docker部署nodejs开发环境，基础示例篇

一直想写一个关于多容器开发环境，以后会逐步更新，今天先从简单的hello world开始吧

下面的例子来自于
https://nodejs.org/zh-cn/docs/guides/nodejs-docker-webapp/

一共4个文件，分别是

1. dockerfile

2. docker-compose.yml

3. package.json

4. server.js

# 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 <[email protected]>",
    "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 

注意哦！！！第10行 volumes里必须要把container中的node_modules映射出来，否则会报错
internal/modules/cjs/loader.js:818
code: 'MODULE_NOT_FOUND',
requireStack: [ '/usr/src/app/server.js' ]
这是因为宿主机目录中没有node_modules而引起的莫名错误。。。

普通的目录结构
👇

docker-compose up

运行成功!😃，打开浏览器访问
localhost:3000

总结：

非常简单方便的docker容器化部署nodejs，过去自己下载自己配置，弄半天的情景不复存在！这是简单实用基础版本，拥抱docker吧！