php-fpm container livenessProbe with /ping route
If someone is still interested in this topic. I was looking into a sort of the same thing (php-fpm monitoring in combination with pods running in kubernetes).
I added the following health-check setup https://github.com/renatomefi/php-fpm-healthcheck to my container (the one running php-fpm) for checking if php-fpm is playing along nicely :) works pretty simple and gets the job done (marking the the container as "bad" when some of the values are getting out of your predefined limits)