This is driving me up the wall! I feel I'm so close, but I'm probably missing just one tiny detail.
I have a Ubuntu desktop setup to be a CUPS server. I need to add printers via the GUI interface, rather than the CUPS web-interface. When I'm logged in locally to the server, no problem, works great!
However, when I start a remote session via X2Go, with the same user, I can open and see printers that are already attached to the server, but that's its. I can't do anything else. No adding. No removing. No editing. Nothing. (There is one tiny exception to this: If I start a remote session via X2Go, logging in as root, this works. I can modify printers. Not sure on that one what the reason is.)
The "Unlock" icon in the top-right corner of the Printer GUI is greyed out and I get the "System policy prevents changes" when I hover over it. I've done enough research to know that this is something to do with the polkit in Ubuntu; however, I evidently don't have the .pkla file just right as nothing I put in it seems to makes a difference.
This is my current .pkla file:
[Modify printers remotely]
It's stored in: /etc/polkit-1/localauthority/50-local.d.
Am I missing anything in the file that would prevent a remote-connected user from modifying the printers via GUI? Is this just not something that polkit is supposed to support? I'm completely out of ideas.
Server is running Ubuntu 20.04, CUPS 2.3.1, and pkaction version 0.105
Thanks everyone for any help!