feat: add otlp exampler support

[kirankumar-grootan]

Fixes #207

[gaby]

@kirankumar-grootan Can you add a unit-test for this?

[kirankumar-grootan]

@gaby I added a test case for this, which requires some setup for the OTLP part. I included a helper function within the same test file. Should I move it to a separate file, or is it better to keep it at the end of the test file?

[gaby]

Overall looks good to me, just two simple comments.

[gaby]

@kirankumar-grootan Added some comments, thanks for the PR 💪

[kirankumar-grootan]

@gaby addressed all the comments in the MR

[gaby]

@kirankumar-grootan You may have to run "go mod tidy"

[kirankumar-grootan]

@kirankumar-grootan You may have to run "go mod tidy"

applied go mod tidy -go=1.22 but its is changing from go 1.22 to go 1.22.0. and its due to the otlp sdk
go: go.opentelemetry.io/auto/[email protected] requires [email protected], but 1.22 is requested.

this is the version im using in my local go version go1.22.12 darwin/amd64

[gaby]

LGTM, I do wonder if making the "EnableOpenMetrics" a param makes sense though

[gaby]

@kirankumar-grootan Thoughts?

[gaby]

@kirankumar-grootan can you run "go mod tidy" once more. Thanks. Will merge after

[kirankumar-grootan]

LGTM, I do wonder if making the "EnableOpenMetrics" a param makes sense though

Hmm, I hadn't considered making it optional since we're using OTLP and metrics for all our services.

The fact is, traces are only scraped with exemplars when the Accept: application/openmetrics-text header is included, which happens only if Prometheus is enabled with the exemplar feature. Otherwise, it will scrape standard non-exemplar metrics, so the fallback happens automatically without any extra effort.

I will check and let you know if there is a better way to turn this on when required.

[kirankumar-grootan]

@kirankumar-grootan can you run "go mod tidy" once more. Thanks. Will merge after

no changes to commit after go mod tidy

[gaby]

LGTM, I do wonder if making the "EnableOpenMetrics" a param makes sense though

Hmm, I hadn't considered making it optional since we're using OTLP and metrics for all our services.

The fact is, traces are only scraped with exemplars when the Accept: application/openmetrics-text header is included, which happens only if Prometheus is enabled with the exemplar feature. Otherwise, it will scrape standard non-exemplar metrics, so the fallback happens automatically without any extra effort.

I will check and let you know if there is a better way to turn this on when required.

That's fine then.

[gaby]

@kirankumar-grootan can you run "go mod tidy" once more. Thanks. Will merge after

no changes to commit after go mod tidy

Ahhh, you have to rebase your branch. Its complaining about merge conflict with master

[gaby]

LGTM

[gaby]

@kirankumar-grootan For some reason GitHub says that commits do not have verified signatures, so it doesn't let me merge it.

[kirankumar-grootan]

@kirankumar-grootan For some reason GitHub says that commits do not have verified signatures, so it doesn't let me merge it.

IDK what went wrong with my gpg key. now all commits are verified

[gaby]

@kirankumar-grootan That fixed it. Will merge today. Thank you