Installing on Linux server

tipp

On Linux systems, we recommend using wget to download the zip-file. Alternatively, you may use

curl -O https://somefile.zip

Please make sure you have installed every software needed. If not, run this command:

sudo apt-get update
sudo apt-get install screen wget unzip nano

Download the .zip-file or .tar.gz-file from GitHub:

wget https://github.com/JWeinelt/Caesar/releases/version.zip

or

curl -O https://github.com/JWeinelt/Caesar/releases/version.zip

Replace version with the actual version of Caesar backend, mostly the newest. You can either download the file with .zip or .tar.gz.

Now, unpack the archive. If downloaded it as a zip-file, run

unzip Caesar.zip

When using tar, run

tar -xvzf Caesar.tar.gz

When running the command ls you should see an output similar to this:

root@someserver:-$ ls
caesar-server.jar    changelog.txt    modules    start.bat    start.sh

As we are using a Linux system, we can safely delete the file start.bat:

rm start.bat

Now, we have to give the start.sh file the permission to be executed:

chmod +x start.sh

tipp

We highly recommend creating a dedicated user for Caesar to enhance security. First, create a new user:

sudo useradd -r -M -s /usr/sbin/nologin caesar

This command will create a new user named 'caesar'. It has no home directory and you can't login to the server using this user. Now, we need to say the > user, that the Caesar directory is theirs:

sudo chown -R caesar:caesar /home/Caesar

Replace /home/Caesar with the actual path of your installation. Next, go into the installation directory and execute chmod:

cd /home/Caesar
chmod +x start.sh

If you are using a dedicated user for Caesar, you have to edit the file start.sh as the following:

#!/bin/bash

# Remember: when changing this file, backups are good to go :-)

# Uncomment this line to get Caesar executed by its user.
# Change 'caesar' to the user you created.
sudo -u caesar

# Set the directory for the script
cd "$(dirname "$0")"

# Log file
LOGFILE="caesar.log"

# Only start if screen session does not exist
if ! screen -list | grep -q "Caesar-Backend"; then
    echo "Starting Caesar backend..."
    screen -dmS Caesar-Backend bash -c "java -Xmx2G -Xms2G -jar caesar-server.jar --check-updates | tee -a $LOGFILE"
else
    echo "Caesar backend is already running!"
fi

Now, you only have to execute

./start.sh

There you go! Caesar is now starting.