fix(tempo): expose intrinsic span fields in /api/v2/search/tags

[vshulakov-sh]

Describe Your Changes

Intrinsic span fields (name, kind, status, duration) were missing from the intrinsic scope of the Tempo /api/v2/search/tags endpoint, so they did not appear in the Grafana Traces Drilldown attribute breakdown.

Two reasons they were absent:

1. Intrinsic fields have no attribute prefix (unlike resource_attr: / span_attr:), so the field_names tag-discovery loop in searchTags() skipped them.
2. Requesting scope=intrinsic explicitly returned scope: intrinsic is not supported yet.

This change advertises a static intrinsic scope listing the intrinsics that VictoriaTraces can actually filter and group by (name → NameField, kind → KindField, status → StatusCodeField, duration → DurationField), matching Tempo's response shape. The list is included in the scope=all / empty-scope response and returned directly for scope=intrinsic (no storage scan needed, since intrinsics are a fixed set). With this, Grafana Traces Drilldown lists name/kind/status in the breakdown, consistent with real Tempo.

Verified against a real Tempo instance: its /api/v2/search/tags returns these names under an intrinsic scope. Added unit tests covering the scope=intrinsic path and the response shape.

Checklist

The following checks are mandatory:

• My change adheres to VictoriaMetrics contributing guidelines.
• My change adheres to VictoriaMetrics development goals.

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Summary by cubic

Expose intrinsic span fields (name, kind, status, duration) in Tempo /api/v2/search/tags and add scope=intrinsic. This lets Grafana Traces Drilldown show and use them for filtering/grouping.

• Bug Fixes
  • Return a static intrinsic scope with these fields; include it in scope=all and empty-scope responses.
  • Render the intrinsic scope in the response and wire it through the handler.
  • Add unit tests for scope=intrinsic and the response shape; update changelog.

^{Written for commit 5032352. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 5 files

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