
-        self.assertEqual([],
-                         expected_middleware,
-                         ("The expected wsgi middlewares %s are not "
-                          "existed") % expected_middleware)
-
 
 # TODO(stephenfin): This is almost identical to '_IntegratedTestBase' now and
 # could be removed

nova/tests/functional/test_legacy_v2_compatible_wrapper.py

@@ -24,7 +24,21 @@ class LegacyV2CompatibleTestBase(integrated_helpers._IntegratedTestBase):
 
     def setUp(self):
         super(LegacyV2CompatibleTestBase, self).setUp()
-        self._check_api_endpoint('/v2', [openstack.LegacyV2CompatibleWrapper])
+        self._check_api_endpoint()
+
+    def _check_api_endpoint(self):
+        app = self.api_fixture.app().get((None, '/v2'))
+
+        while getattr(app, 'application', False):
+            if isinstance(
+                app.application, openstack.LegacyV2CompatibleWrapper,
+            ):
+                break
+            app = app.application
+        else:
+            raise Exception(
+                'The LegacyV2CompatibleWrapper middleware is not configured.'
+            )
 
     def test_request_with_microversion_headers(self):
         self.api.microversion = '2.100'