Support configuration properties available as env vars in Docker about docker-flink

[patricklucas]

This is something we've considered, but I would greatly prefer anything like this to be supported by Flink upstream first, instead of implementing it as an additional configuration method by the Docker images alone.

Flink already has some fragmentation with respect to how it's configured, and I'm trying hard not to have the Docker images contribute to it. You might consider searching for/opening a ticket on Apache Flink JIRA or starting a discussion on the user mailing list.

[hustclf]

Thanks for your detailed answer and your advice. :)