Auto-instrumenting application code?

[adamk9k]

Hey quick question,

reading the available instrumenters and how they're generating spans, it seems to me there's no way to automatically instrument application code, am I correct in that?

For instance, in this patch for active record

https://github.com/open-telemetry/opentelemetry-ruby-contrib/blob/main/instrumentation/active_record/lib/opentelemetry/instrumentation/active_record/patches/persistence.rb

I see that every AR method is patched to create a child span. Am I understanding correctly that in order to instrument custom application code, I'd need to pepper the codebase with similar child-span creations, there isn't something that does it for me automatically, right?

For instance, if I have

class SomeController < ApplicationController
  def index
    data = DataCalculator.run!

    render json: data
  end
end

and in turn the DataCalculator.run! calls 3 other services, I'd have to manually instrument all 3 dependencies as well as the controller action and the DataCalculator#run method as well.

Thanks in advance, just want to make sure I'm not missing something ;)

[arielvalentin]

You are correct.

We do not have any instrumentation that generates spans for custom application code.

That you must instrument yourself.

[adamk9k]

Thank you for the quick answer 👍