title: How to build docker image from github repository
body: <p>In official docs we can see:</p>
  
  <pre><code># docker build github.com/creack/docker-firefox
  </code></pre>
  
  <p>It just works fine to me. <code>docker-firefox</code> is a repository and has <code>Dockerfile</code> within root dir.<br>
  Then I want to buid redis image and exact version 2.8.10 :</p>
  
  <pre><code># docker build github.com/docker-library/redis/tree/99c172e82ed81af441e13dd48dda2729e19493bc/2.8.10
  2014/11/05 16:20:32 Error trying to use git: exit status 128 (Initialized empty Git repository in /tmp/docker-build-git067001920/.git/
  error: The requested URL returned error: 403 while accessing https://github.com/docker-library/redis/tree/99c172e82ed81af441e13dd48dda2729e19493bc/2.8.10/info/refs
  
  fatal: HTTP request failed
  )
  </code></pre>
  
  <p>I got error above. What's the right format with build docker image from github repos?</p>