Source code for opentelemetry.baggage.propagation

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#     http://www.apache.org/licenses/LICENSE-2.0
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import typing
import urllib.parse

from opentelemetry import baggage
from opentelemetry.context import get_current
from opentelemetry.context.context import Context
from opentelemetry.propagators import textmap


[docs]class W3CBaggagePropagator(textmap.TextMapPropagator): """Extracts and injects Baggage which is used to annotate telemetry.""" _MAX_HEADER_LENGTH = 8192 _MAX_PAIR_LENGTH = 4096 _MAX_PAIRS = 180 _BAGGAGE_HEADER_NAME = "baggage"
[docs] def extract( self, carrier: textmap.CarrierT, context: typing.Optional[Context] = None, getter: textmap.Getter = textmap.default_getter, ) -> Context: """Extract Baggage from the carrier. See `opentelemetry.propagators.textmap.TextMapPropagator.extract` """ if context is None: context = get_current() header = _extract_first_element( getter.get(carrier, self._BAGGAGE_HEADER_NAME) ) if not header or len(header) > self._MAX_HEADER_LENGTH: return context baggage_entries = header.split(",") total_baggage_entries = self._MAX_PAIRS for entry in baggage_entries: if total_baggage_entries <= 0: return context total_baggage_entries -= 1 if len(entry) > self._MAX_PAIR_LENGTH: continue try: name, value = entry.split("=", 1) except Exception: # pylint: disable=broad-except continue context = baggage.set_baggage( urllib.parse.unquote(name).strip(), urllib.parse.unquote(value).strip(), context=context, ) return context
[docs] def inject( self, carrier: textmap.CarrierT, context: typing.Optional[Context] = None, setter: textmap.Setter = textmap.default_setter, ) -> None: """Injects Baggage into the carrier. See `opentelemetry.propagators.textmap.TextMapPropagator.inject` """ baggage_entries = baggage.get_all(context=context) if not baggage_entries: return baggage_string = _format_baggage(baggage_entries) setter.set(carrier, self._BAGGAGE_HEADER_NAME, baggage_string)
@property def fields(self) -> typing.Set[str]: """Returns a set with the fields set in `inject`.""" return {self._BAGGAGE_HEADER_NAME}
def _format_baggage(baggage_entries: typing.Mapping[str, object]) -> str: return ",".join( key + "=" + urllib.parse.quote_plus(str(value)) for key, value in baggage_entries.items() ) def _extract_first_element( items: typing.Optional[typing.Iterable[textmap.CarrierT]], ) -> typing.Optional[textmap.CarrierT]: if items is None: return None return next(iter(items), None)