title: How to run docker images in google-colaboratory?
body: <p>How to run docker images in google-colaboratory ?
  I tried to install docker service in google-colaboratory.</p>
  
  <p>However, I got the error message about " 
  Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?", when I executed the docker's commands.</p>
  
  <p><a href="https://i.stack.imgur.com/URNQ7.png" rel="noreferrer">screen-snap</a></p>
  
  <p>I wonder How to solve this problem?</p>
  
  <p>THX</p>