How to Use Different PHP Version for different projects in Ubuntu

This is one of the most common scenarios which arise when working with multiple projects on the same development server. For instance one of your project is in Drupal 8 running on PHP 7.4 while you are also running a Drupal10 site which requires PHP 8.1. Now how can you manage and enable different PHP versions for each projects. It might feel complex but its a straight forward process :

• Find all the available PHP versions on the server

  • sudo update-alternatives --list php OR

  • cd /etc/php and ls -al

• Nginx

  • Update the nginx configuration of the site and its respective PHP version configuration at :
    • Go To

      • cd /etc/nginx/sites-available/[site-name]

    • Update PHP version in the above file

      • location ~ .php${ fastcgi_pass unix:/run/php/php-8.1-fpm.sock ...... } OR
      • location ~ .php${ fastcgi_pass unix:/run/php/php-7.4-fpm.sock ...... }

  • Now, restart the nginx server

    • sudo service nginx restart

• Navigate back to the project root directory, now if you are running composer you will need the required version available on the command line 

  • sudo update-alternatives --set php /usr/bin/php8.1 OR
  • sudo update-alternatives --set php /usr/bin/php7.4

• Now you can move back to your project run composer and validate your PHP version in your application.

• Done.