These are the instalation steps for GitLab Community Edition, the recommended way to install GitLab is with the Omnibus packages. I follow these steps as described at gitlab website.

Install and configure the necessary dependencies

    ~$ sudo apt-get update
    ~$ apt-get install curl openssh-server ca-certificates postfix

Add the GitLab package server and install the package

    ~$ curl -sS | sudo bash
    ~$ sudo apt-get install gitlab-ce

Configure and start GitLab

~$ sudo gitlab-ctl reconfigure

Browse to the hostname and login

Username: root
Password: 5iveL!fe

After installation, you can do some maintenance commands as described here gitlab maintenance

Get service status

    ~$ sudo gitlab-ctl status; 

        the output should look like this:

        run: nginx: (pid 972) 7s; run: log: (pid 971) 7s
        run: postgresql: (pid 962) 7s; run: log: (pid 959) 7s
        run: redis: (pid 964) 7s; run: log: (pid 963) 7s
        run: sidekiq: (pid 967) 7s; run: log: (pid 966) 7s
        run: unicorn: (pid 961) 7s; run: log: (pid 960) 7s

Tail process logs as described here in gitlab logs

Tail all logs; press Ctrl-C to exit

~$ sudo gitlab-ctl tail

Drill down to a sub-directory of /var/log/gitlab

~$ sudo gitlab-ctl tail gitlab-rails

Drill down to an individual file

~$ sudo gitlab-ctl tail nginx/gitlab_error.log

Starting and stopping

Start all GitLab components

~$ sudo gitlab-ctl start

Stop all GitLab components

~$ sudo gitlab-ctl stop

Restart all GitLab components

~$ sudo gitlab-ctl restart