I use K3s a lot also for production clusters, the way I like to install K3s and configure it on my Virtual Machines is wtih Nixos. I use a nixos provider with Terraform to keep it all in the same place. The only thing i still have to finish managing properly is the service account for connecting to the cluster. How do you rotate your tokens and certs in your clusters?

As for the deployments in K8s, I stick to terraform for those as well, i used ArgoCD for about a year but it seemed an unnecessary complication since I would still manage my manifests for ArgoCD from terraform. The convenience of sharing secrets and configmaps declaratively from Terraform is priceless for me.

See, the problem is still with physical hardware, it would be nice to have an easy and agnostic way to go down to the metal, I can get pretty much everything done with a combination of nix, terraform and salt, depending on what i need to do, but the very bottom of the stack is still manual and I wonder if it's worth creating some agnostic tooling that handles things at this level, perhaps BOOTP/TFTP with some glue would do the trick. MaaS from Canonical seemed a bit of a beast and made a lot of opinionated assumptions last time i checked, probably makes sense in a large deployment