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
{
  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 castore (please read tvix source/docs to learn more).
        '';
      };
      directory-service-addr = lib.mkOption {
        type = lib.types.str;
        default = "sled://%S/tvix-castore/directories.sled";
        description = ''
          `directory-service-addr` option for the castore (please read tvix source/docs to learn more).
        '';
      };
      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";
                };
              };
            }
          )
        );

      };
    };
  };

  config = lib.mkIf cfg.enable {

    systemd.services = lib.mkMerge (
      (lib.singleton {
        tvix-castore = {
          wants = [ "tvix-castore.service" ];
          after = [ "tvix-castore.service" ];
          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
          stateDir = "tvix-binary-cache-${cfg.name}";
        in
        {
          "nar-bridge-${cfg.name}" = {
            wants = [ "tvix-store-${cfg.name}.service" ];
            wantedBy = [ "multi-user.target" ];
            after = [ "tvix-store-${cfg.name}.service" ];
            serviceConfig = rec {
              ExecStart = "${lib.getExe pkgs.nar-bridge-go} --otlp=false --listen-addr=\"[::1]:${builtins.toString cfg.port}\" --store-addr=\"unix://%t/${stateDir}/socket\"";

              DynamicUser = true;
              User = "tvix-binary-cache";
            } // systemdHardening;
          };
          "tvix-store-${cfg.name}" = {
            wants = [ "tvix-castore.service" ];
            after = [ "tvix-castore.service" ];
            environment = {
              BLOB_SERVICE_ADDR = "grpc+unix://%t/tvix-castore/socket";
              DIRECTORY_SERVICE_ADDR = "grpc+unix://%t/tvix-castore/socket";
              PATH_INFO_SERVICE_ADDR = "sled://%S/${stateDir}/pathinfo.sled";
            };
            serviceConfig = {
              ExecStart = "${pkgs.tvix-store}/bin/tvix-store --otlp=false daemon --listen-address=\"%t/${stateDir}/socket\"";

              DynamicUser = true;
              User = "tvix-binary-cache";
              StateDirectory = stateDir;
              RuntimeDirectory = stateDir;
            } // systemdHardening;
          };

        }
      ) cfg.caches)
    );

  };
}