make B3 header checking case-insensitive (#29)

Replaces #23
petabridge · Nov 18, 2019 · ee8ae4a · ee8ae4a
1 parent f1a07b8
commit ee8ae4a
Showing 1 changed file with 16 additions and 4 deletions.
diff --git a/src/Petabridge.Tracing.ApplicationInsights/Propagation/B3Propagation.cs b/src/Petabridge.Tracing.ApplicationInsights/Propagation/B3Propagation.cs
@@ -20,10 +20,22 @@ namespace Petabridge.Tracing.ApplicationInsights.Propagation
     /// </remarks>
     public sealed class B3Propagator : IPropagator<ITextMap>
     {
+        /*
+         * Keep old headers for outbound
+         *
+         */
         internal const string B3TraceId = "X-B3-TraceId";
         internal const string B3SpanId = "X-B3-SpanId";
         internal const string B3ParentId = "X-B3-ParentSpanId";
 
+        /*
+         * Keep new headers for case-insensitive analysis
+         *
+         */
+        internal const string B3TraceIdLower = "x-b3-traceid";
+        internal const string B3SpanIdLower = "x-b3-spanid";
+        internal const string B3ParentIdLower = "x-b3-parentspanid";
+
         public void Inject(ApplicationInsightsSpanContext context, ITextMap carrier)
         {
             carrier.Set(B3TraceId, context.TraceId);
@@ -38,15 +50,15 @@ public ApplicationInsightsSpanContext Extract(ITextMap carrier)
             string spanId = null;
             string parentId = null;
             foreach (var entry in carrier)
-                switch (entry.Key)
+                switch (entry.Key.ToLowerInvariant())
                 {
-                    case B3TraceId:
+                    case B3TraceIdLower:
                         traceId = entry.Value;
                         break;
-                    case B3SpanId:
+                    case B3SpanIdLower:
                         spanId = entry.Value;
                         break;
-                    case B3ParentId:
+                    case B3ParentIdLower:
                         parentId = entry.Value;
                         break;
                 }