Add AddSystemd() and AddWindowsService() IServiceCollection extension methods

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

@@ -8,7 +8,8 @@ namespace Microsoft.Extensions.Hosting
 {
     public static partial class SystemdHostBuilderExtensions
     {
-        public static Microsoft.Extensions.Hosting.IHostBuilder UseSystemd(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder) { throw null; }
+        public static Microsoft.Extensions.DependencyInjection.IServiceCollection UseSystemd(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) { throw null; }
+        public static Microsoft.Extensions.Hosting.IHostBuilder AddSystemd(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder) { throw null; }
     }
 }
 namespace Microsoft.Extensions.Hosting.Systemd
@@ -31,19 +32,19 @@ public static partial class SystemdHelpers
     {
         public static bool IsSystemdService() { throw null; }
     }
-    [System.Runtime.Versioning.UnsupportedOSPlatform("android")]
-    [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
-    [System.Runtime.Versioning.UnsupportedOSPlatform("ios")]
-    [System.Runtime.Versioning.UnsupportedOSPlatform("maccatalyst")]
-    [System.Runtime.Versioning.UnsupportedOSPlatform("tvos")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("android")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("browser")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("ios")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("maccatalyst")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("tvos")]
     public partial class SystemdLifetime : Microsoft.Extensions.Hosting.IHostLifetime, System.IDisposable
     {
         public SystemdLifetime(Microsoft.Extensions.Hosting.IHostEnvironment environment, Microsoft.Extensions.Hosting.IHostApplicationLifetime applicationLifetime, Microsoft.Extensions.Hosting.Systemd.ISystemdNotifier systemdNotifier, Microsoft.Extensions.Logging.ILoggerFactory loggerFactory) { }
         public void Dispose() { }
         public System.Threading.Tasks.Task StopAsync(System.Threading.CancellationToken cancellationToken) { throw null; }
         public System.Threading.Tasks.Task WaitForStartAsync(System.Threading.CancellationToken cancellationToken) { throw null; }
     }
-    [System.Runtime.Versioning.UnsupportedOSPlatform("browser")]
+    [System.Runtime.Versioning.UnsupportedOSPlatformAttribute("browser")]
     public partial class SystemdNotifier : Microsoft.Extensions.Hosting.Systemd.ISystemdNotifier
     {
         public SystemdNotifier() { }

src/libraries/Microsoft.Extensions.Hosting.Systemd/src/SystemdHostBuilderExtensions.cs

@@ -13,7 +13,7 @@ namespace Microsoft.Extensions.Hosting
     public static class SystemdHostBuilderExtensions
     {
         /// <summary>
-        /// Sets the host lifetime to <see cref="SystemdLifetime" />,
+        /// Configures the <see cref="IHost"/> lifetime to <see cref="SystemdLifetime"/>,
         /// provides notification messages for application started and stopping,
         /// and configures console logging to the systemd format.
         /// </summary>
@@ -27,27 +27,63 @@ public static class SystemdHostBuilderExtensions
         ///     notifications. See https://www.freedesktop.org/software/systemd/man/systemd.service.html.
         ///   </para>
         /// </remarks>
-        /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to use.</param>
-        /// <returns></returns>
+        /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to configure.</param>
+        /// <returns>The <paramref name="hostBuilder"/> instance for chaining.</returns>
         public static IHostBuilder UseSystemd(this IHostBuilder hostBuilder)
         {
             if (SystemdHelpers.IsSystemdService())
             {
                 hostBuilder.ConfigureServices((hostContext, services) =>
                 {
-                    services.Configure<ConsoleLoggerOptions>(options =>
-                    {
-                        options.FormatterName = ConsoleFormatterNames.Systemd;
-                    });
-
-                    // IsSystemdService() will never return true for android/browser/iOS/tvOS
-#pragma warning disable CA1416 // Validate platform compatibility
-                    services.AddSingleton<ISystemdNotifier, SystemdNotifier>();
-                    services.AddSingleton<IHostLifetime, SystemdLifetime>();
-#pragma warning restore CA1416 // Validate platform compatibility
+                    AddSystemdLifetime(services);
                 });
             }
             return hostBuilder;
         }
+
+        /// <summary>
+        /// Configures the lifetime of the <see cref="IHost"/> built from <paramref name="services"/> to
+        /// <see cref="SystemdLifetime"/>, provides notification messages for application started
+        /// and stopping, and configures console logging to the systemd format.
+        /// </summary>
+        /// <remarks>
+        ///   <para>
+        ///     This is context aware and will only activate if it detects the process is running
+        ///     as a systemd Service.
+        ///   </para>
+        ///   <para>
+        ///     The systemd service file must be configured with <c>Type=notify</c> to enable
+        ///     notifications. See <see href="https://www.freedesktop.org/software/systemd/man/systemd.service.html"/>.
+        ///   </para>
+        /// </remarks>
+        /// <param name="services">
+        /// The <see cref="IServiceCollection"/> used to build the <see cref="IHost"/>.
+        /// For example, <see cref="HostApplicationBuilder.Services"/> or the <see cref="IServiceCollection"/> passed to the
+        /// <see cref="IHostBuilder.ConfigureServices(System.Action{HostBuilderContext, IServiceCollection})"/> callback.
+        /// </param>
+        /// <returns>The <paramref name="services"/> instance for chaining.</returns>
+        public static IServiceCollection AddSystemd(this IServiceCollection services)
+        {
+            if (SystemdHelpers.IsSystemdService())
+            {
+                AddSystemdLifetime(services);
+            }
+            return services;
+        }
+
+        private static void AddSystemdLifetime(IServiceCollection services)
+        {
+            services.Configure<ConsoleLoggerOptions>(options =>
+            {
+                options.FormatterName = ConsoleFormatterNames.Systemd;
+            });
+
+            // IsSystemdService() will never return true for android/browser/iOS/tvOS
+#pragma warning disable CA1416 // Validate platform compatibility
+            services.AddSingleton<ISystemdNotifier, SystemdNotifier>();
+            services.AddSingleton<IHostLifetime, SystemdLifetime>();
+#pragma warning restore CA1416 // Validate platform compatibility
+
+        }
     }
 }

src/libraries/Microsoft.Extensions.Hosting.Systemd/tests/UseSystemdTests.cs

@@ -12,16 +12,28 @@ public class UseSystemdTests
         [Fact]
         public void DefaultsToOffOutsideOfService()
         {
-            var host = new HostBuilder()
-                .UseSystemd()
+            using IHost host = new HostBuilder()
+                .AddSystemd()
                 .Build();
 
-            using (host)
+            var lifetime = host.Services.GetRequiredService<IHostLifetime>();
+            Assert.IsNotType<SystemdLifetime>(lifetime);
+        }
+
+        [Fact]
+        public void ServiceCollectionExtensionMethodDefaultsToOffOutsideOfService()
+        {
+            var builder = new HostApplicationBuilder(new HostApplicationBuilderSettings
             {
-                var lifetime = host.Services.GetRequiredService<IHostLifetime>();
-                Assert.NotNull(lifetime);
-                Assert.IsNotType<SystemdLifetime>(lifetime);
-            }
+                // Disable defaults that may not be supported on the testing platform like EventLogLoggerProvider.
+                DisableDefaults = true,
+            });
+
+            builder.Services.UseSystemd();
+            using IHost host = builder.Build();
+
+            var lifetime = host.Services.GetRequiredService<IHostLifetime>();
+            Assert.IsNotType<SystemdLifetime>(lifetime);
         }
     }
 }

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

@@ -8,6 +8,8 @@ namespace Microsoft.Extensions.Hosting
 {
     public static partial class WindowsServiceLifetimeHostBuilderExtensions
     {
+        public static Microsoft.Extensions.DependencyInjection.IServiceCollection AddWindowsService(this Microsoft.Extensions.DependencyInjection.IServiceCollection services) { throw null; }
+        public static Microsoft.Extensions.DependencyInjection.IServiceCollection UseWindowsService(this Microsoft.Extensions.DependencyInjection.IServiceCollection services, System.Action<Microsoft.Extensions.Hosting.WindowsServiceLifetimeOptions> configure) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder UseWindowsService(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder) { throw null; }
         public static Microsoft.Extensions.Hosting.IHostBuilder UseWindowsService(this Microsoft.Extensions.Hosting.IHostBuilder hostBuilder, System.Action<Microsoft.Extensions.Hosting.WindowsServiceLifetimeOptions> configure) { throw null; }
     }
@@ -21,10 +23,10 @@ namespace Microsoft.Extensions.Hosting.WindowsServices
 {
     public static partial class WindowsServiceHelpers
     {
-        [System.Runtime.Versioning.SupportedOSPlatformGuard("windows")]
+        [System.Runtime.Versioning.SupportedOSPlatformGuardAttribute("windows")]
         public static bool IsWindowsService() { throw null; }
     }
-    [System.Runtime.Versioning.SupportedOSPlatform("windows")]
+    [System.Runtime.Versioning.SupportedOSPlatformAttribute("windows")]
     public partial class WindowsServiceLifetime : System.ServiceProcess.ServiceBase, Microsoft.Extensions.Hosting.IHostLifetime
     {
         public WindowsServiceLifetime(Microsoft.Extensions.Hosting.IHostEnvironment environment, Microsoft.Extensions.Hosting.IHostApplicationLifetime applicationLifetime, Microsoft.Extensions.Logging.ILoggerFactory loggerFactory, Microsoft.Extensions.Options.IOptions<Microsoft.Extensions.Hosting.HostOptions> optionsAccessor) { }

src/libraries/Microsoft.Extensions.Hosting.WindowsServices/src/WindowsServiceLifetimeHostBuilderExtensions.cs

@@ -8,6 +8,7 @@
 using Microsoft.Extensions.Hosting.WindowsServices;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.EventLog;
+using Microsoft.Extensions.Options;
 
 namespace Microsoft.Extensions.Hosting
 {
@@ -17,62 +18,137 @@ namespace Microsoft.Extensions.Hosting
     public static class WindowsServiceLifetimeHostBuilderExtensions
     {
         /// <summary>
-        /// Sets the host lifetime to WindowsServiceLifetime, sets the Content Root,
-        /// and enables logging to the event log with the application name as the default source name.
+        /// Sets the host lifetime to <see cref="WindowsServiceLifetime"/>, sets the <see cref="IHostEnvironment.ContentRootPath"/>
+        /// to <see cref="AppContext.BaseDirectory"/>, and enables logging to the event log with the application name as the default source name.
         /// </summary>
         /// <remarks>
         /// This is context aware and will only activate if it detects the process is running
         /// as a Windows Service.
         /// </remarks>
         /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to operate on.</param>
-        /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
+        /// <returns>The <paramref name="hostBuilder"/> instance for chaining.</returns>
         public static IHostBuilder UseWindowsService(this IHostBuilder hostBuilder)
         {
             return UseWindowsService(hostBuilder, _ => { });
         }
 
         /// <summary>
-        /// Sets the host lifetime to WindowsServiceLifetime, sets the Content Root,
-        /// and enables logging to the event log with the application name as the default source name.
+        /// Sets the host lifetime to <see cref="WindowsServiceLifetime"/>, sets the <see cref="IHostEnvironment.ContentRootPath"/>
+        /// to <see cref="AppContext.BaseDirectory"/>, and enables logging to the event log with the application name as the default source name.
         /// </summary>
         /// <remarks>
         /// This is context aware and will only activate if it detects the process is running
         /// as a Windows Service.
         /// </remarks>
         /// <param name="hostBuilder">The <see cref="IHostBuilder"/> to operate on.</param>
-        /// <param name="configure"></param>
-        /// <returns>The same instance of the <see cref="IHostBuilder"/> for chaining.</returns>
+        /// <param name="configure">An <see cref="Action{WindowsServiceLifetimeOptions}"/> to configure the provided <see cref="WindowsServiceLifetimeOptions"/>.</param>
+        /// <returns>The <paramref name="hostBuilder"/> instance for chaining.</returns>
         public static IHostBuilder UseWindowsService(this IHostBuilder hostBuilder, Action<WindowsServiceLifetimeOptions> configure)
         {
             if (WindowsServiceHelpers.IsWindowsService())
             {
                 // Host.CreateDefaultBuilder uses CurrentDirectory for VS scenarios, but CurrentDirectory for services is c:\Windows\System32.
                 hostBuilder.UseContentRoot(AppContext.BaseDirectory);
-                hostBuilder.ConfigureLogging((hostingContext, logging) =>
+                hostBuilder.ConfigureServices(services =>
                 {
-                    Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+                    AddWindowsServiceLifetime(services, configure);
+                });
+            }
 
-                    logging.AddEventLog();
-                })
-                .ConfigureServices((hostContext, services) =>
-                {
-                    Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+            return hostBuilder;
+        }
 
-                    services.AddSingleton<IHostLifetime, WindowsServiceLifetime>();
-                    services.Configure<EventLogSettings>(settings =>
-                    {
-                        Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+        /// <summary>
+        /// Configures the lifetime of the <see cref="IHost"/> built from <paramref name="services"/> to
+        /// <see cref="WindowsServiceLifetime"/>, verifies the <see cref="IHostEnvironment.ContentRootPath"/>
+        /// is equal to <see cref="AppContext.BaseDirectory"/>, and enables logging to the event log with
+        /// the application name as the default source name.
+        /// </summary>
+        /// <remarks>
+        /// This is context aware and will only activate if it detects the process is running
+        /// as a Windows Service.
+        /// </remarks>
+        /// <param name="services">
+        /// The <see cref="IServiceCollection"/> used to build the <see cref="IHost"/>.
+        /// For example, <see cref="HostApplicationBuilder.Services"/> or the <see cref="IServiceCollection"/> passed to the
+        /// <see cref="IHostBuilder.ConfigureServices(Action{HostBuilderContext, IServiceCollection})"/> callback.
+        /// </param>
+        /// <returns>The <paramref name="services"/> instance for chaining.</returns>
+        public static IServiceCollection AddWindowsService(this IServiceCollection services)
+        {
+            return AddWindowsService(services, _ => { });
+        }
 
-                        if (string.IsNullOrEmpty(settings.SourceName))
-                        {
-                            settings.SourceName = hostContext.HostingEnvironment.ApplicationName;
-                        }
-                    });
-                    services.Configure(configure);
-                });
+        /// <summary>
+        /// Configures the lifetime of the <see cref="IHost"/> built from <paramref name="services"/> to
+        /// <see cref="WindowsServiceLifetime"/>, verifies the <see cref="IHostEnvironment.ContentRootPath"/>
+        /// is equal to <see cref="AppContext.BaseDirectory"/>, and enables logging to the event log with
+        /// the application name as the default source name.
+        /// </summary>
+        /// <remarks>
+        /// This is context aware and will only activate if it detects the process is running
+        /// as a Windows Service.
+        /// </remarks>
+        /// <param name="services">
+        /// The <see cref="IServiceCollection"/> used to build the <see cref="IHost"/>.
+        /// For example, <see cref="HostApplicationBuilder.Services"/> or the <see cref="IServiceCollection"/> passed to the
+        /// <see cref="IHostBuilder.ConfigureServices(Action{HostBuilderContext, IServiceCollection})"/> callback.
+        /// </param>
+        /// <param name="configure">An <see cref="Action{WindowsServiceLifetimeOptions}"/> to configure the provided <see cref="WindowsServiceLifetimeOptions"/>.</param>
+        /// <returns>The <paramref name="services"/> instance for chaining.</returns>
+        public static IServiceCollection AddWindowsService(this IServiceCollection services, Action<WindowsServiceLifetimeOptions> configure)
+        {
+            if (WindowsServiceHelpers.IsWindowsService())
+            {
+                AddWindowsServiceUnchecked(services, configure);
             }
 
-            return hostBuilder;
+            return services;
+        }
+
+        // This is a separate method for testing.
+        private static void AddWindowsServiceUnchecked(IServiceCollection services, Action<WindowsServiceLifetimeOptions> configure)
+        {
+            services.Configure<WindowsServiceLifetimeOptions>(options =>
+            {
+                // Host.CreateDefaultBuilder uses CurrentDirectory for VS scenarios, but CurrentDirectory for services is c:\Windows\System32.
+                options.ValidateContentRoot = true;
+            });
+            AddWindowsServiceLifetime(services, configure);
+        }
+
+        private static void AddWindowsServiceLifetime(IServiceCollection services, Action<WindowsServiceLifetimeOptions> configure)
+        {
+            Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+
+            services.AddLogging(logging =>
+            {
+                Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+                logging.AddEventLog();
+            });
+            services.AddSingleton<IHostLifetime, WindowsServiceLifetime>();
+            services.AddSingleton<IConfigureOptions<EventLogSettings>, EventLogSettingsSetup>();
+            services.Configure(configure);
+        }
+
+        private sealed class EventLogSettingsSetup : IConfigureOptions<EventLogSettings>
+        {
+            private readonly string? _applicationName;
+
+            public EventLogSettingsSetup(IHostEnvironment environment)
+            {
+                _applicationName = environment.ApplicationName;
+            }
+
+            public void Configure(EventLogSettings settings)
+            {
+                Debug.Assert(RuntimeInformation.IsOSPlatform(OSPlatform.Windows));
+
+                if (string.IsNullOrEmpty(settings.SourceName))
+                {
+                    settings.SourceName = _applicationName;
+                }
+            }
         }
     }
 }

src/libraries/Microsoft.Extensions.Hosting.WindowsServices/src/WindowsServiceLifetimeOptions.cs

@@ -11,5 +11,11 @@ public class WindowsServiceLifetimeOptions
         /// The name used to identify the service to the system.
         /// </summary>
         public string ServiceName { get; set; } = string.Empty;
+
+        // Used by the IServiceCollection overload of UseWindowsService to indicate that WindowsServiceLifetime
+        // should verify IHostEnvironment.ContentRootPath = AppContext.BaseDirectory (usually the default).
+        // This should also be the content root for the IHostBuilder overload unless it's been overridden, but
+        // we don't want to break people who might have successfully overridden IHostBuilder's ContentRoot.
+        internal bool ValidateContentRoot { get; set; }
     }
 }