Make hosted service generic (#157)

* Make hosted service generic * inject hosted service and generic application
marcwittke · Dec 27, 2023 · 83cb4cd · 83cb4cd
1 parent 2a289a6
commit 83cb4cd
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Showing 6 changed files with 72 additions and 69 deletions.
diff --git a/src/environments/Backend.Fx.AspNetCore/BackendFxApplicationHostedService.cs b/src/environments/Backend.Fx.AspNetCore/BackendFxApplicationHostedService.cs
@@ -3,22 +3,27 @@
 using System.Threading.Tasks;
 using Backend.Fx.Logging;
 using Backend.Fx.Patterns.DependencyInjection;
+using JetBrains.Annotations;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using ILogger = Microsoft.Extensions.Logging.ILogger;
 
 namespace Backend.Fx.AspNetCore
 {
-    public interface IBackendFxApplicationHostedService : IHostedService
+    [PublicAPI]
+    public interface IBackendFxApplicationHostedService<out TApplication> : IHostedService
+        where TApplication : IBackendFxApplication
     {
-        IBackendFxApplication Application { get; }
+        TApplication Application { get; }
     }
-
-    public abstract class BackendFxApplicationHostedService : IBackendFxApplicationHostedService
+
+    public abstract class BackendFxApplicationHostedService<TApplication> : IBackendFxApplicationHostedService<TApplication>
+        where TApplication : IBackendFxApplication
     {
-        private static readonly ILogger Logger = Log.Create<BackendFxApplicationHostedService>();
+        private static readonly ILogger Logger = Log.Create<BackendFxApplicationHostedService<TApplication>>();
 
-        public abstract IBackendFxApplication Application { get; }
+        public abstract TApplication Application { get; }
 
         public virtual async Task StartAsync(CancellationToken ct)
         {
@@ -45,4 +50,20 @@ public virtual Task StopAsync(CancellationToken cancellationToken)
             }
         }
     }
+
+    public static class BackendFxApplicationHostedServiceExtensions
+    {
+        public static void AddBackendFxApplication<THostedService, TApplication>(this IServiceCollection services)
+            where THostedService : class, IBackendFxApplicationHostedService<TApplication>
+            where TApplication : class, IBackendFxApplication
+        {
+            services.AddSingleton<THostedService>();
+
+            // this registration ensures starting of the hosted service
+            services.AddSingleton<IHostedService>(provider => provider.GetRequiredService<THostedService>());
+
+            // this registration makes the application instance available as singleton
+            services.AddSingleton(provider => provider.GetRequiredService<THostedService>().Application);
+        }
+    }
 }
diff --git a/src/environments/Backend.Fx.AspNetCore/BackendFxApplicationStartup.cs b/src/environments/Backend.Fx.AspNetCore/BackendFxApplicationStartup.cs
diff --git a/tests/Backend.Fx.AspNetCore.Tests/SampleApp/SampleApplicationHostedService.cs b/tests/Backend.Fx.AspNetCore.Tests/SampleApp/SampleApplicationHostedService.cs
@@ -1,22 +1,18 @@
 using Backend.Fx.AspNetCore.Tests.SampleApp.Runtime;
 using Backend.Fx.Environment.MultiTenancy;
-using Backend.Fx.InMemoryPersistence;
 using Backend.Fx.Logging;
-using Backend.Fx.Patterns.DependencyInjection;
-using Backend.Fx.Patterns.EventAggregation.Integration;
+using JetBrains.Annotations;
 
 namespace Backend.Fx.AspNetCore.Tests.SampleApp
 {
-    public class SampleApplicationHostedService : BackendFxApplicationHostedService
+    [UsedImplicitly]
+    public class SampleApplicationHostedService : BackendFxApplicationHostedService<SampleApplication>
     {
-        public  ITenantService TenantService { get; }
-        public override IBackendFxApplication Application { get; }
+        public override SampleApplication Application { get; }
 
-        public SampleApplicationHostedService(IExceptionLogger exceptionLogger)
+        public SampleApplicationHostedService(IExceptionLogger exceptionLogger, ITenantService tenantService)
         {
-            IMessageBus messageBus = new InMemoryMessageBus();
-            TenantService = new TenantService(messageBus, new InMemoryTenantRepository());
-            Application = new SampleApplication(TenantService.TenantIdProvider, exceptionLogger);
+            Application = new SampleApplication(tenantService.TenantIdProvider, exceptionLogger);
         }
     }
 }
diff --git a/tests/Backend.Fx.AspNetCore.Tests/SampleApp/Startup.cs b/tests/Backend.Fx.AspNetCore.Tests/SampleApp/Startup.cs
@@ -1,8 +1,18 @@
+using System.Security.Principal;
+using Backend.Fx.AspNetCore.MultiTenancy;
+using Backend.Fx.AspNetCore.Mvc;
+using Backend.Fx.AspNetCore.Mvc.Activators;
 using Backend.Fx.AspNetCore.Tests.SampleApp.Domain;
+using Backend.Fx.AspNetCore.Tests.SampleApp.Runtime;
+using Backend.Fx.Environment.MultiTenancy;
+using Backend.Fx.InMemoryPersistence;
 using Backend.Fx.Logging;
+using Backend.Fx.Patterns.DependencyInjection;
+using Backend.Fx.Patterns.EventAggregation.Integration;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Mvc.Controllers;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace Backend.Fx.AspNetCore.Tests.SampleApp
@@ -27,15 +37,20 @@ public void ConfigureServices(IServiceCollection services)
 
             // enabling MVC
             services.AddMvc();
+            services.AddSingleton<IControllerActivator, BackendFxApplicationControllerActivator>();
 
             // integrate backend fx application as hosted service
-            services.AddBackendFxApplication<SampleApplicationHostedService>();
+            services.AddBackendFxApplication<SampleApplicationHostedService, SampleApplication>();
+
+            services.AddSingleton<IMessageBus, InMemoryMessageBus>();
+            services.AddSingleton<ITenantRepository, InMemoryTenantRepository>();
+            services.AddSingleton<ITenantService, TenantService>();
         }
 
         public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
         {
             // log exceptions to file
-            _exceptionLoggers.Add(new ExceptionLogger(Log.Create("Mep.WebHost")));
+            _exceptionLoggers.Add(new ExceptionLogger(Log.Create("Sample.WebHost")));
 
             // use the ASP.Net Core routing middleware that decides the endpoint to be hit later
             app.UseRouting();
@@ -48,7 +63,24 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
 
             app.UseMiddleware<TenantAdminMiddleware>();
 
-            app.UseBackendFxApplication<SampleApplicationHostedService, MultiTenantMiddleware>();
+            app.UseMiddleware<MultiTenantMiddleware>();
+
+            app.Use(async (context, requestDelegate) =>
+            {
+                IBackendFxApplication application = app.ApplicationServices.GetRequiredService<SampleApplication>();
+                application.WaitForBoot();
+            
+                // set the instance provider for the controller activator
+                context.SetCurrentInstanceProvider(application.CompositionRoot.InstanceProvider);
+            
+                // the ambient tenant id has been set before by a TenantMiddleware
+                var tenantId = context.GetTenantId();
+            
+                // the invoking identity has been set before by an AuthenticationMiddleware
+                IIdentity actingIdentity = context.User.Identity;
+            
+                await application.AsyncInvoker.InvokeAsync(_ => requestDelegate.Invoke(), actingIdentity, tenantId);
+            });
 
             app.UseEndpoints(endpointRouteBuilder =>
             {

diff --git a/tests/Backend.Fx.AspNetCore.Tests/SampleApp/TenantAdminMiddleware.cs b/tests/Backend.Fx.AspNetCore.Tests/SampleApp/TenantAdminMiddleware.cs
@@ -1,12 +1,13 @@
 using Backend.Fx.AspNetCore.MultiTenancy;
+using Backend.Fx.Environment.MultiTenancy;
 using Microsoft.AspNetCore.Http;
 
 namespace Backend.Fx.AspNetCore.Tests.SampleApp
 {
     public class TenantAdminMiddleware : TenantAdminMiddlewareBase 
     {
-        public TenantAdminMiddleware(RequestDelegate next, SampleApplicationHostedService hostedService) 
-            : base(next, hostedService.TenantService)
+        public TenantAdminMiddleware(RequestDelegate next, ITenantService tenantService) 
+            : base(next, tenantService)
         {
         }
 

diff --git a/tests/Backend.Fx.AspNetCore.Tests/SampleAppWebApplicationFactory.cs b/tests/Backend.Fx.AspNetCore.Tests/SampleAppWebApplicationFactory.cs
@@ -39,7 +39,7 @@ protected override TestServer CreateServer(IWebHostBuilder builder)
         {
             TestServer server = base.CreateServer(builder);
 
-            ITenantService tenantService = server.Services.GetRequiredService<SampleApplicationHostedService>().TenantService;
+            ITenantService tenantService = server.Services.GetRequiredService<ITenantService>();
             for (int i = 0; i < 100; i++)
             {
                 var x = tenantService.CreateTenant($"t{i:000}", $"Tenant {i:000}", false);