Mongoose models scheme in separate modul
Why don't you try to export the mongoose instance from your app-core module and use it later in the web-app to connect to a database
app-core index.js
var mongoose = require('mongoose');module.exports = { mongooseInstance: mongoose };
web-app index.js
var core = require('app-core'), mongoose = core.mongooseInstance,mongooseClient = mongoose.connect(DB_URL);// and so on
This might work as long as you require your models in your controllers which are initialized after the code from the index.js. I hope my response is helpful.