title: Does docker push pus all layers if the tag is GIT_COMMIT_HASH instead of string "latest"?
body: <p>I would like to make sure that I use docker tags correctly and avoid resending entire image to AWS ECR from my local VM.</p>
  <p>I would also like the ability to have different images for different commits of my repo. this way I can rollback to an older image from older commit very easily.</p>
  <p>However, I'm concerned that docker push with the commit_id as tag will re-send entire image and make it very slow.</p>
  <p>Any help on docker image tagging best practices and above use case will help</p>