feat: Add per-plugin nodeSelector support

pkg/framework/plugins/nodeutilization/highnodeutilization.go

@@ -52,6 +52,7 @@ type HighNodeUtilization struct {
 	resourceNames  []v1.ResourceName
 	highThresholds api.ResourceThresholds
 	usageClient    usageClient
+	nodeSelector   map[string]string
 }
 
 // NewHighNodeUtilization builds plugin from its arguments while passing a handle.
@@ -126,6 +127,7 @@ func NewHighNodeUtilization(
 			resourceNames,
 			handle.GetPodsAssignedToNodeFunc(),
 		),
+		nodeSelector: args.NodeSelector,
 	}, nil
 }
 
@@ -140,6 +142,28 @@ func (h *HighNodeUtilization) Name() string {
 func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *frameworktypes.Status {
 	logger := klog.FromContext(klog.NewContext(ctx, h.logger)).WithValues("ExtensionPoint", frameworktypes.BalanceExtensionPoint)
 
+	// Filter nodes by nodeSelector if specified
+	if len(h.nodeSelector) > 0 {
+		filteredNodes := []*v1.Node{}
+		for _, node := range nodes {
+			if nodeMatchesSelector(node, h.nodeSelector) {
+				filteredNodes = append(filteredNodes, node)
+			}
+		}
+
+		if len(filteredNodes) == 0 {
+			logger.V(1).Info("No nodes match the nodeSelector, skipping")
+			return nil
+		}
+
+		logger.V(1).Info(
+			"Filtered nodes by nodeSelector",
+			"totalNodes", len(nodes),
+			"matchedNodes", len(filteredNodes),
+		)
+		nodes = filteredNodes
+	}
+
 	if err := h.usageClient.sync(ctx, nodes); err != nil {
 		return &frameworktypes.Status{
 			Err: fmt.Errorf("error getting node usage: %v", err),
@@ -273,3 +297,13 @@ func (h *HighNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *fr
 
 	return nil
 }
+
+// nodeMatchesSelector checks if a node matches all labels in the selector
+func nodeMatchesSelector(node *v1.Node, selector map[string]string) bool {
+	for key, value := range selector {
+		if nodeValue, exists := node.Labels[key]; !exists || nodeValue != value {
+			return false
+		}
+	}
+	return true
+}

pkg/framework/plugins/nodeutilization/lownodeutilization.go

@@ -52,6 +52,7 @@ type LowNodeUtilization struct {
 	resourceNames         []v1.ResourceName
 	extendedResourceNames []v1.ResourceName
 	usageClient           usageClient
+	nodeSelector          map[string]string
 }
 
 // NewLowNodeUtilization builds plugin from its arguments while passing a
@@ -126,6 +127,7 @@ func NewLowNodeUtilization(
 		extendedResourceNames: extendedResourceNames,
 		podFilter:             podFilter,
 		usageClient:           usageClient,
+		nodeSelector:          args.NodeSelector,
 	}, nil
 }
 
@@ -140,6 +142,28 @@ func (l *LowNodeUtilization) Name() string {
 func (l *LowNodeUtilization) Balance(ctx context.Context, nodes []*v1.Node) *frameworktypes.Status {
 	logger := klog.FromContext(klog.NewContext(ctx, l.logger)).WithValues("ExtensionPoint", frameworktypes.BalanceExtensionPoint)
 
+	// Filter nodes by nodeSelector if specified
+	if len(l.nodeSelector) > 0 {
+		filteredNodes := []*v1.Node{}
+		for _, node := range nodes {
+			if nodeMatchesSelector(node, l.nodeSelector) {
+				filteredNodes = append(filteredNodes, node)
+			}
+		}
+
+		if len(filteredNodes) == 0 {
+			logger.V(1).Info("No nodes match the nodeSelector, skipping")
+			return nil
+		}
+
+		logger.V(1).Info(
+			"Filtered nodes by nodeSelector",
+			"totalNodes", len(nodes),
+			"matchedNodes", len(filteredNodes),
+		)
+		nodes = filteredNodes
+	}
+
 	if err := l.usageClient.sync(ctx, nodes); err != nil {
 		return &frameworktypes.Status{
 			Err: fmt.Errorf("error getting node usage: %v", err),

pkg/framework/plugins/nodeutilization/nodeselector_test.go

@@ -0,0 +1,132 @@
+package nodeutilization
+
+import (
+	"testing"
+
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestNodeMatchesSelector(t *testing.T) {
+	tests := []struct {
+		name     string
+		node     *v1.Node
+		selector map[string]string
+		expected bool
+	}{
+		{
+			name: "node matches single label",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"env": "prod",
+					},
+				},
+			},
+			selector: map[string]string{
+				"env": "prod",
+			},
+			expected: true,
+		},
+		{
+			name: "node matches multiple labels",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"env":  "prod",
+						"zone": "us-west",
+						"type": "worker",
+					},
+				},
+			},
+			selector: map[string]string{
+				"env":  "prod",
+				"zone": "us-west",
+			},
+			expected: true,
+		},
+		{
+			name: "node does not match label value",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"env": "dev",
+					},
+				},
+			},
+			selector: map[string]string{
+				"env": "prod",
+			},
+			expected: false,
+		},
+		{
+			name: "node missing required label",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"zone": "us-west",
+					},
+				},
+			},
+			selector: map[string]string{
+				"env": "prod",
+			},
+			expected: false,
+		},
+		{
+			name: "empty selector matches all nodes",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"env": "prod",
+					},
+				},
+			},
+			selector: map[string]string{},
+			expected: true,
+		},
+		{
+			name: "node with no labels and non-empty selector",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:   "test-node",
+					Labels: map[string]string{},
+				},
+			},
+			selector: map[string]string{
+				"env": "prod",
+			},
+			expected: false,
+		},
+		{
+			name: "cluster-autoscaler scale-down disabled label",
+			node: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test-node",
+					Labels: map[string]string{
+						"cluster-autoscaler.kubernetes.io/scale-down-disabled": "true",
+						"node.kubernetes.io/instance-type":                     "m5.large",
+					},
+				},
+			},
+			selector: map[string]string{
+				"cluster-autoscaler.kubernetes.io/scale-down-disabled": "true",
+			},
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := nodeMatchesSelector(tt.node, tt.selector)
+			if result != tt.expected {
+				t.Errorf("nodeMatchesSelector() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}

pkg/framework/plugins/nodeutilization/types.go

@@ -49,6 +49,11 @@ type LowNodeUtilizationArgs struct {
 
 	// evictionLimits limits the number of evictions per domain. E.g. node, namespace, total.
 	EvictionLimits *api.EvictionLimits `json:"evictionLimits,omitempty"`
+
+	// NodeSelector filters which nodes are considered for eviction.
+	// Only nodes matching all specified labels will be processed by this plugin.
+	// If not set, all nodes are considered.
+	NodeSelector map[string]string `json:"nodeSelector,omitempty"`
 }
 
 // +k8s:deepcopy-gen=true
@@ -71,6 +76,11 @@ type HighNodeUtilizationArgs struct {
 	// considered while considering resources used by pods
 	// but then filtered out before eviction
 	EvictableNamespaces *api.Namespaces `json:"evictableNamespaces,omitempty"`
+
+	// NodeSelector filters which nodes are considered for eviction.
+	// Only nodes matching all specified labels will be processed by this plugin.
+	// If not set, all nodes are considered.
+	NodeSelector map[string]string `json:"nodeSelector,omitempty"`
 }
 
 // MetricsUtilization allow to consume actual resource utilization from metrics