Basic HTTP authentication is one simple way to limit public access to your website prior to launch.
The first thing you need is .htaccess file which contains all the configurations. The second one is .htpasswd containing username and password. You can use this website to generate .htpasswd file for you http://www.htaccesstools.com/htpasswd-generator/
In the sample below, I am trying to enable HTTP authentication only on certain domain. On the first line, I set enviroment variable if the domain name is equal to “www.bundabergfestival.com.au”. On line 7, I tell .htaccess file to deny any access by using the live_uri variable. I hope that explanation is pretty straight forward.