Once configured and restarting successfully on Apache. just it is not sure where you need serve from, so it's choosing your localhost (127.0.0.1) by default. To avoid this message, that you want to serve from localhost (127.0.0.1), just the below line in Apache configure file.
* Restarting web server apache2
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 172.30.1.16. Set the 'ServerName' directive globally to suppress this message [ OK ]
Open the configure file and appand a line,
# vim /etc/apache2/apache2.conf
Finally, restart the Apache service.
# service apache2 restart