{
  networking.firewall.allowedTCPPorts = [ 6443 80 443 33073 ];
  networking.firewall.allowedUDPPorts = [ 3479 ];

  services.k3s = {
    enable = true;
    role = "server";
    extraFlags = "--write-kubeconfig-mode 644";
  };

  # k3s manifests live in a separate repo (git.archfox.org/poslop/k3s),
  # cloned at /home/poslop/k3s. Bind-mounting (not symlinking!) into
  # k3s's manifest dir lets k3s's native recursive directory watch pick
  # up new/changed files automatically -- no nixos-rebuild, no kubectl
  # apply needed for changes under apps/. Symlinked dirs are explicitly
  # NOT picked up by k3s's watcher (see k3s-io/k3s#9288), hence bind mount.
  #
  # TODO: once Flux is set up, replace this bind mount with a Flux
  # GitRepository/Kustomization pointing at the same repo, and remove
  # this fileSystems entry.
  fileSystems."/var/lib/rancher/k3s/server/manifests/apps" = {
    device = "/home/poslop/k3s/apps";
    fsType = "none";
    options = [ "bind" "ro" ];
  };
}