How to Create a Custom Systemd Service on Ubuntu

In this guide, we will walk you through the steps to create a custom systemd service on Ubuntu that checks if Google Chrome is running every 5 seconds. This can be particularly useful for monitoring purposes.

Prerequisites

• A system running Ubuntu
• Basic knowledge of the terminal and command-line interface
• Google Chrome installed on your system

Step 1: Create the Monitoring Script

First, we need to create a Bash script that will check if Google Chrome is running.

1. Open your terminal.
2. Create a new script file named check_chrome.sh
3. Add the following content to the script file.

#!/bin/bash

while true; do
    # Get the current time
    current_time=$(date +"%Y-%m-%d %H:%M:%S")

    # Check if Google Chrome is running using pgrep
    if pgrep -x "chrome" > /dev/null
    then
        echo "[$current_time] Google Chrome is running." >> /home/hp/Pradeep-practice/linux/chrome-status.txt
    else
        echo "[$current_time] Google Chrome is not running." >> /home/hp/Pradeep-practice/linux/chrome-status.txt
    fi

    # Wait for 5 seconds before repeating the loop
    sleep 5
done

Replace /home/hp/Pradeep-practice/linux/chrome-status.txt with the actual path to your txt, Save the file, and exit the editor (Ctrl + X, then Y, then Enter)
Make the script executable
chmod +x check_chrome.sh

Step 2: Create the Systemd Service Unit File

Next, we will create a systemd service unit file to manage our script.

1. Open the terminal and create a new service file:
   sudo nano /etc/systemd/system/check_chrome.service
2. Add the following content to the file

[Unit]
Description=chrome status checker
After=network.target

[Service]
ExecStart=/home/hp/Pradeep-practice/linux/check_chrome.sh

[Install]
WantedBy=multi-user.target

Replace /home/hp/Pradeep-practice/linux/check_chrome.sh with the actual path to your script.

Step 3: Enable and Start the Service

To enable and start your custom systemd service, follow these steps:

1. Reload the systemd manager configuration:
   sudo systemctl daemon-reload
2. Enable the service to start on boot
   sudo systemctl enable check_chrome.service
3. Start the service
   sudo systemctl start check_chrome.service

Step 4: Verify the Service

Finally, check if the service is running correctly.

Check the status of the service: sudo systemctl status check_chrome.service
You should see an output indicating that the service is active and running.

Conclusion

You have now created a custom systemd service on Ubuntu that continuously monitors if Google Chrome is running every 5 seconds.You can use similar steps to create other custom services for different applications as needed.