{ pkgs, vars, ... }:

{
  # Install the remote builder key on each client host (do not commit private keys):
  #   sudo install -d -m 0700 /root/.ssh
  #   sudo install -m 0600 ./nixremote /root/.ssh/nixremote
  #   sudo ssh -i /root/.ssh/nixremote nixremote@nix-cache nix-store --version
  nix = {
    distributedBuilds = true;

    buildMachines = [
      {
        hostName = vars.nixCacheHost;
        sshUser = vars.remoteBuilderUser;
        sshKey = "/root/.ssh/${vars.remoteBuilderUser}";
        inherit (pkgs.stdenv.hostPlatform) system;
        maxJobs = 4;
        speedFactor = 2;
        supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
      }
    ];

    settings = {
      builders-use-substitutes = true;
      max-jobs = "auto";
    };
  };
}