deprecate UpdateMode Auto in VPA

Author: rushmash91

vertical-pod-autoscaler/docs/api.md

@@ -218,7 +218,7 @@ _Appears in:_
 | `Off` | UpdateModeOff means that autoscaler never changes Pod resources.<br />The recommender still sets the recommended resources in the<br />VerticalPodAutoscaler object. This can be used for a "dry run".<br /> |
 | `Initial` | UpdateModeInitial means that autoscaler only assigns resources on pod<br />creation and does not change them during the lifetime of the pod.<br /> |
 | `Recreate` | UpdateModeRecreate means that autoscaler assigns resources on pod<br />creation and additionally can update them during the lifetime of the<br />pod by deleting and recreating the pod.<br /> |
-| `Auto` | UpdateModeAuto means that autoscaler assigns resources on pod creation<br />and additionally can update them during the lifetime of the pod,<br />using any available update method. Currently this is equivalent to<br />Recreate.<br /> |
+| `Auto` | **Deprecated** - UpdateModeAuto means that autoscaler assigns resources on pod creation<br />and additionally can update them during the lifetime of the pod,<br />using any available update method. Currently this is equivalent to<br />Recreate. **This mode is deprecated and will be removed in a future API version.**<br />**Use explicit modes like "Recreate", "Initial", or "InPlaceOrRecreate" instead.**<br />See [issue #8424](https://github.com/kubernetes/autoscaler/issues/8424) for more details.<br /> |
 | `InPlaceOrRecreate` | UpdateModeInPlaceOrRecreate means that autoscaler tries to assign resources in-place.<br />If this is not possible (e.g., resizing takes too long or is infeasible), it falls back to the<br />"Recreate" update mode.<br />Requires VPA level feature gate "InPlaceOrRecreate" to be enabled<br />on the admission and updater pods.<br />Requires cluster feature gate "InPlacePodVerticalScaling" to be enabled.<br /> |
 
 

vertical-pod-autoscaler/pkg/admission-controller/logic/server.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/autoscaler/vertical-pod-autoscaler/pkg/admission-controller/resource/pod"
 	"k8s.io/autoscaler/vertical-pod-autoscaler/pkg/admission-controller/resource/pod/patch"
 	"k8s.io/autoscaler/vertical-pod-autoscaler/pkg/admission-controller/resource/vpa"
+	vpa_types "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/apis/autoscaling.k8s.io/v1"
 	"k8s.io/autoscaler/vertical-pod-autoscaler/pkg/utils/limitrange"
 	metrics_admission "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/utils/metrics/admission"
 )
@@ -58,6 +59,42 @@ func (s *AdmissionServer) RegisterResourceHandler(resourceHandler resource.Handl
 	s.resourceHandlers[resourceHandler.GroupResource()] = resourceHandler
 }
 
+// addDeprecationWarnings adds deprecation warnings to the admission response for VPA objects using deprecated modes
+func (s *AdmissionServer) addDeprecationWarnings(req *admissionv1.AdmissionRequest, resp *admissionv1.AdmissionResponse) {
+	if req.Object.Raw == nil {
+		return
+	}
+
+	// Check if this is a VPA object
+	admittedGroupResource := metav1.GroupResource{
+		Group:    req.Resource.Group,
+		Resource: req.Resource.Resource,
+	}
+	
+	if admittedGroupResource.Group != "autoscaling.k8s.io" || admittedGroupResource.Resource != "verticalpodautoscalers" {
+		return
+	}
+
+	var vpa vpa_types.VerticalPodAutoscaler
+	if err := json.Unmarshal(req.Object.Raw, &vpa); err != nil {
+		// If we can't unmarshal, skip warning
+		return
+	}
+
+	if vpa.Spec.UpdatePolicy != nil && vpa.Spec.UpdatePolicy.UpdateMode != nil &&
+		*vpa.Spec.UpdatePolicy.UpdateMode == vpa_types.UpdateModeAuto {
+		
+		warning := `UpdateMode "Auto" is deprecated and will be removed in a future API version. ` +
+			`Use explicit update modes like "Recreate", "Initial", or "InPlaceOrRecreate" instead. ` +
+			`See https://github.com/kubernetes/autoscaler/issues/8424 for more details.`
+		
+		if resp.Warnings == nil {
+			resp.Warnings = []string{}
+		}
+		resp.Warnings = append(resp.Warnings, warning)
+	}
+}
+
 func (s *AdmissionServer) admit(ctx context.Context, data []byte) (*admissionv1.AdmissionResponse, metrics_admission.AdmissionStatus, metrics_admission.AdmissionResource) {
 	// we don't block the admission by default, even on unparsable JSON
 	response := admissionv1.AdmissionResponse{}
@@ -124,6 +161,9 @@ func (s *AdmissionServer) admit(ctx context.Context, data []byte) (*admissionv1.
 		metrics_admission.OnAdmittedPod(status == metrics_admission.Applied)
 	}
 
+	// Add deprecation warnings for VPA objects using deprecated modes
+	s.addDeprecationWarnings(ar.Request, &response)
+
 	return &response, status, resource
 }
 

vertical-pod-autoscaler/pkg/admission-controller/resource/vpa/handler.go

@@ -95,7 +95,8 @@ func (h *resourceHandler) GetPatches(_ context.Context, ar *v1.AdmissionRequest)
 	patches := []resource.PatchRecord{}
 	if vpa.Spec.UpdatePolicy == nil {
 		// Sets the default updatePolicy.
-		defaultUpdateMode := vpa_types.UpdateModeAuto
+		// Changed from UpdateModeAuto to UpdateModeRecreate as part of Auto mode deprecation
+		defaultUpdateMode := vpa_types.UpdateModeRecreate
 		patches = append(patches, resource.PatchRecord{
 			Op:    "add",
 			Path:  "/spec/updatePolicy",

vertical-pod-autoscaler/pkg/apis/autoscaling.k8s.io/v1/types.go

@@ -170,6 +170,9 @@ const (
 	// and additionally can update them during the lifetime of the pod,
 	// using any available update method. Currently this is equivalent to
 	// Recreate.
+	// Deprecated: This value is deprecated and will be removed in a future API version.
+	// Use explicit update modes like "Recreate", "Initial", or "InPlaceOrRecreate" instead.
+	// See https://github.com/kubernetes/autoscaler/issues/8424 for more details.
 	UpdateModeAuto UpdateMode = "Auto"
 	// UpdateModeInPlaceOrRecreate means that autoscaler tries to assign resources in-place.
 	// If this is not possible (e.g., resizing takes too long or is infeasible), it falls back to the

vertical-pod-autoscaler/pkg/updater/logic/updater.go

@@ -51,6 +51,16 @@ import (
 	vpa_api_util "k8s.io/autoscaler/vertical-pod-autoscaler/pkg/utils/vpa"
 )
 
+// logDeprecationWarnings logs deprecation warnings for VPAs using deprecated modes
+func logDeprecationWarnings(vpa *vpa_types.VerticalPodAutoscaler) {
+	if vpa.Spec.UpdatePolicy != nil && vpa.Spec.UpdatePolicy.UpdateMode != nil &&
+		*vpa.Spec.UpdatePolicy.UpdateMode == vpa_types.UpdateModeAuto {
+		
+		klog.Warningf("VPA %s/%s uses deprecated UpdateMode 'Auto'. This mode is deprecated and will be removed in a future API version. Please use explicit update modes like 'Recreate', 'Initial', or 'InPlaceOrRecreate'. See https://github.com/kubernetes/autoscaler/issues/8424",
+			vpa.Namespace, vpa.Name)
+	}
+}
+
 // Updater performs updates on pods if recommended by Vertical Pod Autoscaler
 type Updater interface {
 	// RunOnce represents single iteration in the main-loop of Updater
@@ -159,6 +169,10 @@ func (u *updater) RunOnce(ctx context.Context) {
 			klog.V(3).InfoS("Skipping VPA object in ignored namespace", "vpa", klog.KObj(vpa), "namespace", vpa.Namespace)
 			continue
 		}
+		
+		// Log deprecation warnings for VPAs using deprecated modes
+		logDeprecationWarnings(vpa)
+		
 		if vpa_api_util.GetUpdateMode(vpa) != vpa_types.UpdateModeRecreate &&
 			vpa_api_util.GetUpdateMode(vpa) != vpa_types.UpdateModeAuto && vpa_api_util.GetUpdateMode(vpa) != vpa_types.UpdateModeInPlaceOrRecreate {
 			klog.V(3).InfoS("Skipping VPA object because its mode is not  \"InPlaceOrRecreate\", \"Recreate\" or \"Auto\"", "vpa", klog.KObj(vpa))