Firebase Stream Filter

A Firebase stream doesn't tail a file - it holds a Cloud Logging filter. The editor builds that filter for you from structured controls under the Cloud Logging filter heading; a live Preview shows the exact query that will be sent to Cloud Logging as you change them.

Resource

The Google Cloud resource type to tail. On a Firebase-project source the list is trimmed to the types Firebase developers actually use:

Any - every log entry in the project (no resource constraint).
Cloud Function - Cloud Functions for Firebase.
Cloud Run - Cloud Run services, including App Hosting backends and 2nd-gen functions.
Firebase Auth
Firebase Hosting
Firebase Realtime Database
Pub/Sub Topic and Pub/Sub Subscription - handy for Functions / Extensions triggers.

Raw-infrastructure types (GKE, GCE, App Engine, Cloud SQL, Dataflow, BigQuery) are hidden here because they're rarely relevant to a Firebase project. If you do need one, add the same project as a plain GCP Project source - that source shows the full list. (Editing a stream that already uses a hidden type keeps that type, so nothing is lost.)

Per-resource fields

Picking a resource reveals its narrowing fields - for example Service name + Location for Cloud Run, or Site name + Domain for Firebase Hosting. Each is a combo box that suggests values discovered from your project: from recent log activity, and from Cloud Asset Inventory when your credentials carry roles/cloudasset.viewer. You can also type a value if it isn't listed, or leave a field blank to not constrain it.

A resource only produces output - and only suggests values - if your project actually logs it. Firebase Hosting request logs are opt-in, for instance: until you enable them for the site there are no Hosting entries to tail, and the Site name / Domain fields will stay empty.

Severity

Sets a severity>= floor - e.g. Warning keeps WARNING and above. Any applies no severity constraint.

Preview

The compiled, read-only filter. Empty means "tail every log entry in the project." A built filter looks like:

resource.type="cloud_run_revision" AND resource.labels.service_name="ping" AND severity>=ERROR

The Test Cloud Logging Filter button runs ListLogEntries(pageSize: 1) with the compiled filter against the project. The result shows Filter works (✓) or Filter rejected (✗) with the specific API error.

The rest of the sheet

Name, the display Filter (wildcard pills applied to what's shown), Strip matched text, and Auto-stream at startup behave the same as any stream - see Streams. For setting up the Firebase source itself (project ID, auth) and for reading structured GCP output, see GCP & Firebase Sources.