Replace console logger by ILogger when a background service had a critical error and is shutting down the application.

AspNetCoreTestProject/CriticalBackgroundServices.cs

@@ -4,13 +4,14 @@ namespace AspNetCoreTestProject
     using System.Threading;
     using System.Threading.Tasks;
     using BetterHostedServices;
+    using Microsoft.Extensions.Logging;
 
     public class ImmediatelyCrashingCriticalBackgroundService : CriticalBackgroundService
     {
         protected override Task ExecuteAsync(CancellationToken stoppingToken) =>
             throw new Exception("Crash right away");
 
-        public ImmediatelyCrashingCriticalBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder)
+        public ImmediatelyCrashingCriticalBackgroundService(IApplicationEnder applicationEnder, ILogger<ImmediatelyCrashingCriticalBackgroundService> criticalLogger) : base(applicationEnder, criticalLogger)
         {
         }
     }
@@ -23,7 +24,7 @@ protected override async Task ExecuteAsync(CancellationToken stoppingToken)
             throw new Exception("Crash after yielding");
         }
 
-        public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder)
+        public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder applicationEnder, ILogger<ImmediatelyCrashingCriticalBackgroundService> criticalLogger) : base(applicationEnder, criticalLogger)
         {
         }
     }
@@ -38,7 +39,7 @@ protected override async Task ExecuteAsync(CancellationToken stoppingToken)
             this.Activated = true;
         }
 
-        public StubCriticalBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder)
+        public StubCriticalBackgroundService(IApplicationEnder applicationEnder, ILogger<ImmediatelyCrashingCriticalBackgroundService> criticalLogger) : base(applicationEnder, criticalLogger)
         {
         }
     }

README.md

@@ -45,7 +45,7 @@ public class YieldingAndThenCrashingBackgroundService: CriticalBackgroundService
         throw new Exception("Oh no something really bad happened");
     }
 
-    public YieldingAndThenCrashingBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder) { }
+    public YieldingAndThenCrashingBackgroundService(IApplicationEnder applicationEnder, ILogger<YieldingAndThenCrashingBackgroundService> logger) : base(applicationEnder, logger) { }
 }
 ```
 And then you can use it like any other IHostedService. E.g. inside `ConfigureServices` you add the following:
@@ -76,7 +76,7 @@ public class YieldingAndThenCrashingCriticalBackgroundService : CriticalBackgrou
         this._applicationEnder.ShutDownApplication(); // or simply call base.OnError
     }
 
-    public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder)
+    public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder applicationEnder, ILogger<YieldingAndThenCrashingCriticalBackgroundService> logger) : base(applicationEnder, logger)
     {
     }
 }

src/CriticalBackgroundService.cs

@@ -2,6 +2,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 
 namespace BetterHostedServices
 {
@@ -20,12 +21,14 @@ public abstract class CriticalBackgroundService : IHostedService, IDisposable
         /// Use this if you want to shutdown the application.
         /// </summary>
         protected IApplicationEnder _applicationEnder;
+        private readonly ILogger<CriticalBackgroundService> _logger;
 
         /// <summary>
         /// </summary>
-        protected CriticalBackgroundService(IApplicationEnder applicationEnder)
+        protected CriticalBackgroundService(IApplicationEnder applicationEnder, ILogger<CriticalBackgroundService> logger)
         {
             this._applicationEnder = applicationEnder;
+            this._logger = logger;
         }
 
         /// <summary>
@@ -45,7 +48,8 @@ protected CriticalBackgroundService(IApplicationEnder applicationEnder)
         protected virtual void OnError(Exception exceptionFromExecuteAsync)
         {
             Console.Error.WriteLine($"Error happened while executing CriticalBackgroundTask {this.GetType().FullName}. Shutting down.");
-            Console.Error.WriteLine(exceptionFromExecuteAsync.ToString());
+            this._logger.LogError(exceptionFromExecuteAsync, $"Error happened while executing CriticalBackgroundTask {this.GetType().FullName}. Shutting down.");
+
             this._applicationEnder.ShutDownApplication();
         }
 

src/IServiceCollectionExtensions.cs

@@ -66,9 +66,12 @@ public static void AddPeriodicTask<TPeriodicTask>(this IServiceCollection servic
 
             services.AddHostedService<PeriodicTaskRunnerBackgroundService<TPeriodicTask>>((services) =>
             {
+                var logger = services.GetRequiredService<ILogger<PeriodicTaskRunnerBackgroundService<TPeriodicTask>>>();
+
                 return new PeriodicTaskRunnerBackgroundService<TPeriodicTask>(
                     applicationEnder: services.GetRequiredService<IApplicationEnder>(),
-                    logger: services.GetRequiredService<ILogger<PeriodicTaskRunnerBackgroundService<TPeriodicTask>>>(),
+                    logger: logger,
+                    criticalLogger: logger,
                     serviceProvider: services.GetRequiredService<IServiceProvider>(),
                     periodicTaskFailureMode: failureMode,
                     timeBetweenTasks: timeBetweenTasks

src/PeriodicTaskRunnerBackgroundService.cs

@@ -24,15 +24,17 @@ public class PeriodicTaskRunnerBackgroundService<TPeriodicTask> : CriticalBackgr
         /// </summary>
         /// <param name="applicationEnder"></param>
         /// <param name="logger"></param>
+        /// <param name="criticalLogger"></param>
         /// <param name="serviceProvider"></param>
         /// <param name="periodicTaskFailureMode"></param>
         /// <param name="timeBetweenTasks"></param>
         public PeriodicTaskRunnerBackgroundService(
             IApplicationEnder applicationEnder,
             ILogger<PeriodicTaskRunnerBackgroundService<TPeriodicTask>> logger,
+            ILogger<CriticalBackgroundService> criticalLogger, 
             IServiceProvider serviceProvider,
             PeriodicTaskFailureMode periodicTaskFailureMode,
-            TimeSpan timeBetweenTasks) : base(applicationEnder)
+            TimeSpan timeBetweenTasks) : base(applicationEnder, criticalLogger)
         {
             this.logger = logger;
             this.serviceProvider = serviceProvider;

tests/HostedServices/CriticalBackgroundServices.cs

@@ -4,13 +4,14 @@ namespace BetterHostedServices.Test.HostedServices
     using System.Threading;
     using System.Threading.Tasks;
     using Microsoft.Extensions.Hosting;
+    using Microsoft.Extensions.Logging;
 
 
-        public class ImmediatelyCrashingCriticalBackgroundService: CriticalBackgroundService
+    public class ImmediatelyCrashingCriticalBackgroundService: CriticalBackgroundService
         {
             protected override Task ExecuteAsync(CancellationToken stoppingToken) => throw new Exception("Crash right away");
 
-            public ImmediatelyCrashingCriticalBackgroundService(IApplicationEnder lifeTime) : base(lifeTime)
+            public ImmediatelyCrashingCriticalBackgroundService(IApplicationEnder lifeTime, ILogger<ImmediatelyCrashingCriticalBackgroundService> criticalLogger) : base(lifeTime, criticalLogger)
             {
             }
         }
@@ -23,7 +24,7 @@ protected override async Task ExecuteAsync(CancellationToken stoppingToken)
                 throw new Exception("Crash after yielding");
             }
 
-            public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder lifeTime) : base(lifeTime)
+            public YieldingAndThenCrashingCriticalBackgroundService(IApplicationEnder lifeTime, ILogger<ImmediatelyCrashingCriticalBackgroundService> criticalLogger) : base(lifeTime, criticalLogger)
             {
             }
 

tests/IntegrationUtils/AddHostedServiceAsSingletonTestClasses.cs

@@ -3,6 +3,7 @@ namespace BetterHostedServices.Test.IntegrationUtils
     using System.Threading;
     using System.Threading.Tasks;
     using Microsoft.AspNetCore.Mvc;
+    using Microsoft.Extensions.Logging;
 
 
     public interface ISomeBackgroundService
@@ -12,7 +13,7 @@ public interface ISomeBackgroundService
 
     public class SomeBackgroundService : CriticalBackgroundService, ISomeBackgroundService
     {
-        public SomeBackgroundService(IApplicationEnder applicationEnder) : base(applicationEnder)
+        public SomeBackgroundService(IApplicationEnder applicationEnder, ILogger<CriticalBackgroundService> logger) : base(applicationEnder, logger)
         {
         }