I have read a lot of articles/blogs as well as completed the https://lab.github.com/githubtraining/github-actions:-continuous-delivery-with-aws course and I am confused about docker image promotion from staging environment to production environment.
From what I can tell, people are generally rebuilding the docker image between the different environments, and thus technically deploying different artificats between staging and production. Normally, I would think that a docker image should be created and then deployed to a staging environment, and then that same image is then promoted/deployed to the production environment. That way it is known that the images are truly the same.
Is this something that is encouraged to be done using GitHub Actions? Is there a way to promote/deploy an already existing image to a production environment?