The manual release feature is great! I was just pondering on how to do that. For anyone wondering where to start with Gitlab CI I wrote a short post about our very simple but still very useful CI setup: https://pilloxa.gitlab.io/posts/ci-with-gitlab-and-docker/
Glad to hear you like it. Thanks for your post. BTW now that we have the container registry you no longer need to create an account at Dockerhub I think.