title: Docker Busybox container add groups and user
body: <p>I need users in my docker containers. My build is from the busybox image which is missing groupadd, I tried to add it using apt-get but that's also missing. What do I need to add to my Dockerfile to get groupadd?</p>
  
  <p>So far I have</p>
  
  <pre><code>FROM busybox
  RUN apt-get install bash
  RUN groupadd -r postgres &amp;&amp; useradd -r -g postgres postgres
  CMD /bin/sh
  </code></pre>