chore: Add comments on calls to kubeClient Update() (#1130)

kubernetes-sigs · Mar 27, 2024 · 23c4af9 · 23c4af9
1 parent b770a19
commit 23c4af9
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diff --git a/pkg/controllers/nodeclaim/disruption/controller.go b/pkg/controllers/nodeclaim/disruption/controller.go
@@ -93,6 +93,9 @@ func (c *Controller) Reconcile(ctx context.Context, nodeClaim *v1beta1.NodeClaim
 		results = append(results, res)
 	}
 	if !equality.Semantic.DeepEqual(stored, nodeClaim) {
+		// We call Update() here rather than Patch() because patching a list with a JSON merge patch
+		// can cause races due to the fact that it fully replaces the list on a change
+		// Here, we are updating the status condition list
 		if err := c.kubeClient.Status().Update(ctx, nodeClaim); err != nil {
 			if errors.IsConflict(err) {
 				return reconcile.Result{Requeue: true}, nil

diff --git a/pkg/controllers/nodeclaim/termination/controller.go b/pkg/controllers/nodeclaim/termination/controller.go
@@ -95,6 +95,9 @@ func (c *Controller) Finalize(ctx context.Context, nodeClaim *v1beta1.NodeClaim)
 	}
 	controllerutil.RemoveFinalizer(nodeClaim, v1beta1.TerminationFinalizer)
 	if !equality.Semantic.DeepEqual(stored, nodeClaim) {
+		// We call Update() here rather than Patch() because patching a list with a JSON merge patch
+		// can cause races due to the fact that it fully replaces the list on a change
+		// https://github.com/kubernetes/kubernetes/issues/111643#issuecomment-2016489732
 		if err = c.kubeClient.Update(ctx, nodeClaim); err != nil {
 			if errors.IsConflict(err) {
 				return reconcile.Result{Requeue: true}, nil