nixConfig/nixos/roles/default.nix

{
  pkgs,
  lib,
  modulesPath,
  ...
}: {
  imports = [
    ./admins.nix
    ./nix_keys.nix
    ./prometheusNodeExporter.nix
    (modulesPath + "/virtualisation/xen-domU.nix")
    ../modules/impermanence.nix
  ];
  nix = {
    extraOptions = ''
      experimental-features = nix-command flakes
      builders-use-substitutes = true
    '';
  };

  networking = {
    firewall = {
      # these shoud be default, but better make sure!
      enable = true;
      allowPing = true;
    };
    nftables.enable = true;
    useDHCP = false; # We don't speak DHCP and even if we would, we should enable it per interface
    # hosts = # TODO write something to autogenerate ip adresses!
  };

  users = {
    mutableUsers = false;
    users.root.hashedPassword = "!";
  };

  impermanence.enable = true;

  sops.age.sshKeyPaths = ["/etc/ssh/ssh_host_ed25519_key"];

  environment = {
    systemPackages = builtins.attrValues {
      inherit
        (pkgs)
        htop
        lsof
        tmux
        btop
        ;
    };
  };

  services = {
    journald.extraConfig = "SystemMaxUse=5G";

    nginx = {
      recommendedOptimisation = true;
      recommendedGzipSettings = true;
      recommendedTlsSettings = true;
    };

    openssh = {
      enable = true;
      settings = {
        PermitRootLogin = "no";
        PasswordAuthentication = false;
      };
    };
    #Prevent clock drift due to interaction problem with xen hardware clock
    timesyncd.enable = lib.mkForce true;
  };
}