I've configured Jupyterhub with SudoSpawner (which runs as a non-root user) and I'm able to run it without any trouble. But when I logged in with the user rhea (as provided in the example) with admin permissions set, I'm not able to add users in the system. I'm getting the following error:

[E 2019-07-24 08:26:56.638 JupyterHub users:94] Failed to create user: newuser
Traceback (most recent call last):
File "/opt/conda/lib/python3.6/site-packages/jupyterhub/apihandlers/users.py", line 92, in post
await maybe_future(self.authenticator.add_user(user))
File "/opt/conda/lib/python3.6/site-packages/jupyterhub/auth.py", line 711, in add_user
await maybe_future(self.add_system_user(user))
File "/opt/conda/lib/python3.6/site-packages/jupyterhub/auth.py", line 771, in add_system_user
raise RuntimeError("Failed to create system user %s: %s" % (name, err))
RuntimeError: Failed to create system user newuser: adduser: Only root may add a user or group to the system.

I'm guessing it is caused by running JupyterHub as a non-root user and also using PAM Authentication which eventually uses the system users. The only limitation for my project is I must not run JupyterHub as a root user. Is there a way to add users using sudospawner with a different authenticator, else Is there a way to give restricted sudo permission for the user rhea to be able to add users to the system?? @minrk @willingc @yuvipanda