Sometimes when we start or restart Apache2, we get the following error in the terminal:
Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName
Which means:
The correct domain name for the server could not be determined, 127.0.0.1 will be used as ServerName
To solve it we simply must execute the following command:
echo "ServerName localhost" >> /etc/apache2/conf.d/fqdn
The above command must be executed with administrative privileges, either using the account of root or putting at the beginning of the command sudo
This will be enough to solve the problem, from now on when they start or restart Apache2 they will no longer show that error.
regards