How to activate / install PHP

Hi, i have a standard openhab 1.8.1 installation on a raspberry. I want to use some PHP based admin tools. How can i activate the openhab Jetty server to enable PHP?

Searched a bit around in the forum, see others having the same idea, but could not find a easy to understand guideline

Hi, i did not find a solution, however, its quite simple to run apache2 and php5 in parallel.

What i however find not nice, i have an other webserver (apache2) running. Would prefer enabling PHP5 on the openhab jetty server. Maybe someone of you had the same need and a much better solution then mine.