Firebase SDK for Cloud Functions Quickstart - Cloud Storage trigger

This quickstart demonstrates using Firebase SDK for Cloud Functions setup with a Cloud Storage trigger.


This sample automatically generates thumbnails for images that are uploaded to Cloud Storage.

Functions Code

See file functions/index.js for the thumbnail generation code.

The thumbnail generation is performed using sharp.

The dependencies are listed in functions/package.json.

Trigger rules

The function triggers on upload of any file to your Firebase project's default Cloud Storage bucket.

Deploy and test

To deploy and test the sample:

  • Create a Firebase project on the Firebase Console and visit the Storage tab.
  • Get the code, for instance using git clone
  • Enter the correct directory cd functions-samples/quickstarts/thumbnails
  • Setup the CLI to use your Firebase project using firebase use --add and select your Firebase project
  • Deploy your project's code using firebase deploy
  • Go to the Firebase Console Storage tab and upload an image. After a short time a thumbnail image with the same name but a thumb_ prefix will be created in the same folder (make sure you refresh the UI to see the new file).


We'd love that you contribute to the project. Before doing so please read our Contributor guide.


© Google, 2016. Licensed under an Apache-2 license.