通过备案的域名访问，不需要添加端口号（nginx反向代理，直接域名访问）

yum install -y nginx

    server {
        listen       80;
        listen       [::]:80;
        server_name  xxx.com.cn;
        root         /usr/share/nginx/html;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        location / {
#           root   html;
#           index  index.html index.htm;
            proxy_pass  http://101.43.39.xx:8090;
        }

        error_page 404 /404.html;
        location = /404.html {
        }

        error_page 500 502 503 504 /50x.html;
        location = /50x.html {
        }
    }

cd /usr/sbin
./nginx -s reload