opentelemetry-instrumentation-grpc - code()/details()-bug in ServicerContext

[CoLa5]

Describe your environment

python version: 3.7.12
grpcio: 1.43.0

Steps to reproduce

Call inside of a RPC-method-implementation of a grpc service the methods:

• context.code()
• context.details()

which are supported since grpcio v1.38.0 (s. here).

Example:

Add the functions into e.g. helloworld/greeter_server.py:

class Greeter(helloworld_pb2_grpc.GreeterServicer):

    def SayHello(self, request, context):
        print("code before: %r" % context.code())
        context.set_code(grpc.StatusCode.OK)
        print("code after: %r" % context.code())

        print("details before: %r" % context.details())
        context.set_details("test")
        print("details after: %r" % context.details())

        return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)

What is the expected behavior?

This should print:

code before: None
code after: <StatusCode.OK: (0, 'ok')> 
details before: None
details after: 'test'

What is the actual behavior?

There are TypeError raised:

TypeError: 'StatusCode' object is not callable

TypeError: 'NoneType' object is not callable

Additional context

The _OpenTelemetryServicerContext inside of _server.py implements code and details as attributes while the official grpcio API implements them as methods.

Proposed Bugfix

Stick with the attributes to support older grpcio versions, but make them private. Furthermore, add code() and details() with RuntimeError:

class _OpenTelemetryServicerContext(grpc.ServicerContext):

    def __init__(self, servicer_context, active_span):
        self._servicer_context = servicer_context
        self._active_span = active_span
        self._code = grpc.StatusCode.OK
        self._details = None
        super().__init__()

    # ...

    def abort(self, code, details):
        self._code = code
        self._details = details
        self._active_span.set_attribute(
            SpanAttributes.RPC_GRPC_STATUS_CODE, code.value[0]
        )
        self._active_span.set_status(
            Status(
                status_code=StatusCode.ERROR,
                description=f"{code}:{details}",
            )
        )
        return self._servicer_context.abort(code, details)

    def code(self):
        if not hasattr(self._servicer_context, "code"):
            raise RuntimeError(
                "code() is not supported with the installed version of grpcio"
            )
        return self._servicer_context.code()

    def set_code(self, code):
        self._code = code
        # use details if we already have it, otherwise the status description
        details = self._details or code.value[1]
        self._active_span.set_attribute(
            SpanAttributes.RPC_GRPC_STATUS_CODE, code.value[0]
        )
        if code != grpc.StatusCode.OK:
            self._active_span.set_status(
                Status(
                    status_code=StatusCode.ERROR,
                    description=f"{code}:{details}",
                )
            )
        return self._servicer_context.set_code(code)

    def details(self):
        if not hasattr(self._servicer_context, "details"):
            raise RuntimeError(
                "details() is not supported with the installed version of "
                "grpcio"
            )
        return self._servicer_context.details()

    def set_details(self, details):
        self._details = details
        if self._code != grpc.StatusCode.OK:
            self._active_span.set_status(
                Status(
                    status_code=StatusCode.ERROR,
                    description=f"{self._code}:{details}",
                )
            )
        return self._servicer_context.set_details(details)

[huwcbjones]

I've also noticed that grpc.aio.ServicerContext::abort has details as an optional argument, whereas the otel servicer context mandates it.

https://github.com/grpc/grpc/blob/v1.38.0/src/python/grpcio/grpc/aio/_base_server.py#L172-L176

vs

opentelemetry-python-contrib/instrumentation/opentelemetry-instrumentation-grpc/src/opentelemetry/instrumentation/grpc/_server.py

Line 121 in 4d341e8

def abort(self, code, details):

[srikanthccv]

Fixed in #1578