nginx 自定义响应头 ，日志

 location /
        {
                proxy_pass http://x.x.x.x:8018;
                proxy_set_header Host $host;
                proxy_set_header upstream 32;    #自定义的内容
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $remote_addr;

        }

log_format sns_www '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$request_time" $request_body "$http_referer" "$http_user_agent" $http_x_forwarded_for $scheme $http_host $http_cookie $http_upstream';

#http_upstream 就是自定义的