[OpenTelemetry.Extensions] Add baggage Activity processor (#1659)

Co-authored-by: Cijo Thomas <cithomas@microsoft.com>
Co-authored-by: Piotr Kiełkowicz <pkiekowicz@splunk.com>

.github/component_owners.yml

@@ -20,6 +20,7 @@ components:
     - SergeyKanzhelev
   src/OpenTelemetry.Extensions/:
     - codeblanch
+    - mikegoldsmith
   src/OpenTelemetry.Extensions.AWS/:
     - srprash
     - atshaw43
@@ -114,6 +115,7 @@ components:
     - SergeyKanzhelev
   test/OpenTelemetry.Extensions.Tests/:
     - codeblanch
+    - mikegoldsmith
   test/OpenTelemetry.Extensions.AWS.Tests/:
     - srprash
     - atshaw43

src/OpenTelemetry.Extensions/.publicApi/net462/PublicAPI.Unshipped.txt

@@ -11,3 +11,4 @@ OpenTelemetry.Logs.LogToActivityEventConversionOptions.StateConverter.set -> voi
 OpenTelemetry.Trace.TracerProviderBuilderExtensions
 static Microsoft.Extensions.Logging.OpenTelemetryLoggingExtensions.AttachLogsToActivityEvent(this OpenTelemetry.Logs.OpenTelemetryLoggerOptions! loggerOptions, System.Action<OpenTelemetry.Logs.LogToActivityEventConversionOptions!>? configure = null) -> OpenTelemetry.Logs.OpenTelemetryLoggerOptions!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddAutoFlushActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder, System.Func<System.Diagnostics.Activity!, bool>! predicate, int timeoutMilliseconds = 10000) -> OpenTelemetry.Trace.TracerProviderBuilder!
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddBaggageActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry.Extensions/.publicApi/net6.0/PublicAPI.Unshipped.txt

@@ -11,3 +11,4 @@ OpenTelemetry.Logs.LogToActivityEventConversionOptions.StateConverter.set -> voi
 OpenTelemetry.Trace.TracerProviderBuilderExtensions
 static Microsoft.Extensions.Logging.OpenTelemetryLoggingExtensions.AttachLogsToActivityEvent(this OpenTelemetry.Logs.OpenTelemetryLoggerOptions! loggerOptions, System.Action<OpenTelemetry.Logs.LogToActivityEventConversionOptions!>? configure = null) -> OpenTelemetry.Logs.OpenTelemetryLoggerOptions!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddAutoFlushActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder, System.Func<System.Diagnostics.Activity!, bool>! predicate, int timeoutMilliseconds = 10000) -> OpenTelemetry.Trace.TracerProviderBuilder!
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddBaggageActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry.Extensions/.publicApi/netstandard2.0/PublicAPI.Unshipped.txt

@@ -11,3 +11,4 @@ OpenTelemetry.Logs.LogToActivityEventConversionOptions.StateConverter.set -> voi
 OpenTelemetry.Trace.TracerProviderBuilderExtensions
 static Microsoft.Extensions.Logging.OpenTelemetryLoggingExtensions.AttachLogsToActivityEvent(this OpenTelemetry.Logs.OpenTelemetryLoggerOptions! loggerOptions, System.Action<OpenTelemetry.Logs.LogToActivityEventConversionOptions!>? configure = null) -> OpenTelemetry.Logs.OpenTelemetryLoggerOptions!
 static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddAutoFlushActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder, System.Func<System.Diagnostics.Activity!, bool>! predicate, int timeoutMilliseconds = 10000) -> OpenTelemetry.Trace.TracerProviderBuilder!
+static OpenTelemetry.Trace.TracerProviderBuilderExtensions.AddBaggageActivityProcessor(this OpenTelemetry.Trace.TracerProviderBuilder! builder) -> OpenTelemetry.Trace.TracerProviderBuilder!

src/OpenTelemetry.Extensions/CHANGELOG.md

@@ -8,6 +8,9 @@
 * Update OpenTelemetry SDK version to `1.8.1`.
   ([#1668](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/1668))
 
+* Add Baggage Activity Processor.
+  ([#1659](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/1659))
+
 ## 1.0.0-beta.4
 
 Released 2023-Feb-27

src/OpenTelemetry.Extensions/README.md

@@ -37,3 +37,18 @@ public static TracerProviderBuilder AddMyExporter(this TracerProviderBuilder bui
         .AddAutoFlushActivityProcessor(a => a.Parent == null && (a.Kind == ActivityKind.Server || a.Kind == ActivityKind.Consumer), 5000);
 }
 ```
+
+### BaggageActivityProcessor
+
+The BaggageActivityProcessor reads entries stored in Baggage from the current `Baggage`
+and adds the baggage keys and values to the `Activity` as tags (attributes) on start.
+
+Add this activity processor to a tracer provider.
+
+Example of adding BaggageActivityProcessor to `TracerProvider`:
+
+```cs
+var tracerProvider = Sdk.CreateTracerProviderBuilder()
+    .AddBaggageActivityProcessor()
+    .Build();
+```

src/OpenTelemetry.Extensions/Trace/BaggageActivityProcessor.cs

@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+using System.Diagnostics;
+
+namespace OpenTelemetry.Trace;
+
+/// <summary>
+/// Activity processor that adds <see cref="Baggage"/> fields to every new span.
+/// </summary>
+internal sealed class BaggageActivityProcessor : BaseProcessor<Activity>
+{
+    /// <inheritdoc />
+    public override void OnStart(Activity activity)
+    {
+        foreach (var entry in Baggage.Current)
+        {
+            activity.SetTag(entry.Key, entry.Value);
+        }
+    }
+}

src/OpenTelemetry.Extensions/TracerProviderBuilderExtensions.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Diagnostics;
 using System.Threading;
+using OpenTelemetry.Internal;
 
 namespace OpenTelemetry.Trace;
 
@@ -45,6 +46,21 @@ public static TracerProviderBuilder AddAutoFlushActivityProcessor(
 
 #pragma warning disable CA2000 // Dispose objects before losing scope
         return builder.AddProcessor(new AutoFlushActivityProcessor(predicate, timeoutMilliseconds));
+#pragma warning restore CA2000 // Dispose objects before losing scope
+    }
+
+    /// <summary>
+    /// Adds the <see cref="BaggageActivityProcessor"/> to the <see cref="TracerProviderBuilder"/>.
+    /// </summary>
+    /// <param name="builder"><see cref="TracerProviderBuilder"/> to add the <see cref="BaggageActivityProcessor"/> to.</param>
+    /// <returns>The instance of <see cref="TracerProviderBuilder"/> to chain the calls.</returns>
+    public static TracerProviderBuilder AddBaggageActivityProcessor(
+        this TracerProviderBuilder builder)
+    {
+        Guard.ThrowIfNull(builder);
+
+#pragma warning disable CA2000 // Dispose objects before losing scope
+        return builder.AddProcessor(new BaggageActivityProcessor());
 #pragma warning restore CA2000 // Dispose objects before losing scope
     }
 }