data sink for nginx

nginx.conf

http {
  log_format datasink $request_body;
}

server {
  listen 1.2.3.4;
  
  location /datasink {
    return 200;
  }

  location / {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_redirect off;
    proxy_pass $scheme://1.2.3.4:$server_port/datasink;
    access_log  /var/log/nginx/datasink.log datasink;
  }
}

Nginx data sink allows to easily debug various incoming requests and capture samples of real traffic as received by the webserver, with no extra tools (nc?) needed. Shown are only relevant parts of the configuration, you might want to extend at least http part of it with necessary directives.