var express = require('express')
var app = express();
//發送請求，獲取客戶端ip
app.get('/', function (req, res) {
 var clientIp = getIp(req)
 console.log('客戶端ip',clientIp)
 res.send('Hello World');
})
//通過req的hearers來獲取客戶端ip
var getIp = function(req) {
 var ip = req.headers['x-real-ip'] || req.headers['x-forwarded-for'] || req.connection.remoteAddres || req.socket.remoteAddress || '';
 if(ip.split(',').length>0){
 ip = ip.split(',')[0];
 }
 return ip;
};
// 指定ipv4格式
var server = app.listen(8081, '0.0.0.0',function () {
 var host = server.address().address
 var port = server.address().port
 console.log('服務啟動...')
})