otlp-json

otpl-json is an OTLP serialisation library.

It's written in pure Python, without dependencies.

It serialises a bunch of spans into OTLP 1.5 JSON format.

Motivation

Tracing should be on by default.

OTLP is the standard data format and API, and the standard Python package is opentelemetry-exporter-otlp-proto-http. It brings in a total of 18 packages and adds 9MB to the project virtual environment.

A typical Python application, that's being instrumented, only generates own tracing data and needs to send it out. It doesn't need that much complexity.

Usage

from otlp_json import CONTENT_TYPE, encode_spans


class SomeExporter:
    def export(self.spans: Sequece[ReadableSpan]) -> None:
        requests.post(
            "http://localhost:4318/v1/traces",
            data=encode_spans(spans),
            headers={"Content-Type": CONTENT_TYPE},
        )

Library size

• 3KB whl, containing:
  • 4KB Python source
  • ?? metadata

TODO(doc)

• link to rust library
• link to urllib sender
• link to test vector generator

TODO(features)

• Events
• Links
• Baggage
• Schemata, when open-telemetry/opentelemetry-python#4359 lands

TODO(fixes)

• Status fields
• validate what fields are in fact optional
• ???

Limitations

This library is meant to marshal tracing data that's collected in the same Python process.

It is not meant to be used for data received and forwarded.