faking proxy_pass for POST logging with NGINX

site.nginx.conf

# pin postdata as a fake upstream log format  name
log_format postdata '$request_body';

server {
	listen 80  default_server;
	listen [::]:80 default_server;

	root /var/www/html;

	# Add index.php to the list if you are using PHP
	index index.html index.htm index.nginx-debian.html;

	server_name localhost;
# here we fake proxypass -> sink, so we log POST data without PHP or anything
	location = /pixel.gif  {
		access_log /var/log/nginx/push.log postdata;
		proxy_pass http://127.0.0.1/logsink;
		break;
	}
#	it goes here and always returns SUCCESS!
	location /logsink {
	  return 200;
	}

    location / { }

}