Install Gitlab on Debian/Ubuntu

Install requirements

echo "postfix postfix/main_mailer_type string 'Internet Site'" | debconf-set-selections
echo "postfix postfix/mailname string localhost" | debconf-set-selections
curl -Ls https://packages.gitlab.com/gpg.key | apt-key add -
apt-get update
apt-get --force-yes -y upgrade
apt-get clean

Setup repo/dependency

wget https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh
bash script.deb.sh

Install gitlab

apt-get install -y gitlab-ce