Add workflow spans for tagging the logs with step name

[Caio-Nogueira]

This is a proposal to add arbitrary step-related tags on console logs emitted from within workflow instances (more specifically, steps).

#6608 got merged, meaning that the tracing api is now using async context to store active spans. This means that user spans can in theory be attributed to the correct span, once the log instrumentation is changed to do so

[codspeed-hq]

Merging this PR will not alter performance

✅ 72 untouched benchmarks
⏩ 129 skipped benchmarks¹

---

_{Comparing caio/workflows-tracing (e7de698) with main (0138dcb)}

Footnotes

1. 129 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.61%. Comparing base (0138dcb) to head (e7de698).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6088   +/-   ##
=======================================
  Coverage   66.60%   66.61%           
=======================================
  Files         402      402           
  Lines      115908   115908           
  Branches    19427    19427           
=======================================
+ Hits        77205    77209    +4     
+ Misses      27104    27101    -3     
+ Partials    11599    11598    -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[ask-bonk]

@Caio-Nogueira Bonk workflow was cancelled.

View workflow run · To retry, trigger Bonk again.

[jasnell]

Tagging either @fhanau or @mar-cf to provide additional review on the bits that touch the tracing apis. These LGTM but want to make sure I'm not missing any critical detail.

[jasnell]

Follow-up review. Most prior feedback was addressed — thanks for the updates.

Remaining findings:

• Formatting: The file needs just format — missing indentation in KJ_IF_SOME body, flush-left code in runStep, misleading closing-brace comments
• Misleading comment: setWorkflowInfo docstring claims buffered trace update that doesn't happen
• Dead code: TraceContext::addLog added but never called
• Missing bounds check: argv[0] accessed without size check

(These comments were generated with AI assistance and may contain errors.)

[github-actions]

The generated output of @cloudflare/workers-types matches the snapshot in types/generated-snapshot 🎉

[fhanau]

Reviewed the tracing-related changes and left some feedback. This excludes the handling of the async storage, which I'm less familiar with.

[danlapid]

This PR combines too much in one.
It also seems to have feature crept since the last time I looked at it.
The changes to add workflowName and workflowInstanceId should be pulled out, especially since I'm not sure this is the right implementation but we can discuss that in the split PR.

[Caio-Nogueira]

This PR combines too much in one. It also seems to have feature crept since the last time I looked at it. The changes to add workflowName and workflowInstanceId should be pulled out, especially since I'm not sure this is the right implementation but we can discuss that in the split PR.

I removed the invocation level fields from the trace event. Although I think we should think about them (could be in a separate PR). Keeping only the log-to-span attribution logic for now.

[Caio-Nogueira]

Update:

Since #6608 got merged we can just rely on the internal tracing module to wrap the user's callback.

I rebased with main and removed the log instrumentation logic - that comes later (EW-10672).

All we need from the workflows end is to trace the step.do's callback.

[jmorrell-cloudflare]

@danlapid @fhanau Do we still need to allowlist all spans in the internal repo?

[danlapid]

@danlapid @fhanau Do we still need to allowlist all spans in the internal repo?

yes, but not ones created with the JS tracing API

[Caio-Nogueira]

@danlapid @fhanau Do we still need to allowlist all spans in the internal repo?

yes, but not ones created with the JS tracing API

Ah I thought internal spans also had to be whitelisted. You're right - tests seem to be passing without any changes to it 👍🏼