How to Install PHP on Debian 9

Debian 9 ships with PHP version 7.0 will soon reach end-of-life for support and no longer receive security updates.

In this tutorial, we will walk you through the steps for installing PHP 7.2 on a Debian 9 server. We will also show you how to configure Apache and Nginx to run PHP.

Prerequisites #

Before starting with this tutorial, make sure you are logged in as a user with sudo privileges .

Installing PHP 7.2 on Debian 9 #

The following steps describe how to install PHP 7.2 using the Ondrej Sury repository.

1. First, update the apt package list and install the dependencies necessary to add a new repository over HTTPS:

   sudo apt updatesudo apt install apt-transport-https ca-certificates curl software-properties-common

2. Start by importing the repository’s GPG key using the following curl command :

   curl -fsSL https://packages.sury.org/php/apt.gpg | sudo apt-key add -

   Add the ondrej’s repository to your system’s software repository list by typing:

   sudo add-apt-repository "deb https://packages.sury.org/php/ $(lsb_release -cs) main"

3. Now that we have the ondrej’s repository enabled on our system, we can install PHP by specifying the version we want to use:

   sudo apt updatesudo apt install php7.2-common php7.2-cli

4. Verify the installation, by running the following command which will print the PHP version.

   php -v

   PHP 7.2.8-1+0~20180725124257.2+stretch~1.gbp571e56 (cli) (built: Jul 25 2018 12:43:00) ( NTS )
   Copyright (c) 1997-2018 The PHP Group
   Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
       with Zend OPcache v7.2.8-1+0~20180725124257.2+stretch~1.gbp571e56, Copyright (c) 1999-2018, by Zend Technologies

Configuring Apache to run PHP #

If you are using Apache as your web server to install PHP and Apache PHP module run the following command:

sudo apt install php7.2 libapache2-mod-php

Once the packages are installed to enable the php7.2 module just restart the Apache service:

sudo systemctl restart apache2

Configuring Nginx to run PHP #

Unlike Apache, Nginx doesn’t have a built in support for processing PHP files so we need to install a separate application such as PHP FPM (“fastCGI process manager”) which will handle PHP files.

To install the PHP and PHP FPM packages run the following command:

sudo apt install php7.2-fpm

Once the packages are installed the PHP FPM service will start automatically. You can check the service status with:

systemctl status php7.2-fpm

● php7.2-fpm.service - The PHP 7.2 FastCGI Process Manager
   Loaded: loaded (/lib/systemd/system/php7.2-fpm.service; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2018-08-30 21:06:53 UTC; 1min 4s ago
     Docs: man:php-fpm7.2(8)
 Main PID: 16791 (php-fpm7.2)
   Status: "Processes active: 0, idle: 2, Requests: 0, slow: 0, Traffic: 0req/sec"
   CGroup: /system.slice/php7.2-fpm.service
           ├─16791 php-fpm: master process (/etc/php/7.2/fpm/php-fpm.conf)
           ├─16792 php-fpm: pool www
           └─16793 php-fpm: pool www

You can now edit your domain Nginx server block and add the following lines so that Nginx can process PHP files:

server {

    # . . . other code

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.2-fpm.sock;
    }
}

Restart the Nginx service so that the new configuration take effect:

sudo systemctl restart nginx

Installing PHP extensions #

We can extend the core functionality of PHP by installing additional extensions. PHP extensions are available as packages and can be easily installed with:

sudo apt install php-[extname]

For example if you want to install MySQL and GD PHP extensions you should run the following command:

sudo apt install php7.2-mysql php7.2-gd

After installing a new PHP extension do not forget to restart the Apache or the PHP FPM service, depending on your setup.

Testing PHP Processing #

To test whether your web server is configured properly for PHP processing, create a new file called info.php inside the /var/www/html directory with the following code:

<?php

phpinfo();

Save the file, open your browser of choice and visit http://your_server_ip/info.php

The phpinfo function will print information about your PHP configuration as shown on the image below:

Conclusion #

You have successfully installed PHP on your Debian 9 server and learned how to configure your web server to process PHP files.

If you have any questions or feedback, do not hesitate to leave a comment.