So far, you have your server.js file and a configure module that is used to wire up all of the necessary middleware for the application. The next step is to implement a proper router and controller.

The router is going to be a map of each of the available URL paths for the app. Every route on the server will correspond to a function in a controller. Here is what our routes table will look like for the particular application we are writing:

GET  /(index) - home.index (render the homepage of the site)
GET  /images/image_id -
 image.index (render the page for a specific image)
POST /images - image.create (when a user submits and uploads a new image)
POST /images/image_id/like - image.like (when a user clicks the Like button)
POST /images/image_id/comment - image.comment (when a user posts a comment)

You can see that we are handling two different GET requests and three different POST requests. In addition, we have two main controllers: home and image. Controllers are really...