Evaluate k3s-based control plane for mini-lab

[Gerrit91]

Description

As described in MEP-18 it is required to come up with an initial "small and hopefully easy-to-maintain" K8s cluster for bootstrapping metal-stack and Gardener.

Maybe we can look into K3s already in the mini-lab, like developing an Ansible role for this to see how difficult it is to set up in a clustered configuration. Then, it makes sense to deploy the metal control plane into it and test an update of K3s (e.g. updating the Kubernetes version).

It would be good to compare it to other solutions if there are suitable candidates?

[Gerrit91]

@qrnvttrl What's the current progress on this?

[Gerrit91]

@qrnvttrl Ping?

[qrnvttrl]

We are currently working on setting up a real k3s cluster with the control planes in our test-environment. Now we have finally set up the network and will continue to deploy k3s with these ansible collections: https://github.com/k3s-io/k3s-ansible
As k3s is installed in systemd, I'm not sure if it is really desirable to use it in the mini-lab. That's why I initially tried out the containerized version k3d in this PR: #255