Add support for file based url list

index.js

@@ -4,33 +4,61 @@
 // 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 m = url.match(r);
-    if (!m) {
-      return;
-    }
-    var path = url.slice(m[0].length);
-    console.log('proxy:', url, '->', dest);
-    return {url: path, dest: dest};
+var fs = require('fs');
+
+function getMatchers(urls) {
+  var matchers = [],
+      matcher,
+      url,
+      r;
+
+  for (url in urls) {
+    // Call the 'matcher' function above, and store the resulting closure.
+    // First, turn the URL into a regex.  
+    // NOTE: Turning user input directly into a Regular Expression is NOT SAFE.
+    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.
+    matcher = (function(r) {
+      var dest = urls[url];
+      return function (url) {
+        var m = url.match(r);
+        if (!m) {
+          return;
+        }
+        var path = url.slice(m[0].length);
+        console.log('proxy:', url, '->', dest);
+        return ({url: path, dest: dest});
+      }})(r);
+    matchers.push(matcher);
   }
+  return matchers;
 }
 
 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]));
+  var matchers,
+      urlFile;
+  if (typeof urls === 'string') {
+    //
+    // If we are passed a string then assume it is a
+    // file path, parse that file and watch it for changes
+    //
+    urlsFile = urls,
+    urls = JSON.parse(fs.readFileSync(urlsFile));
+    fs.watchFile(urlsFile, function () {
+      console.log("Reloading urls...");
+      fs.readFile(urlsFile, function (err, data) {
+        if (err) {
+          self.emit('error', err);
+        }
+        urls = JSON.parse(data);
+        matchers = getMatchers(urls);
+      });
+    });
   }
+  matchers = getMatchers(urls);
 
   // This closure is returned as the request handler.
   middleware = function (req, res, next) {
@@ -61,6 +89,7 @@ module.exports = function (urls) {
     //
     // Same as above, but for WebSocket
     //
+    console.log("Websocket proxying : " + req.url);
     var proxy = next;
     for (var k in matchers) {
       // for each URL matcher, try the request's URL.