In thefiles, why are certain enumerations done with a dash, and others without?
services: web: # the enumeration of [build, ports, volumes, environment] doesn't use a - build: . ports: - "5000:5000" # why the - here? could we remove it and have ports: "5000:5000"? volumes: - .:/code # why the - here? environment: FLASK_ENV: development # why no - here? redis: image: "redis:alpine"
version: '2' services: db: image: mysql:5.7 volumes: - ./mysql:/var/lib/mysql # could we remove this - prefix? restart: always environment: MYSQL_ROOT_PASSWORD: somewordpress # no - in this enumeration, why? MYSQL_DATABASE: wordpress MYSQL_USER: wordpress MYSQL_PASSWORD: wordpress wordpress: depends_on: - db # would it be ok without - ? image: wordpress:latest volumes: - ./wp:/var/www/html # same ...