fix(otlp): don't configure an automatic OTel propagator

src/Sentry.OpenTelemetry.Exporter/SentryOptionsExtensions.cs

@@ -1,4 +1,3 @@
-using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Trace;
 using Sentry.OpenTelemetry.Exporter;
 
@@ -21,24 +20,18 @@ public static class SentryOptionsExtensions
     /// <param name="tracerProviderBuilder"><see cref="TracerProviderBuilder"/></param>
     /// <param name="collectorUrl">A custom endpoint to export OLTP trace information to. If no url is provided, the
     /// endpoint will be inferred automatically from the DSN.</param>
-    /// <param name="defaultTextMapPropagator">
-    ///     <para>The default TextMapPropagator to be used by OpenTelemetry.</para>
-    ///     <para>
-    ///         If this parameter is not supplied, the <see cref="OpenTelemetry.SentryPropagator"/> will be used, which propagates the
-    ///         baggage header as well as Sentry trace headers.
-    ///     </para>
-    ///     <para>
-    ///         The <see cref="OpenTelemetry.SentryPropagator"/> is required for Sentry's OpenTelemetry integration to work, but you
-    ///         could wrap this in a <see cref="CompositeTextMapPropagator"/> if you needed other propagators as well.
-    ///     </para>
-    /// </param>
-    public static void UseOtlp(this SentryOptions options, TracerProviderBuilder tracerProviderBuilder, Uri? collectorUrl = null, TextMapPropagator? defaultTextMapPropagator = null)
+    /// <remarks>
+    /// This method does not configure an OpenTelemetry propagator.
+    /// Cross-service trace propagation should be enabled via the OpenTelemetry SDK (e.g. by calling
+    /// <c>Sdk.SetDefaultTextMapPropagator</c>).
+    /// </remarks>
+    public static void UseOtlp(this SentryOptions options, TracerProviderBuilder tracerProviderBuilder, Uri? collectorUrl = null)
     {
         if (string.IsNullOrWhiteSpace(options.Dsn))
         {
             throw new ArgumentException("Sentry DSN must be set before calling `SentryOptions.UseOtlp`", nameof(options.Dsn));
         }
-        tracerProviderBuilder.AddSentryOtlpExporter(options.Dsn, collectorUrl, defaultTextMapPropagator);
+        tracerProviderBuilder.AddSentryOtlpExporter(options.Dsn, collectorUrl);
         options.UseOtlp();
     }
 

src/Sentry.OpenTelemetry.Exporter/SentryTracerProviderBuilderExtensions.cs

@@ -1,7 +1,5 @@
-using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Exporter;
 using Sentry;
-using Sentry.OpenTelemetry;
 
 // ReSharper disable once CheckNamespace -- Discoverability
 namespace OpenTelemetry.Trace;
@@ -27,20 +25,14 @@ public static class SentryTracerProviderBuilderExtensions
     /// <param name="dsnString">The DSN for your Sentry project</param>
     /// <param name="collectorUrl">A custom endpoint to export OLTP trace information to. If no url is provided, the
     /// endpoint will be inferred automatically from the DSN.</param>
-    /// <param name="defaultTextMapPropagator">
-    ///     <para>The default TextMapPropagator to be used by OpenTelemetry.</para>
-    ///     <para>
-    ///         If this parameter is not supplied, the <see cref="SentryPropagator"/> will be used, which propagates the
-    ///         baggage header as well as Sentry trace headers.
-    ///     </para>
-    ///     <para>
-    ///         The <see cref="SentryPropagator"/> is required for Sentry's OpenTelemetry integration to work, but you
-    ///         could wrap this in a <see cref="CompositeTextMapPropagator"/> if you needed other propagators as well.
-    ///     </para>
-    /// </param>
     /// <returns>The supplied <see cref="TracerProviderBuilder"/> for chaining.</returns>
+    /// <remarks>
+    /// This method does not configure an OpenTelemetry propagator.
+    /// Cross-service trace propagation should be enabled via the OpenTelemetry SDK (e.g. by calling
+    /// <c>Sdk.SetDefaultTextMapPropagator</c>).
+    /// </remarks>
     public static TracerProviderBuilder AddSentryOtlpExporter(this TracerProviderBuilder tracerProviderBuilder,
-        string dsnString, Uri? collectorUrl = null, TextMapPropagator? defaultTextMapPropagator = null)
+        string dsnString, Uri? collectorUrl = null)
     {
         if (Dsn.IsDisabled(dsnString))
         {
@@ -52,9 +44,6 @@ public static TracerProviderBuilder AddSentryOtlpExporter(this TracerProviderBui
             throw new ArgumentException(MissingDsnWarning, nameof(dsnString));
         }
 
-        defaultTextMapPropagator ??= new SentryPropagator();
-        Sdk.SetDefaultTextMapPropagator(defaultTextMapPropagator);
-
         collectorUrl ??= dsn.GetOtlpTracesEndpointUri();
         tracerProviderBuilder.AddOtlpExporter(options => OtlpConfigurationCallback(options, collectorUrl, dsn.PublicKey));
         return tracerProviderBuilder;

test/Sentry.OpenTelemetry.Exporter.Tests/SentryOptionsExtensionsTests.cs

@@ -1,4 +1,3 @@
-using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Trace;
 
 namespace Sentry.OpenTelemetry.Exporter.Tests;
@@ -119,19 +118,4 @@ public void UseOtlp_WithTracerProviderBuilder_WithCustomCollectorUrl_DoesNotThro
         // Assert
         act.Should().NotThrow();
     }
-
-    [Fact]
-    public void UseOtlp_WithCustomPropagator_DoesNotThrow()
-    {
-        // Arrange
-        var options = new SentryOptions { Dsn = DsnSamples.ValidDsn };
-        var tracerProviderBuilder = Substitute.For<TracerProviderBuilder>();
-        var customPropagator = Substitute.For<TextMapPropagator>();
-
-        // Act
-        var act = () => options.UseOtlp(tracerProviderBuilder, defaultTextMapPropagator: customPropagator);
-
-        // Assert
-        act.Should().NotThrow();
-    }
 }

test/Sentry.OpenTelemetry.Exporter.Tests/SentryTracerProviderBuilderExtensionsTests.cs

@@ -1,3 +1,5 @@
+using OpenTelemetry;
+using OpenTelemetry.Context.Propagation;
 using OpenTelemetry.Exporter;
 using OpenTelemetry.Trace;
 
@@ -35,6 +37,24 @@ public void AddSentryOtlpExporter_DisabledSdkDsn_ReturnsWithoutConfiguringExport
         tracerProviderBuilder.DidNotReceive().AddInstrumentation(Arg.Any<Func<object>>());
     }
 
+    [Fact]
+    public void AddSentryOtlpExporter_DoesNotConfigureDefaultPropagator()
+    {
+        // Arrange
+        // The OTLP integration spec requires that we MUST NOT set up an automatic propagator. Cross-service trace
+        // propagation is left to the propagateTraceparent option or to user-configured OTel propagators.
+        // See https://develop.sentry.dev/sdk/telemetry/traces/otlp/#integration-spec
+        var sentinel = new TraceContextPropagator();
+        Sdk.SetDefaultTextMapPropagator(sentinel);
+        var tracerProviderBuilder = Substitute.For<TracerProviderBuilder>();
+
+        // Act
+        tracerProviderBuilder.AddSentryOtlpExporter("https://examplePublicKey@o0.ingest.sentry.io/123456");
+
+        // Assert
+        Propagators.DefaultTextMapPropagator.Should().BeSameAs(sentinel);
+    }
+
     [Fact]
     public void OtlpConfigurationCallback_WithCustomCollectorUrl_SetsEndpointToCustomUrl()
     {