How do I limit a Ubuntu machine to a Python GUI?

Question

I wrote a python GUI in Tkinter for a time-clock system. The micro machine is wall mounted and the employees only have access to the touchscreen menu I programmed and a barcode swipe. I know how to get the script to start on startup, but how do I prevent them from exiting out or opening other menus? Basically the sole purpose of this console is to run the time-clock GUI.

Answer 1

I'd consider replacing the whole frontend with something like nodm. I've already covered the details for this in another answer.

You'd essentially start with Ubuntu Server, layer on a few packages and then create a ~/.xsession script to load your Python application. It's extremely lightweight and users can't mess around with anything else.

If the application crashes or the user finds a way to exit it, nodm will restart and will just load the app back up. Perfect for single-purpose machines.

Answer 2

I'll give the same answer I gave on stackoverflow:

You can use wm_overrideredirect, then make the UI full screen. This will remove all window decorations so there's no way to close the window. If that's not enough, as a final step you can do a global grab. With that, you effectively control everything that they can do.

Be very careful about coding global grabs -- make sure you can ssh into that box to kill the process, otherwise you can effectively denial-of-service your box.