Validating configuration (e.g., using IValidateOptions)?

You can validate bound config using IValidateOptions<T>:

public class MySettingsValidator : IValidateOptions<MySettings> {
public ValidateOptionsResult Validate(string name, MySettings

options) {

if (string.IsNullOrWhiteSpace(options.ApiKey)) {
return ValidateOptionsResult.Fail("ApiKey is

required.");

}
return ValidateOptionsResult.Success;
}
}

Register with DI:

services.AddSingleton<IValidateOptions<MySettings>,

MySettingsValidator>();