Make the www-gitlab-com image smaller
For the website, the main packages we need are Ruby, LaTeX and pandoc. I see it installs mysql and postgres so we could strip it down. Possibly there are other packages that we can remove.
A good base image would be https://github.com/phusion/baseimage-docker.
Alpine would also be an alternative. The thing is LaTeX and pandoc are not packaged for Alpine and pandoc is the beast here. See my findings in this snippet https://gitlab.com/snippets/25724.