Added changes to AWSXRayPropagator

src/OpenTelemetry.Extensions.AWS/Trace/AWSXRayPropagator.cs

@@ -1,6 +1,9 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+#if NETFRAMEWORK
+using System.Net;
+#endif
 using System.Diagnostics;
 using System.Globalization;
 using System.Numerics;
@@ -99,6 +102,34 @@ public override void Inject<T>(PropagationContext context, T carrier, Action<T,
             return;
         }
 
+#if !NETFRAMEWORK
+        if (carrier.GetType() == typeof(HttpRequestMessage))
+        {
+            var httpRequestMessage = (HttpRequestMessage)(object)carrier;
+
+            // If X-Amzn-Trace-Id already exists in the headers and the carrier is of HttpRequestMessage,
+            // This means that the request is coming from the AWS SDK Instrumentation library and in this
+            // case, we don't want to overwrite the propagation context from the AWS SDK Span with the
+            // context from the outgoing HttpRequest
+            if (httpRequestMessage.Headers.Contains(AWSXRayTraceHeaderKey))
+            {
+                return;
+            }
+        }
+#endif
+
+#if NETFRAMEWORK
+        if (carrier.GetType() == typeof(HttpWebRequest))
+        {
+            var httpWebRequest = (HttpWebRequest)(object)carrier;
+
+            if (httpWebRequest.Headers.Get(AWSXRayTraceHeaderKey) != null)
+            {
+                return;
+            }
+        }
+#endif
+
         var sb = new StringBuilder();
         sb.Append(RootKey);
         sb.Append(KeyValueDelimiter);

test/OpenTelemetry.Extensions.AWS.Tests/Trace/AWSXRayPropagatorTests.cs

@@ -1,6 +1,9 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+#if NETFRAMEWORK
+using System.Net;
+#endif
 using System.Diagnostics;
 using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Extensions.AWS.Trace;
@@ -26,8 +29,20 @@ public class AWSXRayPropagatorTests
         carrier[name] = value;
     };
 
+#if NETFRAMEWORK
+    private static readonly Action<HttpWebRequest, string, string> HeaderValueSetter = (request, name, value) => request.Headers.Add(name, value);
+#endif
+
     private readonly AWSXRayPropagator awsXRayPropagator = new();
 
+#if !NETFRAMEWORK
+    private static Action<HttpRequestMessage, string, string> HeaderValueSetter => (request, name, value) =>
+    {
+        request.Headers.Remove(name);
+        request.Headers.Add(name, value);
+    };
+#endif
+
     [Fact]
     public void TestInjectTraceHeader()
     {
@@ -56,6 +71,49 @@ public void TestInjectTraceHeaderNotSampled()
         Assert.Equal("Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=0", carrier[AWSXRayTraceHeaderKey]);
     }
 
+    [Fact]
+    public void TestInjectTraceHeaderAlreadyExists()
+    {
+        var traceIdHeader = "Root=1-00000-00000000000000000;Parent=123456789;Sampled=0";
+
+#if !NETFRAMEWORK
+        var carrier = new HttpRequestMessage();
+#else
+        var carrier = (HttpWebRequest)WebRequest.Create(new Uri("http://www.google.com/"));
+#endif
+        carrier.Headers.Add(AWSXRayTraceHeaderKey, traceIdHeader);
+        var traceId = ActivityTraceId.CreateFromString(TraceId.AsSpan());
+        var parentId = ActivitySpanId.CreateFromString(ParentId.AsSpan());
+        var traceFlags = ActivityTraceFlags.None;
+        var activityContext = new ActivityContext(traceId, parentId, traceFlags);
+        this.awsXRayPropagator.Inject(new PropagationContext(activityContext, default), carrier, HeaderValueSetter);
+
+#if !NETFRAMEWORK
+        Assert.True(carrier.Headers.Contains(AWSXRayTraceHeaderKey));
+        Assert.Equal(traceIdHeader, carrier.Headers.GetValues(AWSXRayTraceHeaderKey).FirstOrDefault());
+#else
+        Assert.Equal(traceIdHeader, carrier.Headers.Get(AWSXRayTraceHeaderKey));
+#endif
+    }
+
+    [Fact]
+    public void TestInjectTraceHeaderAlreadyExistsButNotHttpRequestMessage()
+    {
+        var traceIdHeader = "Root=1-00000-00000000000000000;Parent=123456789;Sampled=0";
+        var carrier = new Dictionary<string, string>()
+        {
+            { AWSXRayTraceHeaderKey, traceIdHeader },
+        };
+        var traceId = ActivityTraceId.CreateFromString(TraceId.AsSpan());
+        var parentId = ActivitySpanId.CreateFromString(ParentId.AsSpan());
+        var traceFlags = ActivityTraceFlags.None;
+        var activityContext = new ActivityContext(traceId, parentId, traceFlags);
+        this.awsXRayPropagator.Inject(new PropagationContext(activityContext, default), carrier, Setter);
+
+        Assert.True(carrier.ContainsKey(AWSXRayTraceHeaderKey));
+        Assert.Equal("Root=1-5759e988-bd862e3fe1be46a994272793;Parent=53995c3f42cd8ad8;Sampled=0", carrier[AWSXRayTraceHeaderKey]);
+    }
+
     [Fact]
     public void TestExtractTraceHeader()
     {