Use server span when determining status from code

[kitschysynq]

Switches to SpanStatusFromHTTPStatusCodeAndSpanKind with a span kind
of SpanKindServer so that 4xx status codes don't get labelled as
errors. Since these codes represent client errors, they make it
difficult to differentiate bad server behavior from bad client behavior.

[Aneurysm9]

Seems reasonable. Can you please add a test and CHANGELOG entry for this new behavior?

[kitschysynq]

Sure thing, thanks for looking!

[kitschysynq]

I pushed the CHANGELOG entry but it's not clear to me how to test the result. Do you have any advice for checking the state of a span after the handler and middleware have returned?

[MrAlias]

I pushed the CHANGELOG entry but it's not clear to me how to test the result. Do you have any advice for checking the state of a span after the handler and middleware have returned?

You'll probably need to create a test case similar to this:

opentelemetry-go-contrib/instrumentation/github.com/gorilla/mux/otelmux/test/mux_test.go

Line 35 in 826e886

func TestSDKIntegration(t *testing.T) {

The test module is used to check integration and will be able to determine the final span state the default SDK will produce.

[codecov]

Codecov Report

Merging #1973 (353f3c5) into main (20f04ef) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #1973   +/-   ##
=====================================
  Coverage   69.4%   69.4%           
=====================================
  Files        135     135           
  Lines       6114    6114           
=====================================
+ Hits        4244    4247    +3     
+ Misses      1742    1739    -3     
  Partials     128     128           

Impacted Files	Coverage Δ
...trumentation/github.com/gorilla/mux/otelmux/mux.go	86.2% <100.0%> (+3.7%)	⬆️

[kitschysynq]

Thanks for the info. Added that test and caught the branch up with main.