inital

.gitignore

+node_modules
+node_modules/*
+npm_debug.log

index.js

+//
+// This is an example of a url-routing middleware.
+// This is not intended for production use, but rather as
+// an example of how to write a middleware.
+//
+
+function matcher (url, dest) {
+  // First, turn the URL into a regex.  
+  // NOTE: Turning user input directly into a Regular Expression is NOT SAFE.
+  var r = new RegExp(url.replace(/\//, '\\/'));
+  // This next block of code may look a little confusing. 
+  // It returns a closure (anonymous function) for each URL to be matched,
+  // storing them in an array - on each request, if the URL matches one that has
+  // a function stored for it, the function will be called.
+  return function (url) {
+
+    var path = url.slice(m[0].length);
+    console.log('proxy:', url, '->', dest);
+    return {url: path, dest: dest};
+  }
+}
+
+module.exports = function (urls) {
+  // This is the entry point for our middleware.
+  // 'matchers' is the array of URL matchers, as mentioned above.
+  var matchers = [];
+  for (var url in urls) {
+    // Call the 'matcher' function above, and store the resulting closure.
+    matchers.push(matcher(url, urls[url]));
+  }
+
+  // This closure is returned as the request handler.
+  return function (req, res, next) {
+    //
+    // in node-http-proxy middlewares, `proxy` is the prototype of `next`
+    // (this means node-http-proxy middlewares support both the connect API (req, res, next)
+    // and the node-http-proxy API (req, res, proxy)
+    //
+    var proxy = next;
+    for (var k in matchers) {
+      // for each URL matcher, try the request's URL.
+      var m = matchers[k](req.url);
+      // If it's a match:
+      if (m) {
+        // Replace the local URL with the destination URL.
+        req.url = m.url;
+        // If routing to a server on another domain, the hostname in the request must be changed.
+        req.headers.host = m.host;
+        // Once any changes are taken care of, this line makes the magic happen.
+        proxy.proxyRequest(req, res, m.dest);
+      }
+    }
+  }
+}

package.json

+{ "name": "proxy-by-url"
+, "version": "0.0.0"
+, "description": "custom logic for node-http-proxy to proxy basedon incoming url"
+, "homepage": "http://github.com/dominictarr/proxy-by-url"
+, "repository": 
+  { "type": "git"
+  , "url": "https://github.com/dominictarr/proxy-by-url.git" }
+, "dependencies": {}
+, "devDependencies": {}
+, "author": "Dominic Tarr <dominic.tarr@gmail.com> (http://bit.ly/dominictarr)"
+, "scripts": { "test": "meta-test test/*.js" } }
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