OpenTelemetry gRPC exporter fails because SpanKind is None

• Package Name: azure-core-tracing-opentelemetry
• Package Version: 1.0.0b9
• Operating System: Windows Server 2012 R2
• Python Version: 3.8.10

Describe the bug When trying to use opentelemetry-exporter-otlp-proto-grpc to export OpenTelemetry traces created by Azure Python SDK, some traces fail to get exported because the generated OpenTelemetry Spans are not created with a valid SpanKind (is set to None)

Exception while exporting Span batch.
Traceback (most recent call last):
  File "F:\Repo vm-deploy\venv\lib\site-packages\opentelemetry\sdk\trace\export\__init__.py", line 358, in _export_batch
    self.span_exporter.export(self.spans_list[:idx])  # type: ignore
  File "F:\Repo vm-deploy\venv\lib\site-packages\opentelemetry\exporter\otlp\proto\grpc\trace_exporter\__init__.py", line 291, in export
    return self._export(spans)
  File "F:\Repo vm-deploy\venv\lib\site-packages\opentelemetry\exporter\otlp\proto\grpc\exporter.py", line 293, in _export
    request=self._translate_data(data),
  File "F:\Repo vm-deploy\venv\lib\site-packages\opentelemetry\exporter\otlp\proto\grpc\trace_exporter\__init__.py", line 277, in _translate_data
    f"SPAN_KIND_{sdk_span.kind.name}",
AttributeError: 'NoneType' object has no attribute 'name'

The spans can be exported to ConsoleSpanExporter and they look like this:

{
    "name": "VirtualMachinesOperations.get",
    "context": {
        "trace_id": "0xc2b6ac1e000327beb3a5d257d1baaaa3",
        "span_id": "0x2517d83d04756b74",
        "trace_state": "[]"
    },
    "kind": "None",
    "parent_id": null,
    "start_time": "2022-04-26T11:18:07.412171Z",
    "end_time": "2022-04-26T11:18:07.809196Z",
    "status": {
        "status_code": "UNSET"
    },
    "attributes": {},
    "events": [],
    "links": [],
    "resource": {
        "service.name": "vm-deploy",
        "service.version": "1.0.0",
        "deployment.environment": "dev"
    }
}

The issue can be traced back to this line:

https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core/azure/core/tracing/decorator.py#L81

Where no kind is specified, and when the OpenTelemetrySpan is instantiated, None is assigned to the kind in this line:

https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core-tracing-opentelemetry/azure/core/tracing/ext/opentelemetry_span/__init__.py#L67

And then this check passes because value exists (although is assigned to None)

https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core-tracing-opentelemetry/azure/core/tracing/ext/opentelemetry_span/__init__.py#L69

I think that when the OpenTelemetrySpan is instantiated, SpanKind should never default to None, since it is not a SpanKind supported by OpenTelemetry API: https://opentelemetry.io/docs/reference/specification/trace/api/#spankind

To Reproduce I will try to create a minimal example of the error and link it to the issue as soon as possible.

Expected behavior Spans should be exported to gRPC exporter with no errors

Screenshots N/A

Additional context OpenTelemetry documentation states in this link that SpanKind should default to SpanKind.Internal.

If I change this line

https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/core/azure-core-tracing-opentelemetry/azure/core/tracing/ext/opentelemetry_span/__init__.py#L67

to OpenTelemetrySpanKind.INTERNAL

the exporter works as expected.

[lmazuel]

PR has been merged, will be released next week (probably Wednesday)

[cpiment]

Hi @lmazuel, sorry for the delay. I have just tested it and it works flawlessly 😄 Thanks!