I am trying to run a Java application as a system service with systemd. The .service file for the service has the following command line:
ExecStart=/usr/bin/java -cp $CLASSPATH:/path/to/my.jar org.example.MainClass -myoption
where -myoption is an option intended to be passed to the main() method of the main class.
The command line works as expected when I launch it from bash; the option is passed to the main class.
However, when I try to start the service with systemctl start and then query its status with systemctl status, I see that the JVM terminated with:
Unrecognized option: -myoption
Apparently, the JVM is trying to make some sense of -myoption instead of passing it to the main class as an argument.
As the service is designed to exit upon the JVM being sent a SIGINT, I cannot use workarounds which will obscure the PID of the JVM from systemd.
How can I pass a command line option to the main class when launching it as a systemd service?
Environment variables in ExecStart must be enclosed in braces unless they are separate words (and cannot be used in the path to the executable itself).
The following works as expected:
ExecStart=/usr/bin/java -cp ${CLASSPATH}:/path/to/my.jar org.example.MainClass -myoption