yaml.scanner.ScannerError: mapping values are not allowed here in "./docker-compose.yml", line 12, column 14

Question

I am getting the following error:

yaml.scanner.ScannerError: mapping values are not allowed here in "./docker-compose.yml", line 12, column 14

my docker compose file:

version: '2'
services:
  mongodb:
    image: mongo
    ports:
      - "27017:27017"
    volumes:
      - ./mongodb/mongodata:/data/db
    command: mongod --auth
  siteacess:
    build: .
      context: ./siteaccess/
    enviroment:
      - MONGO_DB_HOST=mongo
      - MONGO_PORT=27017
      - MONGO_DB=fad
      - MONGO_DB_USER=user
      - MONGO_DB_PASS=pass
    ports:
      - "5000:5000"
    links:
      - mongodb