Replacing Kubernetes with systemd (2024)

Summary

Yes, I'm fully aware those are two separate things, but hear me out here for a moment.Back in 2018 I was hearing a lot of stuff from all angles and all sorts of friends and influences about Kubernetes, and from what I heard it seemed like a pretty promising piece of kit to use. At the time, I actually went out and bought a NUC to act as a little hypervisor so that I could play around with a small cluster at home.Funnily enough, my blog post on this was six years ago to the very day.The main lesson that I learned is that although Kubernetes is made up of all sorts of pieces and web services and sidecars and webhooks, basically acts as a giant while loop as follows:while (true) { var current_state = GetCurrentState(); var desired_state = GetDesiredState(); var diff = CalculateDiff(current_state, desired_state); ApplyDiff(diff); }If I said there should be a Pod here, and there wasn't, Kubernetes would create it. If I said there should be 3 replicas and there were 4, Kubernetes would get rid of one.This actually extended out in really cool ways, such as with cert-manager. If I said there should be a valid TLS certificate for some domain, and told Kubernetes how it could request one, then if the certificate was missing or expiring, Kubernetes would go out and get a new certificate and install it in the web server automagically.But as the memes go, what I was using Kubernetes for was fun to experiment with, but total overkill."Deployed my blog on Kubernetes." - @dexhorthy, https://twitter.com/dexhorthy/status/856639005462417409?lang=enWhilst most problems I encountered did provide a legitimate learning experience, it turns out that Kubernetes, particularly on a NUC, is not bedroom-friendly. Kubernetes chews through a lot of resources, and while (true) loops tend to chew through a lot of CPU. This made my computers run constantly, run hot, keep the fan running, and made it hotter and noisier and harder to sleep.Even in the cloud, this effect gets felt in different ways. My...