Add resTransformStream and reqTransformStream options

Author: albanm

examples/http/transform-stream-proxy.js

@@ -0,0 +1,64 @@
+/*
+  latent-proxy.js: Example of proxying over HTTP with latency
+
+  Copyright (c) 2013 - 2016 Charlie Robbins, Jarrett Cruger & the Contributors.
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+var util = require('util'),
+    colors = require('colors'),
+    Transform = require('stream').Transform
+    http = require('http'),
+    httpProxy = require('../../lib/http-proxy');
+
+//
+// Http Proxy Server with transform streams on request and response
+// A good candidate would be a throttle stream for example
+//
+var proxy = httpProxy.createProxyServer();
+http.createServer(function (req, res) {
+  proxy.web(req, res, {
+    target: 'http://localhost:9008',
+    reqTransformStream: new Transform({
+      transform(chunk, encoding, callback) {
+        callback(null, 'Ni! ')
+      }
+    }),
+    resTransformStream: new Transform({
+      transform(chunk, encoding, callback) {
+        callback(null, 'iki iki iki ')
+      }
+    })
+  });
+}).listen(8008);
+
+//
+// Target Http Server
+//
+http.createServer(function (req, res) {
+  res.writeHead(200, { 'Content-Type': 'text/plain' });
+  res.write('Whatever, this will be ovewritten by resTransformStream');
+  res.end();
+}).listen(9008);
+
+util.puts('http proxy server '.blue + 'started '.green.bold + 'on port '.blue + '8008 '.yellow + 'with transform streams'.magenta.underline);
+util.puts('http server '.blue + 'started '.green.bold + 'on port '.blue + '9008 '.yellow);

lib/http-proxy/passes/web-incoming.js

@@ -158,7 +158,12 @@ module.exports = {
       }
     }
 
-    (options.buffer || req).pipe(proxyReq);
+    if (options.reqTransformStream) {
+      (options.buffer || req).pipe(options.reqTransformStream).pipe(proxyReq);
+    } else {
+      (options.buffer || req).pipe(proxyReq);
+    }
+
 
     proxyReq.on('response', function(proxyRes) {
       if(server) { server.emit('proxyRes', proxyRes, req, res); }
@@ -171,7 +176,12 @@ module.exports = {
         server.emit('end', req, res, proxyRes);
       });
 
-      proxyRes.pipe(res);
+      if (options.resTransformStream) {
+        proxyRes.pipe(options.resTransformStream).pipe(res);
+      } else {
+        proxyRes.pipe(res);
+      }
+
     });
 
     //proxyReq.end();