Docker部署前端应用时bundle.js加载报Unexpected token '<'错误排查

• 学习场景：跟随线上教程学习Docker，当前任务仅要求编写Dockerfile，初步判断问题出在Dockerfile编写环节，暂未梳理出高效的问题调试路径
• 核心故障：
  • 基于构建完成的Docker镜像启动容器后，访问localhost可正常渲染index.html页面，但bundle.js无法正常加载，浏览器控制台抛出Uncaught SyntaxError: Unexpected token '<'错误
  • 本地环境直接执行webpack打包后，打开生成的index.html页面可正常渲染
• 排查进展：已移除Dockerfile中Node构建阶段原本的CMD行，将原单独执行的RUN npm install指令调整为RUN npm install && npm start；当前已验证bundle.js文件可正常生成，且成功拷贝至nginx的静态资源目录，但原有报错仍未消除

Dockerfile 配置 #

FROM node:8.15-alpine as build-stage
COPY . /app
RUN npm install && npm start

FROM nginx:1.15
EXPOSE  80
COPY --from=build-stage /app /usr/share/nginx/html
COPY --from=build-stage /app/nginx.conf /etc/nginx/conf.d/default.conf

入口页面 index.html #

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Todo App</title>
    <link href="https://fonts.googleapis.com/css?family=Roboto+Slab" rel="stylesheet">
    <link rel="stylesheet" href="./styles/main.css" >
  </head>
  <body>
    <div id="content"></div>
    <script src="./bundle.js"></script>
  </body>
</html>

项目脚本与依赖配置 package.json #

{
  "name": "todos",
  "version": "1.0.0",
  "description": "This README would normally document whatever steps are necessary to get the application up and running.",
  "main": "index.js",
  "directories": {
    "test": "test"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "webpack --mode=development"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@babel/core": "^7.1.2",
    "@babel/preset-env": "^7.1.0",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.2.2",
    "lodash": "^4.17.4",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-redux": "^5.0.6",
    "redux": "^3.7.2",
    "webpack": "^4.20.2",
    "webpack-cli": "^3.1.2"
  },
  "devDependencies": {}
}

Webpack 打包配置 webpack.config.js #

const path = require('path');

module.exports = {
  context: __dirname,
  entry: './frontend/todo_redux.jsx',
  output: {
    path: path.resolve(__dirname),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /(node_modules)/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/env', '@babel/react']
          }
        },
      }
    ]
  },
  devtool: 'source-map',
  resolve: {
    extensions: [".js", ".jsx", "*"]
  }
};

Nginx 服务配置 nginx.conf #

# 配置nginx服务用于渲染的静态资源路径
server {
  # 服务监听80端口
  location / {
    # 静态资源根路径配置
    root /usr/share/nginx/html;
    index index.html index.htm;
    try_files $uri $uri/ /index.html =404;
  }
}

内容的提问来源于stack exchange，提问作者Samuel Samuelson