# dockerfile以下
FROM node:12
 
# Create app directory
WORKDIR /usr/src/app
 
# Install app dependencies
# A wildcard is used to ensure both package.json AND package-lock.json are copied
# where available (npm@5+)
COPY package*.json ./
 
RUN npm install
# If you are building your code for production
# RUN npm ci --only=production
 
# Bundle app source
COPY . .
 
EXPOSE 3000
CMD [ "node", "server.js" ]

# package.json
{
    "name": "docker_web_app",
    "version": "1.0.0",
    "description": "Node.js on Docker",
    "author": "First Last <first.last@example.com>",
    "main": "server.js",
    "scripts": {
      "start": "node server.js"
    },
    "dependencies": {
      "express": "^4.16.1"
    }
  }

# server.js
'use strict';
 
const express = require('express');
 
// Constants
const PORT = 3000;
const HOST = '0.0.0.0';
 
// App
const app = express();
app.get('/', (req, res) => {
  res.send('Hello World');
});
 
app.listen(PORT, HOST, () => {
  console.log(`Running on http://${HOST}:${PORT}`);
});

# docker-compose.yml
version: '3.0'
services:
  node-web: 
    build: ./
    ports:
      - "3000:3000"
    volumes:
      - ./:/usr/src/app
      - /usr/src/app/node_modules
    command:  npm start 

docker-compose up