How to use MongoDB\Client\ in PHP DO Function

The reason that MongoDB\Driver\Manager does not cause the “Error: Class <class> not found” error message but MongoDB\Client does is that MongoDB\Driver\Manager is included in the PHP runtime right now.

Because MongoDB\Client is not provided by the runtime, in order to use it, you’ll have to include a composer.json file that references its package on Packagist and include a build script. See https://github.com/digitalocean/sample-functions-php-numberstowords for a sample function that does this.

Note that while some classes, like MongoDB\Driver\Manager, are included in the PHP runtime, and can therefore be used without using Composer like this, we don’t officially support anything except what’s built into PHP in the PHP runtime right now. Therefore, the best practice right now is to explicitly list all dependencies you use in your composer.json file. We have plans to address this long term. We are always open to feedback about Functions and our other products, and you can provide it using our official feedback platform at https://ideas.digitalocean.com/.