nixos install

  # Disable firewall.
  #
  # You could whitelist all the ports needed, but this is easier for
  # development.
  networking.firewall = {
    enable = false;
  };

  # Setup K3s.
  services.k3s = {
    enable = true;
    role = "server";
  };

stop/start cluster

You can control the cluster with systemd.

sudo systemctl stop k3s

destroy cluster

To stop all of the K3s containers and reset the containerd state, the k3s-killall.sh script can be used.

/usr/local/bin/k3s-killall.sh