grpc GrpcInstrumentorClient does not call request/response hooks for streaming rpcs

[simon-weber]

Describe your environment

OS: Ubuntu
Python version: Python 3.8.18
Package version: 0.48b0
Package: opentelemetry-instrumentation-grpc

What happened?

The request/response hooks added in https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1706/files only seem to work for unary requests, not streaming requests.

Steps to Reproduce

Instrument using GrpcInstrumentorClient, pass request_hook and response_hook, then make a response-streaming rpc with a client.

Expected Result

Calls to the configured hooks. Maybe once per message and again when the request finishes?

Actual Result

No calls to the hooks.

Additional context

It looks like OpenTelemetryClientInterceptor._intercept calls _trace_result, but OpenTelemetryClientInterceptor._intercept_server_stream does not.

Would you like to implement a fix?

No