title: Tagging docker image with tag from git repository
body: <p>I am using Gitlab for repository and ci/cd.
  Currently trying to set up pipeline that creates a docker image from a build stage.
  All examples I have seen have a simple naming of image where e.g. the branch is used(master)</p>
  
  <p>My question is if I want to tag the image based on the current tag in the repository how do I do this?
  I am presuming I can use a Gitlab runner variable but do not see one to us</p>