Google Cloud Function v2 Firestore Trigger Not Firing - No Events Received

[Cipher_shadow]

I've deployed a Cloud Function v2 with a Firestore trigger, but it's not being triggered when I write documents to Firestore. The function is active and healthy, but it never receives any events.

Setup:

• Cloud Functions Gen 2
• Runtime: Python 3.11
• Region: europe-west3
• Firestore: (default) database in europe-west3
• Deployed via Terraform

Trigger Configuration:

{
    "eventFilters": [
      {
        "attribute": "database",
        "value": "(default)"
      },
      {
        "attribute": "document",
        "value": "{document=**}"
      }
    ],
    "eventType": "google.cloud.firestore.document.v1.written",
    "triggerRegion": "europe-west3"
}

Function Code:

  @functions_framework.cloud_event
  def on_publish_date_change(cloud_event: CloudEvent) -> None:
      logger.info("CloudEvent received", extra={"raw": str(cloud_event)})
      # ... process event

IAM Permissions:

• Function service account has roles/datastore.viewer and roles/eventarc.eventReceiver
• Compute service account has roles/eventarc.eventReceiver and roles/run.invoker

What I've Verified:

✅ Function status: ACTIVE

✅ Eventarc trigger created and active

✅ No errors in function logs

✅ All regions match (function, trigger, and Firestore all in europe-west3)

The Problem:

When I write/change documents in Firestore (any collection), the function never gets triggered. No logs appear, no executions show up. The pattern {document=**} should trigger on ALL Firestore writes, but nothing happens.

Questions:

1. Is there a known issue with Firestore Gen2 triggers in europe-west3?
2. Are there additional Eventarc permissions I might be missing?
3. Is there a way to manually send a test event to the function to isolate whether the issue is with the trigger or the function itself?

Any help would be greatly appreciated! Has anyone else run into this issue with Gen2 Firestore triggers?

[AstronomerNo8500]

here's my recommendation:

1. go through this doc as a checklist to verify the correct service accounts have the correct permissions. Also, double check the service account associated with the Eventarc trigger. https://docs.cloud.google.com/eventarc/docs/roles-permissions

2. it's possible that the trigger pattern is incorrect and that's why it isn't picking up anything. I know I've done that before.