GitLab is a Ruby based web application that manages Git repositories combined with issue tracking, wiki and other team/collaborative functions. It's a "GitHub at home".
GitLab at FreshPorts
Please consult the first installation guide.
After each upgrade of minor version (eg. 8.11.x to 8.11.y) please consult the Update guide for patch versions
After upgrade of a major version (eg. 8.11 to 8.12) please consult the Major GitLab upgrade guide