Host a Minecraft - NeoForge Dedicated Server

# Update system and install Docker
sudo apt update && sudo apt install -y docker.io
sudo systemctl enable --now docker

# Create game server directory
sudo mkdir -p /opt/gameserver

# Server configuration
export GAMEMODE="survival"
export DIFFICULTY="easy"
export LEVEL_NAME="world"
export PVP="true"
export SPAWN_MONSTERS="true"
export WHITE_LIST="false"
export ALLOW_FLIGHT="true"
export SPAWN_PROTECTION="16"
export HARDCORE="false"
export FORCE_GAMEMODE="false"
export ALLOW_NETHER="true"
export LEVEL_TYPE="minecraft:normal"
export GENERATE_STRUCTURES="true"
export ONLINE_MODE="true"
export ENFORCE_WHITELIST="false"
export ENFORCE_SECURE_PROFILE="true"
export ENABLE_RCON="false"
export ENABLE_QUERY="true"
export ENABLE_STATUS="true"
export ENABLE_COMMAND_BLOCK="false"
export VIEW_DISTANCE="10"
export SIMULATION_DISTANCE="10"
export MAX_TICK_TIME="60000"
export NETWORK_COMPRESSION_THRESHOLD="256"

# Pull the container image
docker pull eclipse-temurin:25-jdk-alpine

#!/bin/bash

apt update
apt install -y wget curl jq xmlstarlet

cd /opt/gameserver || { echo "Failed to change directory to /opt/gameserver"; exit 1; }

# Accept EULA
echo "Accepting EULA..."
echo "eula=true" > eula.txt

# Resolve Minecraft version
MC_VERSION="${MINECRAFT_VERSION:-latest}"
NEOFORGE_MAVEN="https://maven.neoforged.net/releases/net/neoforged/neoforge"

if [ "$MC_VERSION" = "latest" ] || [ -z "$MC_VERSION" ]; then
  echo "Fetching latest NeoForge version..."
  XML_DATA=$(curl -sSL "$NEOFORGE_MAVEN/maven-metadata.xml")
  NEOFORGE_VERSION=$(echo "$XML_DATA" | xmlstarlet sel -t -v '/metadata/versioning/release' 2>/dev/null)
  if [ -z "$NEOFORGE_VERSION" ]; then
    NEOFORGE_VERSION=$(echo "$XML_DATA" | grep -oP '<release>[^<]+</release>' | sed 's/<[^>]*>//g')
  fi
  MC_VERSION="1.$(echo "$NEOFORGE_VERSION" | cut -d'.' -f1-2)"
  echo "Latest NeoForge version: $NEOFORGE_VERSION (MC $MC_VERSION)"
else
  echo "Using specified MC version: $MC_VERSION"
  # Derive version key from MC version (e.g., 1.21.4 -> 21.4)
  if echo "$MC_VERSION" | grep -qP '^d+.d+.d+$'; then
    VERSION_KEY="$(echo "$MC_VERSION" | cut -d'.' -f2-)."
  else
    VERSION_KEY="$(echo "$MC_VERSION" | cut -d'.' -f2-)"
  fi

  echo "Resolving NeoForge version for key: $VERSION_KEY"
  XML_DATA=$(curl -sSL "$NEOFORGE_MAVEN/maven-metadata.xml")
  NEOFORGE_VERSION=$(echo "$XML_DATA" | grep -oP '<version>[^<]+</version>' | sed 's/<[^>]*>//g' | grep "^$VERSION_KEY" | tail -1)

  if [ -z "$NEOFORGE_VERSION" ]; then
    echo "ERROR: No NeoForge version found for MC $MC_VERSION!"
    exit 1
  fi
  echo "Resolved NeoForge version: $NEOFORGE_VERSION"
fi

# Download NeoForge installer
INSTALLER_JAR="neoforge-$NEOFORGE_VERSION-installer.jar"
DOWNLOAD_URL="$NEOFORGE_MAVEN/$NEOFORGE_VERSION/$INSTALLER_JAR"
echo "Downloading NeoForge installer..."
wget -q "$DOWNLOAD_URL" -O "$INSTALLER_JAR"

if [ ! -f "$INSTALLER_JAR" ]; then
  echo "ERROR: Failed to download NeoForge installer!"
  exit 1
fi

# Clean previous install for upgrade/downgrade support
rm -rf libraries/net/neoforged/neoforge
rm -f unix_args.txt

# Run installer
echo "Running NeoForge installer..."
java -jar "$INSTALLER_JAR" --installServer || { echo "NeoForge install failed!"; exit 1; }

# Set up unix_args.txt symlink
if [ -d "libraries/net/neoforged/neoforge/$NEOFORGE_VERSION" ]; then
  ln -sf "libraries/net/neoforged/neoforge/$NEOFORGE_VERSION/unix_args.txt" unix_args.txt

fi

if [ ! -f unix_args.txt ]; then
  echo "ERROR: Installer did not generate unix_args.txt!"
  exit 1
fi

# Cleanup
rm -f "$INSTALLER_JAR"
rm -f run.bat run.sh

echo "NeoForge server installed successfully."\n\necho "Install Completed"

sudo ufw allow 25565/tcp
sudo ufw allow 25575/tcp
sudo ufw allow 25566/both