Application listening port is configurable

dev-config.json

@@ -1,4 +1,5 @@
 {
   "title": "Habitat - The fastest path from code to cloud native.",
-  "message": "Welcome to the Habitat Node.js sample app."
+  "message": "Welcome to the Habitat Node.js sample app.",
+  "port": 8000
 }

habitat/config/config.json

@@ -1,4 +1,5 @@
 {
   "title": "{{ cfg.title }}",
-  "message": "You are running version {{ pkg.version }} of the Habitat Node.js sample app."
+  "message": "You are running version {{ pkg.version }} of the Habitat Node.js sample app.",
+  "port": "{{ cfg.port }}"
 }

habitat/default.toml

@@ -5,3 +5,4 @@
 # https://www.habitat.sh/docs/developing-packages/#add-configuration.
 
 title = "Habitat - The fastest path from code to cloud native."
+port = 8000

index.js

@@ -1,6 +1,7 @@
 var app = require('./app');
 var http = require('http');
-var port = process.env.PORT || 8000;
+var nconf = require('nconf');
+var port = process.env.PORT || nconf.get('port') || 8000;
 
 app.set('port', port);