Install PHP and extensions for deploying a Laravel web application

(This is part of a larger guide to deploying a Laravel and Vue.js web application.)

This article covers the installation of PHP (the language on top of which Laravel is built) and the PHP extensions needed for Laravel to run.

Install PHP and PHP extensions

First install PHP:

# Install the latest packaged version of PHP
laravel@server$ sudo apt install php

# (If you know what you're doing and have a good reason do so, you can install
# a specific version of PHP with e.g. `apt install php8.2` for PHP 8.2)

Then install the list of PHP extensions required by Laravel. At the time of writing on a Debian-based system, do this with:

# Install PHP extensions required for Laravel to run.
# As far as I can tell, php-fpm is not listed in the Laravel docs but is still
# required for Laravel to run.
laravel@server$ sudo apt install php-curl php-mbstring php-xml php-fpm

Ensure your PHP version matches the version of your PHP extensions. You only need to worry about this if you explicitly installed a specific version of PHP (e.g. if you explicitly install php8.2, then explicitly install php8.2-curl, php8.2-fpm, etc.).

You’ll also need a PHP extension for your database management system. This depends on your choice of MySQL/MariaDB, SQLite, or PostgreSQL:

# If using MySQL/MariaDB
laravel@server$ sudo apt install php-mysql

# If using SQLite
laravel@server$ sudo apt install php-sqlite3

# If PostgreSQL
laravel@server$ sudo apt install php-pgsql

At this point you can move on to the next article. But if you’re curious here’s a bit more on PHP extensions.

On an Ubuntu 22.10 Digital Ocean droplet at the time of writing…

  1. The following extensions are enabled by default according to php --ini (i.e. you do not have to explicitly install them, and they are not available as dedicated packages from APT):

    • Ctype PHP Extension
    • Fileinfo PHP Extension
    • PDO PHP Extension
    • Tokenizer PHP Extension
  2. The following extensions are installed with apt:

    • cURL PHP Extension php-curl
    • Mbstring PHP Extension php-mbstring
    • XML PHP Extension php-xml
    • DOM PHP Extension (comes with php-xml)
    • FPM PHP Extension php-fpm
    • MySQL php-mysql, PostgreSQL php-psql, or SQLite php-sqlite3 PHP Extensions, depending on your DBMS (not listed in the Laravel docs at the time of writing, but required for PHP to interact with your database)
  3. And the following PHP extensions are suggested in the Laravel docs, but I didn’t find packages for them and didn’t run into any errors without them (perhaps I am missing something, please shoot me an email if you know more!):

    • Filter PHP Extension
    • Hash PHP Extension
    • OpenSSL PHP Extension (do double check you have the openssl package installed though; it should ship by default with Ubuntu)
    • PCRE PHP Extension
    • Session PHP Extension
Which PHP extensions am I currently using? Which are available?

Here’s how to list all PHP extensions available from APT:

# Show all PHP extensions available from apt.
# (Replace 8.1 with your PHP version if necessary (check with `php --version`)).
apt list | grep ^php8.1

Here’s how to list all PHP extensions you have installed:

# Show install PHP extensions 
apt list | grep ^php8.1.*installed

And here is how you can check which extensions are being used by PHP:

# This technically lists the configuration files used by PHP in command line
# mode, but can be used in practice to see which extensions PHP is loading.
php --ini

An example php --ini output after a fresh install of PHP on Ubuntu 22.10 looks like this:

/etc/php/8.1/cli/conf.d/10-pdo.ini,
/etc/php/8.1/cli/conf.d/20-calendar.ini,
/etc/php/8.1/cli/conf.d/20-ctype.ini,
/etc/php/8.1/cli/conf.d/20-exif.ini,
/etc/php/8.1/cli/conf.d/20-ffi.ini,
/etc/php/8.1/cli/conf.d/20-fileinfo.ini,
/etc/php/8.1/cli/conf.d/20-ftp.ini,
/etc/php/8.1/cli/conf.d/20-gettext.ini,
/etc/php/8.1/cli/conf.d/20-iconv.ini,
/etc/php/8.1/cli/conf.d/20-phar.ini,
/etc/php/8.1/cli/conf.d/20-posix.ini,
/etc/php/8.1/cli/conf.d/20-readline.ini,
/etc/php/8.1/cli/conf.d/20-shmop.ini,
/etc/php/8.1/cli/conf.d/20-sockets.ini,
/etc/php/8.1/cli/conf.d/20-sysvmsg.ini,
/etc/php/8.1/cli/conf.d/20-sysvsem.ini,
/etc/php/8.1/cli/conf.d/20-sysvshm.ini,
/etc/php/8.1/cli/conf.d/20-tokenizer.ini

How to interpret: the above php --ini output tells us that the PDO, Calendar, Ctype, Exif, FFI, Fileinfo, etc. PHP extensions are already installed and being used by PHP.

Caution: there are some subtleties with php --ini, for example after installing the XML extension, php --ini shows the conf files 20-xmlreader.ini and 20-xmlwriter.ini instead of 20-xml.ini, and the FPM extension does not have an entry at all (you enable FPM from your web server config; which we’ll do in the article on Nginx configuration)!

Next: The next article covers the installation and basic set up a database management system.

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