{ config, lib, ... }: {
  nix.buildMachines = let
    base = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
    x86-64 = [ "gccarch-x86-64" "gccarch-x86-64-v2" "gccarch-x86-64-v3" ];
    aarch64 = [ "gccarch-armv8-a" "gccarch-armv8.1-a" "gccarch-armv8.2-a" "gccarch-armv8.2-a+fp16+rcpc+dotprod" ];
    riscv64 = [ "gccarch-rv64imac" "gccarch-rv64imacfd" "gccarch-rv64gc" ];
  in [
    {
      hostName = "localhost";
      protocol = null;
      maxJobs = 0;
      speedFactor = 0;
      systems = [ "x86_64-linux" ];
      supportedFeatures = base;
    }
    {
      hostName = "integra.kyouma.net";
      sshUser = "nix-ssh";
      maxJobs = 2;
      speedFactor = 4;
      systems = [ "aarch64-linux" ];
      supportedFeatures = base ++ aarch64;
      sshKey = config.sops.secrets."services/hydra/id_ed25519_hydra".path;
    }
    {
      hostName = "schrodinger.kyouma.net";
      sshUser = "root";
      maxJobs = 0;
      speedFactor = 20;
      systems = [ "riscv64-linux" ];
      supportedFeatures = base ++ riscv64;
      sshKey = config.sops.secrets."services/hydra/id_ed25519_hydra".path;
    }
  ] ++ lib.forEach (lib.range 0 11) (num: {
      hostName = "build-worker-${lib.fixedWidthNumber 2 num}";
      sshUser = "root";
      maxJobs = 2;
      speedFactor = 20;
      systems = [ "i686-linux" "x86_64-linux" ]
        ++ lib.optionals (lib.mod num 5 == 0) [ "aarch64-linux" "riscv64-linux" ];
      supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" ] ++ x86-64
        ++ lib.optionals (lib.mod num 5 == 0) (aarch64 ++ riscv64);
      sshKey = config.sops.secrets."services/hydra/id_ed25519_hydra".path;
  });
  nixpkgs.config.allowUnsupportedSystem = true;
  nix.distributedBuilds = true;
  nix.gc.automatic = lib.mkForce false;
  nix.settings = {
    allowed-uris = [
      "github:"
      "git+https://"
      "git+ssh://"
      "https://"
    ];
  };
  programs.ssh = {
    knownHosts = {
      "build-worker-03.nyantec.com".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIEGqTY74c5g15DSNPNM2Wdr5jAwS7BFgX1XRnhtGOnJc";
      "build-worker-04.nyantec.com".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICOq+5I+nlAN2lJoOtoXrYEDuZ/TMPMa43pIlablYigK";
      "integra.kyouma.net".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIBwEQiSfaDrUAwgul4mktusBPcIVxI4pLNDh9DPopVU";
      "schrodinger.kyouma.net".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKo7vZ6lS1wx76YsbAdhOsGcc20YMAW52ep8SZ/FCHDp";
      "lab.nyantec.com".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIUePtVPtBK+CYosufbaGiMT4EVanti4V5t2Wg0g/Fy4";
      "localhost".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPNVavo3YHVsrYwXRVISu7kDoknn+5inFGySn4azlB8P";
      "[build-worker-kyoumanet.fly.dev]:2200".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJUGzlilikAUfUGKXVCoTeDvPRoWUgDDkNU5WaRUBzls";
      "[build-worker-kyoumanet.fly.dev]:2201".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDL2M97UBHg9aUfjDUxzmzg1r0ga0m3/stummBVwuEAB";
      "[build-worker-kyoumanet.fly.dev]:2202".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOTwVKL0P0chPM2Gz23rbT94844+w1CGJdCaZdzfjThz";
      "[build-worker-kyoumanet.fly.dev]:2203".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAjy2eZGJQeAYy0+fLgW9jiS0jVY2LInY0NDMnzCvvKp";
      "[build-worker-kyoumanet.fly.dev]:2204".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIN72OyD9LYy4hq0WZ7ie5RPV+G54UreEJiA/RubjGoe9";
      "[build-worker-kyoumanet.fly.dev]:2205".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICNh1o1I98XrI2XmOI6Q0aHPfyLCIQwKkKOxGUUeXL9v";
      "[build-worker-kyoumanet.fly.dev]:2206".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIGf0kxGgwOG9KhUhvxxTSiQC5YikrzZXKDgSpBw33qN4";
      "[build-worker-kyoumanet.fly.dev]:2207".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIL9z95a6Fn/dB+iNigEYpuJdBnBwCkIZYaKHcFbGP+RY";
      "[build-worker-kyoumanet.fly.dev]:2208".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAk+FNMhTfAVqk3MfLp4QiG/i5ti53DlpnC0q+sOvU9O";
      "[build-worker-kyoumanet-cdg.fly.dev]:2209".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJGlQD/3fLn/Kyb7v0RIycHRcArGi75jURj803EMpW0S";
      "[build-worker-kyoumanet-cdg.fly.dev]:2210".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMQm1FSGBGdCR5f8MvBvdKM0M4yIQVnH1po7hHO5T1qz";
      "[build-worker-kyoumanet-cdg.fly.dev]:2211".publicKey = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAINlH+v2ZlcDQY3itw4b7aRbwRTqDsTE0R5Ua3vF0VaGr";
    }; 
    extraConfig = ''
      Host machine-0008.cloud-v.co
        Hostname machine.cloud-v.co
        Port 20008
    '' + lib.concatLines (lib.forEach (lib.range 0 11) (num: ''
      Host build-worker-${lib.fixedWidthNumber 2 num}
        Hostname build-worker-kyoumanet${lib.optionalString (num > 8) "-cdg"}.fly.dev
        Port 22${lib.fixedWidthNumber 2 num}
    ''));
  };
}