域名如何去掉端口号

server {
    listen 80;
    server_name www.example.com;

    location / {
        proxy_pass http://backend_server:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

<VirtualHost *:80>
    ServerName www.example.com
    ProxyPass / http://backend_server:8080/
    ProxyPassReverse / http://backend_server:8080/
</VirtualHost>

const http = require('http');

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

server.listen(80, () => {
    console.log('Server running at http://www.example.com/');
});