Stock checker application API

To start with, we'll create our stock checker application with all its functionality enabled for everyone, we'll use IdentityServer to lock down the application to only users that are authenticated, and finally, we'll enable only the correct functionality for the user.

Setup

The first stage will be to create our API. In .NET Core, the concept of an ApiController is replaced with a simple Controller; that is, there is no distinction between a controller method serving data and one serving a web page other than the return type.

Let's create our new project:

We'll create an empty application and add the API manually (targeting .NET Core 3.0):

This should give you a bare...