Once you’ve made changes to your application and want to make them available to your users, you typically push an image to DTR, or have a CI/CD pipeline that does it for you. A team responsible for QA will notice you’ve pushed a new image, run tests, and if the image is working as expected, they’ll promote it to production.

As an example, you push the image to docker/website-dev:3-stable, the QA team will pull and test it, and push it as docker/website-prod:latest

DTR allows you to automate this. If the image you pushed to DTR meets certain criteria, like it has a specific name, and doesn’t have any vulnerabilities, the image is automatically promoted. You can combine multiple promotion criteria, and chain promotion rules, to build complex deployment pipelines.