I have messed around with NUT to trigger a graceful shutdown of my home server running Ubuntu Server. I have struggled with setting NUT up on bare metal, but would like a gui anyway. I saw PVE-UPS which looks good, but I think but I think it is meant for Proxmox. Any alternatives, or a spin of PVE-UPS for docker compose anybody know about?
What was the difficulty with NUT for you? The setup is pretty straightforward, IMHO.

Should be easy to wrap in a container, too.
I was hoping to setup a server and clients to shutdown the other Raspberry Pis and such, scattered around the house if the main server senses a power failure.
Also, I had an issue where it insisted on triggering a shutdown the SECOND the UPS triggered, even if it came right back. I might take another swing at it at some point, but I liked the look of that PVE-UPS things.

