How to create a basic Bash script to monitor a website's uptime

Monitoring a website's uptime is essential to ensuring that your site is always accessible to visitors. With a Bash script, you can automate uptime control and receive immediate notifications in case of downtime. Here's a step-by-step guide on how to create a Bash script to monitor a website's uptime.

We can create the following code:

#!/bin/bash

# Website URL to track
website_url="https://yourwebsite.com"

# Email to receive notifications
notify_email="youremail@example.com"

# Time interval between checks (in seconds)
delay_check=60

# Function to check site uptime
check_website() {
   local status_code=$(curl -o /dev/null -s -w "%{http_code}\n" "$website_url")
   local timestamp=$(date "+%Y-%m-%d %H:%M:%S")
  
   if [ "$status_code" -ne 200 ]; then
     echo "$timestamp - $website_url down. Status code: $status_code" | mail -s "Down" "$notify_email"
   else
     echo "$timestamp - $website_url up. Status code: $status_code"
   fi
}

# Infinite loop to check the site at regular intervals
while true; do
   check_website
   sleep $delay_check
done

This script will start monitoring the uptime of the specified website and will send an email notification whenever the site is unreachable (i.e. when the HTTP status code is not 200).

To make the file executable, type the following command in the terminal:

chmod a+x check-website.sh

You can customize several aspects of the script:

1. Website URL: Change the website_url variable to the address of the site you want to track.
2. Email for notifications: Change the notify_email variable to your email address.
3. Time interval: Adjust the delay_check variable to change the frequency of the checks (in seconds).

You can also completely eliminate the infinite loop and manage the interval between checks using a cronjob. Then the script would be modified as follows:

#!/bin/bash

# Website URL to track
website_url="https://yourwebsite.com"

# Email to receive notifications
notify_email="youremail@example.com"


# Function to check site uptime
check_website() {
   local status_code=$(curl -o /dev/null -s -w "%{http_code}\n" "$website_url")
   local timestamp=$(date "+%Y-%m-%d %H:%M:%S")
  
   if [ "$status_code" -ne 200 ]; then
     echo "$timestamp - $website_url down. Status code: $status_code" | mail -s "Down" "$notify_email"
   else
     echo "$timestamp - $website_url up. Status code: $status_code"
   fi
}

check_website

By then typing crontab -e, you can insert the following line:

* * * * * /bin/bash /usr/local/bin/check-website.sh > /dev/null 2>&1

Conclusion

Monitoring your website's uptime is crucial to ensuring service availability for your users. With a simple Bash script, you can automate this process and receive immediate notifications if there are any problems. This allows you to intervene quickly to resolve any downtime, improving the reliability of your website.