A copy of https://github.com/docker-library/ruby/blob/master/2.2/Dockerfile that uses Ubuntu Trusty as the base image, installs ruby via ruby-build, includes a recent version of node.js, and sets the locale to en_US.UTF-8.
This project is in the worldwide public domain. As stated in CONTRIBUTING:
This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.
All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.