dotfiles/nixng/containers/hydra/hydra.nix

{
  makeSystem,
  nixpkgs,
  hydra,
}:
makeSystem {
  system = "x86_64-linux";
  name = "nixng-hydra";
  inherit nixpkgs;
  config = {
    pkgs,
    config,
    lib,
    nglib,
    ...
  }: {
    config = {
      dumb-init = {
        enable = true;
        type.services = {};
      };
      nix = {
        package = pkgs.nixUnstable;
        loadNixDb = true;
        persistNix = "/nix-persist";
        config = {
          experimental-features = ["nix-command" "flakes"];
          sandbox = true;
          trusted-public-keys = ["cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="];
          substituters = ["https://cache.nixos.org/"];
          ignored-acls = ["system.nfs4_acl"];
          allowed-uris = [
            "https://gitea.redalder.org"
            "https://github.com"
            "https://gitlab.com"
            "https://git.sr.ht"
            "https://raw.githubusercontent.com"
            "https://patch-diff.githubusercontent.com"
            "https://media.forgecdn.net"
          ];

          builders-use-substitutes = true;
          builders = "@/etc/nix/machines";
          secret-key-files = "/secrets/nix-key.private";
          extra-platforms = ["i686-linux" "aarch64-linux"];
        };
      };
      services.hydra = {
        enable = true;
        package = hydra.packages.x86_64-linux.hydra;
        hydraURL = "https://hydra.redalder.org";
        notificationSender = "hydra@redalder.org";
        useSubstitutes = true;
        adjustNiceness = true;

        minimumDiskFree = 200;
        minimumDiskFreeEvaluator = 100;

        dbiFile = "/local/dbi";
        config = {
          compress_num_threads = 4;
          evaluator_max_memory_size = "2048M";
          store_uri = "daemon?secret-key=/secrets/nix-key.private";
          binary_cache_secret_key_file = "/secrets/nix-key.private";
          server_store_uri = "daemon?secret-key=/secrets/nix-key.private";
        };
      };
      services.socklog = {
        enable = true;
        unix = "/dev/log";
      };

      init.services.pgpass = {
        script = pkgs.writeShellScript "pgpass" ''
          ln -nsf /secrets/pgpass /var/lib/hydra/pgpass
          ln -nsf /secrets/pgpass-www /var/lib/hydra/pgpass-www
          ln -nsf /secrets/pgpass-queue-runner /var/lib/hydra/pgpass-queue-runner

          chown hydra:hydra /secrets/pgpass
          chown hydra-www:hydra /secrets/pgpass-www
          chown hydra-queue-runner:hydra /secrets/pgpass-queue-runner
          sv down pgpass
        '';
        enabled = true;
      };

      services.crond.crontabs.autogc = {
        jobs = let
          storegc =
            pkgs.writeShellScript "storegc"
            ''
              nix-collect-garbage -d
            '';
        in [
          "0 4 * * * root ${storegc}"
        ];
      };

      init.services.nix-daemon.environment.PATH = with pkgs;
        lib.makeBinPath [
          utillinux
          runit
          busybox
          openssh
          gzip
        ];

      system.activation = let
        machines = pkgs.writeText "machines" ''
          eu.nixbuild.net x86_64-linux,aarch64-linux,i686-linux - 100 5 benchmark,big-parallel
          localhost x86_64-linux - 2 1 benchmark,big-parallel,kvm,nixos-test,local
        '';
        nix-machines = nglib.dag.dagEntryAnywhere ''
          export PATH=${pkgs.busybox}/bin

          mkdir -p /etc/nix
          ln -s ${machines} /etc/nix/machines
        '';

        ssh_config = pkgs.writeText "ssh_config" ''
          Host eu.nixbuild.net
            PubkeyAcceptedKeyTypes ssh-ed25519
            IdentityFile /ssh-key
        '';
        ssh_known_hosts = pkgs.writeText "ssh_known_hosts" ''
          eu.nixbuild.net ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPIQCZc54poJ8vqawd8TraNryQeJnvH1eLpIDgbiqymM
        '';
        ssh = nglib.dag.dagEntryAnywhere ''
          export PATH=${pkgs.busybox}/bin

          mkdir -p /etc/ssh
          ln -s ${ssh_config} /etc/ssh/ssh_config
          ln -s ${ssh_known_hosts} /etc/ssh/ssh_known_hosts
        '';

        ssh-key = nglib.dag.dagEntryAfter ["users"] ''
          export PATH=${pkgs.busybox}/bin

          cp /secrets/ssh-key /ssh-key
          chmod 600 /ssh-key
          chown hydra-queue-runner:root /ssh-key
        '';
      in {
        inherit ssh-key ssh nix-machines;
      };
    };
  };
}