How do I access Firebase storage from within a Database-triggered Cloud Function?

Question

I would like to perform file manipulation using firebase cloud functions by listening to an event triggered by functions.database.ref().onWrite() (instead of functions.storage.object().onChange()).

I noticed most of the sample using cloud functions functions.storage.object().onChange() to trigger a cloud functions for file manipulation. Is there a way to get a storageRef from within functions.database.ref() and perform file manipulation from there?

Answer 1

To access Firebase Storage from within your database triggered Cloud Function, you can use the Google Cloud SDK.

From one of my apps:

const gcs = require('@google-cloud/storage')();

...
exports
.emojifyStory = functions.database.ref('/stories/{storyId}')
.onWrite(function(event) {
    const filePath = event.data.val().filePath;
    const file = gcs.bucket(bucket).file(filePath);

    // Use the Vision API to detect labels
    return visionClient.detectLabels(file)
      .then(data => {
      ...