Local dev override

services:
  web:
    volumes:
      # Bind-mount the whole project so edits on the host show up inside
      # the container immediately -- no rebuild needed.
      - .:/app
      # Anonymous volume that shadows the bind mount above for just this
      # one path, so the image's own node_modules (built for Linux) isn't
      # replaced by whatever node_modules sits on the host.
      - /app/node_modules
    environment:
      NODE_ENV: development
    # Overrides the image's CMD with the dev server, which the production
    # image doesn't ship at all.
    command: npm run dev