This docker file will create a virtual printer in cupsd that will output to /mnt/output. This will allow printing from a network postcript printer that will output a pdf to a volume or mount. You can change the output path in cups-pdf.conf. One possible use of this is in conjunction with a paperless-ngx consume directory to read pdf's.

In order to make the printer discoverable, avahi needs to be set up. For it to work correctly on the network, it should share the network space with its own IP.

Looks like another case of ripping the container apart to see how to do it right. I mean, come on. It's mDNS. You don't need a static IP address for it (you don't need it in DNS at all), you just have to drop a .service file into the right place (that would be vprint.service).