contrib/envoyproxy: fix resource name

[e-n-0]

What does this PR do?

Fix the ressource.name from the span: change from operation_name to method + path.

Motivation

More clear resources name in the UI.

Reviewer's Checklist

• Changed code has unit tests for its functionality at or near 100% coverage.
• System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• There is a benchmark for any new code, or changes to existing code.
• If this interacts with the agent in a new way, a system test has been added.
• Add an appropriate team label so this PR gets put in the right place for the release notes.
• Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.

Unsure? Have a question? Request a review!

[datadog-datadog-prod-us1]

Datadog Report

Branch report: flavien/envoy/resourcename
Commit report: a774c0c
Test service: dd-trace-go

✅ 0 Failed, 5112 Passed, 70 Skipped, 2m 39.33s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-19 17:35:07

Comparing candidate commit d446c41 in PR branch flavien/envoy/resourcename with baseline commit 144d592 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 59 metrics, 0 unstable metrics.

[rarguelloF]

why do we path.Clean here? shouldn't we just put the original data that was in the request?

also something we are trying to do in other http server integrations is to use the low cardinality http.route (see details here) for the resource name. Would it be possible to have this here?

[e-n-0]

I did a path.Clean here like it's done in the mux.Handler() to get the route. And in the handler, it's calling cleanPath() which is doing a path.Clean

[e-n-0]

Unfortunately, we don't have the http.route information at the proxy level. Only the raw path is available.