chore: Fix possible Registration TTL race condition #1665
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Fixes #N/A
Description
The current liveness TTL has a small race condition. It's possible that the first condition check
l.clock.Since(registered.LastTransitionTime.Time) < registrationTTLcan return atruevalue whereregistrationTTL - l.clock.Since(registered.LastTransitionTime.Time) > 0; however, since the clock can advance while we are in this conditional statement, by the time we get to the linereturn reconcile.Result{RequeueAfter: registrationTTL - l.clock.Since(registered.LastTransitionTime.Time)}, nil,registrationTTL - l.clock.Since(registered.LastTransitionTime.Time)is no longer greater than 0 and is now either equal to 0 or negative.In either case,
controller-runtimedoes not respect anyRequeueAftervalue that is equal to or less than 0. Thus, this effectively results in us returning the responsereconcile.Result{}, nil. This can leave the NodeClaim in a state where it never gets deleted since we returned an empty result.How was this change tested?
make presubmitNo tests were added since it's basically impossible to reproduce this race condition in testing code.
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.