{ pkgs, config, lib, ... }:
{
  imports = [
    ../../nixos-modules/common.nix
  ];

  boot.kernelPackages = pkgs.linuxPackages_latest;

  virtualisation.docker = {
    enable = true;
    # Clean docker images periodically
    autoPrune = {
      enable = true;
      # Do not only remove "dangling" images (orphaned layers)
      # Also remove unused
      flags = [ "--all" ];
    };
  };

  services.gitlab-runner = {
    enable = true;
    configFile = ./config.toml;
  };

  services.cron = {
    enable = true;
    systemCronJobs = [
      "@hourly root ${pkgs.docker-gc}/bin/docker-gc"
    ];
  };

  systemd.services.gitlab-runner-cache = {
    description = "Create gitlab-runner cache directory";
    before = [ "gitlab-runner.service" ];
    wantedBy = [ "multi-user.target" ];
    serviceConfig.Type = "oneshot";
    script = ''
      # Create cache dir next to gitlab workdir
      mkdir -p "/var/db/gitlab-runner-cache"
      chown -R "gitlab-runner":"gitlab-runner" "/var/db/gitlab-runner-cache"
    '';
  };

  networking.hostName = "ci.peterhk.com";
  nix.buildMachines = [
    { hostName = "localhost";
      system = "x86_64-linux";
      supportedFeatures = ["kvm" "nixos-test" "big-parallel" "benchmark"];
      maxJobs = 8;
    }
  ];
}