fix(watsonx): set span with exception information

[jinsongo]

• I have added tests that cover my changes.
• If adding a new instrumentation or changing an existing one, I've added screenshots from some observability platform showing the change.
• PR name follows conventional commits format: feat(instrumentation): ... or fix(instrumentation): ....
• (If applicable) I have updated the documentation accordingly.

Use with statement to catch the exception and automatically mark the span as being in an error state, then if an exception occurs, the span can be properly ended and contain information about the exception.

[jinsongo]

The fix is to resolve the problem of no trace for the erroneous call that's caused by incorrect watsonx API key. cc @gyliu513

[nirga]

I think this won't work well with the generator response. You need to manually close the span on all cases

[jinsongo]

Thanks, I will investigate and update with more details.

[jinsongo]

Explicitly call span.__exit__ for exception, just like using with statement to do it automatically.

[jinsongo]

@nirga please review again. span.__exit__ is the default operation to record exception information and call span.end(), and no impact to generator response.

[jinsongo]

[jinsongo]

BTW, bedrock instrumentation use with statement and no 'Generator' problem, so the exception can be handled by span.__exit__ automatically when exception raised from line 166 response = fn(*args, **kwargs)
https://github.com/traceloop/openllmetry/blob/main/packages/opentelemetry-instrumentation-bedrock/opentelemetry/instrumentation/bedrock/__init__.py#L163-L171

[jinsongo]

span.__exit__ implementation:
https://github.com/open-telemetry/opentelemetry-python/blob/main/opentelemetry-sdk/src/opentelemetry/sdk/trace/__init__.py#L986-L1008
span.__exit__ of parent class:
https://github.com/open-telemetry/opentelemetry-python/blob/main/opentelemetry-api/src/opentelemetry/trace/span.py#L186-L194

[nirga]

Yes @jinsongo but you're setting the exception yourself anyway so you don't really need this, right?

[jinsongo]

I prefer to set the exception information into the span by simply calling __exit__.
As you know, without the fix, I cannot see any span sent after the exception raised.

[nirga]

@jinsongo why? You didn't call __enter__ so I don't think it's preferred on explicitly logging the exception on the span