How to validate configuration settings using IValidateOptions in ASP.NET Core 2.2?

Question

Microsoft\'s ASP.NET Core documentation briefly mentions that you can implement IValidateOptions to validate configuration settings from appsettings

Answer 1

Just build a lib for integrate FluentValidation with Microsoft.Extensions.Options.

https://github.com/iron9light/FluentValidation.Extensions

The nuget is here: https://www.nuget.org/packages/IL.FluentValidation.Extensions.Options/

Sample:

public class MyOptionsValidator : AbstractValidator {
    // ...
}

using IL.FluentValidation.Extensions.Options;

// Registration
services.AddOptions("optionalOptionsName")
    .Configure(o => { })
    .Validate(); // ❗ Register validator type

// Consumption
var monitor = services.BuildServiceProvider()
    .GetService>();

try
{
    var options = monitor.Get("optionalOptionsName");
}
catch (OptionsValidationException ex)
{
}