It turns out that the latest flink:latest docker image is 5 days old, and
thus bug was fixed 4 days ago in the flink-docker github.
The problem is that the docker-entrypoint.sh script chains to jobmanager.sh
by saying "start-foreground cluster" where the "cluster" argument is
obsolete as of Flink
I'm using the standard Kubernetes deploy configs for jobmanager and
taskmanager deployments, and jobmanager service.
However, when the task managers start up, they try to register with the job
manager over Akka on port 6123.
This fails, because the Akka on the jobmanager discards those messages as
