To expand on that topic: You can find all the Dockerfiles of the official images linked at the very top on Docker Hub [1]. Once my pull request is merged a Docker-Redis maintainer will have to open another pull request to update the references of the official image on Docker hub [2].

In fact I already updated the Redis Docker image once. You can see the full process there [3].

[1] https://hub.docker.com/_/redis/ [2] https://github.com/docker-library/official-images/pulls [3] https://github.com/docker-library/redis/pull/25