If you run ssh <hostname> echo hi, users expect it to log in, run just that command, show its output, and log out. No interactive terminal is needed.

Right now, jupyterhub-ssh always puts you in an interactive terminal. This is not expected behavior.

We communicate with the notebook server using the terminado api used by terminals in jupyter notebook. It defaults to setting up for interactive use. We can instead wrap the user command in something that runs it non-interactively, and close our connection when that is done.

This might help with stuff like rsync not working