Couldn't connect to Docker daemon on Mac OS X
<p>I would like to run multi-container application using <code>docker-compose</code> on Mac OS X El Capitan (v10.11.2).</p>

<p>However, the command <code>$ docker-compose up</code> command complains that it can't connect to the Docker daemon.</p>

<blockquote>
  <p>ERROR: Couldn't connect to Docker daemon - you might need to run <code>docker-machine start default</code>.</p>
</blockquote>

<p>Only after executing <code>$ eval "$(docker-machine env default)"</code> I do have access to the <code>docker-compose</code> command.</p>

<p>Why is this and how can I overcome this extra step?</p>