otlp-proto

otlp-proto is a lightweight OTLP serialisation library.

It's written in Rust 🦀, and doesn't have any run-time dependencies.

It serialises a bunch of spans into OTLP 1.5 binary (protobuf) 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_proto 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

• 170KB whl, containing, depending on the target platform
  • 350KB dylib
  • ???KB so

TODO(doc)

• link to pure Python 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)

• 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 receive and forwarded.