Serving Images

The App Engine API for Cloud Storage Tools provides convenience methods for serving image files:

• CloudStorageTools.getImageServingUrl()
• CloudStorageTools.deleteImageServingUrl()

This page describes how to use the legacy bundled services and APIs. This API can only run in first-generation runtimes in the App Engine standard environment. If you are updating to the App Engine PHP 7/8 runtime, refer to the migration guide to learn about your migration options for legacy bundled services.

Note: When running your app locally on the development server, you'll need to install PIL if you wish to use the image sizing options described in this page.

One advantage of using this method to serve images over simply making the files public is the ability to resize and crop dynamically, without needing to store the images in different sizes.

CloudStorageTools::getImageServingUrl returns a serving URL for an image. If the image will be displayed within an HTTPS page, set secure_url to True to avoid mixed-content warnings.

Notice that this URL is publicly readable by everyone, but it is not "guessable".

Important: You cannot serve an image from two separate apps; only the first app that calls getImageServingUrl can get the URL to serve it because that app has obtained ownership of the image to serve it. Any other app that calls getImageServingUrl on the image will therefore be unsuccessful. If a second app needs to serve the image, the app needs to first copy the image and then invoke getImageServingUrl on the copy.

To stop serving the URL, call CloudStorageTools::deleteImageServingUrl.

Note: If you want to delete the file itself, use the PHP unlink() function.

To use this feature, import the CloudStorageTools class:

use google\appengine\api\cloud_storage\CloudStorageTools;

Now resize and crop the image image.jpg:

$options = ['size' => 400, 'crop' => true];
$image_file = "gs://${my_bucket}/image.jpg";
$image_url = CloudStorageTools::getImageServingUrl($image_file, $options);