[Feature] Integrate with tracing

[sagikazarmark]

Is there an existing issue for this?

• I have searched the existing issues

Description

Would it make sense/be possible to integrate Rust tracing into Workers observability?

[kflansburg]

I don’t believe Workers Observability supports user defined trace spans yet. Once it does, it should be possible to create a tracing Subscriber to collect spans.

For logging, this example shows using the tracing crate which should then emit logs that are captured by Workers Observability.

[sagikazarmark]

Thanks @kflansburg! I saw that example, but I was wondering if a deeper integration was possible.

Feel free to close the issue (or keep it open for tracking, I couldn't find any other)

[esotuvaka]

I looked into this too and had to fallback to the example that @kflansburg linked. When using tower_http::TraceLayer with axum it calls into the system's Time module, which compiles but panics at runtime on WASM.

I only looked very briefly, but I was unable to find a way to provide my own time's to the TraceLayer middleware via a formatter

[omarabid]

It's possible with a custom executor and you also need to manually propagate context (doesn't really work out of the box like the rest of OTEL stack). I have it working reliably and sending data to honeycomb. The only issue (which seems unsolvable) is that all spans show the same start and end time because Cloudflare doesn't provide access to execution time within the platform. This means every span appears to have zero duration, making it impossible to see the actual execution time of individual functions.