Store internal IP in docker host

node_modules/c9/manifest.js

@@ -1,5 +1,6 @@
 var git = require("./git");
 var hostname = require("./hostname");
+var os = require("os");
 
 exports.load = function(root) {
     var manifest = require(root + "/package.json");
@@ -8,6 +9,7 @@ exports.load = function(root) {
         git.getHeadRevisionSync(root);
 
     manifest.hostname = hostname.get();
+    manifest.internalIP = os.networkInterfaces().eth0 && os.networkInterfaces().eth0[0].address;
 
     return manifest;
 };