docker-compose.yml

version: "3.6"
services:
  app:
    build: .
    volumes:
      - .:/app
      - node_modules:/app/node_modules
    ports:
      - "8000:8000"
    depends_on:
      - mongo
  mongo:
    image: mongo:4.0.3
    ports:
      - "27017:27017"
    volumes:
      - mongo-data:/data/db
volumes:
  mongo-data:
  node_modules:

Dockerfile

FROM mhart/alpine-node:11

WORKDIR /app
COPY . .

RUN npm install

CMD ["npm", "start"]