fix update lease conflict

this commit fixes a bug already addressed in the upstream virtual kubelet repository. It can be dropped when upgrading the kubelet code

deployments/liqo/files/liqo-virtual-kubelet-local-ClusterRole.yaml

@@ -74,6 +74,7 @@ rules:
   verbs:
   - create
   - delete
+  - get
   - update
 - apiGroups:
   - discovery.k8s.io

pkg/virtualKubelet/node/module/node.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/strategicpatch"
 	coordinationv1 "k8s.io/client-go/kubernetes/typed/coordination/v1"
 	v1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/util/retry"
 	"k8s.io/klog/v2"
 )
 
@@ -376,22 +377,40 @@ func ensureLease(ctx context.Context, leases coordinationv1.LeaseInterface, leas
 // If this function returns an errors.IsNotFound(err) error, this likely means
 // that node leases are not supported, if this is the case, call updateNodeStatus
 // instead.
+//
+// NOTE: this code has been modified to fix a bug already addressed in the upstream
+// virtual kubelet repository. It can be dropped when upgrading the kubelet code.
 func updateNodeLease(ctx context.Context, leases coordinationv1.LeaseInterface, lease *coord.Lease) (*coord.Lease, error) {
-	l, err := leases.Update(context.TODO(), lease, metav1.UpdateOptions{})
-	if err != nil {
-		if errors.IsNotFound(err) {
-			klog.V(4).Infof("lease %s/%s not found", lease.Namespace, lease.Name)
-			l, err = ensureLease(ctx, leases, lease)
-		}
+	var l *coord.Lease
+	var err error
+	err = retry.RetryOnConflict(retry.DefaultRetry, func() error {
+		l, err = leases.Update(ctx, lease, metav1.UpdateOptions{})
 		if err != nil {
-			return nil, err
+			if errors.IsNotFound(err) {
+				klog.V(4).Infof("lease %s/%s not found", lease.Namespace, lease.Name)
+				l, err = ensureLease(ctx, leases, lease)
+			}
+			if errors.IsConflict(err) {
+				klog.V(4).Infof("conflict, get lease %s/%s", lease.Namespace, lease.Name)
+				var newErr error
+				lease, newErr = leases.Get(ctx, lease.GetName(), metav1.GetOptions{})
+				if newErr != nil {
+					klog.Error(newErr)
+					return newErr
+				}
+				return err
+			}
+			if err != nil {
+				return err
+			}
+			klog.V(4).Infof("created new lease %s%s", lease.Namespace, lease.Name)
+		} else {
+			klog.V(4).Infof("updated lease %s/%s", lease.Namespace, lease.Name)
 		}
-		klog.V(4).Infof("created new lease %s%s", lease.Namespace, lease.Name)
-	} else {
-		klog.V(4).Infof("updated lease %s/%s", lease.Namespace, lease.Name)
-	}
 
-	return l, nil
+		return nil
+	})
+	return l, err
 }
 
 // just so we don't have to allocate this on every get request.

pkg/virtualKubelet/roles/role.go

@@ -15,4 +15,4 @@ package roles
 // +kubebuilder:rbac:groups=net.liqo.io,resources=tunnelendpoints,verbs=get;list;watch
 // +kubebuilder:rbac:groups=sharing.liqo.io,resources=advertisements,verbs=get;list;watch;update;delete
 
-// +kubebuilder:rbac:groups=coordination.k8s.io,resources=leases,verbs=create;update;delete
+// +kubebuilder:rbac:groups=coordination.k8s.io,resources=leases,verbs=get;create;update;delete