[firebase] How to get a list of all files in Cloud Storage in a Firebase app?

One more way to add the image to Database using Cloud Function to track every uploaded image and store it in Database.

exports.fileUploaded = functions.storage.object().onChange(event => {

    const object = event.data; // the object that was just uploaded
    const contentType = event.data.contentType; // This is the image Mimme type\

    // Exit if this is triggered on a file that is not an image.
    if (!contentType.startsWith('image/')) {
        console.log('This is not an image.');
        return null;
    }

    // Get the Signed URLs for the thumbnail and original image.
    const config = {
        action: 'read',
        expires: '03-01-2500'
    };

    const bucket = gcs.bucket(event.data.bucket);
    const filePath = event.data.name;
    const file = bucket.file(filePath);

    file.getSignedUrl(config, function(err, fileURL) {
        console.log(fileURL);
        admin.database().ref('images').push({
            src: fileURL
        });
    });
});

Full code here: https://gist.github.com/bossly/fb03686f2cb1699c2717a0359880cf84