PyO3 OpenTelemetry

Background

What this is

pyo3_opentelemetry provides a macro to simply and easily instrument your PyO3 bindings so that OpenTelemetry contexts can be easily passed from a Python caller into a Rust library. The #[pypropagate] macro instruments your Rust functions for you so that the global Python OpenTelemetry context is shared across the FFI boundary.

What this is not

• This (currently) does not support propagating an OpenTelemetry context from Rust into Python.
• This does not "magically" instrument Rust code. Without the #[pypropagate] attribute, Rust code is unaffected and will not attach the Python OpenTelemetry context.
• This does not facilitate the processing or collection of OpenTelemetry spans; you still need to initialize and flush tracing providers and subscribers separately in Python and Rust. For more information, please see the respective OpenTelemetry documentation for Python and Rust.

What this is

This repo contains utilities for automatically passing OpenTelemetry contexts from Python into Rust.

What this is not

• This does not facilitate the processing of spans. You still need to separately instrument OpenTelemetry processors on both the Rust and Python side.
• This does not allow you to propagate context into any Rust code from Python. It requires instrumentation of the underlying Rust source code.
• While this repository could extend to pass OpenTelemetry contexts from Rust into Python, it currently does not.

Usage

From Rust:

```rs use pyo3_opentelemetry::prelude::; use pyo3::prelude::; use tracing::instrument;

[pypropagate]

[pyfunction]

[instrument]

fn myfunction() { println!("span \"myfunction\" is active and will share the Python OpenTelemetry context"); }

[pymodule]

fn mymodule(py: Python, m: &PyModule) -> PyResult<()> { m.addfunction(wrappyfunction!(my_function, m)?)?; Ok(()) } ```

These features require no Python code changes, however, opentelemetry-api must be installed.

Development

| Directory | Purpose | |-----------|---------| | crates/macros | Rust macro definitions | | crates/lib | Supporting Rust functions that get OTel context from Python. | | examples/pyo3-opentelemetry-lib | maturin PyO3 project with Python test assertions on Rust OTel spans |

Rust

It should be sufficient to install the Rust toolchain and cargo-make. Then:

sh cargo make check-all

Python

Install:

• Python - installation through pyenv is recommended.
• Poetry - for installing plain Python dependencies.

Python Example

examples/pyo3-opentelemetry-lib contains a full end-to-end pyo3 project with pytests. To build and run them:

sh cd examples/pyo3-opentelemetry-lib cargo make python-check-all