Dynamic Header in OTLP HTTP Exporters

[robdit]

I'm trying to use the metric/trace/log exporters to send data to a collector on a platform that requires a short lived auth token to be passed to it with each request. The token expires every hour so setting it through the constructor argument would only work for an hour. It is similar to this issue in the javascript otel project open-telemetry/opentelemetry-js#2903.

Currently I can update the header when needed by modifying the underlying _session object but this feels like it could break in the future.

Is there a better way to accomplish this?

import time
import random
from opentelemetry.exporter.otlp.proto.http.metric_exporter import OTLPMetricExporter

class TokenOTLPMetricExporter(OTLPMetricExporter):
    def __init___(self, *args, **kwargs):
        self.token, self.exp = self.get_token()
        super().__init__(*args, **kwargs)
        self.update_headers()

    def update_headers(self):
        self._session.headers.update({"Authorization": f"Bearer {self.token}"})

    def get_token(self):
        # dummy token
        return random.randint(0, 100), time.time() + 60 * 60

    def export(self, *args, **kwargs):
        if time.time() > self.exp:
            self.token, self.exp = self.get_token()
            self.update_headers()
        return super().export(*args, **kwargs)