implemented static file serving HTTP module

lib/modules/http.js

@@ -1,7 +1,8 @@
 'use strict';
 
 module.exports.create = function (deps, conf) {
-  var app = require('express')();
+  var express = require('express');
+  var app = express();
   var adminApp = require('./admin').create(deps, conf);
   var domainMatches = require('../match-domain').match;
 
@@ -90,6 +91,38 @@ module.exports.create = function (deps, conf) {
     };
   }
 
+  function createStaticRoute(mod) {
+    var getStaticApp, staticApp;
+    if (/:hostname/.test(mod.root)) {
+      staticApp = {};
+      getStaticApp = function (hostname) {
+        if (!staticApp[hostname]) {
+          staticApp[hostname] = express.static(mod.root.replace(':hostname', hostname));
+        }
+        return staticApp[hostname];
+      };
+    }
+    else {
+      staticApp = express.static(mod.root);
+      getStaticApp = function () {
+        return staticApp;
+      };
+    }
+
+    return function (req, res, next) {
+      var hostname = req.headers.host.split(':')[0];
+      var relevant = mod.domains.some(function (pattern) {
+        return domainMatches(pattern, hostname);
+      });
+
+      if (relevant) {
+        getStaticApp(hostname)(req, res, next);
+      } else {
+        next();
+      }
+    };
+  }
+
   app.use(redirectHttps);
   app.use(handleAdmin);
 
@@ -97,6 +130,9 @@ module.exports.create = function (deps, conf) {
     if (mod.name === 'proxy') {
       app.use(createProxyRoute(mod));
     }
+    else if (mod.name === 'static') {
+      app.use(createStaticRoute(mod));
+    }
     else {
       console.warn('unknown HTTP module', mod);
     }