Fix race condition with using newer NodePool for hash annotation

pkg/controllers/provisioning/provisioner.go

@@ -361,7 +361,7 @@ func (p *Provisioner) Create(ctx context.Context, n *scheduler.NodeClaim, opts .
 	if err := latest.Spec.Limits.ExceededBy(latest.Status.Resources); err != nil {
 		return "", err
 	}
-	nodeClaim := n.ToNodeClaim(latest)
+	nodeClaim := n.ToNodeClaim()
 
 	if err := p.kubeClient.Create(ctx, nodeClaim); err != nil {
 		return "", err

pkg/controllers/provisioning/scheduling/nodeclaimtemplate.go

@@ -23,6 +23,7 @@ import (
 	"github.com/samber/lo"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
 
 	v1 "sigs.k8s.io/karpenter/pkg/apis/v1"
 	"sigs.k8s.io/karpenter/pkg/cloudprovider"
@@ -40,6 +41,7 @@ type NodeClaimTemplate struct {
 	v1.NodeClaim
 
 	NodePoolName        string
+	NodePoolUUID        types.UID
 	InstanceTypeOptions cloudprovider.InstanceTypes
 	Requirements        scheduling.Requirements
 }
@@ -48,36 +50,37 @@ func NewNodeClaimTemplate(nodePool *v1.NodePool) *NodeClaimTemplate {
 	nct := &NodeClaimTemplate{
 		NodeClaim:    *nodePool.Spec.Template.ToNodeClaim(),
 		NodePoolName: nodePool.Name,
+		NodePoolUUID: nodePool.UID,
 		Requirements: scheduling.NewRequirements(),
 	}
+	nct.Annotations = lo.Assign(nct.Annotations, map[string]string{
+		v1.NodePoolHashAnnotationKey:        nodePool.Hash(),
+		v1.NodePoolHashVersionAnnotationKey: v1.NodePoolHashVersion,
+	})
 	nct.Labels = lo.Assign(nct.Labels, map[string]string{v1.NodePoolLabelKey: nodePool.Name})
 	nct.Requirements.Add(scheduling.NewNodeSelectorRequirementsWithMinValues(nct.Spec.Requirements...).Values()...)
 	nct.Requirements.Add(scheduling.NewLabelRequirements(nct.Labels).Values()...)
 	return nct
 }
 
-func (i *NodeClaimTemplate) ToNodeClaim(nodePool *v1.NodePool) *v1.NodeClaim {
+func (i *NodeClaimTemplate) ToNodeClaim() *v1.NodeClaim {
 	// Order the instance types by price and only take the first 100 of them to decrease the instance type size in the requirements
 	instanceTypes := lo.Slice(i.InstanceTypeOptions.OrderByPrice(i.Requirements), 0, MaxInstanceTypes)
 	i.Requirements.Add(scheduling.NewRequirementWithFlexibility(corev1.LabelInstanceTypeStable, corev1.NodeSelectorOpIn, i.Requirements.Get(corev1.LabelInstanceTypeStable).MinValues, lo.Map(instanceTypes, func(i *cloudprovider.InstanceType, _ int) string {
 		return i.Name
 	})...))
 
-	gvk := object.GVK(nodePool)
 	nc := &v1.NodeClaim{
 		ObjectMeta: metav1.ObjectMeta{
 			GenerateName: fmt.Sprintf("%s-", i.NodePoolName),
-			Annotations: lo.Assign(i.Annotations, map[string]string{
-				v1.NodePoolHashAnnotationKey:        nodePool.Hash(),
-				v1.NodePoolHashVersionAnnotationKey: v1.NodePoolHashVersion,
-			}),
-			Labels: i.Labels,
+			Annotations:  i.Annotations,
+			Labels:       i.Labels,
 			OwnerReferences: []metav1.OwnerReference{
 				{
-					APIVersion:         gvk.GroupVersion().String(),
-					Kind:               gvk.Kind,
-					Name:               nodePool.Name,
-					UID:                nodePool.UID,
+					APIVersion:         object.GVK(&v1.NodePool{}).GroupVersion().String(),
+					Kind:               object.GVK(&v1.NodePool{}).Kind,
+					Name:               i.NodePoolName,
+					UID:                i.NodePoolUUID,
 					BlockOwnerDeletion: lo.ToPtr(true),
 				},
 			},

pkg/controllers/provisioning/suite_test.go

@@ -29,6 +29,7 @@ import (
 	storagev1 "k8s.io/api/storage/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/tools/record"
 	clock "k8s.io/utils/clock/testing"
@@ -246,6 +247,31 @@ var _ = Describe("Provisioning", func() {
 			ExpectScheduled(ctx, env.Client, pod)
 		}
 	})
+	It("should not use a different NodePool hash on the NodeClaim if the NodePool changes during scheduling", func() {
+		// This test was added since we were generating the NodeClaim's NodePool hash from a NodePool that was re-retrieved
+		// after scheduling had been completed. This could have resulted in the hash not accurately reflecting the actual NodePool
+		// state that it was generated from
+
+		nodePool := test.NodePool()
+		pod := test.UnschedulablePod()
+		hash := nodePool.Hash()
+		ExpectApplied(ctx, env.Client, nodePool, pod)
+
+		results, err := prov.Schedule(ctx)
+		Expect(err).ToNot(HaveOccurred())
+
+		Expect(results.NewNodeClaims).To(HaveLen(1))
+		Expect(results.NewNodeClaims[0].ToNodeClaim().Annotations).To(HaveKeyWithValue(v1.NodePoolHashAnnotationKey, hash))
+
+		nodeClaims, err := prov.CreateNodeClaims(ctx, results.NewNodeClaims)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(nodeClaims).To(HaveLen(1))
+
+		nodeClaim := &v1.NodeClaim{}
+		Expect(env.Client.Get(ctx, types.NamespacedName{Name: nodeClaims[0]}, nodeClaim)).To(Succeed())
+
+		Expect(nodeClaim.Annotations).To(HaveKeyWithValue(v1.NodePoolHashAnnotationKey, hash))
+	})
 	It("should schedule all pods on one inflight node when node is in deleting state", func() {
 		nodePool := test.NodePool()
 		its, err := cloudProvider.GetInstanceTypes(ctx, nodePool)
@@ -286,7 +312,7 @@ var _ = Describe("Provisioning", func() {
 			Expect(n.Node.Name).ToNot(Equal(node.Name))
 		}
 	})
-	It("should schedule based on the max resource requests of containers and initContainers with sidecar containers when initcontainer comes first", func() {
+	It("should schedule baased on the max resource requests of containers and initContainers with sidecar containers when initcontainer comes first", func() {
 		if env.Version.Minor() < 29 {
 			Skip("Native Sidecar containers is only on by default starting in K8s version >= 1.29.x")
 		}