fallback to URL.Host if Request.Host is empty

[nelzkiddom]

The stdlib http.Request comments for the Host member variable states:

For client requests, Host optionally overrides the Host header to send. If empty, the Request.Write method uses the value of URL.Host. Host may contain an international domain name.

The semconv package(s) wasn't taking url.URL.Host into account when http.Request.Host was empty.

[linux-foundation-easycla]

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• ✅ login: nelzkiddom / name: Nelz (68ff433)

[nelzkiddom]

I found this behavior in the wild, when looking at requests that were created by the aws-sdk-go (v1).

(Notice there's no http.host entry.)

[Aneurysm9]

Thanks for this! Can you please add a CHANGELOG.md entry for this enhancement and apply it to the remaining semconv versions?

[nelzkiddom]

I made this change in the "current"(?) package of v1.7.0.

Proceeding forward for completeness sake, I can't tell which direction this should go in, as related to "versioning":

• will I be told that this is a substantive change, and would require waiting for a new semconv/v1.7.1+ package?
• will I be told that I should make this same change in all the "previous" packages, e.g. v1.6.1 and v1.5.0 and v1.4.0?

[nelzkiddom]

As I typed that, I see now that @Aneurysm9 answered my question. I shall proceed! 🎉

[nelzkiddom]

@Aneurysm9 Made the requested changes. 👍

[codecov]

Codecov Report

Merging #2661 (08f1656) into main (0e4c156) will increase coverage by 0.0%.
The diff coverage is 100.0%.

@@          Coverage Diff          @@
##            main   #2661   +/-   ##
=====================================
  Coverage   75.7%   75.8%           
=====================================
  Files        173     173           
  Lines      11664   11672    +8     
=====================================
+ Hits        8840    8854   +14     
+ Misses      2614    2608    -6     
  Partials     210     210           

Impacted Files	Coverage Δ
semconv/v1.4.0/http.go	96.5% <100.0%> (+<0.1%)	⬆️
semconv/v1.5.0/http.go	96.5% <100.0%> (+<0.1%)	⬆️
semconv/v1.6.1/http.go	96.5% <100.0%> (+<0.1%)	⬆️
semconv/v1.7.0/http.go	96.5% <100.0%> (+<0.1%)	⬆️
exporters/jaeger/jaeger.go	91.1% <0.0%> (+0.8%)	⬆️
sdk/trace/batch_span_processor.go	82.1% <0.0%> (+1.8%)	⬆️