title: Docker: how to create an image with storing some login credentials
body: <p>I have a base image of archlinux - archlinux/base</p>
  
  <p>Now using this image i want to create another image where i want that image to store some login credentials</p>
  
  <p>I have program called <code>sampleprogram</code>. It needs to get logged in. So first step to use this program is to login.</p>
  
  <pre><code>$ sampleprogram login
  </code></pre>
  
  <p>-- it asks for username and password</p>
  
  <p>From next time onwards i dont have to login and start from the second step.</p>
  
  <pre><code>$ sampleprogram connect
  </code></pre>
  
  <p>will connect using the login credetials entered previously.</p>
  
  <p>So I am trying to create an image with sampleprgram login is saved</p>
  
  <p>Dockerfile:</p>
  
  <pre><code>FROM archlinux/base
  RUN pacman -Syy &amp;&amp; pacman -S sampleprogram
  RUN samplepgrogram login (ofcourse i will be using a script with expect)
  
  
  docker build -t archlinux/sampleprogram .
  </code></pre>
  
  <p>Once the image is made (eg: arclinux/sampleprogram)</p>
  
  <p>then i want to use:</p>
  
  <pre><code>docker run -it archlinux/sampleprogram sampleprogram connect
  </code></pre>
  
  <p>Once this container is running, i will be connecting to this container from another container using --link etc to do some tasks.</p>