server {

  listen 80;
  server_name my.site;

  root /path/to/rails/public;
  passenger_enabled on;
  rails_env development;
  passenger_min_instances 1;

  client_max_body_size 5m;

  location ~* /scripts/.*.meta.js {

    error_page 418 = @noparams;

    if ( $arg_version = '' ) {
      return 418;
    }
  }

  location @passenger {
    root /path/to/rails/public;
    proxy_set_header X-Forwarded-Proto http;
    passenger_enabled on;
  }

  location @noparams {
    try_files  /a$uri @passenger =401;
  }

}