Firestore onWrite trigger doesn't have auth information

Question

When I write data to Firestore from a logged in Android Client, I am not able to get the auth information on the onWrite trigger.

When I print the context object which is supposed to store auth object with UID, I see that auth object doesn't exist.

According to this link, https://firebase.google.com/docs/functions/beta-v1-diff?authuser=0#new_properties_for_user_auth_information

I should get this information on any writes on Firestore.

Here is the example code I Used.

exports.testTrigger = functions.firestore
    .document('col1/doc1/col2/{doc2}')
    .onWrite((change, context) => {

        console.log('context = ', context);
        const auth = context.auth;
        console.log('auth = ', auth);

});

Output in Cloud Function Logs:

context =  { eventId: '3c2295a4-2823-4fba-b406-728d7d77f6de-0',
  timestamp: '2018-05-06T17:11:12.771855Z',
  eventType: 'google.firestore.document.write',
  resource: 
   { service: 'firestore.googleapis.com',
     name: 'projects/xyz/databases/(default)/documents/col1/doc1/col2/gFRWgJg37DmB5wchWLBV' },
  params: { request_id: 'gFRWgJg37DmB5wchWLBV' } }

auth = undefined

Answer 1

That documentation you linked to is talking about Realtime Database triggers, not Firestore. Look very carefully at the section headings.

Currently, auth information is not provided in Firestore triggers. It may be available in the future.