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?
Once the timers do what you want, pull the UPS wall plug with the real load on it and watch the whole chain run: server goes on battery, the timer starts, the Pis get their shutdown, and the timer cancels if you plug back in early. It’s the only test that exercises upsmon, upssched and every client together, and it tells you how many minutes you actually have, which the charge reading on the front of the unit doesn’t.
If you’d rather not pull the plug on live gear,
upscmd -l <yourups>lists what your unit supports, and on units that expose ittest.battery.start.deepruns a real battery test.