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System Administration📅 July 20, 2021⏱️ 9 minutes min read

How to Install PHP 8 on Ubuntu, CentOS/RHEL, and AlmaLinux

Comprehensive guide to installing PHP 8 on multiple Linux distributions including Ubuntu, CentOS, RHEL, and AlmaLinux. Learn to configure PHP 8 with Apache and Nginx web servers for optimal performance.

👤 Author: Linux-ID Team
How to Install PHP 8 on Ubuntu, CentOS/RHEL, and AlmaLinux

What is PHP?

PHP (PHP: Hypertext Preprocessor) is a popular open-source server-side scripting language designed for web development. PHP 8, released in November 2020, introduced significant performance improvements and new features that make it an excellent choice for modern web applications.

Major content management systems and frameworks like WordPress, Magento, Laravel, CodeIgniter, and many others are built with PHP, making it essential for web developers and system administrators.

This comprehensive guide covers how to install PHP 8 on multiple Linux distributions including Ubuntu, CentOS/RHEL, and AlmaLinux, along with configuration for both Apache and Nginx web servers.

PHP 8 Features and Benefits

Key Features in PHP 8

  • Just-In-Time (JIT) Compilation - Significant performance improvements
  • Named Arguments - Better code readability and flexibility
  • Attributes - Native annotation support
  • Union Types - Enhanced type safety
  • Match Expression - Modern alternative to switch statements
  • Nullsafe Operator - Safer null handling
  • Constructor Property Promotion - Cleaner class definitions

Performance Benefits

  • Up to 3x faster execution compared to PHP 7.4
  • Reduced memory usage for better server efficiency
  • Improved error handling with better debugging capabilities
  • Enhanced security features for safer web applications

Installing PHP 8 on Ubuntu

Ubuntu 22.04 and 24.04

Ubuntu's default repositories may not include the latest PHP 8 versions. We'll use Ondřej Surý's PPA repository for the most up-to-date packages.

Step 1: Update System Packages

bash 
sudo apt update && sudo apt upgrade -y

Step 2: Install Required Dependencies

bash 
sudo apt install -y software-properties-common apt-transport-https ca-certificates

Step 3: Add Ondřej Surý's PHP PPA

bash 
sudo add-apt-repository ppa:ondrej/php
sudo apt update

Step 4: Install PHP 8.4 (Latest Version)

For Apache:

bash 
sudo apt install -y php8.4 php8.4-cli php8.4-common libapache2-mod-php8.4

For Nginx (using PHP-FPM):

bash 
sudo apt install -y php8.4 php8.4-cli php8.4-fpm php8.4-common

Step 5: Install Essential PHP Extensions

bash 
sudo apt install -y php8.4-{curl,gd,mbstring,mysql,xml,zip,intl,bcmath,opcache,json,bz2}

Ubuntu 20.04 LTS

For Ubuntu 20.04, follow the same steps but note that some packages may have different availability.

bash 
# Same steps as above
sudo add-apt-repository ppa:ondrej/php
sudo apt update
sudo apt install -y php8.4 php8.4-cli php8.4-fpm php8.4-common

Installing PHP 8 on CentOS/RHEL

Prerequisites for RHEL-based Systems

Before installing PHP 8 on CentOS, RHEL, or AlmaLinux, ensure your system is updated and has the necessary repositories.

Step 1: Update System

bash 
sudo dnf update -y
# or for older systems:
# sudo yum update -y

Step 2: Install EPEL and Remi Repositories

For CentOS/RHEL 8 and 9:

bash 
# Install EPEL repository
sudo dnf install -y epel-release

# Install Remi repository
sudo dnf install -y https://rpms.remirepo.net/enterprise/remi-release-$(rpm -E %rhel).rpm

For older CentOS 7:

bash 
sudo yum install -y epel-release
sudo yum install -y https://rpms.remirepo.net/enterprise/remi-release-7.rpm

Step 3: Install Yum/DNF Utilities

bash 
sudo dnf install -y dnf-utils
# or for CentOS 7:
# sudo yum install -y yum-utils

Step 4: Enable PHP 8.4 Module

For CentOS/RHEL 8+:

bash 
# Reset PHP module
sudo dnf module reset php -y

# Enable PHP 8.4 from Remi repository
sudo dnf module enable php:remi-8.4 -y

Step 5: Install PHP 8.4

bash 
sudo dnf install -y php php-cli php-fpm php-common

Step 6: Install PHP Extensions

bash 
sudo dnf install -y php-{curl,gd,mbstring,mysql,xml,zip,intl,bcmath,opcache,json,bz2}

Installing PHP 8 on AlmaLinux

AlmaLinux follows the same process as CentOS/RHEL since it's a RHEL-compatible distribution.

AlmaLinux 8 and 9

Step 1: Update System

bash 
sudo dnf update -y

Step 2: Add Required Repositories

bash 
# Install EPEL
sudo dnf install -y epel-release

# Install Remi repository for AlmaLinux
sudo dnf install -y https://rpms.remirepo.net/enterprise/remi-release-$(rpm -E %rhel).rpm

Step 3: Configure PHP Module

bash 
sudo dnf module list php
sudo dnf module reset php -y
sudo dnf module enable php:remi-8.4 -y

Step 4: Install PHP 8.4

bash 
sudo dnf install -y php php-cli php-fpm php-common
sudo dnf install -y php-{curl,gd,mbstring,mysql,xml,zip,intl,bcmath,opcache}

Configuring PHP 8 with Web Servers

Apache Configuration

Enable PHP Module (Ubuntu)

bash 
# Enable PHP 8.4 module
sudo a2enmod php8.4

# If upgrading from older version, disable it first
sudo a2dismod php8.1  # or php7.4

# Restart Apache
sudo systemctl restart apache2

Enable PHP Module (CentOS/RHEL/AlmaLinux)

bash 
# Install Apache if not already installed
sudo dnf install -y httpd

# Start and enable Apache
sudo systemctl start httpd
sudo systemctl enable httpd

# PHP module is automatically configured
sudo systemctl restart httpd

Nginx Configuration with PHP-FPM

Configure PHP-FPM

Start and Enable PHP-FPM:

bash 
# Ubuntu
sudo systemctl start php8.4-fpm
sudo systemctl enable php8.4-fpm

# CentOS/RHEL/AlmaLinux
sudo systemctl start php-fpm
sudo systemctl enable php-fpm

Configure Nginx Virtual Host

Create or edit your Nginx server block:

bash 
sudo nano /etc/nginx/sites-available/default  # Ubuntu
# or
sudo nano /etc/nginx/conf.d/default.conf      # CentOS/RHEL/AlmaLinux

Add the following PHP configuration:

nginx 
server {
    listen 80;
    server_name your_domain.com;
    root /var/www/html;
    index index.php index.html index.htm;

    location / {
        try_files $uri $uri/ =404;
    }

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;  # Ubuntu
        # include /etc/nginx/fastcgi_params;  # CentOS/RHEL/AlmaLinux
        
        # Ubuntu
        fastcgi_pass unix:/var/run/php/php8.4-fpm.sock;
        
        # CentOS/RHEL/AlmaLinux
        # fastcgi_pass unix:/var/run/php-fpm/www.sock;
        
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include fastcgi_params;
    }

    location ~ /\.ht {
        deny all;
    }
}

Test and Restart Nginx

bash 
# Test Nginx configuration
sudo nginx -t

# Restart Nginx
sudo systemctl restart nginx

Verification and Testing

Check PHP Version

bash 
php -v

Expected output:

text 
PHP 8.4.x (cli) (built: ...) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.4.x, Copyright (c) Zend Technologies
    with Zend OPcache v8.4.x, Copyright (c), by Zend Technologies

Check Loaded Extensions

bash 
php -m

Create PHP Info Test File

bash 
sudo nano /var/www/html/info.php

Add the following content:

php 
<?php
phpinfo();
?>

Set Proper Permissions

bash 
# Ubuntu
sudo chown www-data:www-data /var/www/html/info.php
sudo chmod 644 /var/www/html/info.php

# CentOS/RHEL/AlmaLinux
sudo chown apache:apache /var/www/html/info.php
sudo chmod 644 /var/www/html/info.php

Access PHP Info Page

Open your web browser and navigate to:

  • http://your-server-ip/info.php
  • http://your-domain.com/info.php

You should see the PHP information page showing PHP 8.4 details.

Security Note: Remove the info.php file after testing:

bash 
sudo rm /var/www/html/info.php

Managing Multiple PHP Versions

Ubuntu - Switch Between PHP Versions

If you have multiple PHP versions installed:

bash 
# List available PHP versions
sudo update-alternatives --config php

# Set default PHP version
sudo update-alternatives --set php /usr/bin/php8.4

# For Apache, switch modules
sudo a2dismod php8.1
sudo a2enmod php8.4
sudo systemctl restart apache2

Configure PHP-FPM for Different Versions

You can run multiple PHP-FPM versions simultaneously:

bash 
# Start multiple PHP-FPM services
sudo systemctl start php8.1-fpm
sudo systemctl start php8.4-fpm

# Configure different sockets in Nginx
# /run/php/php8.1-fpm.sock
# /run/php/php8.4-fpm.sock

Optimizing PHP Configuration

Essential php.ini Settings

Edit the PHP configuration file:

bash 
# Ubuntu
sudo nano /etc/php/8.4/apache2/php.ini    # For Apache
sudo nano /etc/php/8.4/fpm/php.ini       # For PHP-FPM

# CentOS/RHEL/AlmaLinux
sudo nano /etc/php.ini

Recommended settings for production:

ini 
; Basic Settings
max_execution_time = 300
max_input_time = 300
memory_limit = 512M
post_max_size = 64M
upload_max_filesize = 64M

; Error Handling
display_errors = Off
log_errors = On
error_log = /var/log/php_errors.log

; Security
expose_php = Off
allow_url_fopen = Off
allow_url_include = Off

; OPcache (Performance)
opcache.enable = 1
opcache.memory_consumption = 256
opcache.interned_strings_buffer = 8
opcache.max_accelerated_files = 10000
opcache.revalidate_freq = 2

Restart Services After Configuration Changes

bash 
# Ubuntu
sudo systemctl restart apache2     # For Apache
sudo systemctl restart php8.4-fpm  # For Nginx with PHP-FPM

# CentOS/RHEL/AlmaLinux
sudo systemctl restart httpd       # For Apache
sudo systemctl restart php-fpm     # For Nginx with PHP-FPM
sudo systemctl restart nginx       # Don't forget Nginx

Troubleshooting Common Issues

Issue 1: Package Not Found

Problem: PHP 8.4 packages not available.

Solution:

bash 
# Ubuntu - Ensure PPA is added correctly
sudo add-apt-repository ppa:ondrej/php
sudo apt update

# CentOS/RHEL/AlmaLinux - Check Remi repository
sudo dnf module list php
sudo dnf module enable php:remi-8.4

Issue 2: PHP-FPM Socket Permission Errors

Problem: Nginx cannot connect to PHP-FPM socket.

Solution:

bash 
# Check socket permissions
ls -la /var/run/php/

# Fix permissions
sudo chown www-data:www-data /var/run/php/php8.4-fpm.sock  # Ubuntu
sudo chown nginx:nginx /var/run/php-fpm/www.sock          # CentOS/RHEL/AlmaLinux

Issue 3: Apache Module Not Loading

Problem: PHP not processing after installation.

Solution:

bash 
# Ubuntu
sudo a2enmod php8.4
sudo systemctl restart apache2

# CentOS/RHEL/AlmaLinux
# Check if PHP module is loaded
sudo httpd -M | grep php
sudo systemctl restart httpd

Security Considerations

Disable Dangerous Functions

Add to php.ini:

ini 
disable_functions = exec,passthru,shell_exec,system,proc_open,popen,curl_exec,curl_multi_exec,parse_ini_file,show_source

Set Proper File Permissions

bash 
# Web root permissions
sudo chown -R www-data:www-data /var/www/html    # Ubuntu
sudo chown -R apache:apache /var/www/html        # CentOS/RHEL/AlmaLinux

# Set directory permissions
sudo find /var/www/html -type d -exec chmod 755 {} \;

# Set file permissions
sudo find /var/www/html -type f -exec chmod 644 {} \;

Configure Firewall

bash 
# Ubuntu (UFW)
sudo ufw allow 'Apache Full'    # or 'Nginx Full'
sudo ufw enable

# CentOS/RHEL/AlmaLinux (firewalld)
sudo firewall-cmd --permanent --add-service=http
sudo firewall-cmd --permanent --add-service=https
sudo firewall-cmd --reload

Conclusion

PHP 8 brings significant performance improvements and new features that benefit modern web development. By following this comprehensive guide, you can successfully install PHP 8 on Ubuntu, CentOS/RHEL, and AlmaLinux systems.

Key Takeaways:

  • PHP 8.4 is the latest stable version with enhanced performance and features
  • Multiple installation methods are available for different Linux distributions
  • Proper web server configuration is essential for optimal performance
  • Security considerations should always be implemented in production environments
  • Regular updates ensure you have the latest security patches and improvements

Whether you're building new applications or upgrading existing ones, PHP 8 provides the performance and features needed for modern web development. Remember to test thoroughly in a development environment before upgrading production systems.

For complex server management needs, consider consulting with experienced system administrators or utilizing professional managed services that specialize in PHP and web server optimization.

Tags:

phpubuntucentosrhelalmalinuxapachenginxweb-development

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