Instrument signals with OTel

[iravid]

What was changed

Add instrumentation to signal in the client interceptor and handleSignal in the workflow inbound interceptor.

Why?

We're starting activities from signal handlers and would like to see them on the same trace.

Checklist

2. How was this tested:

Haven't seen tests in this module - lmk if needed! Will test this soon on our own project.

4. Any docs updates needed?

Don't think so!

[CLAassistant]

All committers have signed the CLA.

[mjameswh]

Thanks @iravid for sharing this.

There's a few things that needs to happen before we can merge this:

• Handle WorkflowOutboundCallsInterceptor.signalWorkflow so that spans propagate when a workflow signals another workflow;
• Add a corresponding check in test-otel.ts.

Also, if you feel up to the task, we should do the same with handleUpdate and friends.

[iravid]

Thanks @mjameswh! Will happily address those two; thanks for the pointer to the tests.

I'm a bit short on time this week so if alright by you will save instrumentation of the other operations for another PR?

[mjameswh]

I'm a bit short on time this week so if alright by you will save instrumentation of the other operations for another PR?

Sure, no problem.

[iravid]

Hey @mjameswh apologies for the delay here (😅) - added the requested adjustments and tested locally by removing the .skip on the integration test and running npm run test with RUN_INTEGRATION_TESTS=true

[iravid]

Hi @mjameswh - any chance you could have a look here?