Add ConfigureHostOptions extension method on IHostBuilder (#51410)

- Add two `ConfigureHostOptions` extension methods
  - Two overloads exist, per [Maryam's comment](https://github.com/dotnet/runtime/pull/49502/files#r596466330)
- Add corresponding unit tests to ensure these new methods function correctly 

Fixes #48743

src/libraries/Microsoft.Extensions.Hosting/ref/Microsoft.Extensions.Hosting.cs

@@ -45,6 +45,8 @@ public static partial class HostingHostBuilderExtensions
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureAppConfiguration(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Configuration.IConfigurationBuilder> configureDelegate) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureContainer<TContainerBuilder>(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<TContainerBuilder> configureDelegate) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureDefaults(this Microsoft.Extensions.Hosting.IHostBuilder builder, string[] args) { throw null; }
+        public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureHostOptions(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Hosting.HostBuilderContext, Microsoft.Extensions.Hosting.HostOptions> configureOptions) { throw null; }
+        public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureHostOptions(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Hosting.HostOptions> configureOptions) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureLogging(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Hosting.HostBuilderContext, Microsoft.Extensions.Logging.ILoggingBuilder> configureLogging) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureLogging(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Logging.ILoggingBuilder> configureLogging) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder ConfigureServices(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.DependencyInjection.IServiceCollection> configureDelegate) { throw null; }

src/libraries/Microsoft.Extensions.Hosting/src/HostingHostBuilderExtensions.cs

@@ -100,6 +100,31 @@ public static IHostBuilder ConfigureLogging(this IHostBuilder hostBuilder, Actio
         {
             return hostBuilder.ConfigureServices((context, collection) => collection.AddLogging(builder => configureLogging(builder)));
         }
+
+        /// <summary>
+        /// Adds a delegate for configuring the <see cref="HostOptions"/> of the <see cref="IHost"/>.
+        /// </summary>
+        /// <param name="hostBuilder">The <see cref="IHostBuilder" /> to configure.</param>
+        /// <param name="configureOptions">The delegate for configuring the <see cref="HostOptions"/>.</param>
+        /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
+        public static IHostBuilder ConfigureHostOptions(this IHostBuilder hostBuilder, Action<HostBuilderContext, HostOptions> configureOptions)
+        {
+            return hostBuilder.ConfigureServices(
+                (context, collection) => collection.Configure<HostOptions>(options => configureOptions(context, options)));
+        }
+
+        /// <summary>
+        /// Adds a delegate for configuring the <see cref="HostOptions"/> of the <see cref="IHost"/> instance
+        /// related to th.
+        /// </summary>
+        /// <param name="hostBuilder">The <see cref="IHostBuilder" /> to configure.</param>
+        /// <param name="configureOptions">The delegate for configuring the <see cref="HostOptions"/>.</param>
+        /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
+        public static IHostBuilder ConfigureHostOptions(this IHostBuilder hostBuilder, Action<HostOptions> configureOptions)
+        {
+            return hostBuilder.ConfigureServices(collection => collection.Configure(configureOptions));
+        }
+
         /// <summary>
         /// Sets up the configuration for the remainder of the build process and application. This can be called multiple times and
         /// the results will be additive. The results will be available at <see cref="HostBuilderContext.Configuration"/> for
@@ -245,7 +270,7 @@ public static IHostBuilder ConfigureDefaults(this IHostBuilder builder, string[]
         /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
         public static IHostBuilder UseConsoleLifetime(this IHostBuilder hostBuilder)
         {
-            return hostBuilder.ConfigureServices((context, collection) => collection.AddSingleton<IHostLifetime, ConsoleLifetime>());
+            return hostBuilder.ConfigureServices(collection => collection.AddSingleton<IHostLifetime, ConsoleLifetime>());
         }
 
         /// <summary>
@@ -257,7 +282,7 @@ public static IHostBuilder UseConsoleLifetime(this IHostBuilder hostBuilder)
         /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
         public static IHostBuilder UseConsoleLifetime(this IHostBuilder hostBuilder, Action<ConsoleLifetimeOptions> configureOptions)
         {
-            return hostBuilder.ConfigureServices((context, collection) =>
+            return hostBuilder.ConfigureServices(collection =>
             {
                 collection.AddSingleton<IHostLifetime, ConsoleLifetime>();
                 collection.Configure(configureOptions);

src/libraries/Microsoft.Extensions.Hosting/tests/UnitTests/HostBuilderTests.cs

@@ -257,8 +257,8 @@ public void HostConfigParametersReadCorrectly()
         {
             var parameters = new Dictionary<string, string>()
             {
-                { "applicationName", "MyProjectReference"},
-                { "environment", Environments.Development},
+                { "applicationName", "MyProjectReference" },
+                { "environment", Environments.Development },
                 { "contentRoot", Path.GetFullPath(".") }
             };
 
@@ -332,6 +332,66 @@ public void DefaultCreatesLoggerFactory()
             }
         }
 
+        public static IEnumerable<object[]> ConfigureHostOptionsTestInput = new[]
+        {
+            new object[] { BackgroundServiceExceptionBehavior.Ignore, TimeSpan.FromDays(3) },
+            new object[] { BackgroundServiceExceptionBehavior.StopHost, TimeSpan.FromTicks(long.MaxValue) },
+        };
+
+        [Theory]
+        [MemberData(nameof(ConfigureHostOptionsTestInput))]
+        public void CanConfigureHostOptionsWithOptionsOverload(
+            BackgroundServiceExceptionBehavior testBehavior, TimeSpan testShutdown)
+        {
+            using var host = new HostBuilder()
+                .ConfigureDefaults(Array.Empty<string>())
+                .ConfigureHostOptions(
+                    options =>
+                    {
+                        options.BackgroundServiceExceptionBehavior = testBehavior;
+                        options.ShutdownTimeout = testShutdown;
+                    })
+                .Build();
+
+            var options = host.Services.GetRequiredService<IOptions<HostOptions>>();
+            Assert.NotNull(options.Value);
+
+            var hostOptions = options.Value;
+            Assert.Equal(testBehavior, hostOptions.BackgroundServiceExceptionBehavior);
+            Assert.Equal(testShutdown, hostOptions.ShutdownTimeout);
+        }
+
+        [Theory]
+        [MemberData(nameof(ConfigureHostOptionsTestInput))]
+        public void CanConfigureHostOptionsWithContenxtAndOptionsOverload(
+            BackgroundServiceExceptionBehavior testBehavior, TimeSpan testShutdown)
+        {
+            using var host = new HostBuilder()
+                .ConfigureDefaults(Array.Empty<string>())
+                .ConfigureHostOptions(
+                    (context, options) =>
+                    {
+                        context.HostingEnvironment.ApplicationName = "TestApp";
+                        context.HostingEnvironment.EnvironmentName = Environments.Staging;
+
+                        options.BackgroundServiceExceptionBehavior = testBehavior;
+                        options.ShutdownTimeout = testShutdown;
+                    })
+                .Build();
+
+            var options = host.Services.GetRequiredService<IOptions<HostOptions>>();
+            Assert.NotNull(options.Value);
+
+            var hostOptions = options.Value;
+            Assert.Equal(testBehavior, hostOptions.BackgroundServiceExceptionBehavior);
+            Assert.Equal(testShutdown, hostOptions.ShutdownTimeout);
+
+            var env = host.Services.GetRequiredService<IHostEnvironment>();
+
+            Assert.Equal("TestApp", env.ApplicationName);
+            Assert.Equal(Environments.Staging, env.EnvironmentName);
+        }
+
         [Fact]
         public void MultipleConfigureLoggingInvokedInOrder()
         {
@@ -552,7 +612,7 @@ public void HostServicesSameServiceProviderAsInHostBuilder()
         {
             var hostBuilder = Host.CreateDefaultBuilder();
             var host = hostBuilder.Build();
-            
+
             var type = hostBuilder.GetType();
             var field = type.GetField("_appServices", BindingFlags.Instance | BindingFlags.NonPublic)!;
             var appServicesFromHostBuilder = (IServiceProvider)field.GetValue(hostBuilder)!;