Day4: Task 2 Monitoring Metrics Script of the Bash Script! 🚀

📍Introduction:

Welcome to the world of Linux process monitoring! In this blog, we will write a Bash script that monitors system metrics like CPU usage, memory usage, and disk space usage. The script will provide a user-friendly interface, allow continuous monitoring with a specified sleep interval, and extend its capabilities to monitor specific services like Nginx.

📋The Tasks: Implementing the Perfect Monitoring Script

Enhance the script by providing a user-friendly interface that allows users to interact with the script through the terminal. Display a simple menu with options to view the metrics and an option to exit the script.

1. Implementing Basic Metrics Monitoring 📊 we will write a Bash script that monitors the CPU usage, memory usage, and disk space usage of the system using the top, free, and df commands. These commands provide real-time data on CPU usage, memory usage, and disk space, respectively.

2. User-Friendly Interface 🤝 we will enhance the script by providing a user-friendly interface that allows users to interact with the script through the terminal. Display a simple menu with options to view the metrics and an option to exit the script.

3. Continuous Monitoring with Sleep ⏰ Continuous monitoring is a key feature. We'll introduce a loop to keep fetching metrics until the user decides to exit. We'll also add a "sleep" mechanism to pause monitoring at a specified interval.

4. Monitoring Nginx Service 🌐 Extending the script's capabilities, we'll check if the Nginx service is running and display its status. If it's not running, the user can start it using the script.

5. Monitoring a Different Service 🛠️ We'll take it a step further by allowing users to monitor any service of their choice. The script will prompt the user to enter the service name and display its status accordingly.

6. Error Handling ❌ To make the script robust, we'll implement error handling. Meaningful error messages will guide users on troubleshooting and fixing issues.

📝 Let's Dive into the Script!

#!/bin/bash

# Function to display system metrics (CPU, memory, disk space)
function view_system_metrics() {
    echo "---- System Metrics ----"
    # Fetch CPU usage using `top` command and extract the value using awk
    cpu_usage=$(top -bn 1 | grep '%Cpu' | awk '{print $2}')
    # Fetch memory usage using `free` command and extract the value using awk
    mem_usage=$(free | grep Mem | awk '{printf("%.1f", $3/$2 * 100)}')
    # Fetch disk space usage using `df` command and extract the value using awk
    disk_usage=$(df -h / | tail -1 | awk '{print $5}')

    echo "CPU Usage:  $cpu_usage%   Mem Usage:  $mem_usage%   Disk Space:  $disk_usage"
}

# Function to monitor a specific service
function monitor_service() {
    echo "---- Monitor a Specific Service ----"
    read -p "Enter the name of the service to monitor: " service_name

    # Check if the service is running using `systemctl` command
    if systemctl is-active --quiet $service_name; then
        echo "$service_name is running."
    else
        echo "$service_name is not running."
        read -p "Do you want to start $service_name? (Y/N): " choice
        if [ "$choice" = "Y" ] || [ "$choice" = "y" ]; then
            # Start the service using `systemctl` command
            systemctl start $service_name
            echo "$service_name started successfully."
        fi
    fi
}

# Main loop for continuous monitoring
while true; do
    echo "---- Monitoring Metrics Script ----"
    echo "1. View System Metrics"
    echo "2. Monitor a Specific Service"
    echo "3. Exit"

    read -p "Enter your choice (1, 2, or 3): " choice

    case $choice in
        1)
            view_system_metrics
            ;;
        2)
            monitor_service
            ;;
        3)
            echo "Exiting the script. Goodbye!"
            exit 0
            ;;
        *)
            echo "Error: Invalid option. Please choose a valid option (1, 2, or 3)."
            ;;
    esac

    # Sleep for 5 seconds before displaying the menu again
    sleep 5
done

🔍 Running the Script

Now that we are ready with the script, we're ready to make it executable.

To make your script executable use the command:

chmod 744 monitoring_script.sh

After making it executable we're ready to run it using the command below

./monitoring_script.sh

🖥️ Output Screens

📍 Conclusion

With this powerful and user-friendly Bash script, you can now effortlessly monitor your system's performance and crucial services.

Hope you found this blog useful! 😊

Thank you for reading!

Contact me at :

linkedin: https://www.linkedin.com/in/sutish-pradhan/

E-mail: psutish@gmail.com