TL;DR – My bootc hosts stage new images every hour, but nothing rebooted them into those images. Now a small timer on each host checks a time window, its own health and its neighbours, takes a lock from a ~200-line Python FleetLock server, and only then reboots. No Kubernetes, no etcd, and protocol-compatible with the Fedora CoreOS tooling in case I outgrow it.

In how I tweak my base image I described how I replaced bootc-fetch-apply-updates.timer with my own bootc-fetch.timer: every hour bootc update pulls the newest image and stages it, but doesn’t reboot. I ended that post with “the actual reboot is a separate step I control manually or via another timer”. This post is about that missing step.