Install GitLab 8 on Ubuntu Server 16.04

sudo apt-get update
sudo apt-get install curl openssh-server ca-certificates postfix
curl -sS https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sudo bash
sudo apt-get install gitlab-ce
sudo gitlab-ctl reconfigure
sudo gitlab-ctl pg-upgrade

Open GitLab by web browser
http://localhost:8080
username is root
password is 5iveL!f