This sample demonstrates how to automatically extract images metadata that are uploaded to Firebase Storage ImageMagick.

See file functions/index.js for the code.

The image metadata is provided using ImagMagick identify tool which is installed by default on all Cloud Functions instances. This is a CLI for which we use a NodeJS wrapper. The image is first downloaded locally from the Firebase Storage bucket to the tmp folder using the google-cloud SDK.

The dependencies are listed in functions/package.json.

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

Users upload an image to Firebase Storage to the path /<timestamp>/<filename> and in return the Function will write to the /<timestamp>/<filename> path in the database. The filename typically contains illegal characters for a Firebase Realtime Database keys (such as .) so we're replacing all these by the * character.

For example the metadata for the file at path /1477402116302/mypic.jpg will be written to the corresponding Database path /1477402116302/mypic*jpg

This sample comes with a Function and web-based UI for testing the function. To configure it:

1. Create a Firebase Project using the Firebase Console.
2. Enable the Anonymous sign-in in the Auth section.
3. Clone or download this repo and open the exif-image directory.
4. You must have the Firebase CLI installed. If you don't have it install it with npm install -g firebase-tools and then configure it with firebase login.
5. Configure the CLI locally by using firebase use --add and select your project in the list.
6. Install dependencies locally by running: cd functions; npm install; cd -

To test the sample:

1. Deploy your project using firebase deploy
2. Open the app using firebase open hosting:site, this will open a browser.
3. Upload an image using the Web UI.
4. You should see the metadata displayed below after a bit.