MongoDB (v2.6.4) dockerfile
For the simplest case, a standalone MongoDB server, you should only need to run the docker image. It will automatically create a VOLUME in which to store the database.
You may, alternatively, bind-mount your own volume to /data or specify the database path to use with the environment variable DBPATH.
For anything more complicated, including shard, configuration, and webstatus servers, pass the full commandlines through as the docker command.