Make sure unknown extensions return 404

At the moment, if an extension doens't exist and we call a show method
with wrong id then the exception is not captured. There is a need to
return NOTFOUND exception.
Fixes bug 869153.

Change-Id: Ie0b2c2e87c5a61f6db74bb10a4740add2ab8ea27

Authors

@@ -1,6 +1,7 @@
 Aaron Lee <aaron.lee@rackspace.com>
 Adam Gandelman <adamg@canonical.com>
 Adam Johnson <adjohn@gmail.com>
+Ahmad Hassan <ahmad.hassan@hp.com>
 Alex Meade <alex.meade@rackspace.com>
 Alexander Sakhnov <asakhnov@mirantis.com>
 Andrey Brindeyev <abrindeyev@griddynamics.com>

nova/api/openstack/extensions.py

@@ -197,8 +197,12 @@ def index(self, req):
         return dict(extensions=extensions)
 
     def show(self, req, id):
-        # NOTE(dprince): the extensions alias is used as the 'id' for show
-        ext = self.extension_manager.extensions[id]
+        try:
+            # NOTE(dprince): the extensions alias is used as the 'id' for show
+            ext = self.extension_manager.extensions[id]
+        except KeyError:
+            return faults.Fault(webob.exc.HTTPNotFound())
+
         return dict(extension=self._translate(ext))
 
     def delete(self, req, id):

nova/tests/api/openstack/test_extensions.py

@@ -150,6 +150,13 @@ def test_get_extension_json(self):
                 "alias": "FOXNSOX",
                 "links": []})
 
+    def test_get_non_existing_extension_json(self):
+        app = openstack.APIRouterV11()
+        ext_midware = extensions.ExtensionMiddleware(app)
+        request = webob.Request.blank("/123/extensions/4")
+        response = request.get_response(ext_midware)
+        self.assertEqual(404, response.status_int)
+
     def test_list_extensions_xml(self):
         app = openstack.APIRouterV11()
         ext_midware = extensions.ExtensionMiddleware(app)