For a while now I've had an idea for a VERY lightweight CI/CD solution based on Kubernetes CronJobs, and a bespoke set of heuristic "version checkers" that can parse a single source -- HTTP downloads listing, a GitHub repository's release feed, etc. -- and determine if you need to go download a new thing.
This is a quick hacky sketch of what those checkers might look like, because it's late, I can't sleep, and I'm otherwise unoccupied.