ASP.NET Core managed config

• ASP.NET Core MVC
• ASP.NET Core logging with Serilog
• ASP.NET Core managed config
• ASP.NET Core MVC with /api/-area
• ASP.NET Core API versioning
• ASP.NET Core API with Swagger UI
• ASP.NET Core EF in separate project
• ASP.NET Core AutoMapper
• ASP.NET Core response cache
• ASP.NET Core memory cache
• ASP.NET Core TypeScript

Reading config is pretty straight forward task that most applications need. For many years I used Nini, which scratched that itch fairly well. With the advent of better libraries its not too difficult to deserialize your favorite formatted config file into a class.

With .Net Core we finally got some decent/easy to use config system built in by the help of the Options pattern. In short, reading config by deserializing sections of appsettings.json into DI-hosted objects.

Install

Install-Package Microsoft.Extensions.Options.ConfigurationExtensions

Implement

In Startup.cs ConfigureServices method:

services.Configure<AppSettings>(Configuration);
services.Configure<OneSectionSettings>(Configuration.GetSection("TheSection"));

This would require a couple of classes, for example:

public class AppSettings
{
    public string RootValue { get; set; }
    public OneSectionSettings TheSection { get; set; }
}
public class OneSectionSettings
{
    public string SomeValue { get; set; }
}

And a corresponding config section

"RootValue":  "Yes, yes",
"OneSection": {
  "SomeValue": "Test"
}

If config section/values do not exist it will not produce any error.

Using

public class HomeController : Controller
{
    private AppSettings _appSettings;

    public HomeController(IOptions<AppSettings> appSettings)
    {
        _appSettings = appSettings.Value;
    }
...
}

Recall config object by IOptions<object> and use its “Value” property to extract object.