title: Unable to execute docker command while docker is running
body: <p>I am trying to run the following docker commmand:</p>
  
  <pre><code>docker run --name my_postgres -d -p 127.0.0.1:5432:5432 -v /volumes/data:/var/lib/postgresql/data postgres
  </code></pre>
  
  <p>But I receive the following error:</p>
  
  <pre><code>2015/09/15 20:57:57 Cannot connect to the Docker daemon. Is 'docker -d' running on this host?
  </code></pre>
  
  <p>This is odd since I have docker up and running on my computer:</p>
  
  <pre><code>~  ps aux | grep docker
  root     31083  0.1  0.0 355636 15420 ?        Ssl  20:58   0:00 /usr/bin/docker.io -d
  </code></pre>