[Feature]: decouple http dependency from OTEL http client

[GlenDC]

Related Problems?

Issues where custom HTTP Client was supported I suppose.

Describe the solution you'd like:

It is currently already possible to bring your own HTTP client.
However that client makes use of the http crate for its request and response.

So might be nice if we can also make that possible to customise, where the http client is not as dumb as just sending bytes, but more like a Request builder and instead of giving you a http response give you something more focussed on the content you really need. This way the underlying client implementation can do what it want without having to convert to/from the http crate types if it is not built around the http crate.

Considered Alternatives

One can just convert of course, but this is pretty wasteful. Not the end of the world, but neither something desired. It's akin to storing all your data as String values. Sure it is possible, but it would be frowned upon with suspicion.

Additional Context

I am willing to help implement this.

Tip

_{React with 👍 to help prioritize this issue. Please use comments to provide useful context, avoiding +1 or me too, to help us triage it. Learn more here.}

[scottgerring]

Hey @GlenDC do you have a concrete use case in mind you can share to flesh this out a bit?

[GlenDC]

Concrete use case is the same as why you support a custom client already today I think. Not every http stack is built around hyperium or its http crate. And there is nothing else in open telemetry stack that requires that either. Meaning you now pull in those dependencies that you do not really need and on top of that have to convert between that http request/response and your own request/response if you support a custom client not built around http crate types.

Given how much traffic open telemetry can generate that's a lot of wasted allocations / resources for little use except to serve an abstraction that is anyway not core to open telemetry, but I imagine just an artifact of the fact that the original support was built around an hyperium based http client (which is still the default AFAIK as well).