buildfarm-client.nix

{ pkgs, config, ... }:

{
  nix.buildMachines = [
      {
        hostName = "iridium";
        maxJobs = 8;
        sshKey = "/root/.ssh/id_buildfarm";
        sshUser = "nixbuildfarm";
        system = "x86_64-linux";
        supportedFeatures = ["big-parallel"];
      }
  ];
  nix.distributedBuilds = true;
  nix.binaryCachePublicKeys = ["iridium-1:EVENAPUBLICKEYCANBECENSORED"];
}

buildfarm.nix

{ pkgs, config, ... }:

{
  users.extraUsers.nixbuildfarm = {
    uid = 31000;
    useDefaultShell = true;
    openssh.authorizedKeys.keyFiles = [
      ../../ssh/cobalt_buildfarm.pub
    ];
  };
  nix.extraOptions = ''
  secret-key-files = /etc/_credentials/nix-store-iridium.private
  '';
  nix.trustedUsers = ["root" "nixbuildfarm"];
}