title: How to set mysql username in dockerfile
body: <p>When installing mysql in ubuntu with <code>apt-get install mysql-server</code>, the mysql username and password are asked during the installation.</p>
  
  <p>But when using a dockerfile to build a mysql image, how can the username and password be provided?</p>
  
  <p>I tried using the dockerfile as follows:</p>
  
  <pre><code>FROM ubuntu:14.04
  apt-get update
  apt-get install -y mysql-server
  </code></pre>
  
  <p>But when building the image, I found out we can login in the mysql without username and password.</p>
  
  <p>How can I set the username and password when I use dockerfile to build my images?</p>