Google Cloud Firestore Emulator

A Google Cloud Firestore Emulator container image. The image creates a local, standalone Firestore emulator for testing Firestore-backed apps.

Quickstart

To run the emulator in a standalone Docker container:

docker run \
  --name firestore-emulator \
  --env "FIRESTORE_PROJECT_ID=dummy-project-id" \
  --env "PORT=8080" \
  --publish 8080:8080 \
  mtlynch/firestore-emulator-docker

Example docker-compose configuration

To run the emulator in a docker-compose configuration with your app, use the following example configuration for reference.

version: "3.2"
services:
  firestore_emulator:
    image: mtlynch/firestore-emulator
    environment:
      - FIRESTORE_PROJECT_ID=dummy-project-id
      - PORT=8200
    ports:
      - 8200:8200
  app:
    image: your-app-image
    environment:
      - FIRESTORE_EMULATOR_HOST=firestore_emulator:8200
      - FIRESTORE_PROJECT_ID=dummy-project-id
  depends_on:
    - firestore_emulator

Environment variables

• FIRESTORE_PROJECT_ID: This is the Google Cloud Project ID that the emulator uses.
  • This does not have to correspond to a real Google Cloud Project ID, although it can if you want it to.
  • Your application must set its firestore project ID value to match this environment variable.
  • default: dummy-firestore-id
• PORT: The port on which the firestore emulator listens for HTTP requests.
  • default: 8080

Connecting to the emulator

If you're using a standard Firestore client library and set the environment variable FIRESTORE_EMULATOR_HOST, then your app will connect to the emulator instead of the production Firestore URL. The variable specifies a host:port pair where the emulator is listening, for example firestore_emulator:8080.

Your app must also set the FIRESTORE_PROJECT_ID or explicitly set a Firestore project ID to match the FIRESTORE_PROJECT_ID you set in the emulator. The image's default project ID is dummy-firestore-id.