title: Why can't I run Docker on my Mac OSX?
body: <p>I installed Docker on my Mac OSX machine (El-Capitan) using Homebrew.</p>
  
  <p>But when I try to run it, it gives me the error shown below.</p>
  
  <pre><code>$ docker --version
  Docker version 17.06.0-ce, build 02c1d87
  
  $ docker-compose --version
  docker-compose version 1.14.0, build unknown
  
  $ docker-machine --version
  docker-machine version 0.12.2, build 9371605 
  
  $ docker ps
  Cannot connect to the Docker daemon at unix:///var/run/docker.sock. 
  Is the docker daemon running?
  </code></pre>
  
  <p>How can I fix it?</p>