I watched the videos on setting it up that Bryan linked, and set up a Docker Compose configuration here:
https://github.com/MikeThomsen/nifi-docker-compose It's the docker-compose-registry.yml file. Uses NiFi 1.6.0 and Registry 0.1. On the SSL and docker networking side, the two can clearly communicate without handshaking issues, etc. Even when I set up the registry to allow demo.nifi to proxy a user, it still didn't appear to work. Can someone take a look so I can update and tell me if I'm doing something obviously wrong? All of the certs are in for_registry in that project. Thanks, Mike
