title: How can I detect if there's a new docker image without using docker pull?
body: <p>I want to pull and restart a docker service everyday at the same time but only if there's a new image available. Is there a docker command that returns true where I can run my update service?</p>
  
  <p>Eg something like</p>
  
  <pre><code>docker new-update-available myname/myimage &amp;&amp; ./myupdateandrestart.sh
  </code></pre>