Recently, I decided to start hosting a Minecraft server for me and a few of my friends. While this was mostly because…well…I wanted to play Minecraft, it also occured to me that this is an excellent project for a less experienced user to familiarize themselves with some key skills and concepts that any Linux administrator will find useful.

By the end of this tutorial, we will have:

  • A Minecraft server running for the gaming enjoyment of you and your friends.
  • A custom systemd service to supervise the server process.
  • Appropriately configured firewall rules to allow your friends access to the server.

I will assume you already have a suitable system with any modern GNU/Linux distribution installed. For this tutorial, I will be using an Ampere Altra VPS from Oracle Cloud with AlmaLinux 9.4, but the instructions should be mostly identical for any systemd-based Linux distribution. Recommended specs for a Minecraft server depend heavily on which type of server you would like to run (vanilla, spigot, modded, etc) as well as how many players you are expecting to support, so I will not be going over this here.

You’ll also need git and gcc installed for installing mcrcon.

With all that out of the way, let’s jump in!

Prerequisites#

We’ll start by obtaining a suitable version of Java depending on the Minecraft version we would like to host (more information on that here). In my case, I am running a modded 1.20.1 server, so I’ll install Java 17 with my distribution’s package manager (adjust accordingly for your distribution).

# dnf install java-17-openjdk

Now we’ll download and install mcrcon according to its official installation instructions. This is a basic command-line utility that will allow us to easily manage our server from the command line via the RCON protocol. A popular alternative to using RCON as the primary management interface is to simply launch the server in a screen/tmux session that we can attach to whenever you want to run commands from the server side, but I find this a bit clunky when used in combination with systemd, as we’ll get to later.

$ git clone https://github.com/Tiiffi/mcrcon.git
$ cd mcrcon
$ make
$ sudo make install

Let’s prepare the minecraft system user, as well as some directories.

# useradd --system minecraft
# mkdir -p /opt/minecraft/{server,backup}

Our server will be installed into the /opt/minecraft/server directory. We also have a backup directory for world backups should we choose to utilize it.

Installing the Minecraft server#

Now it’s time to download and install our Minecraft server. This will vary depending on the type of server you want to install, so I’ve included some links to helpful documentation for each.

Once the server .jar file has been placed in the /opt/minecraft/server directory, I like to manually start the server at least once to generate the world and populate the directory with the various configuration files you can use to manage your server.

First let’s change the ownership of the /opt/minecraft directory to the minecraft user.

$ sudo chown -R minecraft:minecraft /opt/minecraft

Accept the Minecraft EULA writing the following to eula.txt.

eula=true

Then we can start the server.

# sudo -i -u minecraft
$ java -Xmx4096M -Xms1024M -jar server.jar --nogui

Change the -Xmx and -Xms arguments to your desired maximum and minimum RAM allocations respectively for the server, and server.jar to whatever the name of the jarfile for the server you are running is. Once the server is loaded you’ll be dropped into the server console. Type stop to shutdown the server and exit back to your shell.

In the server.properties file, make sure you set the rcon.password field to a password of your choice and set enable-rcon to true.

Managing the server with systemd#

Lets start by creating some scripts in the server directory to start and stop our server.

#!/bin/sh

### start.sh

java -Xmx4096M -Xms1024M -jar server.jar --nogui

Like earlier, edit the Java arguments and jarfile name appropriately.

#!/bin/sh

### stop.sh

mcrcon -H localhost -p rconpassword 'stop'

Set rconpassword to the password you set earlier in server.properties.

Note for SELinux users:#

If you’re using SELinux, you’ll have to change the context of these scripts to allow systemd to execute them.

# semanage fcontext -a -t bin_t "/opt/minecraft/server(/.*)?"
# restorecon -R /opt/minecraft/server

In this case I just decided to change the context of the entire directory in case I wanted to add more/different scripts later.

Now we can create our systemd unit file in /etc/systemd/system/minecraft.service.

[Unit]
Description=Minecraft Server

Wants=network.target
After=network.target

[Service]
User=minecraft
WorkingDirectory=/opt/minecraft/server

ProtectHome=read-only
ProtectSystem=full
PrivateDevices=no
NoNewPrivileges=yes
PrivateTmp=no
InaccessiblePaths=/root /sys /srv /media -/lost+found
ReadWritePaths=/opt/minecraft

ExecStart=/opt/minecraft/server/run.sh
ExecStop=/opt/minecraft/server/stop.sh
Restart=always
RestartSec=10

This isn’t a systemd tutorial so I won’t be explaining in great detail what everything here does, but it’s mostly self-explanatory. The middle section of the [Service] stanza contains a variety of options to help enhance the security of our system in case the Minecraft server is compromised.

Now that our systemd unit file is written, we can (as root) run systemctl enable --now minecraft.service to start the server and enable it at boot. We can now manage our server with the typical systemctl commands such as stop, start, restart, etc.

Allow others to connect#

The final step is to configure our system firewall to allow external connections to Minecraft. To do this we just need to open TCP port 25565.

# firewall-cmd --permanent --add-port 25565/tcp
# firewall-cmd --reload

All done!#

That’s it! We now have a fully functional Minecraft server for cozy gaming with friends. From here, you may want to refer to the Minecraft wiki to configure things such as the server whitelist, server operators, MOTD, etc.

We can make backups of your server’s worldfile by simply compressing an archive of the world directory into the /opt/minecraft/backup folder we created earlier. If you’re interested in getting automated backups setup, consider using a tool like Restic.