Firewall single Docker Container?

Hi,

is is possible to put a single Container behind some kind of firewall? I want to forbid all outgoing connections except like 2 or 3 websites. Is this possible? Does an Docker Image exist which could make that possible.
Iam running Docker on an QNAP NAS so it should be another Docker Image.

Thanks in advance.

So, its a no i guess? :frowning: