feat(bun): Set http response header attributes instead of response context headers#19821
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feat(bun): Set http response header attributes instead of response context headers#19821
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size-limit report 📦
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node-overhead report 🧳Note: This is a synthetic benchmark with a minimal express app and does not necessarily reflect the real-world performance impact in an application.
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Lms24
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Mar 16, 2026
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| if (headerValue == null) { | ||
| return; | ||
| } | ||
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| const normalizedKey = `http.${lifecycle}.header.${normalizeAttributeKey(headerKey)}${cookieKey ? `.${normalizeAttributeKey(cookieKey)}` : ''}`; | ||
| spanAttributes[normalizedKey] = headerValue; | ||
| } |
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These are just minimal optimizations for performance/bundle size but I don't think they fully paid off. Main reasoning: If we do nothing on headerValue === undefined we can also early return and save the little time it takes to compute the header key. Happy to revert if reviewers prefer the old version.
s1gr1d
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Mar 17, 2026
Lms24
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This PR addresses the issue reported in #19790 where our Bun serve instrumentation blindly attached all HTTP response headers to request contexts. This was problematic as explained in the issue since sensitive headers could have been sent.
This PR ensures we no longer do this, while retaining safe response header:
httpHeadersToSpanAttributeshelper from core to also generatehttp.responseheaders if an optionallifecycleparameter is added to the callcontexts.response.headers: We never do this. In Node, we only set the response status on this context.http.serverspan. By leveraginghttpHeadersToSpanAttributeswe now have the same sensitive data mechanisms in place as with request headers which we already send this way. Meaning, a bunch of authorization headers are filtered always, and cookie/set-cookie headers are filtered depending onsendDefaultPii.Note: This can be considered a subtle behaviour break but given the incorrectness of always setting response headers unconditionally before, I think this is justified. Contexts are not indexed, hence alerts can't be built on top of them and neither saved discover or explore queries. I'm also not aware of Relay promoting
respnose.header.*values to tags, so we should be safe here.Closes #19790