Have the index use the same abort method

util/http.py

@@ -0,0 +1,27 @@
+from flask import request, abort as flask_abort
+from auth.auth import process_auth, extract_namespace_repo_from_session, get_authenticated_user, get_validated_token
+
+DEFAULT_MESSAGE = {}
+DEFAULT_MESSAGE[400] = 'Invalid Request'
+DEFAULT_MESSAGE[403] = 'Forbidden'
+DEFAULT_MESSAGE[404] = 'Not Found'
+
+def abort(status_code, message=None, **kwargs):
+  if status_code == 403 and not message:
+    # Create a default error message for auth failure.
+    message = 'Forbidden. '
+    auth_user = get_authenticated_user()
+    auth_token = get_validated_token()
+    if auth_user:
+      message = message + 'Current user: ' + auth_user
+    elif auth_token:
+      message = message + 'Current token: ' + auth_token
+
+  message = message % kwargs if message else DEFAULT_MESSAGE[status_code] 
+
+  # Log the abort.
+  log.error('Error %s: %s. Arguments: %s' % (status_code, message, request.view_args))
+
+  # Report the abort to the user.
+  flask_abort(make_response(HTTPException(message), status_code, headers))
+