003/node.js--代理服务(解决跨域问题)

业务描述：

1。web前端发送http请求

2。web后端为https协议

如何保证web前端发送http请求到web后端（跨域问题：域名不一致即跨域），

因此用node.js写了个代理服务，转发前端http请求到后端，再获取后端数据返回给前端。

代码如下所示：

 'use strict';

 const express = require('express');
 const fs = require('fs');
 const path = require('path');
 const https = require('https');
 const http=require('http');
 const cookieParser = require('cookie-parser');
 const bodyParser = require('body-parser');
 const app = express();
 const url = require("url");
 app.use(cookieParser());
 app.use(bodyParser.urlencoded({
   extended: true
 }));
 app.use(bodyParser.json());

 //设置跨域访问
 app.all('*', function(req, res, next) {
   res.header("Access-Control-Allow-Origin", "http://localhost:8080");
   res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
   res.header('Access-Control-Allow-Credentials', true);
   res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
   res.header("X-Powered-By", ' 3.2.1');
   res.header("Content-Type", "application/json;charset=utf-8");
   if (req.method == "OPTIONS") res.send();
   else next();
 });
 // Https代理请求
 app.post('/rancher', function(req1, res1) {
   let urlbody=url.parse(req1.body.url)
   console.log("urlbody=========");
   console.log(urlbody);
   let postData =req1.body.postData||'';
   var opts = {
       method:req1.body.type,
       host:urlbody.host,
       port:urlbody.port||'',
     //   path:urlbody.path+(urlbody.search||''),
       path:urlbody.path,
       headers:{
           'Content-Type':'application/json',
           'Content-Length':postData.length,
           'Authorization':'Basic xx',
           'Cookie':'',
           'Cluster-id':req1.body.cid||''
       },
       rejectUnauthorized:false
   }
   console.log("opts=========");
   console.log(opts);
   var req = https.request(opts,function(res){
       var datas = [];
       var size = ;
       res.on('data',function(data){
           datas.push(data);
           size += data.length;
       })
       res.on('end', function(){
           var buff = Buffer.concat(datas, size);
           console.log('success'+datas);
           res1.send(buff);
       })
   })
   req.on('error',function(err){
       console.log('异常,异常原因'+err);
   })
   if (req1.body.type!="get") {
     req.write(postData);
   }
   req.end();

 });

 // Http代理请求
 app.post('/http/rancher', function(req, res1) {
   let urlbody=url.parse(req.body.url)
   console.log("urlbody=========");
   console.log(urlbody);
   let postData =req.body.postData||'';
   //发送 http Post 请求
   var opts = {
     method:req.body.type,
     host:urlbody.hostname,
     port:urlbody.port&&urlbody.port||'',
     path:urlbody.path,
     headers:{
         'Content-Type':'application/json',
         'Content-Length':postData.length,
         'Authorization':'Basic xx',
         'Cookie': 'xx',
     },
   }
   var req=http.request(opts, function(res) {
       console.log('Opts:',opts);
       console.log('Status:',res.statusCode);
       console.log('headers:',JSON.stringify(res.headers));
       res.setEncoding('utf-8');
       res.on('data',function(chun){
           console.log('body分隔线---------------------------------\r\n');
           console.info(chun);
           res1.send(chun);
       });
       res.on('end',function(){
           console.log('No more data in response.********');
       });
   });
   req.on('error',function(err){
       console.error(err);
   });
   req.write(postData);
   req.end();
 });

 let server = app.listen(, function() {
   let host = server.address().address;
   let port = server.address().port;

   console.log('Example app listening at http://%s:%s', host, port);
 });