Docker machinery

Trellis/Cassandra provides Docker images for use. Build them with mvn -Pdocker install.

In some containerized deployments, you may receive an error like java.net.SocketException: Protocol family unavailable, which indicates that the appplication is trying to bind to an IPv6 port. You can prevent this if needed by adding

-Djava.net.preferIPv4Stack=true

to your invocation.