@sivy I haven't done it myself, but I found these instructions and it looks like an absolute SLOG that breaks the best part of a functioning letsencrypt installation: automatic updates by cron.
https://about.gitlab.com/2016/04/11/tutorial-securing-your-gitlab-pages-with-tls-and-letsencrypt/
@stylus Yeah, that's what I've been using. The Jekyll build is just not working. I know I've done it before (which is why I'm doing this at all - my cert expired earlier this year)