EnrichWithHttpRequest - Changes to Activity DisplayName gets overridden with route template/path in AspNetCoreInstrumentation

[chandramouleswaran]

Bug Report

Here is a small snippet to repro the issue

.AddAspNetCoreInstrumentation(options =>
{
    const string incomingSpanName = "IncomingSpanName";
    options.EnrichWithHttpRequest = (activity, httpRequest) =>
    {
        if (httpRequest.Headers.TryGetValue(Header.ClientActionName, out StringValues clientActionHeaders))
        {
            var displayName = $"{serviceRole}.Incoming.{clientActionHeaders}";
            activity.AddTag(incomingSpanName, displayName);

            // Ideally this should be sufficient - however, OT ends up resetting this value to the action's route template
            activity.DisplayName = displayName;
        }
    };

    options.EnrichWithHttpResponse = (activity, response) =>
    {
        // Hack to get the value added to the tag to setup the display name
        var incomingSpan = activity.GetTagItem(incomingSpanName);
        if (incomingSpan != null)
        {
            activity.DisplayName = incomingSpan.ToString();
        }
    };
});

Symptom

We need the ability to setup DisplayName of the activity as part of the request flow - it looks like OT ends up changing the DisplayName based on the route template somewhere along the request lifecycle.

What is the expected behavior?

What did you expect to see?

What is the actual behavior?

What did you see instead?

Reproduce

See code snippet above with repro.

Packages used while reproducing
OpenTelemetry 1.4.0-beta.3
OpenTelemetry.Api 1.4.0-beta.3
OpenTelemetry.Exporter.CredScan 2.0.12
OpenTelemetry.Extensions.Hosting 1.0.0-rc9.9
OpenTelemetry.Exporter.Zipkin 1.4.0-beta.3
OpenTelemetry.Exporter.Geneva 1.4.0-beta.5
OpenTelemetry.Instrumentation.AspNetCore 1.0.0-rc9.9
OpenTelemetry.Instrumentation.GrpcNetClient 1.0.0-rc9.9
OpenTelemetry.Instrumentation.Http 1.0.0-rc9.9
OpenTelemetry.Instrumentation.Process 1.0.0-alpha.2
OpenTelemetry.Instrumentation.Runtime 1.1.0-beta.1

Runtime version: net7.0

[cijothomas]

@vishweshbankwar Can you check this?

[vishweshbankwar]

it happens due to this

opentelemetry-dotnet/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs

Line 338 in bb0c381

activity.DisplayName = template;

. This is done to comply with spec. We need to find the alternate way of not overriding the DisplayName if it was changed using enrich options.

[vishweshbankwar]

@chandramouleswaran - Could you try the following. Try setting the DisplayName using EnrichWithHttpResponse

.AddAspNetCoreInstrumentation(o =>
{
  o.EnrichWithHttpResponse = (activity, response) =>
  {
      if (response.HttpContext.Request.Headers.TryGetValue(Header.ClientActionName, out StringValues clientActionHeaders))
      {
          var displayName = $"{serviceRole}.Incoming.{clientActionHeaders}";

          activity.DisplayName = displayName;
      }
  };
});

[utpilla]

@chandramouleswaran Does the above-mentioned suggestion work?

[vishweshbankwar]

@chandramouleswaran Closing this issue. please re-open if the above shared workaround does not work for you.