# The goal of this configuration is to make it so you can write systemd units that
# can wait until tailscale is up and connected, by putting After=tailscaled.service
# in their unit file.
# https://github.com/tailscale/tailscale/issues/11504#issuecomment-2113331262
{
  pkgs,
  lib,
  ...
}:
{
  systemd.services.tailscaled = {
    serviceConfig.ExecStartPost = pkgs.writeShellScript "tailscale-wait-for-ip" ''
      echo "Waiting for tailscale0 to get an IP address..."
      for i in {1..15}; do
        if ${lib.getExe' pkgs.iproute2 "ip"} addr show dev tailscale0 2>/dev/null | ${lib.getExe' pkgs.gnugrep "grep"} -q 'inet '; then
          echo "tailscale0 has IP address"
          exit 0
        fi
        echo "Attempt $i"
        sleep 1
      done
      echo "Warning: tailscale0 did not get IP address within 15 seconds"
      exit 0
    '';
  };

  services.tailscale = {
    enable = true;
    useRoutingFeatures = "client";
  };
}