How to Schedule Project Zomboid Server Reboots with systemd on Ubuntu 24.04 LTS

Follow the directions on the PZwiki to setup a Project Zomboid server. Upon completion of that guide the Zomboid Server will be installed in /opt/pzserver/

Installing RCON

Commands will be sent to the server via its RCON interface. A reliable RCON interface is rcon-cli. rcon-cli is not available through Ubuntu's software repositories and will be acquired through github.

The following commands will download rcon-cli, extract the downloaded archive, change the name of the resultant directory from rcon-0.10.3-amd64_linux to just rcon, and finally it will change the ownership of rcon to pzuser.

root@server # cd /opt/pzserver && wget https://github.com/gorcon/rcon-cli/releases/download/v0.10.3/rcon-0.10.3-amd64_linux.tar.gz && tar xf rcon-0.10.3-amd64_linux.tar.gz && mv rcon-0.10.3-amd64_linux rcon && chown -R pzuser:pzuser rcon

Edit the configuration file /opt/pzserver/rcon/rcon.yaml so that there is a zomboid entry with the correct server details. The port will need to be changed if the server is operating on non standard ports.

default:
  address: "" # host:port, for example 127.0.0.1:16260
  password: ""
  log: "rcon-default.log"
  type: "" # rcon, telnet, web.
  timeout: "10s"
zomboid:
  address: "127.0.0.1:16261"
  password: "your_server_admin_password_here"
  timeout: "10s"
  log: "rcon-zomboid.log"

This configuration file can be tested with the following command as pzuser.

pzuser@server $ cd /opt/pzserver/rcon && ./rcon -e zomboid "servermsg \"test\""

The command will return Message sent. to the terminal while players on the server will see the test server message.

Creating the Reboot Shell Scripts

Two scripts will be used to reboot the zomboid server. The first of which will inform players of the impending reboot every minute for five minutes. Once players are notified, it calls a shutdown script located in the same directory.

Create the following file /opt/pzserver/rcon/zomboid-reboot.sh with the following contents.

#!/bin/bash
SHUTDOWN_TIMER_MIN=5; #Every minute this script will send the users a message via RCON that the server is rebooting in n minutes.
cd "$(dirname "$0")";

for ((i = $SHUTDOWN_TIMER_MIN; i > 0; i--));
do
        MSG="Rebooting the server in ${i} ";

        if [[ i -eq 1 ]]
        then
                MSG+="minute.";
        else
                MSG+="minutes.";
        fi

        ./rcon -e zomboid "servermsg \"${MSG}\"";
        sleep 60;
done

./zomboid-shutdown.sh

Create the second script file /opt/pzserver/rcon/zomboid-shutdown.sh which will reboot the server by issuing RCON save and quit commands.

#!/bin/bash
cd "$(dirname "$0")";
./rcon -e zomboid "save";
./rcon -e zomboid "quit";
sleep 20;
timestamp=$(date +%Y%m%d_%H%M%S);
echo -en "${timestamp} : Server is shutdown\n" >> shutdown.txt;

Change the permissions of zomboid-shutdown.sh and zomboid-reboot.sh so that the scripts are executable.

root@server # chmod +x /opt/pzserver/rcon/zomboid-shutdown.sh /opt/pzserver/rcon/zomboid-reboot.sh

Creating systemd Scripts for Scheduled Reboots

These scripts can be executed on their own, however having scheduled server reboots is desirable for hands-off administration.

Create the systemd service file /etc/systemd/system/zombiod.service to launch the Project Zomboid server. When this service is started, it will always ensure that the Project Zomboid server is running.

[Unit]
Description=Start the Project Zomboid Service
Requires=network-online.target
After=network-online.target

[Service]
Type=simple
Restart=always
RestartSec=10
User=pzuser
Group=pzuser
WorkingDirectory=/opt/pzserver/
ExecStart=/opt/pzserver/start-server.sh -servername doltpocalypse
ExecStop=/opt/pzserver/rcon/zomboid-shutdown.sh

[Install]
WantedBy=multi-user.target

Create the systemd service file /etc/systemd/system/zomboid-reboot.service. This service file handles the server reboot process.

[Unit]
Description=Reboot the Project Zomboid Server via RCON in /opt/pzserver/rcon

[Service]
Type=oneshot
User=pzuser
Group=pzuser
WorkingDirectory=/opt/pzserver/rcon/
ExecStart=/opt/pzserver/rcon/zomboid-reboot.sh

Lastly, create a systemd timer file /etc/systemd/system/zomboid-reboot.timer which executes the zomboid-reboot.service every four hours.

[Unit]
Description=Functions as a timer for zomboid-reboot.service.

[Timer]
Unit=zomboid-reboot.service
OnCalendar=00/4:00 

[Install]
WantedBy=timers.target

Start and enable the zomboid.service and the zomboid-reboot.timer services.

root@server # systemctl enable --now zomboid.service
root@server # systemctl enable --now zomboid-reboot.timer

The Project Zomboid server now reboots every four hours and warns players before a reboot.