将以下文件保存到:/etc/nginx/conf.d/http.conf

upstream servers {
    server localhost:8001;
    server localhost:8002;
    server localhost:8003;
    server localhost:8004;
}

server {
    listen 9000;

    location / {
        proxy_pass  http://servers;
        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;
        proxy_set_header Host $http_host;
        proxy_set_header X-NginX-Proxy true;
        proxy_redirect off;
        # Socket.IO Support
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
   }
}

然后运行(CentOS):systemctl restart nginx
即可将9000端口上的请求转发到本机的:8001,8002,8003,8004端口