Minecraft Modpack Server

Operational Steps

1. 确认输入参数完整
2. 执行核心操作（参考本目录下的 scripts/ 或 references/）
3. 验证输出符合契约
4. 保存结果并报告

IO_CONTRACT

• input: server_spec: str — 用户请求描述、上下文信息
• output: server_config: dict — 服务器配置

对应原则：P2（机械原子暴露输入输出规范）

Minecraft Modpack Server Setup

When to use

• User wants to set up a modded Minecraft server from a server pack zip
• User needs help with NeoForge/Forge server configuration
• User asks about Minecraft server performance tuning or backups

Gather User Preferences First

Before starting setup, ask the user for:

• Server name / MOTD — what should it say in the server list?
• Seed — specific seed or random?
• Difficulty — peaceful / easy / normal / hard?
• Gamemode — survival / creative / adventure?
• Online mode — true (Mojang auth, legit accounts) or false (LAN/cracked friendly)?
• Player count — how many players expected? (affects RAM & view distance tuning)
• RAM allocation — or let agent decide based on mod count & available RAM?
• View distance / simulation distance — or let agent pick based on player count & hardware?
• PvP — on or off?
• Whitelist — open server or whitelist only?
• Backups — want automated backups? How often?

Use sensible defaults if the user doesn't care, but always ask before generating the config.

Steps

1. Download & Inspect the Pack

mkdir -p ~/minecraft-server
cd ~/minecraft-server
wget -O serverpack.zip "<URL>"
unzip -o serverpack.zip -d server
ls server/

Look for: startserver.sh, installer jar (neoforge/forge), user_jvm_args.txt, mods/ folder. Check the script to determine: mod loader type, version, and required Java version.

2. Install Java

• Minecraft 1.21+ → Java 21: sudo apt install openjdk-21-jre-headless
• Minecraft 1.18-1.20 → Java 17: sudo apt install openjdk-17-jre-headless
• Minecraft 1.16 and below → Java 8: sudo apt install openjdk-8-jre-headless
• Verify: java -version

3. Install the Mod Loader

Most server packs include an install script. Use the INSTALL_ONLY env var to install without launching:

cd ~/minecraft-server/server
ATM10_INSTALL_ONLY=true bash startserver.sh
# Or for generic Forge packs:
# java -jar forge-*-installer.jar --installServer

This downloads libraries, patches the server jar, etc.

4. Accept EULA

echo "eula=true" > ~/minecraft-server/server/eula.txt

5. Configure server.properties

Key settings for modded/LAN:

motd=\u00a7b\u00a7lServer Name \u00a7r\u00a78| \u00a7aModpack Name
server-port=25565
online-mode=true          # false for LAN without Mojang auth
enforce-secure-profile=true  # match online-mode
difficulty=hard            # most modpacks balance around hard
allow-flight=true          # REQUIRED for modded (flying mounts/items)
spawn-protection=0         # let everyone build at spawn
max-tick-time=180000       # modded needs longer tick timeout
enable-command-block=true

Performance settings (scale to hardware):

# 2 players, beefy machine:
view-distance=16
simulation-distance=10

# 4-6 players, moderate machine:
view-distance=10
simulation-distance=6

# 8+ players or weaker hardware:
view-distance=8
simulation-distance=4

6. Tune JVM Args (user_jvm_args.txt)

Scale RAM to player count and mod count. Rule of thumb for modded:

• 100-200 mods: 6-12GB
• 200-350+ mods: 12-24GB
• Leave at least 8GB free for the OS/other tasks

-Xms12G
-Xmx24G
-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

7. Open Firewall

sudo ufw allow 25565/tcp comment "Minecraft Server"

Check with: sudo ufw status | grep 25565

8. Create Launch Script

cat > ~/start-minecraft.sh << 'EOF'
#!/bin/bash
cd ~/minecraft-server/server
java @user_jvm_args.txt @libraries/net/neoforged/neoforge/<VERSION>/unix_args.txt nogui
EOF
chmod +x ~/start-minecraft.sh

Note: For Forge (not NeoForge), the args file path differs. Check startserver.sh for the exact path.

9. Set Up Automated Backups

Create backup script:

cat > ~/minecraft-server/backup.sh << 'SCRIPT'
#!/bin/bash
SERVER_DIR="$HOME/minecraft-server/server"
BACKUP_DIR="$HOME/minecraft-server/backups"
WORLD_DIR="$SERVER_DIR/world"
MAX_BACKUPS=24
mkdir -p "$BACKUP_DIR"
[ ! -d "$WORLD_DIR" ] && echo "[BACKUP] No world folder" && exit 0
TIMESTAMP=$(date +%Y-%m-%d_%H-%M-%S)
BACKUP_FILE="$BACKUP_DIR/world_${TIMESTAMP}.tar.gz"
echo "[BACKUP] Starting at $(date)"
tar -czf "$BACKUP_FILE" -C "$SERVER_DIR" world
SIZE=$(du -h "$BACKUP_FILE" | cut -f1)
echo "[BACKUP] Saved: $BACKUP_FILE ($SIZE)"
BACKUP_COUNT=$(ls -1t "$BACKUP_DIR"/world_*.tar.gz 2>/dev/null | wc -l)
if [ "$BACKUP_COUNT" -gt "$MAX_BACKUPS" ]; then
    REMOVE=$((BACKUP_COUNT - MAX_BACKUPS))
    ls -1t "$BACKUP_DIR"/world_*.tar.gz | tail -n "$REMOVE" | xargs rm -f
    echo "[BACKUP] Pruned $REMOVE old backup(s)"
fi
echo "[BACKUP] Done at $(date)"
SCRIPT
chmod +x ~/minecraft-server/backup.sh

Add hourly cron:

(crontab -l 2>/dev/null | grep -v "minecraft/backup.sh"; echo "0 * * * * $HOME/minecraft-server/backup.sh >> $HOME/minecraft-server/backups/backup.log 2>&1") | crontab -

Pitfalls

• ALWAYS set allow-flight=true for modded — mods with jetpacks/flight will kick players otherwise
• max-tick-time=180000 or higher — modded servers often have long ticks during worldgen
• First startup is SLOW (several minutes for big packs) — don't panic
• "Can't keep up!" warnings on first launch are normal, settles after initial chunk gen
• If online-mode=false, set enforce-secure-profile=false too or clients get rejected
• The pack's startserver.sh often has an auto-restart loop — make a clean launch script without it
• Delete the world/ folder to regenerate with a new seed
• Some packs have env vars to control behavior (e.g., ATM10 uses ATM10_JAVA, ATM10_RESTART, ATM10_INSTALL_ONLY)

Verification

• pgrep -fa neoforge or pgrep -fa minecraft to check if running
• Check logs: tail -f ~/minecraft-server/server/logs/latest.log
• Look for "Done (Xs)!" in the log = server is ready
• Test connection: player adds server IP in Multiplayer

验证清单 · VERIFICATION

• java -version 与 Mod 包 Minecraft 版本匹配（1.21+→Java21, 1.18-1.20→Java17, ≤1.16→Java8）
• server.properties 含 allow-flight=true、max-tick-time=180000；若 online-mode=false 则同时 enforce-secure-profile=false
• JVM -Xms/-Xmx 按 Mod 数量分配（100-200→6-12G，200-350+→12-24G），且系统保留 ≥8GB 空闲
• ufw status | grep 25565 确认 25565/tcp 已放行
• 用独立启动脚本（引用 user_jvm_args.txt 与 Loader 参数）替代自带 startserver.sh，规避自动重启循环
• 启动后 tail logs/latest.log 出现 "Done (Xs)!" 且 pgrep -fa neoforge|minecraft 有进程；备份脚本+hourly cron 已生效并限制最多 24 份

约束规则 · RULES

1. 输入约束: 参数类型、范围、格式必须校验
2. 输出约束: 返回值结构、编码、命名必须一致
3. 异常约束: 错误信息必须包含上下文和恢复建议
4. 安全约束: 不执行未验证的任意代码，不暴露内部状态

Golden 集合 · GOLDEN SET

• Golden Input: 标准输入样本（覆盖正常路径）
• Golden Output: 预期输出（精确匹配或格式校验）
• Golden Error: 预期错误信息（覆盖失败路径）

Golden 集合是测试的单一真理来源。所有改进必须通过 golden 测试。

违反规则的操作视为不安全，必须拒绝或隔离。

每项验证必须可执行、可记录、可复现。验证失败时记录原因和修复。

示例 · EXAMPLES

示例 1 · 完整搭建 ATM10 服务器（正常路径）

• 输入: server_spec="ATM10 server pack zip URL, 4 名玩家, 正版"
• 操作: 下载解包 → 安装 OpenJDK 21 → ATM10_INSTALL_ONLY=true bash startserver.sh → 写 eula.txt → 配置 server.properties（view-distance=10/simulation-distance=6，allow-flight=true，max-tick-time=180000）→ user_jvm_args.txt 设 -Xms12G -Xmx24G → ufw allow 25565/tcp → 独立启动脚本
• 输出: server_config: dict（含 server.properties 关键字段与 JVM 参数）
• 验证: tail logs/latest.log 出现 "Done (Xs)!"；pgrep -fa neoforge 有进程

示例 2 · 局域网非正版模式（失败路径规避）

• 输入: server_spec="局域网联机, online-mode=false"
• 操作: 设 online-mode=false 后必须同步 enforce-secure-profile=false
• 输出: 修正后的 server.properties 片段
• 验证: 客户端可正常连接，无 "rejected" 拒绝日志

示例 3 · 自动化备份（配置路径）

• 输入: server_spec="需每小时自动备份, 保留 24 份"
• 操作: 生成 backup.sh（tar 压缩 world 目录、超 24 份自动清理）+ hourly cron 条目
• 输出: 备份脚本 + crontab 条目
• 验证: crontab -l | grep backup.sh 有任务；手动执行后 backups/ 出现 world_*.tar.gz

Minecraft Modpack Server

Genes (策略基因)

紧凑策略表示。条件→策略。需要深度时参考完整文档。

• [MINE-001] 开始配置前 → 必须询问用户关于服务器名称、种子、难度、游戏模式、在线模式、玩家数量、内存分配、视距、PvP、白名单及备份策略的偏好，若用户未指定则使用合理默认值
• [MINE-002] 部署 Mod 包服务器 → 必须设置 allow-flight=true 以防止拥有飞行能力的 Mod 物品或坐骑导致玩家被踢出
• [MINE-003] 处理 Mod 包服务器性能 → 必须将 max-tick-time 设置为 180000 或更高，以容纳 Mod 包在生成世界或加载区块时的长 Tick 时间
• [MINE-004] 配置 JVM 内存参数 → 根据 Mod 数量（100-200 个需 6-12GB，200-350+ 个需 12-24GB）分配 RAM，并确保系统保留至少 8GB 空闲内存
• [MINE-005] 配置网络与认证模式 → 若设置 online-mode=false（局域网/非正版），必须同时设置 enforce-secure-profile=false 以避免客户端连接被拒绝
• [MINE-006] 创建启动脚本 → 必须编写独立的启动脚本引用 user_jvm_args.txt 和 Loader 参数，避免使用 Mod 包自带的 startserver.sh 以防其内置的自动重启循环干扰
• [MINE-007] 设置自动化备份 → 必须创建备份脚本定期压缩 world 文件夹，并配置 Cron 任务限制最大备份数量（如 24 个）以自动清理旧备份