Install GitLab on existing Apache2 web server

First, setup a domain to point to the server such as gitlab.example.com.

Second, follow the procedure at https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/install/installation.md till the end of Step 6. Do not proceed with 7 to install Nginx.

If you are using MySQL, remember to setup mysql database.

Third, configure apache2

Enable proxy_http
```
sudo a2enmod proxy_http
```

Create gitlab.conf with the following

<VirtualHost *:80>
        ServerName gitlab.example.com
        #git lab passthrough
        ProxyPass         / http://localhost:8080/
        ProxyPassReverse  / http://localhost:8080/
</VirtualHost>

Start apache2

sudo a2ensite gitlab.conf
sudo service apache2 reload

Configure sending emails through smtp. Add the following to /home/git/gitlab/config/environments

config.action_mailer.delivery_method = :smtp
config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = true

config.action_mailer.smtp_settings = {
  :address              => "smtp.gmail.com",
  :port                 => 587,
  :domain               => 'gmail.com',
  :user_name            => 'account@gmail.com',
  :password             => 'password',
  :authentication       =>  :plain,
  :enable_starttls_auto => true
}