OpenTelemetry Baggage Span Processor
====================================
|pypi|
.. |pypi| image:: https://badge.fury.io/py/opentelemetry-processor-baggage.svg
:target: https://pypi.org/project/opentelemetry-processor-baggage/
The BaggageSpanProcessor reads entries stored in Baggage
from the parent context and adds the baggage entries' keys and
values to the span as attributes on span start.
Installation
------------
::
pip install opentelemetry-processor-baggage
Add this span processor to a tracer provider.
Keys and values added to Baggage will appear on subsequent child
spans for a trace within this service *and* be propagated to external
services in accordance with any configured propagation formats
configured. If the external services also have a Baggage span
processor, the keys and values will appear in those child spans as
well.
[!WARNING]
Do not put sensitive information in Baggage.
To repeat: a consequence of adding data to Baggage is that the keys and
values will appear in all outgoing HTTP headers from the application.
## Usage
Add the span processor when configuring the tracer provider.
To configure the span processor to copy all baggage entries during configuration:
::
from opentelemetry.processor.baggage import BaggageSpanProcessor, ALLOW_ALL_BAGGAGE_KEYS
tracer_provider = TracerProvider()
tracer_provider.add_span_processor(BaggageSpanProcessor(ALLOW_ALL_BAGGAGE_KEYS))
Alternatively, you can provide a custom baggage key predicate to select which baggage keys you want to copy.
For example, to only copy baggage entries that start with `my-key`:
::
starts_with_predicate = lambda baggage_key: baggage_key.startswith("my-key")
tracer_provider.add_span_processor(BaggageSpanProcessor(starts_with_predicate))
For example, to only copy baggage entries that match the regex `^key.+`:
::
regex_predicate = lambda baggage_key: baggage_key.startswith("^key.+")
tracer_provider.add_span_processor(BaggageSpanProcessor(regex_predicate))
References
----------
* `OpenTelemetry Project <https://opentelemetry.io/>`_
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