Fix 500 error for showing deleted flavor details

Displaying deleted flavor details throws 500 internal server error.
Added 404 HttpNotFound status code in "@extension.expected_errors".

APIImpact: Return 404 status code for list extra specs
for a deleted flavor.

Closes-Bug: #1538896

Change-Id: Iba33296c28c3c3d6ba60052fe434107ac9c00c61

nova/api/openstack/compute/flavors_extraspecs.py

@@ -52,7 +52,7 @@ class FlavorExtraSpecsController(wsgi.Controller):
                 raise webob.exc.HTTPBadRequest(
                           explanation=error.format_message())
 
-    @extensions.expected_errors(())
+    @extensions.expected_errors(404)
     def index(self, req, flavor_id):
         """Returns the list of extra specs for a given flavor."""
         context = req.environ['nova.context']

nova/tests/unit/api/openstack/compute/test_flavors_extra_specs.py

@@ -90,6 +90,14 @@ class FlavorsExtraSpecsTestV21(test.TestCase):
 
         self.assertEqual(0, len(res_dict['extra_specs']))
 
+    def test_index_flavor_not_found(self):
+        req = self._get_request('1/os-extra_specs',
+                                use_admin_context=True)
+        with mock.patch('nova.db.flavor_get_by_flavor_id') as mock_get:
+            mock_get.side_effect = exception.FlavorNotFound(flavor_id='1')
+            self.assertRaises(webob.exc.HTTPNotFound, self.controller.index,
+                              req, 1)
+
     def test_show(self):
         flavor = dict(test_flavor.fake_flavor,
                       extra_specs={'key5': 'value5'})