fix: add wall-clock certificate expiry check to webhook TLS rotation#1175
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fix: add wall-clock certificate expiry check to webhook TLS rotation#1175
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lfrancke
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The rotation interval uses tokio's monotonic clock, but certificate validity uses wall-clock time. When these diverge (hibernation, VM migration, cgroup freezing), the certificate can expire before rotation. Add a periodic wall-clock check (every 5 minutes) that compares SystemTime::now() against the certificate's not_after field and triggers early rotation if the cert is within 4 hours of expiry. Fixes: #1174
Remove the monotonic 20h rotation interval and the supplementary wall-clock check. Instead, use a single periodic check (every 5 min) that compares wall-clock time against the certificate's not_after. Also derive the expiry buffer from the certificate lifetime (1/6) so it scales if the lifetime ever changes, and add comments documenting the relationship between lifetime and check interval.
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Tested the secret operator against this branch and it looks good (it doesn't introduce additional breakage): |
razvan
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A changelog entry is missing and I made a small suggestion but otherwise very nice.
Techassi
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Mar 17, 2026
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Description
The rotation interval uses tokio's monotonic clock, but certificate validity uses wall-clock time. When these diverge (hibernation, VM migration, cgroup freezing), the certificate can expire before rotation.
Add a periodic wall-clock check (every 5 minutes) that compares SystemTime::now() against the certificate's not_after field and triggers early rotation if the cert is within 4 hours of expiry.
Fixes: #1174
Definition of Done Checklist
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Acceptance