Mark WebHostBuilder class as obsolete

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

@@ -25,8 +25,12 @@ public async Task WebhostLoadsKeyRingBeforeServerStarts()
             .Returns(Mock.Of<IKeyRing>())
             .Callback(() => tcs.TrySetResult());
 
-        var builder = new WebHostBuilder()
-            .UseStartup<TestStartup>()
+        var builder = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseStartup<TestStartup>();
+            })
             .ConfigureServices(s =>
                 s.AddDataProtection()
                 .Services

src/Hosting/Hosting/src/WebHostBuilder.cs

@@ -20,6 +20,7 @@ namespace Microsoft.AspNetCore.Hosting;
 /// <summary>
 /// A builder for <see cref="IWebHost"/>
 /// </summary>
+[Obsolete("TODO: Add Obsolete message")]
 public class WebHostBuilder : IWebHostBuilder
 {
     private readonly HostingEnvironment _hostingEnvironment;

src/Hosting/Hosting/test/WebHostBuilderTests.cs

@@ -429,6 +429,7 @@ public void DoNotCaptureStartupErrorsByDefault(IWebHostBuilder builder)
     public void ServiceProviderDisposedOnBuildException()
     {
         var service = new DisposableService();
+#pragma warning disable CS0618 // Type or member is obsolete
         var hostBuilder = new WebHostBuilder()
             .UseServer(new TestServer())
             .ConfigureServices(services =>
@@ -437,6 +438,7 @@ public void ServiceProviderDisposedOnBuildException()
                 services.AddSingleton(sp => service);
             })
             .UseStartup<StartupWithResolvedDisposableThatThrows>();
+#pragma warning restore CS0618 // Type or member is obsolete
 
         Assert.Throws<InvalidOperationException>(() => hostBuilder.Build());
         Assert.True(service.Disposed);
@@ -1483,14 +1485,18 @@ private IWebHostBuilder CreateWebHostBuilder()
             .AddInMemoryCollection(vals);
         var config = builder.Build();
 
+#pragma warning disable CS0618 // Type or member is obsolete
         return new WebHostBuilder().UseConfiguration(config);
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
+#pragma warning disable CS0618 // Type or member is obsolete
     public static TheoryData<IWebHostBuilder> DefaultWebHostBuilders => new TheoryData<IWebHostBuilder>
         {
             new WebHostBuilder(),
             new GenericWebHostBuilderWrapper(new HostBuilder())
         };
+#pragma warning restore CS0618 // Type or member is obsolete
 
     public static TheoryData<IWebHostBuilder> DefaultWebHostBuildersWithConfig
     {
@@ -1506,10 +1512,12 @@ public static TheoryData<IWebHostBuilder> DefaultWebHostBuildersWithConfig
                 .AddInMemoryCollection(vals);
             var config = builder.Build();
 
+#pragma warning disable CS0618 // Type or member is obsolete
             return new TheoryData<IWebHostBuilder> {
                     new WebHostBuilder().UseConfiguration(config),
                     new GenericWebHostBuilderWrapper(new HostBuilder()).UseConfiguration(config)
                 };
+#pragma warning restore CS0618 // Type or member is obsolete
         }
     }
 
@@ -1783,3 +1791,4 @@ public void Dispose()
         public void AddProvider(ILoggerProvider provider) { }
     }
 }
+//#pragma warning restore CS0618 // Type or member is obsolete

src/Hosting/Hosting/test/WebHostTests.cs

@@ -1103,7 +1103,9 @@ private IWebHost CreateHost(RequestDelegate requestDelegate)
 
     private IWebHostBuilder CreateBuilder(IConfiguration config = null)
     {
+#pragma warning disable CS0618 // Type or member is obsolete
         return new WebHostBuilder().UseConfiguration(config ?? new ConfigurationBuilder().Build()).UseStartup("Microsoft.AspNetCore.Hosting.Tests");
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
     private static bool[] RegisterCallbacksThatThrow(IServiceCollection services)

src/Hosting/TestHost/test/Microsoft.AspNetCore.TestHost.Tests.csproj

@@ -2,6 +2,8 @@
 
   <PropertyGroup>
     <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+    <!-- CS0618: WebHostBuilder is obsolete -->
+    <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/Hosting/WindowsServices/test/Microsoft.AspNetCore.Hosting.WindowsServices.Tests.csproj

@@ -2,6 +2,8 @@
 
   <PropertyGroup>
     <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
+    <!-- CS0618: WebHostBuilder is obsolete -->
+    <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/Hosting/test/testassets/IStartupInjectionAssemblyName/IStartupInjectionAssemblyName.csproj

@@ -3,6 +3,8 @@
   <PropertyGroup>
     <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
     <OutputType>Exe</OutputType>
+    <!-- CS0618: WebHostBuilder is obsolete -->
+    <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/Hosting/test/testassets/Microsoft.AspNetCore.Hosting.TestSites/Microsoft.AspNetCore.Hosting.TestSites.csproj

@@ -3,6 +3,8 @@
   <PropertyGroup>
     <TargetFramework>$(DefaultNetCoreTargetFramework)</TargetFramework>
     <OutputType>Exe</OutputType>
+    <!-- CS0618: WebHostBuilder is obsolete -->
+    <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/Servers/IIS/IIS/test/testassets/InProcessWebSite/Program.cs

@@ -56,9 +56,13 @@
                 return 12;
             case "HangOnStop":
                 {
-                    var host = new WebHostBuilder()
-                        .UseIIS()
-                        .UseStartup<Startup>()
+                    var host = new HostBuilder()
+                        .ConfigureWebHost(webHostBuilder =>
+                        {
+                            webHostBuilder
+                                .UseIIS()
+                                .UseStartup<Startup>();
+                        })
                         .Build();
                     host.Run();
 
@@ -67,10 +71,14 @@
                 break;
             case "IncreaseShutdownLimit":
                 {
-                    var host = new WebHostBuilder()
-                        .UseIIS()
-                        .UseShutdownTimeout(TimeSpan.FromSeconds(120))
-                        .UseStartup<Startup>()
+                    var host = new HostBuilder()
+                        .ConfigureWebHost(webHostBuilder =>
+                        {
+                            webHostBuilder
+                                .UseIIS()
+                                .UseShutdownTimeout(TimeSpan.FromSeconds(120))
+                                .UseStartup<Startup>();
+                        })
                         .Build();
 
                     host.Run();
@@ -94,11 +102,15 @@
                 return 0;
             case "OverriddenServer":
                 {
-                    var host = new WebHostBuilder()
-                            .UseIIS()
-                            .ConfigureServices(services => services.AddSingleton<IServer, DummyServer>())
-                            .Configure(builder => builder.Run(async context => { await context.Response.WriteAsync("I shouldn't work"); }))
-                            .Build();
+                    var host = new HostBuilder()
+                        .ConfigureWebHost(webHostBuilder =>
+                        {
+                            webHostBuilder
+                                .UseIIS()
+                                .ConfigureServices(services => services.AddSingleton<IServer, DummyServer>())
+                                .Configure(builder => builder.Run(async context => { await context.Response.WriteAsync("I shouldn't work"); }));
+                        })
+                        .Build();
                     host.Run();
                 }
                 break;
@@ -111,18 +123,22 @@
 #if !FORWARDCOMPAT
             case "DecreaseRequestLimit":
                 {
-                    var host = new WebHostBuilder()
+                    var host = new HostBuilder()
                         .ConfigureLogging((_, factory) =>
                         {
                             factory.AddConsole();
                             factory.AddFilter("Console", level => level >= LogLevel.Information);
                         })
-                        .UseIIS()
-                        .ConfigureServices(services =>
+                        .ConfigureWebHost(webHostBuilder =>
                         {
-                            services.Configure<IISServerOptions>(options => options.MaxRequestBodySize = 2);
+                            webHostBuilder
+                                .UseIIS()
+                                .ConfigureServices(services =>
+                                {
+                                    services.Configure<IISServerOptions>(options => options.MaxRequestBodySize = 2);
+                                })
+                                .UseStartup<Startup>();
                         })
-                        .UseStartup<Startup>()
                         .Build();
 
                     host.Run();
@@ -131,15 +147,19 @@
 #endif
             case "ThrowInStartup":
                 {
-                    var host = new WebHostBuilder()
-                                    .ConfigureLogging((_, factory) =>
-                                    {
-                                        factory.AddConsole();
-                                        factory.AddFilter("Console", level => level >= LogLevel.Information);
-                                    })
-                                    .UseIIS()
-                                    .UseStartup<ThrowingStartup>()
-                                    .Build();
+                    var host = new HostBuilder()
+                        .ConfigureLogging((_, factory) =>
+                        {
+                            factory.AddConsole();
+                            factory.AddFilter("Console", level => level >= LogLevel.Information);
+                        })
+                        .ConfigureWebHost(webHostBuilder =>
+                        {
+                            webHostBuilder
+                                .UseIIS()
+                                .UseStartup<ThrowingStartup>();
+                        })
+                        .Build();
 
                     host.Run();
                 }
@@ -189,16 +209,20 @@
 
     private static int StartServer()
     {
-        var host = new WebHostBuilder()
+        var host = new HostBuilder()
             .ConfigureLogging((_, factory) =>
             {
                 factory.AddConsole();
                 factory.AddFilter("Console", level => level >= LogLevel.Information);
             })
-            .UseKestrel()
-            .UseIIS()
-            .UseIISIntegration()
-            .UseStartup<Startup>()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseKestrel()
+                    .UseIIS()
+                    .UseIISIntegration()
+                    .UseStartup<Startup>();
+            })
             .Build();
 
         host.Run();

src/Servers/Kestrel/test/Interop.FunctionalTests/Http3/Http3TlsTests.cs

@@ -345,39 +345,43 @@ public async Task TlsHandshakeCallbackOptions_Invoked()
     [InlineData(false, false, false)]
     public async Task UseKestrelCore_CodeBased(bool useQuic, bool useHttps, bool useHttpsEnablesHttpsConfiguration)
     {
-        var hostBuilder = new WebHostBuilder()
-                .UseKestrelCore()
-                .ConfigureKestrel(serverOptions =>
-                {
-                    serverOptions.ListenAnyIP(0, listenOptions =>
+        var hostBuilder = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseKestrelCore()
+                    .ConfigureKestrel(serverOptions =>
                     {
-                        listenOptions.Protocols = HttpProtocols.Http3;
-                        if (useHttps)
+                        serverOptions.ListenAnyIP(0, listenOptions =>
                         {
-                            if (useHttpsEnablesHttpsConfiguration)
+                            listenOptions.Protocols = HttpProtocols.Http3;
+                            if (useHttps)
                             {
-                                listenOptions.UseHttps(httpsOptions =>
+                                if (useHttpsEnablesHttpsConfiguration)
                                 {
-                                    httpsOptions.ServerCertificate = TestResources.GetTestCertificate();
-                                });
-                            }
-                            else
-                            {
-                                // Specifically choose an overload that doesn't enable https configuration
-                                listenOptions.UseHttps(new HttpsConnectionAdapterOptions
+                                    listenOptions.UseHttps(httpsOptions =>
+                                    {
+                                        httpsOptions.ServerCertificate = TestResources.GetTestCertificate();
+                                    });
+                                }
+                                else
                                 {
-                                    ServerCertificate = TestResources.GetTestCertificate()
-                                });
+                                    // Specifically choose an overload that doesn't enable https configuration
+                                    listenOptions.UseHttps(new HttpsConnectionAdapterOptions
+                                    {
+                                        ServerCertificate = TestResources.GetTestCertificate()
+                                    });
+                                }
                             }
-                        }
-                    });
-                })
-                .Configure(app => { });
+                        });
+                    })
+                    .Configure(app => { });
 
-        if (useQuic)
-        {
-            hostBuilder.UseQuic();
-        }
+                if (useQuic)
+                {
+                    webHostBuilder.UseQuic();
+                }
+            });
 
         var host = hostBuilder.Build();
 
@@ -400,25 +404,29 @@ public async Task UseKestrelCore_CodeBased(bool useQuic, bool useHttps, bool use
     [InlineData(false)]
     public void UseKestrelCore_ConfigurationBased(bool useQuic)
     {
-        var hostBuilder = new WebHostBuilder()
-                .UseKestrelCore()
-                .ConfigureKestrel(serverOptions =>
-                {
-                    var config = new ConfigurationBuilder().AddInMemoryCollection(new[]
+        var hostBuilder = new HostBuilder()
+            .ConfigureWebHost(webHostBuilder =>
+            {
+                webHostBuilder
+                    .UseKestrelCore()
+                    .ConfigureKestrel(serverOptions =>
                     {
-                        new KeyValuePair<string, string>("Endpoints:end1:Url", "https://127.0.0.1:0"),
-                        new KeyValuePair<string, string>("Endpoints:end1:Protocols", "Http3"),
-                        new KeyValuePair<string, string>("Certificates:Default:Path", Path.Combine("shared", "TestCertificates", "aspnetdevcert.pfx")),
-                        new KeyValuePair<string, string>("Certificates:Default:Password", "testPassword"),
-                    }).Build();
-                    serverOptions.Configure(config);
-                })
-                .Configure(app => { });
-
-        if (useQuic)
-        {
-            hostBuilder.UseQuic();
-        }
+                        var config = new ConfigurationBuilder().AddInMemoryCollection(new[]
+                        {
+                            new KeyValuePair<string, string>("Endpoints:end1:Url", "https://127.0.0.1:0"),
+                            new KeyValuePair<string, string>("Endpoints:end1:Protocols", "Http3"),
+                            new KeyValuePair<string, string>("Certificates:Default:Path", Path.Combine("shared", "TestCertificates", "aspnetdevcert.pfx")),
+                            new KeyValuePair<string, string>("Certificates:Default:Password", "testPassword"),
+                        }).Build();
+                        serverOptions.Configure(config);
+                    })
+                    .Configure(app => { });
+
+                if (useQuic)
+                {
+                    webHostBuilder.UseQuic();
+                }
+            });
 
         var host = hostBuilder.Build();