user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log debug;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {

    map $http_upgrade $connection_upgrade {
        default upgrade;
        '' close;
    }

    upstream websocket {
        server myapp.onbluemix.net:80;
    }

    server {
       listen 80;
       location / {
             proxy_http_version 1.1;
             proxy_set_header Upgrade $http_upgrade;
             proxy_set_header Connection $connection_upgrade;
             proxy_pass http://websocket;
           }
    }
}

HTTP/1.1 500 Error
Server: nginx/1.13.3
Content-Type: text/xml
Transfer-Encoding: chunked
Connection: keep-alive
X-Backside-Transport: FAIL FAIL