server {

        listen  80;         server_name  xxx.com;              proxy_redirect off ;              proxy_set_header Host $host;              proxy_set_header X-Real-IP $remote_addr;              proxy_set_header REMOTE-HOST $remote_addr;              proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;              client_max_body_size 50m;              client_body_buffer_size 256k;              proxy_connect_timeout 30;              proxy_send_timeout 30;              proxy_read_timeout 60;              proxy_buffer_size 256k;              proxy_buffers 4 256k;              proxy_busy_buffers_size 256k;              proxy_temp_file_write_size 256k;              proxy_next_upstream error timeout invalid_header http_500 http_503 http_404;              proxy_max_temp_file_size 128m;       location / {

            proxy_pass http://ip;         }     }