From 06e84b79b4be8c684bd568b8294baccf9b14d8b1 Mon Sep 17 00:00:00 2001
From: gabriel-doriath-dohler <gabriel.doriath.dohler@ens.fr>
Date: Sat, 13 Nov 2021 01:52:04 +0100
Subject: [PATCH] add minecraft server to public-cof

---
 machines/public-cof/configuration.nix |  6 +-
 machines/public-cof/minecraft.nix     | 84 +++++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 machines/public-cof/minecraft.nix

diff --git a/machines/public-cof/configuration.nix b/machines/public-cof/configuration.nix
index 1556fd3..049bd69 100644
--- a/machines/public-cof/configuration.nix
+++ b/machines/public-cof/configuration.nix
@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ config, pkgs, lib, ... }:
 
 {
   imports =
@@ -9,9 +9,13 @@
       ./acme.nix
       ./networking.nix
       ./nextcloud.nix
+      ./minecraft.nix
       # TODO monitoring
     ];
 
+  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
+    "minecraft-server"
+  ];
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;
 
diff --git a/machines/public-cof/minecraft.nix b/machines/public-cof/minecraft.nix
new file mode 100644
index 0000000..0838a64
--- /dev/null
+++ b/machines/public-cof/minecraft.nix
@@ -0,0 +1,84 @@
+{ lib, pkgs, ... }:
+let
+  papermc = {
+    ram = 4; # In GB
+    version = "1.17.1";
+    build = 189;
+    sha256 = "06g2vs8z7k9bl8asjgdz9h8fkd93xam2lbrgmzgamwjp94gvfvrn";
+  };
+  port = 43000;
+  rconPort = 25575;
+in
+{
+  # Remote administration
+  environment.systemPackages = [ pkgs.mcrcon ];
+
+  # Use papermc
+  nixpkgs.overlays = [
+    (self: super: {
+      minecraft-server = super.minecraft-server.overrideAttrs (old: {
+        src = pkgs.fetchurl {
+          url = with papermc;
+            "https://papermc.io/api/v2/projects/paper/versions/${version}/builds/${toString build}/downloads/paper-${version}-${toString build}.jar";
+          sha256 = papermc.sha256;
+        };
+      });
+    })
+  ];
+
+  services.minecraft-server = {
+    enable = true;
+    eula = true;
+    declarative = true;
+
+    jvmOpts = with papermc;
+      "-Xms${toString ram}G -Xmx${toString ram}G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1";
+
+    # To get the uuids: https://mcuuid.net/
+    whitelist = {
+      gabriel_dr_dl = "53fced49-da51-4c82-b1d0-37168029db08";
+      aimie_dodo = "d10be020-a612-47e5-b0d0-938b9a7eb58e";
+    };
+
+    serverProperties = {
+      server-port = port;
+      difficulty = "normal";
+      gamemode = "survival";
+      max-players = 42;
+      motd = "This is a test and it will break";
+
+      view-distance = 7;
+
+      # Map settings
+      level-seed = "9058136630944956755";
+      level-name = "Public COF";
+
+      level-type = "default";
+      spawn-animals = true;
+      spawn-monsters = true;
+      spawn-npcs = true;
+      generate-structures = true;
+
+      enable-command-block = false;
+
+      # Whitelist
+      white-list = true;
+      enforce-whitelist = true;
+
+      # Admin
+      enable-rcon = true;
+      "rcon.password" =
+        ''yQZ>O.%]fB{'E.X=HI1/En~i-''; # TODO Warning: it is written in clear in /var/lib/... with read permissions and mcrcom will transmit it without encryption
+      "rcon.port" = rconPort;
+      admin-slot = true;
+
+      snoop-enabled = false;
+      public = false;
+
+      # enable-jmx-monitoring = true; # https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html
+    };
+  };
+
+  networking.firewall.allowedTCPPorts = [ port ];
+  networking.firewall.allowedUDPPorts = [ port ];
+}