Creating spans in current context

[robin-thoene]

My setup

I have setup a small sample project to learn about the implementation of OTEL in Rust.

Passing the Context between applications work. When I receive a request I can use the HeaderExtractor to get the context (see here).

However, my setup is:

cli-client --[fetches with http client]--> axum-api --[fetches with http client]--> axum-downstream-api

Problem

My problem is that I lose the context when using the http client in the axum-api to fetch another api. To solve this I currently pass the extracted context from the endpoint handler manually to the fetch method of the http client (see handler, http_client]).

Tried solution

First I was trying to use Context::current() to receive the current context in the http client, but it was None. I thought it should work that way, because for each incoming request I have set up a middleware that extracts the context from the previous application and adds a new span to it (see here).

Expected vs unexpected results

This is the result when trying to use Context::current():

using this code:

And this is the desired output that I get using the current code (see this):

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Thanks in advance, I hope I described everything well enough. If not, feel free to ask for more information.

[robin-thoene]

For anyone who might stumble upon the same problem:

Here I managed to pass the context from my middleware to the handler, so that Context::current() will actually result in the correct context