{ config, lib, pkgs, ... }:
 
with lib;
{
  imports = [ <nixpkgs> ];
  ec2.hvm = true;
 
  # Set timezone
  time.timeZone = "Europe/London";
 
  services.postgresql.enable = true;
 
  # networking
  networking.firewall.enable = false;
 
  # define a user
  #users.extraUsers.hydra = {
  # isNormalUser = true;
  # uid = 1000;
  # extraGroups = [ "wheel" ];
  # };  
 
  # Select internationalization properties.
  i18n = {
      consoleFont = "Lat2-Terminus16";
      consoleKeyMap = "us";
      defaultLocale = "en_US.UTF-8";
  };
 
  # System packages
  environment.systemPackages = with pkgs; [
 wget vim
        wget git
  ];
 
  ## Hydra configuration (recommended by nixos IRC channel to do it here as running just hydra-server is not enough)
  nix.buildMachines = [
    { hostName = "localhost"; sshKey = "/var/run/keys/hydra_rsa"; system = "x86_64-linux,i686-linux"; maxJobs = 4; supportedFeatures = [ "kvm" ]; }
  ];
 
  services.nginx.enable = true;
  services.nginx.recommendedGzipSettings = true;
  services.nginx.recommendedOptimisation = true;
  services.nginx.recommendedProxySettings = true;
 
  services.hydra.enable = true;
  services.hydra.hydraURL = "my-real-url-here.com";
  services.hydra.notificationSender = "hydra@example.org";
 
  services.hydra.port = 3000;
  services.hydra.useSubstitutes = true;
  users.users.hydra.extraGroups = [ "keys" ];
  users.users.hydra-queue-runner.extraGroups = [ "keys" ];
  system.stateVersion = "17.09";
}