You can use Cloud Storage to store application data from your App Engine app. Cloud Storage can be used to store and serve files, such as movies or images or other static content.
You can integrate Cloud Storage into your PHP 7 app using the Google Cloud Client Library. The library provides an idiomatic PHP 7 client to Cloud Storage, allowing you to store and retrieve data using Cloud Storage in an App Engine app.
The PHP 7 client also provides an API-backed stream wrapper which can be used to interact with Cloud Storage as a specialized filesystem.
For more information
For more information on Cloud Storage, see the Cloud Storage documentation.