binary-cache/modules/default.nix

{
  pkgs,
  lib,
  config,
  ...
}:
let
  cfg = config.services.tvix-binary-cache;
  systemdHardening = {
    PrivateDevices = true;
    PrivateTmp = true;
    ProtectControlGroups = true;
    ProtectKernelTunables = true;
    RestrictSUIDSGID = true;

    ProtectSystem = "strict";
    ProtectKernelLogs = true;
    ProtectProc = "invisible";
    PrivateUsers = true;
    ProtectHome = true;
    UMask = "0077";
    RuntimeDirectoryMode = "0750";
    StateDirectoryMode = "0750";
  };
in
{
  imports = [ ./nginx.nix ];
  options = {
    services.tvix-binary-cache = {
      enable = lib.mkEnableOption "BinaryCache using tvix ca-store";
      blob-service-addr = lib.mkOption {
        type = lib.types.str;
        default = "objectstore+file://%S/tvix-castore/blobs.object-store";
        description = ''
          `blob-service-addr` option for the mutualized content addressed storage.
        '';
      };
      directory-service-addr = lib.mkOption {
        type = lib.types.str;
        default = "sled://%S/tvix-castore/directories.sled";
        description = ''
          `directory-service-addr` option for the mutualized content addressed storage.
        '';
      };
      caches = lib.mkOption {
        type = lib.types.attrsOf (
          lib.types.submodule (
            { name, ... }:
            {
              options = {
                port = lib.mkOption {
                  type = lib.types.port;
                  default = 9000;
                };
                name = lib.mkOption {
                  type = lib.types.str;
                  description = "Name of the cache";
                  default = name;
                  defaultText = lib.literalMD "Defaults to attribute name in services.tvix-binary-cache.caches";
                };
                path-info-service-addr = lib.mkOption {
                  type = with lib.types; str;
                  description = "Path info service path";
                  default = "sled://%S/%N/pathinfo.sled";
                };
                remote-path-info-service-addr = lib.mkOption {
                  type = with lib.types; nullOr str;
                  description = "Upstream cache to substitute from if nothing in ";
                  example = "nix+https://cache.nixos.org?trusted-public-keys=cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=";
                  default = null;
                };
                blob-service-addr = lib.mkOption {
                  type = with lib.types; nullOr str;
                  default = null;
                  description = ''
                    Use a specific blob service and do not use the mutualized one.
                  '';
                };
                directory-service-addr = lib.mkOption {
                  type = with lib.types; nullOr str;
                  default = null;
                  description = ''
                    Use a specific directory address and do not use the mutualized one.
                  '';
                };
              };
            }
          )
        );
      };
    };
  };

  config = lib.mkIf cfg.enable {

    environment.systemPackages = [ pkgs.tvix-store ];

    systemd.services = lib.mkMerge (
      (lib.singleton {
        tvix-castore = {
          environment = {
            BLOB_SERVICE_ADDR = cfg.blob-service-addr;
            DIRECTORY_SERVICE_ADDR = cfg.directory-service-addr;
            PATH_INFO_SERVICE_ADDR = "sled://%S/tvix-castore/pathinfo.sled"; # Unused but probably needed
          };
          serviceConfig = {
            ExecStart = "${pkgs.tvix-store}/bin/tvix-store --otlp=false daemon --listen-address=\"%t/tvix-castore/socket\"";
            DynamicUser = true;
            User = "tvix-binary-cache";
            StateDirectory = "tvix-castore";
            RuntimeDirectory = "tvix-castore";
          } // systemdHardening;

        };
      })
      ++ (lib.mapAttrsToList (
        name: cfg:
        let
          unitName = "tvix-store-${cfg.name}";
        in
        {
          ${unitName} = {
            wantedBy = [ "multi-user.target" ];
            wants = [ "tvix-castore.service" ];
            after = [ "tvix-castore.service" ];
            environment = {
              BLOB_SERVICE_ADDR =
                if cfg.blob-service-addr != null then
                  cfg.blob-service-addr
                else
                  "grpc+unix://%t/tvix-castore/socket";
              DIRECTORY_SERVICE_ADDR =
                if cfg.directory-service-addr != null then
                  cfg.directory-service-addr
                else
                  "grpc+unix://%t/tvix-castore/socket";
              PATH_INFO_SERVICE_ADDR = cfg.path-info-service-addr;
              REMOTE_PATH_INFO_SERVICE_ADDR = lib.mkIf (
                cfg.remote-path-info-service-addr != null
              ) cfg.remote-path-info-service-addr;
            };
            serviceConfig = {
              ExecStart = "${pkgs.nar-bridge}/bin/nar-bridge --otlp=false --listen-address=\"[::1]:${builtins.toString cfg.port}\"";
              DynamicUser = true;
              User = "tvix-binary-cache";
              StateDirectory = unitName;
              RuntimeDirectory = unitName;
            } // systemdHardening;
          };

        }
      ) cfg.caches)
    );

  };
}