Add [Obsolete] attribute to WebHost, IWebHost, and WebHostService

Added ASPDEPR008 diagnostic code for WebHost and IWebHost related APIs
Added ASPDEPR009 diagnostic code for WebHostService and related APIs

Author: Copilot

src/Components/test/testassets/ComponentsApp.Server/Program.cs

@@ -1,7 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.AspNetCore;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 
 namespace ComponentsApp.Server;
 
@@ -12,10 +13,13 @@ public static void Main(string[] args)
         BuildWebHost(args).Run();
     }
 
-    public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-        WebHost.CreateDefaultBuilder(args)
-            .UseStartup<Startup>();
+    public static IHostBuilder CreateHostBuilder(string[] args) =>
+        Host.CreateDefaultBuilder(args)
+            .ConfigureWebHostDefaults(webBuilder =>
+            {
+                webBuilder.UseStartup<Startup>();
+            });
 
-    public static IWebHost BuildWebHost(string[] args) =>
-        CreateWebHostBuilder(args).Build();
+    public static IHost BuildWebHost(string[] args) =>
+        CreateHostBuilder(args).Build();
 }

src/DataProtection/DataProtection/test/Microsoft.AspNetCore.DataProtection.Tests/HostingTests.cs

@@ -36,7 +36,9 @@ public async Task WebhostLoadsKeyRingBeforeServerStarts()
                     new FakeServer(onStart: () => tcs.TrySetException(new InvalidOperationException("Server was started before key ring was initialized")))));
 #pragma warning restore ASPDEPR004 // Type or member is obsolete
 
+#pragma warning disable ASPDEPR008 // IWebHost is obsolete
         using (var host = builder.Build())
+#pragma warning restore ASPDEPR008 // IWebHost is obsolete
         {
             await host.StartAsync();
         }

src/DefaultBuilder/samples/SampleApp/Program.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+#pragma warning disable ASPDEPR008 // Type or member is obsolete
+
 using Microsoft.AspNetCore;
 
 namespace SampleApp;

src/DefaultBuilder/src/ConfigureWebHostBuilder.cs

@@ -28,10 +28,12 @@ internal ConfigureWebHostBuilder(WebHostBuilderContext webHostBuilderContext, Co
         _context = webHostBuilderContext;
     }
 
+#pragma warning disable ASPDEPR008 // IWebHost is obsolete
     IWebHost IWebHostBuilder.Build()
     {
         throw new NotSupportedException($"Call {nameof(WebApplicationBuilder)}.{nameof(WebApplicationBuilder.Build)}() instead.");
     }
+#pragma warning restore ASPDEPR008 // IWebHost is obsolete
 
     /// <inheritdoc />
     public IWebHostBuilder ConfigureAppConfiguration(Action<WebHostBuilderContext, IConfigurationBuilder> configureDelegate)

src/DefaultBuilder/src/GenericHostBuilderExtensions.cs

@@ -61,7 +61,9 @@ public static IHostBuilder ConfigureWebHostDefaults(this IHostBuilder builder, A
 
         return builder.ConfigureWebHost(webHostBuilder =>
         {
+#pragma warning disable ASPDEPR008 // Type or member is obsolete
             WebHost.ConfigureWebDefaults(webHostBuilder);
+#pragma warning restore ASPDEPR008 // Type or member is obsolete
 
             configure(webHostBuilder);
         }, configureOptions);

src/DefaultBuilder/src/WebApplicationBuilder.cs

@@ -127,7 +127,9 @@ internal WebApplicationBuilder(WebApplicationOptions options, bool slim, Action<
         bootstrapHostBuilder.ConfigureSlimWebHost(
             webHostBuilder =>
             {
+#pragma warning disable ASPDEPR008 // Type or member is obsolete
                 AspNetCore.WebHost.ConfigureWebDefaultsSlim(webHostBuilder);
+#pragma warning restore ASPDEPR008 // Type or member is obsolete
 
                 // Runs inline.
                 webHostBuilder.Configure(ConfigureApplication);

src/DefaultBuilder/src/WebHost.cs

@@ -21,6 +21,7 @@ namespace Microsoft.AspNetCore;
 /// <summary>
 /// Provides convenience methods for creating instances of <see cref="IWebHost"/> and <see cref="IWebHostBuilder"/> with pre-configured defaults.
 /// </summary>
+[Obsolete("WebHost is obsolete. Use HostBuilder or WebApplicationBuilder instead. For more information, visit https://aka.ms/aspnet/deprecate/008.", DiagnosticId = "ASPDEPR008")]
 public static class WebHost
 {
     /// <summary>

src/DefaultBuilder/test/Microsoft.AspNetCore.FunctionalTests/WebHostFunctionalTests.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+#pragma warning disable ASPDEPR008 // Type or member is obsolete
+
 using System.Net.Http;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Server.IntegrationTesting;

src/DefaultBuilder/test/Microsoft.AspNetCore.Tests/WebApplicationTests.cs

@@ -377,7 +377,9 @@ public void WebApplicationBuilderHost_ThrowsWhenBuiltDirectly(CreateBuilderFunc
     [MemberData(nameof(CreateBuilderFuncs))]
     public void WebApplicationBuilderWebHost_ThrowsWhenBuiltDirectly(CreateBuilderFunc createBuilder)
     {
+#pragma warning disable ASPDEPR008 // IWebHost is obsolete
         Assert.Throws<NotSupportedException>(() => ((IWebHostBuilder)createBuilder().WebHost).Build());
+#pragma warning restore ASPDEPR008 // IWebHost is obsolete
     }
 
     [Theory]

src/DefaultBuilder/test/Microsoft.AspNetCore.Tests/WebHostTests.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+#pragma warning disable ASPDEPR008 // IWebHost is obsolete
+
 using System.Collections.Concurrent;
 using System.Diagnostics.Tracing;
 using Microsoft.AspNetCore.Builder;