Monitor script for php-fpm on GCE.

Inspired by the munin plugin.
It enables you to see charts for active/idle processes of the fpm pool. This script is a porting it to the monitoring panel on Google Cloud Console.

Usage:

1. Make a copy config-example.php as config.php and edit it to point the correct location of php-fpm status URL.
2. Run script with your credential json file as an env like:
   > GOOGLE_APPLICATION_CREDENTIALS=/path/to/my-google-service.json php ./main.php
3. Check the Monitoring section on Google Cloud Console. php_fpm entries can be found at Metric Explorer > Global > Custom Metrics.
4. Register it as a cron or systemd-timer script, to run every 5 minutes.