How to deploy Firestore listener functions to GCP Cloud? - google-cloud-firestore

Question

I'm using the following approach (source) to build a GCP Cloud Function that handles Firestore events.
const functions = require('firebase-functions');
exports.myFunction = functions.firestore
.document('my-collection/{docId}')
.onWrite((change, context) => { /* ... */ });
There is no example on how to deploy this correctly to GCP Functions though, only Firebase ones.
using the regular gcloud deploy commands such as this one won't work.
gcloud functions deploy FUNCTION_NAME \
--entry-point ENTRY_POINT \
--runtime RUNTIME \
--trigger-event "providers/cloud.firestore/eventTypes/document.write" \
--trigger-resource "projects/YOUR_PROJECT_ID/databases/(default)/documents/messages/{pushId}"
Any ideas on how to do this?

Answer 1

You can achieve the required effect with creating Cloud Firestore Trigger of your choice
For Cloud Functions (1st gen):
In the Trigger type field, select Cloud Firestore.
Select Event Type: Write
Mention the Document on which you want to trigger this function, eg.users/{doc_id}
Check Retry on failure Check box if you want to retry if it did not trigger
Click On Save
Modify your Function as per your requirement
Click Deploy
Make Modification on provided documented path, in our case users/{doc_id}
Check the logs for cloud functions. You will see the function got triggered.
For Cloud Functions (2nd gen):
Under HTTPS, in the Authentication field, select an option depending on whether you want to allow unauthenticated invocations of your function. By default, authentication is required.
Click on Add Eventarc Trigger (A modal will appear)
Choose Trigger Type : First Party
Choose Event Provider: Cloud Firestore
Event: google.firestore.v1.Firestore.Write
Resource : If you are having exact path for document choose Specific Resource else you want to target multiple documents using wildcard pattern
choose Path Pattern
Check Retry on failure Check box if you want to retry if it did not trigger
Click on Save Trigger
Click Next
Modify your Function as per your requirement
Click Deploy
Make modification on the targeted documents
Check the logs for cloud functions. You will see the function got triggered.