[v0.14] Prevent false drift from null field rendering #4997
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* Prevent false drift from Helm v4 null field rendering Helm v4 can emit explicit null values for omitted fields (e.g., spec.strategy.rollingUpdate: null), while Helm v3 omitted these fields entirely. When combined with Kubernetes server-side defaulting, this creates false drift detection: the merge patch interprets null as "delete this field," conflicting with defaulted live resources. Solution: - Add normalizeNullPatch to recursively strip null-valued fields from merge patches before drift comparison - Handle nested structures (maps and arrays) to cover all potential Helm v4 null emissions beyond just deployment strategy * Add fast-path optimization for null patch normalization in diff.go Add bytes.Contains fast-path check before expensive unmarshal/walk/ marshal operations when patch doesn't contain 'null'. This provides ~55x performance improvement for patches without nulls: - WithoutNulls: 127.9 ns/op (vs 7063 ns/op with nulls) - 97% fewer allocations (1 vs 72 allocs/op) - 97% less memory (176 B vs 5404 B per op) Also add benchmark tests and fast-path test coverage. (cherry picked from commit 7a7732f) Refers to rancher#4969
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Why are we backporting a Helm v4 fix to Fleet 0.14 ? 🤔 |
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As it turned out, the cause is not Helm 4, but an issue that we have introduced and backported down to Fleet v0.11. But the changes are the right one to fix this issue anyway. |
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Ok, then please adapt the title to reflect that. |
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thardeck
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* Revert "[v0.14] Prevent false drift from null field rendering (#4997)" This reverts commit fcd6873. * Revert "[v0.14] Remove k8s.io/kubernetes, use client-go scheme (#4902)" This reverts commit 58f0054. * Align k8s.io/kubernetes to v1.34.6 to match other k8s libraries After reverting the k8s.io/kubernetes removal (PR #4902), bump k8s.io/kubernetes from v1.34.5 to v1.34.6 and update all replace directives to v0.34.6, matching the kubernetes dependencies that were already at v0.34.6 on this branch (bumped in #4901). Refs: #4969
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Cherry-pick from #4664
Refers to #4969
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