I try to set some configuration values during the startup before I configure Kestrel. I try to do this to use some settings from singleton and a ILogger during the configuration.

Simplified sample:

var builder = WebApplication.CreateBuilder(options);

builder.Services.Configure<MyKestrelOptions>(optionsKestrel =>
{
    //Debugger nerver stops here
    var configService = builder.Services.BuildServiceProvider().GetRequiredService<IConfigurationService>();
    var logger = builder.Services.BuildServiceProvider().GetRequiredService<ILogger<Program>>();
    KestrelStartup.BuildOptions(configService, optionsKestrel, null);
});

builder.Services.AddSingleton<IConfigurationService, ConfigurationService>();

builder.WebHost.ConfigureKestrel((context, serverOptions) =>
{
    var optionsKestrel = context.Configuration.Get<KestrelOptions>();
    if (optionsKestrel != null)
    {
        optionsKestrel.Logger?.LogDebug("DEBUG POSSIBLE");
    }
});

public class KestrelOptions
{
    public String? ServerPfxPath { get; set; }
    public ILogger? Logger { get; set; }
}

While Debugging I never stopped in the Configure lamba. And optionsKestrel.Logger is allways null.

How to achieve this as I need some configuration settings to be read in ConfigurationService for configure Kestrel and what to log during some callbacks (ClientCertificateValidation) configured in builder.WebHost.ConfigureKestrel.