This little script watches a the websocket on a harmony hub for activity starts, and when appropriate changes the autologin user and restarts GDM.
It depends on https://github.com/vi/websocat
This is quicker and more robust than programming the harmony hub to login with a given username and password.
To use this script edit it with values from your harmony hub and copy it to /usr/local/sbin then copy the systemd service file to /etc/systemd/services/ enable it and run it.