dev/configs/nixos/guests/palworld.nix

{
  config,
  lib,
  ...
}:
let
  cfg = config.guests.palworld;
  steamDir = "/data/steamcmd";
  installDir = "/data/server";
  stateDir = "/data/state";
in
{
  options.guests.palworld = {
    steamPath = lib.mkOption {
      type = lib.types.nullOr lib.types.str;
      default = null;
      example = "/srv/steamcmd";
      description = "Host path bind-mounted as SteamCMD's metadata directory.";
    };

    installPath = lib.mkOption {
      type = lib.types.nullOr lib.types.str;
      default = null;
      example = "/srv/palworld/server";
      description = "Host path bind-mounted as Palworld's server install directory.";
    };

    statePath = lib.mkOption {
      type = lib.types.nullOr lib.types.str;
      default = null;
      example = "/srv/palworld/state";
      description = "Host path bind-mounted as Palworld's durable state directory.";
    };

    serverName = lib.mkOption {
      type = lib.types.str;
      default = "palworld";
      description = "Name shown for the Palworld server.";
    };

    port = lib.mkOption {
      type = lib.types.port;
      default = 8211;
      description = "UDP port for the Palworld server.";
    };

    publicIP = lib.mkOption {
      type = lib.types.nullOr lib.types.str;
      default = null;
      description = "Public IP address advertised by the Palworld server.";
    };

    autoStart = lib.mkOption {
      type = lib.types.bool;
      default = true;
      description = "Start the Palworld server after the guest reaches network readiness.";
    };

    passwordSecret = lib.mkOption {
      type = lib.types.str;
      default = "services/game-servers/password";
      description = "SOPS secret name containing the Palworld server password.";
    };

    adminPasswordSecret = lib.mkOption {
      type = lib.types.str;
      default = "services/game-servers/password";
      description = "SOPS secret name containing the Palworld admin password.";
    };
  };

  config = lib.mkIf cfg.enable {
    assertions = [
      {
        assertion = cfg.steamPath != null;
        message = "guests.palworld.steamPath must point at the host directory that stores SteamCMD metadata.";
      }
      {
        assertion = cfg.installPath != null;
        message = "guests.palworld.installPath must point at the host directory that stores Palworld server files.";
      }
      {
        assertion = cfg.statePath != null;
        message = "guests.palworld.statePath must point at the host directory that stores Palworld durable state.";
      }
    ];

    guests.palworld = {
      interior.modules.services.games.palworld = {
        enable = true;
        inherit (cfg)
          serverName
          port
          publicIP
          autoStart
          ;
        inherit steamDir installDir stateDir;
        passwordFile = "/run/secrets/${cfg.passwordSecret}";
        adminPasswordFile = "/run/secrets/${cfg.adminPasswordSecret}";
      };

      mounts = {
        ${steamDir} = {
          directory = cfg.steamPath;
          owner = config.registry."stable-uid".${config.networking.hostName}.steamcmd;
          group = "storage";
          mode = "0770";
        };
        ${installDir} = {
          directory = cfg.installPath;
          owner = config.registry."stable-uid".${config.networking.hostName}.steamcmd;
          group = "storage";
          mode = "0770";
        };
        ${stateDir} = {
          directory = cfg.statePath;
          owner = config.registry."stable-uid".${config.networking.hostName}.steamcmd;
          group = "storage";
          mode = "0770";
        };
        ${"/run/secrets/${cfg.passwordSecret}"} = {
          file = config.sops.secrets.${cfg.passwordSecret}.path;
          readOnly = true;
        };
      }
      // lib.optionalAttrs (cfg.adminPasswordSecret != cfg.passwordSecret) {
        ${"/run/secrets/${cfg.adminPasswordSecret}"} = {
          file = config.sops.secrets.${cfg.adminPasswordSecret}.path;
          readOnly = true;
        };
      };

      limits = {
        memory = lib.mkDefault "8G";
        cpu = lib.mkDefault "400%";
        tasksMax = lib.mkDefault 2048;
      };
    };

    sops.secrets = {
      ${cfg.passwordSecret} = {
        owner = "root";
        group = "storage";
        mode = "0440";
      };
    }
    // lib.optionalAttrs (cfg.adminPasswordSecret != cfg.passwordSecret) {
      ${cfg.adminPasswordSecret} = {
        owner = "root";
        group = "storage";
        mode = "0440";
      };
    };
  };
}