nixos/system/services/minecraft.nix

{ config, pkgs, ... }:
{
  nixpkgs.overlays = [
    # Fetch papermc v1.21 from unstable branch of nixpkgs
    (
      final: prev:
      let
        pinnedPkgs = import (builtins.fetchTarball {
          url = "https://github.com/NixOS/nixpkgs/archive/03a94c776f261b78b95de0971a94dea0199b4cd8.tar.gz";
          sha256 = "0vngf4g468qd5fqch85nzyvn7bpa6p2i6rdmzc6ws2653x868w3g";
        }) { inherit (pkgs) system; };
      in
      {
        inherit (pinnedPkgs) papermc papermcServers;
      }
    )
  ];
  services.minecraft-server = {
    enable = true;
    package = pkgs.papermcServers.papermc-1_21;
    eula = true;
    openFirewall = true;
    declarative = true;
    jvmOpts = "-Xmx4G -Xms4G";
    whitelist = {
      "pixelifytica" = "b1848d60-4ddd-4fa4-a328-fb269910b6ae";
      "HomeInTheClouds" = "d49f0aee-f217-477b-9516-9d5906f7fc87";
    };
    serverProperties = {
      server-port = 25565;
      difficulty = "easy";
      gamemode = "survival";
      force-gamemode = true;
      max-players = 10;
      # level-seed = 238902389203;
      motd = "NixOS Minecraft server!";
      white-list = true;
    };
  };
}