fix: Added missing extension to enable mediator tracing

docs/AspNetCore/README.md

@@ -101,4 +101,10 @@ container.RegisterMediatorTracingDecorators();
 container.RegisterMediator( /* Mediator configuration */ );
 ```
 
+Also, when configuring the OpenTelemetry-Tracer, you need to enable the instrumentation:
+```
+services.AddOpenTelemetry()
+        .WithTracing(tracer => tracer.AddMediatorInstrumentation());
+```
+
 Note that the order matters. You must register the tracing decorators before mediator.

src/AspNetCore/src/OpenTelemetry/ContainerExtensions.cs

@@ -9,7 +9,8 @@ namespace Fusonic.Extensions.AspNetCore.OpenTelemetry;
 public static class ContainerExtensions
 {
     /// <summary>
-    /// Adds decorators for tracing mediator requests and notifications.
+    /// Adds decorators for tracing mediator requests and notifications.<br/>
+    /// Note: You also need to call <see cref="TracerProviderBuilderExtensions.AddMediatorInstrumentation"/> to enable tracing.
     /// </summary>
     /// <param name="container">The SimpleInjector container</param>
     public static void RegisterMediatorTracingDecorators(this Container container)

src/AspNetCore/src/OpenTelemetry/TracerProviderBuilderExtensions.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using OpenTelemetry.Trace;
+
+namespace Fusonic.Extensions.AspNetCore.OpenTelemetry;
+
+public static class TracerProviderBuilderExtensions
+{
+    /// <summary>
+    /// Enables tracing for mediator requests and notifications.<br/>
+    /// Note: You also need to call <see cref="ContainerExtensions.RegisterMediatorTracingDecorators"/> to enable tracing.
+    /// </summary>
+    public static TracerProviderBuilder AddMediatorInstrumentation(this TracerProviderBuilder builder)
+        => builder.AddSource(MediatorTracer.ActivitySourceName);
+}

src/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>9.3.0</Version>
+    <Version>9.3.1</Version>
     <TargetFramework>net8.0</TargetFramework>
   </PropertyGroup>