In Plesk 12, the Plesk developers added the ability to install a custom Plesk-built binary for different PHP versions. This way if you require PHP 5.3 or PHP 7 and your system installed version is PHP 5.4, you can selectively enable the version you want to use on a per-domain basis.
The only downside to having multiple PHP versions installed is that if the modules / libraries you wish to use are not available in the Plesk yum repository, you can’t use them. This is because any 3rd party libraries would need to be compiled against not only the PHP version you’re using, but specifically against the custom paths of the Plesk binary, such as
The key to solving this problem is to ensure you always use the custom path when working with 3rd party utilities. Here’s how to install a local copy of Composer:
1. Download Composer
/opt/plesk/php/7.3/bin/php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
wget --no-check-certificate -O composer-setup.php https://getcomposer.org/installer
2. Install Composer using PHP 7 binary
If you need to use composer to install additional packages, you can do so, but make sure not to simply run
composer or even
php composer it must be:
Followed by the normal remainder of the command.
Tips: 1) you can run this wherever the
composer.phar is, so feel free to move it around if you wish, prior to installing anything. You’ll need to avoid moving it after you’ve begun installing libraries with composer. 2) You can use whichever version of PHP that you have installed in Plesk simply by swapping out the version number in the command. At time of latest update to this article, common options are: 70., 7.1, 7.2