Opentelemetry-dotnet: gRPC call metadata not added in nested calls

[JamesNK]

Bug Report

I have an OpenTelemetry sample that has a client that makes a gRPC call to a service, and the service then calls itself.

The first call is detected as gRPC and gRPC specific metadata is present in Zipkin:

The nested call is not:

Symptom

I investigated why and found it is caused by HttpInListener.cs replacing that activity with a new activity: ActivityCreatedByHttpInListener. Grpc.AspNetCore.Server looks for Microsoft.AspNetCore.Hosting.HttpRequestIn because that is where gRPC tags should be added, but it is not there.

Why is this happening - there are no comments in HttpInListener.cs about why it is doing what it is doing - and what is the fix here?

Additional Context

.NET 5 RC1 and OT 0.6.0-beta.1.

[cijothomas]

Not closing as we have to validate if the #1286 issue fixes this issue. @alanwest has volunteered to help validation.

[alanwest]

I've created a similar set up using the Aggregator example. #1286 appears to have resolved the issue