Adding proper OpenTelemetry integration via. registration helpers and better context propagation

RabbitMQDotNetClient.sln

@@ -40,6 +40,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Common", "projects\Test\Com
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ToxiproxyNetCore", "projects\toxiproxy-netcore\src\ToxiproxyNetCore\ToxiproxyNetCore.csproj", "{AB5B7C53-D7EC-4985-A6DE-70178E4B688A}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RabbitMQ.Client.OpenTelemetry", "projects\RabbitMQ.Client.OpenTelemetry\RabbitMQ.Client.OpenTelemetry.csproj", "{16BF2086-AC7D-4EC3-8660-CC16E663ACB1}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -90,6 +92,10 @@ Global
 		{AB5B7C53-D7EC-4985-A6DE-70178E4B688A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{AB5B7C53-D7EC-4985-A6DE-70178E4B688A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{AB5B7C53-D7EC-4985-A6DE-70178E4B688A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{16BF2086-AC7D-4EC3-8660-CC16E663ACB1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{16BF2086-AC7D-4EC3-8660-CC16E663ACB1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{16BF2086-AC7D-4EC3-8660-CC16E663ACB1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{16BF2086-AC7D-4EC3-8660-CC16E663ACB1}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

projects/RabbitMQ.Client.OpenTelemetry/README.md

@@ -0,0 +1,54 @@
+# RabbitMQ .NET Client - OpenTelemetry Instrumentation
+
+## Introduction
+This library makes it easy to instrument your RabbitMQ .NET Client applications with OpenTelemetry.
+
+## Examples
+The following examples demonstrate how to use the RabbitMQ .NET Client OpenTelemetry Instrumentation.
+
+### Basic Usage
+
+#### ASP.NET Core Configuration Example
+```csharp
+using OpenTelemetry.Trace;
+
+// Configure the OpenTelemetry SDK to trace ASP.NET Core, the RabbitMQ .NET Client and export the traces to the console.
+// Also configures context propagation to propagate the TraceContext and Baggage using the W3C specification.
+
+var compositeTextMapPropagator = new CompositeTextMapPropagator(new TextMapPropagator[]
+{
+    new TraceContextPropagator(),
+    new BaggagePropagator()
+});
+
+Sdk.SetDefaultTextMapPropagator(compositeTextMapPropagator);
+
+builder.Services.AddOpenTelemetry()
+    .ConfigureResource(resource => resource
+        .AddService(serviceName: builder.Environment.ApplicationName))
+    .WithTracing(tracing => tracing
+        .AddAspNetCoreInstrumentation()
+        .AddRabbitMQInstrumentation()
+        .AddConsoleExporter());
+```
+
+#### Console Application Configuration Example
+```csharp
+using OpenTelemetry.Trace;
+
+// Configure the OpenTelemetry SDK to trace ASP.NET Core, the RabbitMQ .NET Client and export the traces to the console.
+// Also configures context propagation to propagate the TraceContext and Baggage using the W3C specification.
+
+var compositeTextMapPropagator = new CompositeTextMapPropagator(new TextMapPropagator[]
+{
+    new TraceContextPropagator(),
+    new BaggagePropagator()
+});
+
+Sdk.SetDefaultTextMapPropagator(compositeTextMapPropagator);
+
+var tracerProvider = Sdk.CreateTracerProviderBuilder()
+    .AddRabbitMQInstrumentation()
+    .AddConsoleExporter()
+    .Build();
+```

projects/RabbitMQ.Client.OpenTelemetry/RabbitMQ.Client.OpenTelemetry.csproj

@@ -0,0 +1,64 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>net6.0;netstandard2.0</TargetFrameworks>
+    <NoWarn>$(NoWarn);CS1591</NoWarn>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <AssemblyTitle>RabbitMQ OpenTelemetry Integration Package for .NET</AssemblyTitle>
+    <Authors>VMware</Authors>
+    <Company>VMware, Inc. or its affiliates.</Company>
+    <Copyright>Copyright © 2007-2023 VMware, Inc. or its affiliates.</Copyright>
+    <Description>The RabbitMQ OpenTelemetry Library for .NET adds convenience extension methods for RabbitMQ/OpenTelemetry</Description>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <PackageIcon>icon.png</PackageIcon>
+    <PackageLicenseExpression>Apache-2.0 OR MPL-2.0</PackageLicenseExpression>
+    <PackageProjectUrl>https://www.rabbitmq.com/dotnet.html</PackageProjectUrl>
+    <PackageTags>rabbitmq, amqp, oauth2</PackageTags>
+    <Product>RabbitMQ</Product>
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <RepositoryUrl>https://github.com/rabbitmq/rabbitmq-dotnet-client.git</RepositoryUrl>
+    <IncludeSymbols>true</IncludeSymbols>
+    <SymbolPackageFormat>snupkg</SymbolPackageFormat>
+    <AssemblyOriginatorKeyFile>../rabbit.snk</AssemblyOriginatorKeyFile>
+    <SignAssembly>true</SignAssembly>
+    <MinVerTagPrefix>otel-</MinVerTagPrefix>
+    <MinVerVerbosity>minimal</MinVerVerbosity>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <PackageOutputPath>../../packages</PackageOutputPath>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <LangVersion>7.3</LangVersion>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)' == 'Release' And '$(CI)' == 'true'">
+    <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+    <Deterministic>true</Deterministic>
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
+  </PropertyGroup>
+
+  <ItemGroup Condition="'$(Configuration)' == 'Release' and '$(SourceRoot)' == ''">
+    <SourceRoot Include="$(MSBuildThisFileDirectory)/" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Remove="icon.png" />
+    <Content Include="icon.png" PackagePath="" />
+    <None Include="README.md" Pack="true" PackagePath="/" />
+    <InternalsVisibleTo Include="Unit" />
+    <InternalsVisibleTo Include="Benchmarks" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" Version="3.3.4" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="all" />
+    <PackageReference Include="MinVer" Version="5.0.0" PrivateAssets="all" />
+    <PackageReference Include="OpenTelemetry.Api" Version="1.7.0" />
+  </ItemGroup>
+
+  <ItemGroup Condition="$(TargetFramework) == 'netstandard2.0'">
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../RabbitMQ.Client/RabbitMQ.Client.csproj" />
+  </ItemGroup>
+
+</Project>

projects/RabbitMQ.Client.OpenTelemetry/TraceProviderBuilderExtensions.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using OpenTelemetry.Context.Propagation;
+using RabbitMQ.Client;
+
+namespace OpenTelemetry.Trace
+{
+    public static class OpenTelemetryExtensions
+    {
+        public static TracerProviderBuilder AddRabbitMQInstrumentation(this TracerProviderBuilder builder)
+        {
+            RabbitMQActivitySource.UseRoutingKeyAsOperationName = true;
+            RabbitMQActivitySource.ContextExtractor = OpenTelemetryContextExtractor;
+            RabbitMQActivitySource.ContextInjector = OpenTelemetryContextInjector;
+            builder.AddSource("RabbitMQ.Client.*");
+            return builder;
+        }
+
+        private static ActivityContext OpenTelemetryContextExtractor(IReadOnlyBasicProperties props)
+        {
+            // Extract the PropagationContext of the upstream parent from the message headers.
+            var parentContext = Propagators.DefaultTextMapPropagator.Extract(default, props.Headers, OpenTelemetryContextGetter);
+            Baggage.Current = parentContext.Baggage;
+            return parentContext.ActivityContext;
+        }
+
+        private static IEnumerable<string> OpenTelemetryContextGetter(IDictionary<string, object> carrier, string key)
+        {
+            try
+            {
+                if (carrier.TryGetValue(key, out object value) && value is byte[] bytes)
+                {
+                    return new[] { Encoding.UTF8.GetString(bytes) };
+                }
+            }
+            catch (Exception)
+            {
+                //this.logger.LogError(ex, "Failed to extract trace context.");
+            }
+
+            return Enumerable.Empty<string>();
+        }
+
+        private static void OpenTelemetryContextInjector(Activity activity, IDictionary<string, object> props)
+        {
+            // Inject the current Activity's context into the message headers.
+            Propagators.DefaultTextMapPropagator.Inject(new PropagationContext(activity.Context, Baggage.Current), props, OpenTelemetryContextSetter);
+        }
+
+        private static void OpenTelemetryContextSetter(IDictionary<string, object> carrier, string key, string value)
+        {
+            carrier[key] = Encoding.UTF8.GetBytes(value);
+        }
+    }
+}

projects/RabbitMQ.Client/PublicAPI.Unshipped.txt

@@ -956,4 +956,8 @@ virtual RabbitMQ.Client.TcpClientAdapter.ReceiveTimeout.set -> void
 ~static RabbitMQ.Client.IConnectionExtensions.CloseAsync(this RabbitMQ.Client.IConnection connection, System.TimeSpan timeout) -> System.Threading.Tasks.Task
 ~static RabbitMQ.Client.IConnectionExtensions.CloseAsync(this RabbitMQ.Client.IConnection connection, ushort reasonCode, string reasonText, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> System.Threading.Tasks.Task
 ~static RabbitMQ.Client.IConnectionExtensions.CloseAsync(this RabbitMQ.Client.IConnection connection, ushort reasonCode, string reasonText, System.TimeSpan timeout) -> System.Threading.Tasks.Task
+~static RabbitMQ.Client.RabbitMQActivitySource.ContextExtractor.get -> System.Func<RabbitMQ.Client.IReadOnlyBasicProperties, System.Diagnostics.ActivityContext>
+~static RabbitMQ.Client.RabbitMQActivitySource.ContextExtractor.set -> void
+~static RabbitMQ.Client.RabbitMQActivitySource.ContextInjector.get -> System.Action<System.Diagnostics.Activity, System.Collections.Generic.IDictionary<string, object>>
+~static RabbitMQ.Client.RabbitMQActivitySource.ContextInjector.set -> void
 ~virtual RabbitMQ.Client.DefaultBasicConsumer.HandleBasicDeliverAsync(string consumerTag, ulong deliveryTag, bool redelivered, string exchange, string routingKey, RabbitMQ.Client.ReadOnlyBasicProperties properties, System.ReadOnlyMemory<byte> body) -> System.Threading.Tasks.Task

projects/RabbitMQ.Client/client/api/IChannelExtensions.cs

@@ -31,6 +31,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using RabbitMQ.Client.client.impl;
@@ -87,17 +88,20 @@ public static Task<string> BasicConsumeAsync(this IChannel channel, string queue
         /// <remarks>
         /// The publication occurs with mandatory=false and immediate=false.
         /// </remarks>
-        public static ValueTask BasicPublishAsync<T>(this IChannel channel, PublicationAddress addr, in T basicProperties, ReadOnlyMemory<byte> body)
+        public static ValueTask BasicPublishAsync<T>(this IChannel channel, PublicationAddress addr, in T basicProperties,
+            ReadOnlyMemory<byte> body)
             where T : IReadOnlyBasicProperties, IAmqpHeader
         {
             return channel.BasicPublishAsync(addr.ExchangeName, addr.RoutingKey, basicProperties, body);
         }
 
-        public static ValueTask BasicPublishAsync(this IChannel channel, string exchange, string routingKey, ReadOnlyMemory<byte> body = default, bool mandatory = false)
-            => channel.BasicPublishAsync(exchange, routingKey, EmptyBasicProperty.Empty, body, mandatory);
+        public static ValueTask BasicPublishAsync(this IChannel channel, string exchange, string routingKey,
+            ReadOnlyMemory<byte> body = default, bool mandatory = false) =>
+            channel.BasicPublishAsync(exchange, routingKey, EmptyBasicProperty.Empty, body, mandatory);
 
-        public static ValueTask BasicPublishAsync(this IChannel channel, CachedString exchange, CachedString routingKey, ReadOnlyMemory<byte> body = default, bool mandatory = false)
-            => channel.BasicPublishAsync(exchange, routingKey, EmptyBasicProperty.Empty, body, mandatory);
+        public static ValueTask BasicPublishAsync(this IChannel channel, CachedString exchange,
+            CachedString routingKey, ReadOnlyMemory<byte> body = default, bool mandatory = false) =>
+            channel.BasicPublishAsync(exchange, routingKey, EmptyBasicProperty.Empty, body, mandatory);
 
 #nullable disable
 

projects/RabbitMQ.Client/client/impl/ChannelBase.cs

@@ -1048,20 +1048,6 @@ await ModelSendAsync(method, k.CancellationToken)
             }
         }
 
-        private static void InjectTraceContextIntoBasicProperties(object propsObj, string key, string value)
-        {
-            if (!(propsObj is Dictionary<string, object> headers))
-            {
-                return;
-            }
-
-            // Only propagate headers if they haven't already been set
-            if (!headers.ContainsKey(key))
-            {
-                headers[key] = value;
-            }
-        }
-
         public async ValueTask BasicPublishAsync<TProperties>(string exchange, string routingKey,
             TProperties basicProperties, ReadOnlyMemory<byte> body, bool mandatory,
             CancellationToken cancellationToken)
@@ -1083,10 +1069,12 @@ await _confirmSemaphore.WaitAsync(cancellationToken)
 
             try
             {
-                var cmd = new BasicPublish(exchange, routingKey, mandatory, default);
-                RabbitMQActivitySource.TryGetExistingContext(basicProperties, out ActivityContext existingContext);
+                var cmd = new BasicPublishMemory(
+                    Encoding.UTF8.GetBytes(exchange),
+                    Encoding.UTF8.GetBytes(routingKey),
+                    mandatory, default);
                 using Activity sendActivity = RabbitMQActivitySource.PublisherHasListeners
-                    ? RabbitMQActivitySource.Send(routingKey, exchange, body.Length, existingContext)
+                    ? RabbitMQActivitySource.Send(routingKey, exchange, body.Length)
                     : default;
 
                 if (sendActivity != null)
@@ -1144,10 +1132,8 @@ await _confirmSemaphore.WaitAsync(cancellationToken)
             try
             {
                 var cmd = new BasicPublishMemory(exchange.Bytes, routingKey.Bytes, mandatory, default);
-
-                RabbitMQActivitySource.TryGetExistingContext(basicProperties, out ActivityContext existingContext);
                 using Activity sendActivity = RabbitMQActivitySource.PublisherHasListeners
-                    ? RabbitMQActivitySource.Send(routingKey.Value, exchange.Value, body.Length, existingContext)
+                    ? RabbitMQActivitySource.Send(routingKey.Value, exchange.Value, body.Length)
                     : default;
 
                 if (sendActivity != null)
@@ -1908,7 +1894,7 @@ private static BasicProperties PopulateActivityAndPropagateTraceId<TProperties>(
             IDictionary<string, object> headers = props.Headers ?? new Dictionary<string, object>();
 
             // Inject the ActivityContext into the message headers to propagate trace context to the receiving service.
-            DistributedContextPropagator.Current.Inject(sendActivity, headers, InjectTraceContextIntoBasicProperties);
+            RabbitMQActivitySource.ContextInjector(sendActivity, headers);
             props.Headers = headers;
             return props;
         }