sample.nix

{pkgs ? import<nixpkgs>, nodes, lib, ...}:  {
  services.netdata = {
    enable = true;
    config = {
      registry = {
        "enabled" = "yes";
        "registry to announce" = "http://${(lib.elemAt nodes.ch-misc.config.networking.interfaces.eth0.ipv4.addresses 0).addres
s}:19999";
      };
    };
  };

  networking.firewall.extraCommands = ''
    iptables -A nixos-fw -s 167.99.64.211/32 -p tcp -m tcp --dport 19999 -m comment --comment netdata -j nixos-fw-accept
    ${lib.concatMapStringsSep "\n" (s: ''${(lib.elemAt s.config.networking.interfaces.eth0.ipv4.addresses 0).address}'') nodes
}
  '';
}