+DockerHub and GitLab.
+See https://hub.docker.com/u/gromacs and https://gitlab.com/gromacs/gromacs/container_registry
+
+GitLab Container Registry
+=========================
+
+CI Pipelines use a GitLab container registry instead of pulling from Docker Hub.
+
+Project members with role ``Developer`` or higher privilege can
+`push images <https://docs.gitlab.com/ee/user/packages/container_registry/index.html#build-and-push-images-by-using-docker-commands>`__
+to the container registry.
+
+Steps:
+
+1. Create a `personal access token <https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html>`__
+ with ``write_registry`` scope. Save the hash!
+2. Authenticate from the command line with ``docker login registry.gitlab.com -u <token name> -p <hash>``
+3. ``docker push registry.gitlab.com/gromacs/gromacs/<imagename>``