عرض عملي: تشغيل Shop كخدمة systemd

خطوة بخطوة

1. Create a shop system user and copy the JAR to /opt/shop.
2. Write /etc/systemd/system/shop.service with User=shop, ExecStart=java -jar /opt/shop/shop.jar, Restart=on-failure.
3. systemctl daemon-reload, enable --now shop, then check status and journalctl -u shop.
4. Find the port with ss -tlnp and call the health endpoint with curl.
5. Planned mistake: the JAR is owned by root with mode 600, so the service fails with "permission denied"; fix with chown and chmod 640, not 777.
6. kill the process and show systemd restarting it.