title: Nodejs not retaining upper case of request header
body: <p>I am using node js as reverse proxy mostly using http and http-proxy module. While sending the request to to nodejs to redirect to one of my application, i have to pass request headers which will all be in upper case. However, nodejs or rather http is converting all upper case to lower case, because of which one of the validation of my application is failing.</p>
  
  <p>My code snippet is:</p>
  
  <pre><code>http.createServer(function (request, response) {
  
      var redirection = 'http://localhost:8000';
      var path = url.parse(request.url).path;
  
      switch (path) {
          case '/health':
              proxy.web(request, response, { target: redirection });
              break;
  }).listen(8080);
  </code></pre>
  
  <p>Request headers passed are:</p>
  
  <pre><code>curl -H "X-AUTH: PBxqcEm5sU743Cpk" -X GET http://localhost:8080/health
  </code></pre>
  
  <p>Now what is happening is, header "X-AUTH" is getting transformed into "x-auth" and my application is not able to validate it. In my application the header matching is case sensitive. </p>
  
  <p>The request headers printed from node js request object are:</p>
  
  <pre><code>{ host: 'localhost:8080',
    'user-agent': 'curl/7.47.1',
    accept: '*/*',
   'x-auth': 'PBxqcEm5sU743Cpk' }
  </code></pre>
  
  <p>My requirement is to retain the upper case of the header passed in request so that my application can validate and authorize it. 
  Please let me know if there is any way to achieve this</p>
  
  <p>Thanks a lot</p>