Allow superusers to disable user accounts

auth/auth_context.py

@@ -17,6 +17,9 @@ def get_authenticated_user():
 
     logger.debug('Loading deferred authenticated user.')
     loaded = model.get_user_by_uuid(user_uuid)
+    if not loaded.enabled:
+      return None
+
     set_authenticated_user(loaded)
     user = loaded
 
@@ -26,6 +29,9 @@ def get_authenticated_user():
 
 
 def set_authenticated_user(user_or_robot):
+  if not user_or_robot.enabled:
+    raise Exception('Attempt to authenticate a disabled user/robot: %s' % user_or_robot.username)
+
   ctx = _request_ctx_stack.top
   ctx.authenticated_user = user_or_robot