title: docker push to the registry with changed Dockerfile and same tag
body: <p>Imagine, I have docker image based on Dockerfile, I will tag &amp; push it into docker registry</p>
  
  <p>Over time, I change Dockerfile (add/change new instructions, ...)</p>
  
  <p>Now, I will tag new image again with the same tag I used in the first place and push it into docker registry</p>
  
  <ol>
  <li>How does docker registry react to new layers?</li>
  <li>How does docker registry react to changed layers?</li>
  <li>Will it overwrite existing image with the latest version?</li>
  <li>Should I use different tag to make sure I have correct new image in place?</li>
  </ol>