Managing a Minecraft server maze

Childcare

Minecraft

Author

Thomas Hallam

Published

May 15, 2023

Being ok with many hats

Context

I had a very busy weekend with my kids. Climbing, swimming, biking, footballing, bbqing, Minecrafting, tidying, gardening, entertaining, cooking. Exhausting! What’s worse I hardly sleeping with so much stress and work and outside work too.

Anyhow, my kids are now totally immersed in Minecraft (1.19.4 java edition). Most their friends are too, and they all want to play together.

We’ve previous used the ‘Join on Lan’ feature but this is reliant on the host always being connected, we’ve explored hosting options, e.g. using old Linux laptop (too slow / 32bit), buying a server (too expensive), or using a third-party tool (Curseforge, MultiMC). Some are ok, but none have been ideal.

In the latest attempt to get a reliable server working for the local network, I’ve tried the Windows 11 VM tool. It works for now, as many of their mc friends can join the network. It isn’t reliant on external hosting on a third party server/website, and less problems with online chat.

This took quite a bit of reading around various articles, testing the options, but here is a working set-up!

Hope you enjoy it.

Install and run Minecraft Server 1.19.4 for local network access on Windows VM HyperVisor Ubuntu 22.04 - Step-by-step guide

Index:

Dependencies
Ubuntu Live Server
SSH
Create new root account
System hardening
Ubuntu firewall
Java
Minecraft Server
Supervisor
Screens
Test it works
Internet server

System Setup

Dependencies

8gb+ RAM
Enough HDD memory
Installation of Windows 10 or 11
Install WSL2
Enable Windows Developer features
Enable Hyper-V and Hypervisor

Ubuntu Live Server

Download Ubuntu Live Server iso from here
Recommend LTS version (currently 22.04)
Open Hypervisor… Quick Create.. Select .iso file

Enter the VM launch settings:

4-8gb RAM
10-25gb HDD (depends how many worlds or mods you want)
Enable network adapter (WIFI for local network IP, Default for internet-facing IP)
Click start

Ubuntu Installation settings:

English/English
Enable dynamic RAM
Click remove the ‘CD/DVD Drive’ in Hyper-V, click continue on installer if you get the red error message
Install third-party packages
Eventually installing Ubuntu Server is completed, Reboot

After installation:

sudo apt install wget net-tools
sudo apt update

Ubuntu firewall

Setup UFW firewall rules to allow only traffic on SSH (22) and the default Minecraft (25565) ports:

# sudo ufw --version
# sudo apt-get install ufw

sudo ufw default deny

sudo ufw allow from 192.168.1.0/24 to any port 22 
#only open to local network

sudo ufw allow from 192.168.1.0/24 to any port 25565    
#only open to local network

sudo ufw enable

# Command may disrupt existing ssh connections. Proceed with operation (y|n)? yENTER

ufw status verbose
ufw reload

SSH

Connect via SSH with PuTTY with IP and password on port 22
Why bother? because using HyperV the copy-and-paste doesn’t work on Ubuntu Live Server VM, even with Guest Service enabled
Alternatively, generate a new ssh key in the terminal, and export ssh keys and use those to connect

ssh-keygen

Create new root account

sudo -su root

adduser minecraft

usermod -aG sudo minecraft

su - minecraft

System hardening

Enable SWAP, to allow the system to use more memory/ram if required

sudo swapon -s

sudo fallocate -l 4g /swap

sudo chmod 0600 /swap

sudo mkswap /swap

sudo swapon /swap

sudo echo '/swap    none swap defaults 0 0' | sudo tee -a /etc/fstab

sudo free -m

Change the initial root password to a private and strong one, such as r00tyHafs3t334vM%2ka$8E3:

sudo echo 'root:r00tyHafs3t334vM%2ka$8E3' | sudo chpasswd && history -d -1

Create a non-root user account with sudo privileges, such as mcninja, and then also set up a strong password for it, such as sud04QeXaedgad3435gae#6&Cw:

sudo useradd -ms /bin/bash mcninja

sudo echo 'mcninja:sud04QeXaedgad3435gae#6&Cw' | sudo chpasswd && history -d -1

sudo echo 'mcninja    ALL=(ALL)   NOPASSWD: ALL' | sudo tee -a /etc/sudoers.d/designated

sudo chmod 0440 /etc/sudoers.d/designated

At this point it is probably safe to delete any other accounts you have set up with less-secure passwords

Update the system, and then reboot:

sudo apt update

sudo apt upgrade -y

sudo apt autoremove -y

sudo shutdown -r now

Java

Minecraft Java Edition server 1.18.2 requires Java 17.

sudo add-apt-repository ppa:openjdk-r/ppa

sudo apt update

sudo apt install openjdk-17-jre-headless -y

java --version

Minecraft Server

Find latest minecraft server

sudo mkdir /opt/minecraft

sudo chown mcninja:mcninja /opt/minecraft

cd /opt/minecraft

sudo wget https://piston-data.mojang.com/v1/objects/8f3112a1049751cc472ec13e397eade5336ca7ae/server.jar -O minecraft_server.1.19.4.jar

echo "eula=true" > /opt/minecraft/eula.txt

Supervisor

sudo apt install supervisor -y

supervisord -v

Start the Supervisor service:

sudo systemctl daemon-reload

sudo systemctl start supervisor.service

sudo systemctl enable supervisor.service

Create a Supervisor configuration file for the Minecraft Java Edition server:

sudo nano /etc/supervisor/conf.d/minecraft.conf

Populate the file with:

[program:minecraft]

directory=/opt/minecraft/

command=java -Xms1024M -Xmx4G -jar /opt/minecraft/minecraft_server.1.19.4.jar nogui

user=mcninja

autostart=true

autorestart=true

stderr_logfile=/var/log/supervisor/error_minecraft.log

stderr_logfile_maxbytes=100MB

stdout_logfile=/var/log/supervisor/out_minecraft.log

stdout_logfile_maxbytes=100MB

Load the Minecraft Java Edition server configuration file:

sudo supervisorctl reread

sudo supervisorctl update

Determine if the Minecraft Java Edition server is up and running:

tail -f /var/log/supervisor/out_minecraft.log

Screens

Use Screens to manage several processes (e.g. chat log, server log, updating settings, updates):

sudo apt install screen
screen -S "Minecraft Server"

screen -list

To exit the screen session, press CTRL + A then D. To resume the screen session, run:

screen -r XXXX  # to resume a screen

Test it works!

Direct connect on the local ip address: 192.168.0.XX

Change the server settings

sudo nano /opt/minecraft/server.properties

Edit settings if required before launch

Let’s take a closer look at some of the most important properties in this list:

difficulty (default easy) - This sets the difficulty of the game, such as how much damage is dealt and how the elements affect your player. The options are peaceful, easy, normal, and hard.
gamemode (default survival) - This sets the gameplay mode. The options are survival, creative,adventure, and spectator.
level-name (default world) - This sets the name of your server that will appear in the client. Special characters such as apostrophes may need to be preceded by a backslash. This is known is escaping characters, and is common practice when special characters may not otherwise be parsed correctly in context.
motd (default A Minecraft Server) - The message that is displayed in the server list of the Minecraft client.
pvp (default true) - Enables Player versus Player combat. If set to true, players will be able to engage in combat and damage each other.
online-mode - True enables non-premium players to log in to your Minecraft server

Start / Stop your Minecraft Server in HyperVisor

Internet server

It would probably be possible to open the VM to the internet securely, by changing the VM Network to Default, then changing the UFW firewall settings

sudo ufw allow 22 # open VM SSH to internet traffic
sudo ufw allow 25565 #open port to internet traffic

It is maybe/probably possible to route minecraft traffic maybe open ipv4 port forward on the router settings, or use an ipv6 pin hole port. Even, maybe get a cheap/free domain to point at the server and fix the IP address for the machine.

At this point, though, given the additional security effort required and cost it would probably be worth just buying a paid-for and ready-to-use Minecraft server. Or following the above process on AWS using EC2 Small/Medium size Ubuntu server.