Installing Apache2 and PHP

Basically, we only need to install 2-4 packages to run basic PHP websites. First, let's install the web server:

sudo apt install apache2

This is followed by PHP. The Mbstring extension is not mandatory, but is required for various applications such as WordPress. PHP-MySQL just like that, this extension allows you to connect to MySQL databases.

sudo apt install php php-mysql php-mbstring 

Meanwhile, the MySQL extension is loaded automatically. If this does not work for you, restart the Apache web server once:

sudo systemctl restart apache2 

Set permissions and create a test page

By default, Apache serves all files in the /var/www/html folder. However, this belongs to root, i.e. we can only create or edit files there if we use e.g. sudo - this is (unnecessarily) bad practice and should be changed. Our user with whom we want to work on the site (here pi) receives full rights. The group www-data running Apache2 is allowed to read + execute. Everyone else doesn't get any permissions - which makes sense if we're only working with one user.

sudo chown -R pi:www-data -R /var/www/html

chmod 750 -R /var/www/html 

Now we can easily create and edit files with our pi user. As a first test, we create a PHP file called i.php (freely selectable) and display the PHP info. This is a PHP-generated page that displays all relevant information about the PHP configuration - including the version or the installed extensions. So on a fresh install it's a good first test to make sure everything is working as intended:

echo '<?php phpinfo();' > /var/www/html/i.php 

Now we can access this page by IP address or hostname followed by /i.php, for example http://testpi/i.php