cachetool PHP cache clear fails with mod_php

[gregharvey]

From @mig5 (with regard to Apache opcache clearing)...

We should just revert to the old behaviour of reloading Apache.

https://ma.ttias.be/how-to-clear-php-opcache/

$ service httpd reload
$ apachectl graceful

A reload should be sufficient as it will clear the Opcache in PHP. A restart will also work, but is more invasive as it kills all active HTTP connections.

There doesn't appear to be a way to interact with mod_php from cachetool, it's for FPM/FCGI setups.

[gregharvey]

Emlyn's looking at this with another ticket anyway. We were just saying instead of assuming PHP version we can simply have this logic:

if /usr/local/bin/cachetool exists use it;
else do a soft reload of the web server as above (we can assume Apache and mod_php if cachetool doesn't exist)