public class Program
{
  public static async Task Main(string[] args)
  {
    // The service provider factory used here allows for
    // ConfigureContainer to be supported in Startup with
    // a strongly-typed ContainerBuilder.
    var host = Host.CreateDefaultBuilder(args)
      .UseServiceProviderFactory(new AutofacServiceProviderFactory())
      .ConfigureWebHostDefaults(webHostBuilder => {
        webHostBuilder
          .UseContentRoot(Directory.GetCurrentDirectory())
          .UseIISIntegration()
          .UseStartup<Startup>()
      })
      .Build();

    await host.RunAsync();
  }
}

public class Startup
{
  public Startup(IWebHostEnvironment env)
  {
    var builder = new ConfigurationBuilder()
        .SetBasePath(env.ContentRootPath)
        .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
        .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
        .AddEnvironmentVariables();
    this.Configuration = builder.Build();
  }

  public IConfiguration Configuration { get; private set; }

  // ConfigureServices is where you register dependencies. This gets
  // called by the runtime before the ConfigureContainer method, below.
  public void ConfigureServices(IServiceCollection services)
  {
    // Add services to the collection. Don't build or return
    // any IServiceProvider or the ConfigureContainer method
    // won't get called.
    services.AddOptions();
  }

  // ConfigureContainer is where you can register things directly
  // with Autofac. This runs after ConfigureServices so the things
  // here will override registrations made in ConfigureServices.
  // Don't build the container; that gets done for you. If you
  // need a reference to the container, you need to use the
  // "Without ConfigureContainer" mechanism shown later.
  public void ConfigureContainer(ContainerBuilder builder)
  {
      builder.RegisterModule(new AutofacModule());
  }

  // Configure is where you add middleware. This is called after
  // ConfigureContainer. You can use IApplicationBuilder.ApplicationServices
  // here if you need to resolve things from the container.
  public void Configure(
    IApplicationBuilder app,
    ILoggerFactory loggerFactory)
  {
      loggerFactory.AddConsole(this.Configuration.GetSection("Logging"));
      loggerFactory.AddDebug();
      app.UseMvc();
  }
}