Safer Flask teardown request function

[luyun-aa]

Ref: http://flask.pocoo.org/docs/0.12/reqcontext/#callbacks-and-errors

Flask requests that teardown_request function should never fail. The request teardown function implementation in XRay SDK is not robust enough because if before_request is not executed, context.current_segment would return None. Any operation on the "None" segment would fail.

[haotianw465]

Thank you for your feedback. Just want to clarify do you mean this method https://github.com/aws/aws-xray-sdk-python/blob/master/aws_xray_sdk/ext/flask/middleware.py#L58

[luyun-aa]

Ah no, I'm referring to XRayMiddleware. _handle_exception (https://github.com/aws/aws-xray-sdk-python/blob/master/aws_xray_sdk/ext/flask/middleware.py#L73), because it's registered to teardown_request in XRayMiddleware.__init__.

[haotianw465]

Thank you for the clarification. We will work on a fix soon.

[haotianw465]

This is fixed in 2.0.0.

[luyun-aa]

Thanks