Important service directives
ExecStart defines the process to launch. User controls the account it runs under, WorkingDirectory sets its starting directory, and Restart determines when systemd should relaunch it.
DevOps
Systemd Service Builder
Create Linux service unit files and systemctl commands.
Service file + commands
How to create a systemd service
Provide the program, service account, working directory and restart behavior needed by your application. The generated unit file should be reviewed before placing it under /etc/systemd/system/.
Enable and start a unit
After creating or changing a unit, reload the systemd manager configuration. Then enable the service if it should start at boot and start it when you are ready to test.
Troubleshooting
Use systemctl status for the current state and journalctl -u for service logs. An absolute ExecStart path and correct file permissions prevent many common startup failures.