How to: Push to the registry
- run: | 
   docker tag IMAGE_NAME:slim-{{github.run_number}} ${{ secrets.DOCKERHUB_USERNAME }}/IMAGE_NAME:slim-{{github.run_number}}
   docker push ${{ secrets.DOCKERHUB_USERNAME }}/IMAGE_NAME:slim-{{github.run_number}}
```
The workflow above indicates four steps:
- A [Docker Build/Push Github Action](https://github.com/docker/build-push-action) for building a docker image with the image name/tag--IMAGE_NAME:{{github.run_number}}, you should give replace IMAGE_NAME with your desired image name. Note that this Action must have a false option to push the built image--given that you need the image slimmed/minified before pushing it to a container registry. 
- A Docker-Slim Github Action which minifies the target image--IMAGE_NAME:{{github.run_number}}, this Action has the "slim-{{github.run_number}}" tag and adds this tag to the slimmed/minified docker image such that the image name/tag becomes IMAGE_NAME:slim-{{github.run_number}}.
- A Docker Login Github Action which logs into your DockerHub container regristry account, you should store your DockerHub username and personal access token as secrets in the github repository meant for the workflow. Suppose your container registry is not DockerHub, you can check the [Docker Login Github Action documentation](https://github.com/docker/login-action) for the use case of logging into your desired container registry. 
- A docker tag command for naming/tagging the slimmed image with your DockerHub account remote repository name which could be the same name(IMAGE_NAME) as the slimmed image; A docker push command to push the slimmed image to your Dockerhub account remote repository.