Add Ruby example

[kaylareopelle]

During a recent OpenTelemetry spike, the Ruby agent team created an application that closely mirrors the example in New Relic's Python OpenTelemetry Workshop.

We'd like to share this example with the community.

[alanwest]

👋 Heya @kaylareopelle! Thanks for adding a Ruby example. You got this in draft, are you still working it?

[kaylareopelle]

Hi @alanwest! Thanks for pinging me! This is ready for review 😄

[reese-lee]

Hey @kaylareopelle! Thank you so much for putting this Ruby example together, and for separating it out into the directories per our Get Started Guide example in Java! I just have a few notes:

1. I know you mentioned OTel Ruby only has support for traces atm; I haven't gotten a chance to run the example yet, but does the tracing instrumentation produce what you would see here in the screen shots for traces?

2. I did see that it collects the same attributes, but can you rename them to fibonacci.n and fibonacci.result?

3. The last thing (which I spaced on mentioning) is that we'd like all the examples to use the same port; could you update it to port 8080?

Thanks again!

[kaylareopelle]

Hi @reese-lee! Circling back to this today! I've addressed your feedback here:

• Set default port to 8080: ca5a33e
• Use fibonacci.n and fibonacci.result as attribute names: 6a8a298

Here's a Ruby equivalent of the screenshot you shared:

Please let me know if you need anything else!

[reese-lee]

Hey Kayla! This looks pretty good to me. Unfortunately, I ran into issues with gems on my machine so I have not been able to run the app myself; if you can confirm that the trace data the app produces matches the trace data we're looking for here, I am good to get this merged!

[kaylareopelle]

@reese-lee - Sorry to hear you ran into trouble with gems! Here's a permalink to an app on staging with data from the instrumented app: https://staging.onenr.io/06vjAqpDnjP

Things look quite similar. The only difference I see involves traces with errors: https://staging.onenr.io/0znQxBDeBRV
The Ruby application doesn't have a nested span in this scenario. It has a nested span when the request completes successfully: https://staging.onenr.io/0PLREPoXewa

[reese-lee]

@kaylareopelle I think that's good, that might just be how it's handled in Ruby.

[kaylareopelle]

Great! In that case, please merge as you're able! (I don't have permission to do so)

[reese-lee]

@kaylareopelle Okay! We chatted about your PR and it looks pretty good. We also talked about the error trace only having one span, and if you can modify the code so that the error is handled within the calculation, that will create a nested span on the error trace. Because right now it's not doing the calculation if the input is outside the valid range (see here). Does that make sense?

[kaylareopelle]

Hi @reese-lee! Sorry about the delay here. I think that makes sense. Is this what you're looking for? https://staging.onenr.io/0kERzpxLlQr