Use the following command to start your GitLab instance:

sudo service gitlab start

Or use the following command:

sudo /etc/init.d/gitlab restart

If successful, you should see output similar to the following when retrieving the status:

root@93d7eb73dce6:/home/git/gitlab# sudo service gitlab status
Starting GitLab Unicorn
Starting GitLab Sidekiq
Starting GitLab Workhorse
Gitaly is already running with pid 2877, not restarting
The GitLab Unicorn web server with pid 5240 is running.
The GitLab Sidekiq job dispatcher with pid 5312 is running.
The GitLab Workhorse with pid 5290 is running.
Gitaly with pid 2877 is running.
GitLab and all its components are up and running.

The main application is running, so now, we need to put NGINX in front as a reverse proxy.