add new github.com/labstack/echo-contrib/otelecho/v5 sub-module

[vadimi]

This version performs the same instrumentation as previously available otelecho in opentelemetry-go-contrib repo, but with echo v5 support

v5 sub-directory is used specifically in case of new v6, v7, etc versions of echo come out in the future

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.69%. Comparing base (1e69e54) to head (f3a0cc8).
⚠️ Report is 8 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #141      +/-   ##
==========================================
+ Coverage   63.77%   67.69%   +3.91%     
==========================================
  Files           9        9              
  Lines         969      585     -384     
==========================================
- Hits          618      396     -222     
+ Misses        308      157     -151     
+ Partials       43       32      -11     

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[aldas]

Just a quick heads-up that I will be reviewing this over the weekend.

[mojixcoder]

Thanks, this PR is heavily needed and is our only blocker to upgrade to v5.
Moving this package to echo-contrib has a little difference with the otelecho one which is addressed in #143 .
But I think it's out of scope of this PR.

[aldas]

Update: I did review this PR on Saturday+Sunday and decided that I need to research more on that semconv package part and probably do some refactoring. I do not feel comfortable maintaining it in current form.

Let's see what progress I have on Wednesday. Currently this issue is on top of my Echo list.

[vadimi]

thanks @aldas, anything I can do to help?

[aldas]

@vadimi , At the moment nothing. I made good progress yesterday, but have not finished it yet. Today was spent on fixing vulnerility reported in static middleware (fixed in 5.0.3). I will work on it over the weekend.

[aldas]

Hi @vadimi, I forked your PR to a branch in my repo.

• I reworked semconv parts, added proper documentation in code. Hats down for Otel maintainers for Specification website, but having these rules in code is easier for reviewer.
• To be honest, Otel API with the excessive use of functional options and need for ... everywhere is quite poor developer UX in my opinion so for Echo middleware I switched to more Go-esque config structs approach.
• I have not finished with the tests yet
• documentation needs some improvement
• I probably ask Otel people if they are interested in that extraction part. The current code generation + API (without knowing details) feels real overkill for Go HTTP frameworks like Echo/Gin/Chi/Mux etc.

This is how it looks like:
https://github.com/aldas/echo-contrib/tree/echootel/echootel

working example is here: https://github.com/aldas/echo-contrib/blob/echootel/echootel/example/main.go
It is based on Otel Echo example

[vadimi]

Thanks for making the progress @aldas! One difference I've noticed in your branch comparing to the OTel echo is the requestDuration metric:

m.requestDurationHistogram.Inst().Record(ctx, float64(v.RequestDuration.Milliseconds()), o)

OTel echo v4 divides it by 1000 as the bucket boundaries are in seconds:

n.requestDurationHistogram.Inst().Record(ctx, md.ElapsedTime/1000.0, o)

In terms of semver/semnverutil Otel package there was a conversation some time ago: open-telemetry/opentelemetry-go-contrib#4580, doesn't look like there is a consensus.