This is a simple PHP script that can be installed as a CRON job to send notifiction every time Apache is down and send notification to your email. It should work on Debian-like distros (Ubuntu, Mint etc.)

The script can be easily adjusted to any service and any linux.

$ composer install

$ cp .env.example .env
$ nano .env

$ php index.php

First, find out which PHP you are using

$ which php
// ie. /usr/bin/php

Then add a CRON job

$ crontab -e

Add line to run every 5 minutes

*/5 * * * * /usr/bin/php /path_to_apache-monitor/index.php > /dev/null 2>&1
# For debugging:
# */1 * * * * /usr/bin/php /path_to_apache-monitor/index.php >> /path_to_apache-monitor/log.txt