Starting your server automatically with systemd

A systemd service is the proper way to keep something running on Linux: it starts by itself after a reboot, comes back if it crashes and logs everything it writes. The example is a Minecraft server, but it works for anything.

1. A user for the server

Better not to run it as root: if someone breaks in through the game, they do not get the whole machine.

adduser --disabled-password --gecos "" minecraft
# copy your server to /home/minecraft/server and set ownership:
chown -R minecraft:minecraft /home/minecraft/server

2. The service file

Create /etc/systemd/system/minecraft.service:

[Unit]
Description=Minecraft server
After=network-online.target
Wants=network-online.target

[Service]
User=minecraft
WorkingDirectory=/home/minecraft/server
ExecStart=/usr/bin/java -Xms4G -Xmx4G -jar paper.jar --nogui
Restart=on-failure
RestartSec=10

[Install]
WantedBy=multi-user.target

Change WorkingDirectory and ExecStart to your server's folder and command. Always use full paths (which java shows Java's).

3. Enable it

systemctl daemon-reload
systemctl enable --now minecraft

enable makes it start with the VPS; --now starts it right away.

Day to day

systemctl status minecraft      # is it running?
systemctl restart minecraft     # restart it
systemctl stop minecraft        # stop it
journalctl -u minecraft -f      # watch its console live (Ctrl + C to exit)

What about the game console?

As a service you cannot type into its console directly. Manage it with RCON (Minecraft, Rust, ARK and Palworld have it) or with in-game admin commands. On systemctl stop, Minecraft saves the world before closing.

If you would rather keep a console at hand and do not mind starting it yourself after each reboot, screen or tmux may suit you better.