You can build a service provider using the BuildServiceProvider() method on the IServiceCollection:

public void ConfigureService(IServiceCollection services)
    // Configure the services
    services.AddTransient<IFooService, FooServiceImpl>();

    // Build an intermediate service provider
    var sp = services.BuildServiceProvider();

    // Resolve the services from the service provider
    var fooService = sp.GetService<IFooService>();
    var options = sp.GetService<IOptions<AppSettings>>();

You need the Microsoft.Extensions.DependencyInjection package for this.

In the case where you just need to bind some options in ConfigureServices, you can also use the Bind method:

var appSettings = new AppSettings();

This functionality is available through the Microsoft.Extensions.Configuration.Binder package.