Scenario

You have a shell script at /usr/local/bin/check_app.sh that runs periodically and exits with a non-zero code. The script is currently failing due to a simulated error condition.

Task

Create a systemd service named check_app.service that automatically restarts the script when it fails, but stops retrying after 3 restart attempts within 60 seconds. Configure the service to start on boot with a 5-second delay between restart attempts, then start the service and verify it hits the restart limit.

Step 1: Create the systemd service file

sudo nano /etc/systemd/system/check_app.service

Add the service configuration with restart limits in the [Unit] section:

[Unit]
Description=Application Health Check Service
After=network.target
StartLimitBurst=3
StartLimitIntervalSec=60

[Service]
ExecStart=/usr/local/bin/check_app.sh
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

Save and exit (Ctrl+O, Enter, Ctrl+X). StartLimitBurst=3 allows 3 start attempts, StartLimitIntervalSec=60 sets a 60-second window, and RestartSec=5 waits 5 seconds between restarts.

Step 2: Enable, start the service, and wait for restart limit

sudo systemctl enable check_app.service
sudo systemctl start check_app.service
sleep 20

Enable the service for boot, start it immediately, and wait for the service to attempt starts before hitting the restart limit.

Step 3: Verify restart limit was reached

sudo systemctl status check_app.service

Should show "Start request repeated too quickly" and the service in failed state.