Enable support for building services with IHostApplicationBuilder

[pedropaulovc]

.NET 6 brought new builder types inheriting from IHostApplicationBuilder that refactor how to developers may build web / console hosts with fewer callbacks: Comparing WebApplicationBuilder to the Generic Host

WebApplicationBuilder : IHostApplicationBuilder
HostApplicationBuilder : IHostApplicationBuilder

The old IHostBuilder pattern remains supported. A comparision of how both initializations can work is:

IHostBuilder

IHostApplicationBuilder

HostApplicationBuilder builder = Host.CreateApplicationBuilder(args); builder.Configuration.AddUserSecrets<Program>(); builder.Services.Configure<TaskHubOptions>(opt => { opt.CreateIfNotExists = true; }); builder.Services.AddSingleton<IConsole, ConsoleWrapper>(); builder.Services.AddHostedService<TaskEnqueuer>(); builder.Services.AddSingleton(UseLocalEmulator()); builder.ConfigureTaskHubWorker((context, builder) => { builder.AddClient(); builder.UseOrchestrationMiddleware<SampleMiddleware>(); builder.UseActivityMiddleware<SampleMiddleware>(); builder .AddOrchestration<GreetingsOrchestration>() .AddOrchestration<GenericOrchestrationRunner>(); builder.AddActivitiesFromAssembly<Program>(); }); IHost host = builder.Build(); return host.RunAsync();

IHost host = Host.CreateDefaultBuilder(args) .ConfigureAppConfiguration(builder => builder.AddUserSecrets<Program>()) .ConfigureServices(services => { services.Configure<TaskHubOptions>(opt => { opt.CreateIfNotExists = true; }); services.AddSingleton<IConsole, ConsoleWrapper>(); services.AddHostedService<TaskEnqueuer>(); services.AddSingleton(UseLocalEmulator()); }) .ConfigureTaskHubWorker((context, builder) => { builder.AddClient(); builder.UseOrchestrationMiddleware<SampleMiddleware>(); builder.UseActivityMiddleware<SampleMiddleware>(); builder .AddOrchestration<GreetingsOrchestration>() .AddOrchestration<GenericOrchestrationRunner>(); builder.AddActivitiesFromAssembly<Program>(); }) .UseConsoleLifetime() .Build(); return host.RunAsync();

[jviau]

@pedropaulovc thank you for opening this issue, and I agree that not being compatible with the IHostApplicationBuilder model is not ideal. After thinking on this, I think my preferred approach would be to move to work off exclusively IServiceCollection and no longer rely on IHostBuilder or IHostApplicationBuilder at all - this will entirely avoid the need to upgrade the Microsoft.Extensions.* packages.

If you want to take on that work it would be greatly appreciated, as I am not sure when I get around to that.