title: How are official ruby images for Docker hub created?
body: <p>How are official ruby images on Docker hub created? And what specifically are installed inside?</p>
  
  <p>Are they just a <code>docker build</code> results of one of these files in official github repo <a href="https://github.com/docker-library/ruby" rel="nofollow noreferrer">https://github.com/docker-library/ruby</a> ?</p>