A minimal ubuntu based Docker container with JRuby and Bundler installed.
Version tags are based off the installed JRuby version
NOTE: Make sure you grab and build the docker-java base image or change the base image to one that includes java!
Edit the Dockerfile to use the version of JRuby you need.
Build the container, and tag it with the JRuby version.
$ docker build -t='yourname/jruby:_version_'
Set up your Dockerfile to use this image
# in your Dockerfile
FROM yourname/jruby:_version_
...
Then build away!