Docker and php-fpm: why is it recommended not to forward ip?

Question

PHP

The official php images docker page for php-fpm images says:

WARNING: the FastCGI protocol is inherently trusting, and thus extremely insecure to expose outside of a private container network -- unless you know exactly what you are doing (and are willing to accept the extreme risk), do not use Docker's --publish (-p) flag with this image variant.

What is it connected with? What problems can there be?

Answer 1

The most important thing is not to put the php-fpm port out on the Internet so that no one launches any malware on it. If the port sticks out of
the docker and is covered from the outside by a firewall, then you know exactly what you are doing (and are willing to accept the extreme risk)
it doesn’t matter who rnr, database or some other service sticks out - it’s enough to believe that those who want to hack it