A Dockerfile which creates a ARM docker container similar to the library/ruby container on Docker Hub (https://registry.hub.docker.com/u/library/ruby/).
The image for this is available on Docker Hub: https://registry.hub.docker.com/u/aggronerd/rpi-ruby/
After you have installed Docker on your Raspberry Pi clone this repo and run:
docker build .
You can overwrite the environmental vales in the Dockerfile to download and build different versions of Ruby.