Docker compose file to cleanly start your firebase emulator

docker-compose.yml

# We store our Dockerfile and docker-compose.yml in the root of the firebase project
# So instead of using 'image: firebase-emulator' to select a image
# We inform docker-compose to build the container from the dockerfile if it does not exist
version: "3.0"

# It's named services but we only have one service namely firebase
# But in the future you could expand this with like database services or something
# In our upcoming articles we are going to be adding dgraph to this
services:
  firebase:
    build: 
      # Note the "." because we build from the project directory the docker-compose.yml and dockerfile are in
      context: .
    # Mount the firebase project directory to /app
    volumes:
      - ./:/app
    # We specifically use 127.0.0.1 so it only links to the system that is running the container
    # And avoid accidently publishing your emulator on your home network.
    # In the browser you can access the emulator UI by going to (http://localhost:9098/)
    ports:
      - "127.0.0.1:9099:9099"
      - "127.0.0.1:9098:9098"
      - "127.0.0.1:8080:8080"
      - "127.0.0.1:9199:9199"