Options Pattern in ASP.NET Core (edit)
Options pattern in ASP.NET Core
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/options?view=aspnetcore-2.1
ASP.NET Using Options Sample
https://github.com/aspnet/Docs/tree/master/aspnetcore/fundamentals/configuration/options/sample
How to use the IOptions pattern for configuration in ASP.NET Core RC2
https://andrewlock.net/how-to-use-the-ioptions-pattern-for-configuration-in-asp-net-core-rc2/