On the k3d host:
curl -s https://raw.githubusercontent.com/rancher/k3d/master/install.sh | TAG=v3.0.0-alpha.4 bash
k3d create cluster --network host --k3s-server-arg "--token=changeme"
On the k3s host:
curl -sfL https://get.k3s.io | K3S_URL="https://<k3d-host-ip>:6443" K3S_TOKEN="changeme" sh -s -