Instead of GitLab (with its slow Ruby) and unstable (SaaS), better check out Gogs: https://gogs.io
GitLab is from a YC startup, they are looking for an exit as well, just like Github!!
Gogs is "real" open source (no VC baked startup looking for a business model), coded in Golang, uses little HW resources.
(I am not related to Gogs, but I dislike the hype despite its buggy slow nature, I moved to Gogs myself.)