Feat/remove restart policy never if autoscaler v2 and ray 2.55 or greater

ray-operator/controllers/ray/common/pod.go

@@ -213,9 +213,13 @@ func DefaultHeadPodTemplate(ctx context.Context, instance rayv1.RayCluster, head
 		mergeAutoscalerOverrides(&autoscalerContainer, instance.Spec.AutoscalerOptions)
 		podTemplate.Spec.Containers = append(podTemplate.Spec.Containers, autoscalerContainer)
 
+		// The error is ignored here because the function will return false if there's an error parsing the version.
+		// For example, if rayVersion is empty or unparseable, it considers the feature is not valid.
 		if utils.IsAutoscalingV2Enabled(&instance.Spec) {
 			setAutoscalerV2EnvVars(&podTemplate)
-			podTemplate.Spec.RestartPolicy = corev1.RestartPolicyNever
+			if autoscalerRestartValid, _ := utils.IsRayVersionAtLeast(instance.Spec.RayVersion, utils.MinAutoscalerRestartValidVersion); !autoscalerRestartValid {
+				podTemplate.Spec.RestartPolicy = corev1.RestartPolicyNever
+			}
 		} else if utils.IsAutoscalingV1Enabled(&instance.Spec) {
 			setAutoscalerV1EnvVars(&podTemplate)
 		}
@@ -466,7 +470,11 @@ func DefaultWorkerPodTemplate(ctx context.Context, instance rayv1.RayCluster, wo
 		podTemplate.Spec.Containers[utils.RayContainerIndex].Ports = append(podTemplate.Spec.Containers[utils.RayContainerIndex].Ports, metricsPort)
 	}
 
-	if utils.IsAutoscalingEnabled(&instance.Spec) && utils.IsAutoscalingV2Enabled(&instance.Spec) {
+	// Use the headGroupSpec to determine whether the RestartPolicy should be Never or not, since the head pod is the one that runs the autoscaler.
+	// The error is ignored here because the function will return false if there's an error parsing the version.
+	// For example, if rayVersion is empty or unparseable, it considers the feature is not valid.
+	autoscalerRestartValid, _ := utils.IsRayVersionAtLeast(instance.Spec.RayVersion, utils.MinAutoscalerRestartValidVersion)
+	if !autoscalerRestartValid && utils.IsAutoscalingEnabled(&instance.Spec) && utils.IsAutoscalingV2Enabled(&instance.Spec) {
 		podTemplate.Spec.RestartPolicy = corev1.RestartPolicyNever
 	}
 

ray-operator/controllers/ray/common/pod_test.go

@@ -1175,19 +1175,43 @@ func TestHeadPodTemplate_WithAutoscalingEnabled(t *testing.T) {
 
 func TestDefaultHeadPodTemplate_Autoscaling(t *testing.T) {
 	clusterNoAutoscaling := instance.DeepCopy()
+
 	clusterAutoscalingVersionNotSet := instance.DeepCopy()
 	clusterAutoscalingVersionNotSet.Spec.EnableInTreeAutoscaling = new(true)
 	clusterAutoscalingV1 := instance.DeepCopy()
 	clusterAutoscalingV1.Spec.EnableInTreeAutoscaling = new(true)
 	clusterAutoscalingV1.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
 		Version: ptr.To(rayv1.AutoscalerVersionV1),
 	}
+
+	// clusterAutoscalingV2 has no RayVersion set, so IsRayVersionAtLeast
+	// returns false: env var is injected AND RestartPolicy is set to Never.
 	clusterAutoscalingV2 := instance.DeepCopy()
 	clusterAutoscalingV2.Spec.EnableInTreeAutoscaling = new(true)
 	clusterAutoscalingV2.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
 		Version: ptr.To(rayv1.AutoscalerVersionV2),
 	}
 
+	// clusterAutoscalingV2OldRay uses a Ray version strictly below MinAutoscalerRestartValidVersion
+	// (2.55.0): env var is injected AND RestartPolicy is set to Never.
+	clusterAutoscalingV2OldRay := instance.DeepCopy()
+	clusterAutoscalingV2OldRay.Spec.EnableInTreeAutoscaling = new(true)
+	clusterAutoscalingV2OldRay.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
+		Version: ptr.To(rayv1.AutoscalerVersionV2),
+	}
+	clusterAutoscalingV2OldRay.Spec.RayVersion = "2.54.0"
+
+	// clusterAutoscalingV2NewRay uses a Ray version >= MinAutoscalerRestartValidVersion (2.55.0).
+	// With the updated logic, setAutoscalerV2EnvVars is always called when AutoscalerV2 is enabled,
+	// so the env var IS injected. Only RestartPolicy=Never is skipped for newer versions.
+	clusterAutoscalingV2NewRay := instance.DeepCopy()
+	clusterAutoscalingV2NewRay.Spec.EnableInTreeAutoscaling = new(true)
+	clusterAutoscalingV2NewRay.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
+		Version: ptr.To(rayv1.AutoscalerVersionV2),
+	}
+	clusterAutoscalingV2NewRay.Spec.RayVersion = "2.55.0"
+	clusterAutoscalingV2NewRay.Spec.HeadGroupSpec.Template.Spec.RestartPolicy = corev1.RestartPolicyOnFailure
+
 	ctx := context.Background()
 	podName := strings.ToLower(instance.Name + utils.DashSymbol + string(rayv1.HeadNode) + utils.DashSymbol + utils.FormatInt32(0))
 
@@ -1219,13 +1243,28 @@ func TestDefaultHeadPodTemplate_Autoscaling(t *testing.T) {
 			expectedAutoscalerV1EnvVar: true,
 			expectedRestartPolicy:      "",
 		},
-		"Pod template with autoscaling v2 enabled should the correct autoscaler v2 fields": {
+		"Pod template with autoscaling v2 enabled and unparseable Ray image should inject env var and set RestartPolicy to Never": {
 			cluster:                    *clusterAutoscalingV2,
 			expectedHeadContainers:     2,
 			expectedAutoscalerV2EnvVar: true,
 			expectedAutoscalerV1EnvVar: false,
 			expectedRestartPolicy:      corev1.RestartPolicyNever,
 		},
+		"Pod template with autoscaling v2 enabled and Ray version below MinAutoscalerRestartValidVersion should inject env var and set RestartPolicy to Never": {
+			cluster:                    *clusterAutoscalingV2OldRay,
+			expectedHeadContainers:     2,
+			expectedAutoscalerV2EnvVar: true,
+			expectedRestartPolicy:      corev1.RestartPolicyNever,
+		},
+		// setAutoscalerV2EnvVars is now always called when AutoscalerV2 is enabled regardless of
+		// the Ray version, so the env var is injected even for new Ray versions. Only
+		// RestartPolicy=Never is version-gated (skipped when version >= MinAutoscalerRestartValidVersion).
+		"Pod template with autoscaling v2 enabled and Ray version at or above MinAutoscalerRestartValidVersion should inject env var but not set RestartPolicy to Never": {
+			cluster:                    *clusterAutoscalingV2NewRay,
+			expectedHeadContainers:     2,
+			expectedAutoscalerV2EnvVar: true,
+			expectedRestartPolicy:      corev1.RestartPolicyOnFailure,
+		},
 	}
 
 	for name, tc := range tests {
@@ -1443,12 +1482,34 @@ func TestDefaultWorkerPodTemplate_Autoscaling(t *testing.T) {
 	clusterNoAutoscaling := instance.DeepCopy()
 	clusterAutoscalingV1 := instance.DeepCopy()
 	clusterAutoscalingV1.Spec.EnableInTreeAutoscaling = new(true)
+
+	// clusterAutoscalingV2 has no RayVersion set, so IsRayVersionAtLeast
+	// returns false and RestartPolicy should be set to Never.
 	clusterAutoscalingV2 := instance.DeepCopy()
 	clusterAutoscalingV2.Spec.EnableInTreeAutoscaling = new(true)
 	clusterAutoscalingV2.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
 		Version: ptr.To(rayv1.AutoscalerVersionV2),
 	}
 
+	// clusterAutoscalingV2OldRay uses a Ray version strictly below MinAutoscalerRestartValidVersion
+	// (2.55.0), so RestartPolicy should still be set to Never.
+	clusterAutoscalingV2OldRay := instance.DeepCopy()
+	clusterAutoscalingV2OldRay.Spec.EnableInTreeAutoscaling = new(true)
+	clusterAutoscalingV2OldRay.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
+		Version: ptr.To(rayv1.AutoscalerVersionV2),
+	}
+	clusterAutoscalingV2OldRay.Spec.RayVersion = "2.54.0"
+
+	// clusterAutoscalingV2NewRay uses a Ray version >= MinAutoscalerRestartValidVersion (2.55.0),
+	// so autoscalerRestartValid is true and RestartPolicy should NOT be set to Never.
+	clusterAutoscalingV2NewRay := instance.DeepCopy()
+	clusterAutoscalingV2NewRay.Spec.EnableInTreeAutoscaling = new(true)
+	clusterAutoscalingV2NewRay.Spec.AutoscalerOptions = &rayv1.AutoscalerOptions{
+		Version: ptr.To(rayv1.AutoscalerVersionV2),
+	}
+	clusterAutoscalingV2NewRay.Spec.RayVersion = "2.55.0"
+	clusterAutoscalingV2NewRay.Spec.WorkerGroupSpecs[0].Template.Spec.RestartPolicy = corev1.RestartPolicyOnFailure
+
 	ctx := context.Background()
 	podName := strings.ToLower(instance.Name + utils.DashSymbol + string(rayv1.WorkerNode) + utils.DashSymbol + utils.FormatInt32(0))
 	fqdnRayIP := utils.GenerateFQDNServiceName(ctx, instance, instance.Namespace)
@@ -1465,10 +1526,18 @@ func TestDefaultWorkerPodTemplate_Autoscaling(t *testing.T) {
 			cluster:               *clusterAutoscalingV1,
 			expectedRestartPolicy: "",
 		},
-		"Pod template with autoscaling v2 enabled should the correct autoscaler v2 fields": {
+		"Pod template with autoscaling v2 enabled and unparseable Ray image should set RestartPolicy to Never": {
 			cluster:               *clusterAutoscalingV2,
 			expectedRestartPolicy: corev1.RestartPolicyNever,
 		},
+		"Pod template with autoscaling v2 enabled and Ray version below MinAutoscalerRestartValidVersion should set RestartPolicy to Never": {
+			cluster:               *clusterAutoscalingV2OldRay,
+			expectedRestartPolicy: corev1.RestartPolicyNever,
+		},
+		"Pod template with autoscaling v2 enabled and Ray version at or above MinAutoscalerRestartValidVersion should not set RestartPolicy to Never": {
+			cluster:               *clusterAutoscalingV2NewRay,
+			expectedRestartPolicy: corev1.RestartPolicyOnFailure,
+		},
 	}
 
 	for name, tc := range tests {

ray-operator/controllers/ray/utils/constant.go

@@ -296,6 +296,9 @@ const (
 	// MaxRayJobNameLength is the maximum RayJob name to make sure it pass the RayCluster validation
 	// Minus 6 since we append 6 characters to the RayJob name to create the cluster (GenerateRayClusterName).
 	MaxRayJobNameLength = MaxRayClusterNameLength - 6
+
+	// MinAutoscalerRestartValidVersion is the minimum Ray image version that supports the feature of autoscaler restart.
+	MinAutoscalerRestartValidVersion = "2.55.0"
 )
 
 type ServiceType string

ray-operator/controllers/ray/utils/util.go

@@ -23,6 +23,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/json"
 	"k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/apimachinery/pkg/util/version"
 	"k8s.io/utils/ptr"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -1095,6 +1096,30 @@ func IsHTTPRouteEqual(existing, desired *gwv1.HTTPRoute) bool {
 	return true
 }
 
+// IsRayVersionAtLeast reports whether the given rayVersion (from RayClusterSpec.RayVersion)
+// is at least targetVersion.
+//
+// Both rayVersion and targetVersion are parsed with k8s.io/apimachinery/pkg/util/version,
+// which accepts standard semver strings (e.g. "2.46.0").
+// Returns (false, error) if rayVersion is empty or either version string cannot be parsed.
+func IsRayVersionAtLeast(rayVersion string, targetVersion string) (bool, error) {
+	if rayVersion == "" {
+		return false, fmt.Errorf("rayVersion is empty")
+	}
+
+	v, err := version.ParseGeneric(rayVersion)
+	if err != nil {
+		return false, fmt.Errorf("failed to parse Ray version %q: %w", rayVersion, err)
+	}
+
+	minVersion, err := version.ParseGeneric(targetVersion)
+	if err != nil {
+		return false, fmt.Errorf("failed to parse minimum version %q: %w", targetVersion, err)
+	}
+
+	return v.AtLeast(minVersion), nil
+}
+
 // IsGatewayEqual checks if the existing Gateway matches the desired Gateway.
 // This check only compares the fields explicitly managed by the RayService controller.
 // If the controller starts managing additional Gateway fields in the future,

ray-operator/controllers/ray/utils/util_test.go

@@ -2310,3 +2310,92 @@ func TestIsGatewayEqual(t *testing.T) {
 		})
 	}
 }
+
+func TestIsRayVersionAtLeast(t *testing.T) {
+	tests := []struct {
+		name          string
+		rayVersion    string
+		targetVersion string
+		want          bool
+		wantErr       bool
+	}{
+		{
+			name:          "version equal to target",
+			rayVersion:    "2.9.0",
+			targetVersion: "2.9.0",
+			want:          true,
+		},
+		{
+			name:          "version greater than target (minor)",
+			rayVersion:    "2.10.0",
+			targetVersion: "2.9.0",
+			want:          true,
+		},
+		{
+			name:          "version greater than target (major)",
+			rayVersion:    "3.0.0",
+			targetVersion: "2.9.0",
+			want:          true,
+		},
+		{
+			name:          "version greater than target (patch)",
+			rayVersion:    "2.9.1",
+			targetVersion: "2.9.0",
+			want:          true,
+		},
+		{
+			name:          "version with no patch component",
+			rayVersion:    "2.9",
+			targetVersion: "2.9.0",
+			want:          true,
+		},
+		{
+			name:          "version less than target (minor)",
+			rayVersion:    "2.8.0",
+			targetVersion: "2.9.0",
+			want:          false,
+		},
+		{
+			name:          "version less than target (major)",
+			rayVersion:    "1.13.0",
+			targetVersion: "2.0.0",
+			want:          false,
+		},
+		{
+			name:          "version at least target",
+			rayVersion:    "2.46.0",
+			targetVersion: "2.46.0",
+			want:          true,
+		},
+		{
+			name:          "version below target",
+			rayVersion:    "2.45.0",
+			targetVersion: "2.46.0",
+			want:          false,
+		},
+		{
+			name:          "empty rayVersion",
+			rayVersion:    "",
+			targetVersion: "2.9.0",
+			wantErr:       true,
+		},
+		{
+			name:          "unparseable rayVersion",
+			rayVersion:    "latest",
+			targetVersion: "2.9.0",
+			wantErr:       true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := IsRayVersionAtLeast(tt.rayVersion, tt.targetVersion)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				require.NoError(t, err)
+				assert.Equal(t, tt.want, got)
+			}
+		})
+	}
+}

ray-operator/controllers/ray/utils/validation.go

@@ -216,12 +216,16 @@ func ValidateRayClusterSpec(spec *rayv1.RayClusterSpec, annotations map[string]s
 		}
 
 		if IsAutoscalingV2Enabled(spec) {
-			if spec.HeadGroupSpec.Template.Spec.RestartPolicy != "" && spec.HeadGroupSpec.Template.Spec.RestartPolicy != corev1.RestartPolicyNever {
+			// The error is ignored here because the function will return false if there's an error parsing the version.
+			// For example, if rayVersion is empty or unparseable, it considers the feature is not valid.
+			autoscalerRestartValid, _ := IsRayVersionAtLeast(spec.RayVersion, MinAutoscalerRestartValidVersion)
+
+			if !autoscalerRestartValid && spec.HeadGroupSpec.Template.Spec.RestartPolicy != "" && spec.HeadGroupSpec.Template.Spec.RestartPolicy != corev1.RestartPolicyNever {
 				return fmt.Errorf("restartPolicy for head Pod should be Never or unset when using autoscaler V2")
 			}
 
 			for _, workerGroup := range spec.WorkerGroupSpecs {
-				if workerGroup.Template.Spec.RestartPolicy != "" && workerGroup.Template.Spec.RestartPolicy != corev1.RestartPolicyNever {
+				if !autoscalerRestartValid && workerGroup.Template.Spec.RestartPolicy != "" && workerGroup.Template.Spec.RestartPolicy != corev1.RestartPolicyNever {
 					return fmt.Errorf("restartPolicy for worker group %s should be Never or unset when using autoscaler V2", workerGroup.GroupName)
 				}
 			}