[Instrumentation.AspNetCore] Fix issue causing Activity is not exported when used with custom propagator/sampler.

src/OpenTelemetry.Api/Internal/ActivityHelperExtensions.cs

@@ -95,6 +95,24 @@ public static object GetTagValue(this Activity activity, string tagName)
             return null;
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool TryGetTagValue(this Activity activity, string tagName, out object tagValue)
+        {
+            Debug.Assert(activity != null, "Activity should not be null");
+
+            foreach (ref readonly var tag in activity.EnumerateTagObjects())
+            {
+                if (tag.Key == tagName)
+                {
+                    tagValue = tag.Value;
+                    return true;
+                }
+            }
+
+            tagValue = null;
+            return false;
+        }
+
         /// <summary>
         /// Checks if the user provided tag name is the first tag of the <see cref="Activity"/> and retrieves the tag value.
         /// </summary>

src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md

@@ -7,6 +7,10 @@
   which attributes are emitted by setting the environment variable
   `OTEL_SEMCONV_STABILITY_OPT_IN`.
 
+* Fixed an issue affecting NET 7.0+. If custom propagation is being used
+  and tags are added to an Activity during sampling then that Activity would be dropped.
+  ([#4637](https://github.com/open-telemetry/opentelemetry-dotnet/pull/4637))
+
 ## 1.5.0-beta.1
 
 Released 2023-Jun-05

src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs

@@ -323,7 +323,11 @@ public void OnStopActivity(Activity activity, object payload)
                 }
             }
 
+#if NET7_0_OR_GREATER
+            if (activity.TryGetTagValue("IsCreatedByInstrumentation", out var tagValue) && ReferenceEquals(tagValue, bool.TrueString))
+#else
             if (activity.TryCheckFirstTag("IsCreatedByInstrumentation", out var tagValue) && ReferenceEquals(tagValue, bool.TrueString))
+#endif
             {
                 // If instrumentation started a new Activity, it must
                 // be stopped here.

test/OpenTelemetry.Api.Tests/Trace/ActivityExtensionsTest.cs

@@ -212,6 +212,30 @@ public void GetTagValue()
             Assert.Null(activity.GetTagValue("Tag2"));
         }
 
+        [Fact]
+        public void TryGetTagValue_Empty()
+        {
+            using var activity = new Activity("Test");
+
+            Assert.False(activity.TryGetTagValue("Tag1", out var value));
+            Assert.Null(value);
+        }
+
+        [Fact]
+        public void TryGetTagValue()
+        {
+            using var activity = new Activity("Test");
+            activity.SetTag("Tag1", "Value1");
+
+            Assert.True(activity.TryGetTagValue("Tag1", out var value));
+            Assert.Equal("Value1", value);
+
+            Assert.False(activity.TryGetTagValue("tag1", out value));
+            Assert.Null(value);
+            Assert.False(activity.TryGetTagValue("Tag2", out value));
+            Assert.Null(value);
+        }
+
         [Theory]
         [InlineData("Key", "Value", true)]
         [InlineData("CustomTag", null, false)]

test/OpenTelemetry.Instrumentation.AspNetCore.Tests/BasicTests.cs

@@ -219,7 +219,11 @@ public async Task CustomPropagator()
                             builder.ConfigureTestServices(services =>
                             {
                                 Sdk.SetDefaultTextMapPropagator(propagator.Object);
-                                this.tracerProvider = Sdk.CreateTracerProviderBuilder().AddAspNetCoreInstrumentation().AddInMemoryExporter(exportedItems).Build();
+                                this.tracerProvider = Sdk.CreateTracerProviderBuilder()
+                                                        .SetSampler(new TestSampler(SamplingDecision.RecordAndSample, new Dictionary<string, object> { { "SomeTag", "SomeKey" }, }))
+                                                        .AddAspNetCoreInstrumentation()
+                                                        .AddInMemoryExporter(exportedItems)
+                                                        .Build();
                             });
                             builder.ConfigureLogging(loggingBuilder => loggingBuilder.ClearProviders());
                         }))
@@ -1134,15 +1138,17 @@ public override void Inject<T>(PropagationContext context, T carrier, Action<T,
         private class TestSampler : Sampler
         {
             private readonly SamplingDecision samplingDecision;
+            private readonly IEnumerable<KeyValuePair<string, object>> attributes;
 
-            public TestSampler(SamplingDecision samplingDecision)
+            public TestSampler(SamplingDecision samplingDecision, IEnumerable<KeyValuePair<string, object>> attributes = null)
             {
                 this.samplingDecision = samplingDecision;
+                this.attributes = attributes;
             }
 
             public override SamplingResult ShouldSample(in SamplingParameters samplingParameters)
             {
-                return new SamplingResult(this.samplingDecision);
+                return new SamplingResult(this.samplingDecision, this.attributes);
             }
         }