Express

我們需要安裝 express 和 http-proxy-middleware
文章當(dāng)前版本為 node v12 "express": "~4.17.1" "http-proxy-middleware": "^0.20.0"

npm install express http-proxy-middleware

配置多個(gè)代理options(使用http-proxy-middleware的通用配置options)

const express = require('express')
const dev = process.env.NODE_ENV !== 'production'旧蛾；

const proxyOptions = {
    '/api': {
        target: 'http://testgame.quzhuanxiang.com',
        pathRewrite: {
            '^/api': ''
        },
        changeOrigin: true,
        logLevel: 'debug'
    },
    '/huyi': {
        target: '代理的測(cè)試域名/正式域名',
        pathRewrite: {
            '^/huyi': ''
        },
        changeOrigin: true,
        logLevel: 'debug'
    },
}

遍歷配置express使用多個(gè)跨域代理

    const server = express()
    // 需要在處理body之前代理氮凝，否則可能會(huì)有奇怪的問(wèn)題
    if (dev && proxyOptions) {
        const proxyMiddleware = require('http-proxy-middleware')
        Object.keys(proxyOptions).forEach(function (context) {
            server.use(proxyMiddleware(context, proxyOptions[context]))
        })
    }

配置成功運(yùn)行酣衷，調(diào)用跨域url時(shí)終端會(huì)輸出類似這樣的信息:

[HPM] Proxy created: /api  -> http://testgame.quzhuanxiang.com
[HPM] Proxy rewrite rule created: "^/api" ~> ""

檢測(cè)到/api的請(qǐng)求,請(qǐng)求最終會(huì)變成:
http://localhost:3000/api/service/testApi => http://testgame.quzhuanxiang.com/service/testApi
根據(jù)proxyOptions配置记罚，url/api部分會(huì)被pathRewrite為''空字符串

Koa2

koa 是由 Express 原班人馬打造浅妆，比express更輕一些望迎，所以代理配置上與express基本一樣。有很多其他的代理的庫(kù)都是基于http-proxy-middleware的凌外，我們用這個(gè)就行辩尊。
我們需要安裝 Koa2 、 http-proxy-middleware 康辑、koa2-connect

遍歷配置express使用多個(gè)跨域代理

const proxyMiddleware = require('http-proxy-middleware');
const k2c = require('koa2-connect');
const Koa = require('koa2')
const dev = process.env.NODE_ENV !== 'production'摄欲；

if (dev && proxyOptions) {
    Object.keys(proxyOptions).forEach(function (context) {
      server.use(async (ctx, next) => {
        if (ctx.url.startsWith(context)) {
          ctx.respond = false;
          await k2c(proxyMiddleware(context, proxyOptions[context]))(ctx, next);
        }
        await next();
      })
    })
  }

另配上一份完整的koa2配置，包括body參數(shù)處理疮薇，router胸墙，session，跨域代理按咒，redis等迟隅。
該文使用庫(kù)的版本"koa-body": "^4.2.0" "koa-router": "^10.0.0" "koa-session": "^6.2.0" "koa2": "^2.0.0-alpha.7" "koa2-connect": "^1.0.2" "koa2-cors": "^2.0.6"

const next = require('next')
const Koa = require('koa2')
const KoaBody = require('koa-body')
const cors = require('koa2-cors')
const proxyMiddleware = require('http-proxy-middleware');
const k2c = require('koa2-connect');
const { router, setRedis } = require('./util/routerUtil') // 封裝的router處理，api接口等
const session = require('koa-session')
const Redis = require('ioredis')
const RedisSessionStore = require('./util/session-store') // 封裝的redis get set destroy等數(shù)據(jù)處理
// redis
const redis = new Redis()
setRedis(redis);

const proxyOptions = {// 可配置多個(gè)代理
  '/huyi': {
    target: process.env.SERV_ENV === 'release' ? '正式域名' : '測(cè)試域名',
    pathRewrite: {
      '^/huyi': ''
    },
    changeOrigin: true,
    logLevel: 'debug'
  },
}

const port = parseInt(process.env.PORT, 10) || 3000
const dev = process.env.NODE_ENV !== 'production'
const app = next({ dev })
const handle = app.getRequestHandler()

app.prepare().then(() => {
  const server = new Koa();
  let redisStore = new RedisSessionStore(redis);
  server.keys = ['KEY'];
  const SESSION_CONFIG = {
    key: 'dj.sid',
    store: redisStore,
    prefix: 'dj:sess',
    cookie: {
      path: '/',
      httpOnly: true
    }
  }
  // 允許跨域
  server.use(cors());
  // 配置session
  server.use(session(SESSION_CONFIG, server));

  if (dev && proxyOptions) {
    Object.keys(proxyOptions).forEach(function (context) {
      server.use(async (ctx, next) => {
        if (ctx.url.startsWith(context)) {
          ctx.respond = false;
          await k2c(proxyMiddleware(context, proxyOptions[context]))(ctx, next);
        }
        await next();
      })
    })
  }

  server
    .use(router.allowedMethods())
    .use(KoaBody())// 使用body參數(shù)励七，注意：要放在use(router)之前處理完參數(shù)智袭，再傳到router
    .use(router.routes()) // 使用api、請(qǐng)求攔截掠抬、重定向等等路由操作
    .use(async (ctx, next) => {
      await handle(ctx.req, ctx.res)
      ctx.respond = false
    })

  server.on('error', (err, ctx) => {
    if (ctx) {
      ctx.body = {
        code: 9999,
        message: `程序運(yùn)行出錯(cuò)：${err}`
      }
    }
  })
  
  server.listen(port, err => {
    if (err) throw err
    console.log(`> Ready on http://localhost:${port}`)
  })
})