For my most recent side project tailsk8s, I've been hacking on a bare metal Kubernetes cluster that uses Tailscale for networking. I had a lot of fun and learned a lot, but the TL;DR is that each Kubernetes node is a Tailscale subnet router and uses the kubenet CNI to indicate the relevant subnet to the rest of the cluster.

To demonstrate the process of bringing up the cluster and to see the networking in action I recorded two videos. The first one involves only the four¹ bare metal nodes that I literally have in my house. The second video turns it into a hybrid cluster by adding an AWS EC2 VM and a GCP GCE instance.

Bare Metal

Adding Public Cloud VMs

1. The four node cluster also has two control plane nodes because I don't have enough machines. Luckily I don't mind if they can't form a quorum. ↩