title: How to scale Docker containers in production
body: <p>So I recently discovered this awesome tool, and it says </p>
  
  <blockquote>
    <p>Docker is an open-source project to easily create lightweight,
    portable, self-sufficient containers from any application. The same
    container that a developer builds and tests on a laptop can run at
    scale, in production, on VMs, bare metal, OpenStack clusters, public
    clouds and more.</p>
  </blockquote>
  
  <p>Let's say I have a docker image which runs Nginx and a website connects to external database. How do I scale the container in production?</p>