详解Vue SSR（ Vue2 + Koa2 + Webpack4）配置指南

git init
yarn init
touch .gitignore

.DS_Store
node_modules

# 编译后的文件以下两个目录
/dist/web
/dist/api

# Log files
npm-debug.log*
yarn-debug.log*
yarn-error.log*

# Editor directories and files
.idea
.vscode
*.suo
*.ntvs*
*.njsproj
*.sln
*.sw*

echo "yarn add cross-env # 跨平台的环境变量设置工具
 koa
 koa-body # 可选，推荐
 koa-compress # 压缩数据
 compressible # https://github.com/jshttp/compressible
 axios # 此项目作为API请求工具
 es6-promise 
 vue
 vue-router # vue 路由 注意，SSR必选
 vuex # 可选，但推荐使用，本文基于此做Vuex在SSR的优化
 vue-template-compiler
 vue-server-renderer # 关键
 lru-cache # 配合上面一个插件缓存数据
 vuex-router-sync" | sed 's/#[[:space:]].*//g' | tr '\n' ' ' | sed 's/[ ][ ]*/ /g' | bash

echo "yarn add -D webpack
 webpack-cli
 webpack-dev-middleware # 关键
 webpack-hot-middleware # 关键
 webpack-merge # 合并多个Webpack配置文件的配置
 webpack-node-externals # 不打包node_modules里面的模块
 friendly-errors-webpack-plugin # 显示友好的错误提示插件
 case-sensitive-paths-webpack-plugin # 无视路径大小写插件
 copy-webpack-plugin # 用于拷贝文件的Webpack插件
 mini-css-extract-plugin # CSS压缩插件
 chalk # console着色
 @babel/core # 不解释
 babel-loader
 @babel/plugin-syntax-dynamic-import # 支持动态import
 @babel/plugin-syntax-jsx # 兼容JSX写法
 babel-plugin-syntax-jsx # 不重复，必须的
 babel-plugin-transform-vue-jsx
 babel-helper-vue-jsx-merge-props
 @babel/polyfill
 @babel/preset-env
 file-loader
 json-loader
 url-loader
 css-loader
 vue-loader
 vue-style-loader
 vue-html-loader" | sed 's/#[[:space:]].*//g' | tr '\n' ' ' | sed 's/[ ][ ]*/ /g' | bash

|-- public # 静态资源
|-- src
 |-- api # 后端代码
 |-- web # 前端代码

"scripts": {
 "serve": "cross-env NODE_ENV=development node config/server.js",
 "start": "cross-env NODE_ENV=production node config/server.js"
}

module.exports = {
 app: {
 port: 3000, // 监听的端口
 devHost: 'localhost', // 开发环境下打开的地址，监听了0.0.0.0，但是不是所有设备都支持访问这个地址，用127.0.0.1或localhost代替
 open: true // 是否打开浏览器
 }
}

const path = require('path')
const Koa = req uire('koa')
const koaCompress = require('koa-compress')
const compressible = require('compressible')
const koaStatic = require('./koa/static')
const SSR = require('./ssr')
const conf = require('./app')

const isProd = process.env.NODE_ENV === 'production'

const app = new Koa()

app.use(koaCompress({ // 压缩数据
 filter: type => !(/event\-stream/i.test(type)) && compressible(type) // eslint-disable-line
}))

app.use(koaStatic(isProd "htmlcode">

'use strict'

/**
 * From koa-static
 */

const { resolve } = require('path')
const assert = require('assert')
const send = require('koa-send')

/**
 * Expose `serve()`.
 */

module.exports = serve

/**
 * Serve static files from `root`.
 *
 * @param {String} root
 * @param {Object} [opts]
 * @return {Function}
 * @api public
 */

function serve (root, opts) {
 opts = Object.assign({}, opts)

 assert(root, 'root directory is required to serve files')

 // options
 opts.root = resolve(root)
 if (opts.index !== false) opts.index = opts.index || 'index.html'

 if (!opts.defer) {
 return async function serve (ctx, next) {
  let done = false

  if (ctx.method === 'HEAD' || ctx.method === 'GET') {
  if (ctx.path === '/' || ctx.path === '/index.html') { // exclude index.html file
   await next()
   return
  }
  try {
   done = await send(ctx, ctx.path, opts)
  } catch (err) {
   if (err.status !== 404) {
   throw err
   }
  }
  }

  if (!done) {
  await next()
  }
 }
 }

 return async function serve (ctx, next) {
 await next()

 if (ctx.method !== 'HEAD' && ctx.method !== 'GET') return
 // response is already handled
 if (ctx.body != null || ctx.status !== 404) return // eslint-disable-line

 try {
  await send(ctx, ctx.path, opts)
 } catch (err) {
  if (err.status !== 404) {
  throw err
  }
 }
 }
}


我们可以看到， koa-static 仅仅是对 koa-send 进行了简单封装（ yarn add koa-send ）。接下来就是重头戏SSR相关的配置了, config/ssr.js :


const fs = require('fs')
const path = require('path')
const chalk = require('chalk')
const LRU = require('lru-cache')
const {
 createBundleRenderer
} = require('vue-server-renderer')
const isProd = process.env.NODE_ENV === 'production'
const setUpDevServer = require('./setup-dev-server')
const HtmlMinifier = require('html-minifier').minify

const pathResolve = file => path.resolve(__dirname, file)

module.exports = app => {
 return new Promise((resolve, reject) => {
 const createRenderer = (bundle, options) => {
  return createBundleRenderer(bundle, Object.assign(options, {
  cache: LRU({
   max: 1000,
   maxAge: 1000 * 60 * 15
  }),
  basedir: pathResolve('../dist/web'),
  runInNewContext: false
  }))
 }

 let renderer = null
 if (isProd) {
  // prod mode
  const template = HtmlMinifier(fs.readFileSync(pathResolve('../public/index.html'), 'utf-8'), {
  collapseWhitespace: true,
  removeAttributeQuotes: true,
  removeComments: false
  })
  const bundle = require(pathResolve('../dist/web/vue-ssr-server-bundle.json'))
  const clientManifest = require(pathResolve('../dist/web/vue-ssr-client-manifest.json'))
  renderer = createRenderer(bundle, {
  template,
  clientManifest
  })
 } else {
  // dev mode
  setUpDevServer(app, (bundle, options, apiMain, apiOutDir) => {
  try {
   const API = eval(apiMain).default // eslint-disable-line
   const server = API(app)
   renderer = createRenderer(bundle, options)
   resolve(server)
  } catch (e) {
   console.log(chalk.red('\nServer error'), e)
  }
  })
 }

 app.use(async (ctx, next) => {
  if (!renderer) {
  ctx.type = 'html'
  ctx.body = 'waiting for compilation... refresh in a moment.'
  next()
  return
  }

  let status = 200
  let html = null
  const context = {
  url: ctx.url,
  title: 'OK'
  }

  if (/^\/api/.test(ctx.url)) { // 如果请求以/api开头，则进入api部分进行处理。
  next()
  return
  }

  try {
  status = 200
  html = await renderer.renderToString(context)
  } catch (e) {
  if (e.message === '404') {
   status = 404
   html = '404 | Not Found'
  } else {
   status = 500
   console.log(chalk.red('\nError: '), e.message)
   html = '500 | Internal Server Error'
  }
  }
  ctx.type = 'html'
  ctx.status = status || ctx.status
  ctx.body = html
  next()
 })

 if (isProd) {
  const API = require('../dist/api/api').default
  const server = API(app)
  resolve(server)
 }
 })
}




这里新加入了 html-minifier 模块来压缩生产环境的 index.html 文件（ yarn add html-minifier ）。其余配置和官方给出的差不多，不再赘述。只不过Promise返回的是 require('http').createServer(app.callback()) （详见源码）。这样做的目的是为了共用一个koa2实例。此外，这里拦截了 /api 开头的请求，将请求交由API Server进行处理（因在同一个Koa2实例，这里直接next()了）。在 public 目录下必须存在 index.html 文件:


<!DOCTYPE html>
<html lang="zh-cn">
<head>
 <title>{{ title }}</title>
 ...
</head>
<body>
 <!--vue-ssr-outlet-->
</body>
</html>




开发环境中，处理数据的核心在 config/setup-dev-server.js 文件:


const fs = require('fs')
const path = require('path')
const chalk = require('chalk')
const MFS = require('memory-fs')
const webpack = require('webpack')
const chokidar = require('chokidar')
const apiConfig = require('./webpack.api.config')
const serverConfig = require('./webpack.server.config')
const webConfig = require('./webpack.web.config')
const webpackDevMiddleware = require('./koa/dev')
const webpackHotMiddleware = require('./koa/hot')
const readline = require('readline')
const conf = require('./app')
const {
 hasProjectYarn,
 openBrowser
} = require('./lib')

const readFile = (fs, file) => {
 try {
 return fs.readFileSync(path.join(webConfig.output.path, file), 'utf-8')
 } catch (e) {}
}

module.exports = (app, cb) => {
 let apiMain, bundle, template, clientManifest, serverTime, webTime, apiTime
 const apiOutDir = apiConfig.output.path
 let isFrist = true

 const clearConsole = () => {
 if (process.stdout.isTTY) {
  // Fill screen with blank lines. Then move to 0 (beginning of visible part) and clear it
  const blank = '\n'.repeat(process.stdout.rows)
  console.log(blank)
  readline.cursorTo(process.stdout, 0, 0)
  readline.clearScreenDown(process.stdout)
 }
 }

 const update = () => {
 if (apiMain && bundle && template && clientManifest) {
  if (isFrist) {
  const url = 'http://' + conf.app.devHost + ':' + conf.app.port
  console.log(chalk.bgGreen.black(' DONE ') + ' ' + chalk.green(`Compiled successfully in ${serverTime + webTime + apiTime}ms`))
  console.log()
  console.log(` App running at: ${chalk.cyan(url)}`)
  console.log()
  const buildCommand = hasProjectYarn(process.cwd()) "htmlcode">

yarn add memory-fs chokidar readline

yarn add -D opn execa



通过阅读 config/setup-dev-server.js 文件内容，您将发现此处进行了三个webpack配置的处理。


Server for API // 用于处理`/api`开头下的API接口，提供非首屏API接入的能力

Web server for SSR // 用于服务器端对API的代理请求，实现SSR

WEB // 进行常规静态资源的处理



Webpack 配置




|-- config
 |-- webpack.api.config.js // Server for API
 |-- webpack.base.config.js // 基础Webpack配置
 |-- webpack.server.config.js // Web server for SSR
 |-- webpack.web.config.js // 常规静态资源


由于Webpack的配置较常规Vue项目以及Node.js项目并没有太大区别，不再一一赘述，具体配置请翻阅源码。
值得注意的是，我们为API和WEB指定了别名：


alias: {
 '@': path.join(__dirname, '../src/web'),
 '~': path.join(__dirname, '../src/api'),
 'vue$': 'vue/dist/vue.esm.js'
},




此外， webpack.base.config.js 中设定编译时拷贝 public 目录下的文件到 dist/web 目录时并不包含 index.html 文件。
编译脚本：


"scripts": {
 ...
 "build": "rimraf dist && npm run build:web && npm run build:server && npm run build:api",
 "build:web": "cross-env NODE_ENV=production webpack --config config/webpack.web.config.js --progress --hide-modules",
 "build:server": "cross-env NODE_ENV=production webpack --config config/webpack.server.config.js --progress --hide-modules",
 "build:api": "cross-env NODE_ENV=production webpack --config config/webpack.api.config.js --progress --hide-modules"
},




执行 yarn build 进行编译。编译后的文件存于 /dist 目录下。正式环境请尽量分离API及SSR Server。
测试


执行 yarn serve （开发）或 yarn start （编译后）命令，访问 http://localhost:3000 。
通过查看源文件可以看到，首屏渲染结果是这样的：


 ~ curl -s http://localhost:3000/ | grep Hello
 <div id="app" data-server-rendered="true"><div>Hello World SSR</div></div>


至此，Vue SSR配置完成。希望对大家的学习有所帮助，也希望大家多多支持。