AH00558: apache2: Could not reliably determine the server’s fully qualified domain name, using ::1. Set the ‘ServerName’ directive globally to suppress this message
This error isn’t a show stopper but can be a problem. This can normally mean the apache software wasn’t configured yet. It is a simple fix that only requires you to edit the configuration file.
Locate the configuration file for apache, you can type whereis apache2 to find some directories dealing with apache. It is more than likely located in the /etc/apache2 directory.
Open the configuration file and add the following line:
sudo service apache2 restart