const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
 res.statusCode = 200;
 res.setHeader('Content-Type', 'text/plain');
 res.end('Hello World\n');
});

server.listen(port, hostname, () => {
 console.log(`Server running at http://${hostname}:${port}/`);
});

node_modules1

var express = require('express');
app = express(); 
app.use(express.static(__dirname + '/public')); 
app.listen(8081)

curl --silent --location https://rpm.nodesource.com/setup | bash -
yum -y install nodejs
yum install npm

npm install forever -g

forever start app.js

cd /usr/local/nginx/conf/vhost/

vi demonode.coderfix.cn.conf

server {
listen 80;
server_name demonode.coderfix.cn;
  location / {
  proxy_pass http://127.0.0.1:8899;
  }
}

events.js:72
  throw er; // Unhandled 'error' event
     ^
Error: listen EADDRINUSE
  at errnoException (net.js:884:11)
  at Server._listen2 (net.js:1022:14)
  at listen (net.js:1044:10)
  at Server.listen (net.js:1110:5)
  at Object.<anonymous> (folderName/app.js:33:24)
  at Module._compile (module.js:456:26)
  at Object.Module._extensions..js (module.js:474:10)
  at Module.load (module.js:356:32)
  at Function.Module._load (module.js:312:12)
  at Function.Module.runMain (module.js:497:10)1

ps aux | grep node

kill -9 ****