Add required SpanLink attributes for the new feature

DataDog · Jan 9, 2025 · 71321a5 · 71321a5
1 parent 145059c
commit 71321a5
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/tracer/src/Datadog.Trace/Propagators/SpanContextPropagator.cs b/tracer/src/Datadog.Trace/Propagators/SpanContextPropagator.cs
@@ -180,6 +180,7 @@ internal PropagationContext Extract<TCarrier, TCarrierGetter>(TCarrier carrier,
             SpanContext? cumulativeSpanContext = null;
             Baggage? cumulativeBaggage = null;
             List<SpanLink> spanLinks = new();
+            string? initialExtractorDisplayName = null;
 
             foreach (var extractor in _extractors)
             {
@@ -215,6 +216,7 @@ cumulativeSpanContext is not null &&
                 if (cumulativeSpanContext == null)
                 {
                     cumulativeSpanContext = currentExtractedContext.SpanContext;
+                    initialExtractorDisplayName = extractor.DisplayName;
                 }
                 else if (currentExtractedContext.SpanContext is { } extractedSpanContext)
                 {
@@ -231,7 +233,7 @@ cumulativeSpanContext is not null &&
 
             return _extractBehavior switch
             {
-                ExtractBehavior.Restart when cumulativeSpanContext is not null => new PropagationContext(default, cumulativeBaggage, [new SpanLink(cumulativeSpanContext)]),
+                ExtractBehavior.Restart when cumulativeSpanContext is not null => new PropagationContext(default, cumulativeBaggage, [new SpanLink(cumulativeSpanContext, attributes: [new("reason", "propagation_behavior_extract=restart"), new("context_headers", initialExtractorDisplayName!)])]),
                 ExtractBehavior.Restart => new PropagationContext(default, cumulativeBaggage, []),
                 _ => new PropagationContext(cumulativeSpanContext, cumulativeBaggage, spanLinks),