I have a set of services running in Docker containers and are all behind a reverse proxy. Some of those need to contact other non Docker services hosted on different machines.
At the moment, Docker services are configured with the direct url to external services and this implies that each container must know the IP address of the hostname contained in the url.
My question is: could be reasonable to replace the urls with one pointing to the reverse proxy and centralize in its configuration the knowledge of all hostname-IP associations?
In general, my doubt is whether a service behind a reverse proxy should "go outside" with a direct link or delegating to its proxy the address resolution: whether a reverse proxy should also handle connection from its backends to outside and not only from outside to backends.