I am hoping what I need already exists, if not, I am willing to try building it.  But I figured it would be better to ask here first.   I am looking for a docker that simply runs Java, you supply it a command via the variables and it executes that at startup.  Specifically I am trying to setup running a minecraft mod server in a docker container.  But it would be super nice to have java in the docker, and everything else is mapped.   That way I can supply a command like "-Xmx2048M