Install self-managed GitLab Server

1. Install and configure the necessary dependencies

sudo apt-get update
sudo apt-get install -y curl openssh-server ca-certificates tzdata perl

Next, install Postfix (or Sendmail) to send notification emails. If you want to use another solution to send emails please skip this step and configure an external SMTP server after GitLab has been installed.

sudo apt-get install -y postfix

sudo apt-get update

cd /tmp

curl -LO https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh

sudo bash /tmp/script.deb.sh

sudo apt-get install gitlab-ce

Download gitlab https://packages.gitlab.com/gitlab/gitlab-ce/

wget --content-disposition https://packages.gitlab.com/gitlab/gitlab-ce/packages/ubuntu/bionic/gitlab-ce_12.10.1
or particular version 

sudo apt-get install gitlab-ce=11.11.0-ce.0