[api] Add `x-forwarded-proto` and `x-forwarded-port` to proxied HTTP requests

lib/node-http-proxy.js

@@ -344,9 +344,16 @@ HttpProxy.prototype.proxyRequest = function (req, res, options) {
   }
   
   //
-  // Add `x-forwarded-for` header to availible client IP to apps behind proxy
+  // Add common proxy headers to the request so that they can 
+  // be availible to the proxy target server:
+  // 
+  // * `x-forwarded-for`: IP Address of the original request
+  // * `x-forwarded-proto`: Protocol of the original request
+  // * `x-forwarded-port`: Port of the original request. 
   //
-  req.headers['x-forwarded-for'] = req.connection.remoteAddress || req.connection.socket.remoteAddress;
+  req.headers['x-forwarded-for']   = req.connection.remoteAddress || req.connection.socket.remoteAddress;
+  req.headers['x-forwarded-port']  = req.connection.remotePort || req.connection.socket.remotePort;
+  req.headers['x-forwarded-proto'] = res.connection.pair ? 'https' : 'http';
   
   //
   // Emit the `start` event indicating that we have begun the proxy operation.