{ ... }:
{
  boot = {
    loader.grub = {
      enable = true;
      device = "/dev/vda";
    };

    binfmt.emulatedSystems = [
      "armv6l-linux"
      "armv7l-linux"
      "aarch64-linux"
    ];
  };

  networking = {
    hostName = "hydra";
    firewall = {
      enable = true;
      allowedTCPPorts = [ 8443 ];
    };
  };

  users.users.builder = {
    isNormalUser = true;
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIK/plZfxF/RtB+pJsUYx9HUgRcB56EoO0uj+j3AGzZta root@cherry"
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKeIiHkHA5c6/jZx+BB28c5wchdzlFI7R1gbvNmPyoOg root@kiara"
    ];
  };

  nix = {
    settings = {
      trusted-users = [ "builder" ];
      allowed-uris = "http:// https://";
    };
    buildMachines = [
      {
        hostName = "localhost";
        systems = [
          "x86_64-linux"
          "armv6l-linux"
          "armv7l-linux"
          "aarch64-linux"
        ];
      }
    ];
  };

  system.stateVersion = "23.05";
}