SKS-1978: Add 'cluster-api/accelerator' label to GPU node to support autoscaling

controllers/elfmachine_controller.go

@@ -996,14 +996,21 @@
 	}
 
 	nodeGroupName := machineutil.GetNodeGroupName(ctx.Machine)
+	labels := map[string]string{
+		infrav1.HostServerIDLabel:   ctx.ElfMachine.Status.HostServerRef,
+		infrav1.HostServerNameLabel: ctx.ElfMachine.Status.HostServerName,
+		infrav1.TowerVMIDLabel:      *vm.ID,
+		infrav1.NodeGroupLabel:      nodeGroupName,
+	}
+	if len(ctx.ElfMachine.Spec.GPUDevices) > 0 {
+		labels[labelsutil.ClusterAutoscalerCAPIGPULabel] = labelsutil.ConvertToLabelValue(ctx.ElfMachine.Spec.GPUDevices[0].Model)
+	} else if len(ctx.ElfMachine.Spec.VGPUDevices) > 0 {
+		labels[labelsutil.ClusterAutoscalerCAPIGPULabel] = labelsutil.ConvertToLabelValue(ctx.ElfMachine.Spec.VGPUDevices[0].Type)
+	}
+
 	payloads := map[string]interface{}{
 		"metadata": map[string]interface{}{
-			"labels": map[string]string{
-				infrav1.HostServerIDLabel:   ctx.ElfMachine.Status.HostServerRef,
-				infrav1.HostServerNameLabel: ctx.ElfMachine.Status.HostServerName,
-				infrav1.TowerVMIDLabel:      *vm.ID,
-				infrav1.NodeGroupLabel:      nodeGroupName,
-			},
+			"labels": labels,
 		},
 	}
 	// providerID cannot be modified after setting a valid value.

pkg/util/labels/helpers.go

@@ -17,12 +17,25 @@ limitations under the License.
 package labels
 
 import (
+	"regexp"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/validation"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 
 	infrav1 "github.com/smartxworks/cluster-api-provider-elf/api/v1beta1"
 )
 
+const (
+	// ClusterAutoscalerCAPIGPULabel is the label added to nodes with GPU resource, which will be used by clusterAutoscaler-CAPI.
+	// ref: https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/clusterapi/README.md#special-note-on-gpu-instances
+	ClusterAutoscalerCAPIGPULabel = "cluster-api/accelerator"
+)
+
+var (
+	noLabelCharReg = regexp.MustCompile(`[^-a-zA-Z0-9-.]`)
+)
+
 func GetHostServerIDLabel(o metav1.Object) string {
 	return GetLabelValue(o, infrav1.HostServerIDLabel)
 }
@@ -64,3 +77,20 @@ func GetLabelValue(o metav1.Object, label string) string {
 
 	return val
 }
+
+func ConvertToLabelValue(str string) string {
+	result := noLabelCharReg.ReplaceAll([]byte(str), []byte("-"))
+
+	if len(result) > validation.LabelValueMaxLength {
+		return string(result[:validation.LabelValueMaxLength])
+	}
+
+	for len(result) > 0 && (result[0] == '-' || result[0] == '_' || result[0] == '.') {
+		result = result[1:]
+	}
+	for len(result) > 0 && (result[len(result)-1] == '-' || result[len(result)-1] == '_' || result[len(result)-1] == '.') {
+		result = result[:len(result)-1]
+	}
+
+	return string(result)
+}

pkg/util/labels/helpers_test.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2023.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package labels
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/onsi/gomega"
+)
+
+func TestConvertToLabelValue(t *testing.T) {
+	g := gomega.NewGomegaWithT(t)
+
+	testCases := []struct {
+		str        string
+		labelValue string
+	}{
+		{
+			str:        "test",
+			labelValue: "test",
+		}, {
+			str:        "Test",
+			labelValue: "Test",
+		}, {
+			str:        "TEST",
+			labelValue: "TEST",
+		}, {
+			str:        "Tesla V100-PCIE-16GB",
+			labelValue: "Tesla-V100-PCIE-16GB",
+		}, {
+			str:        "Tesla T4",
+			labelValue: "Tesla-T4",
+		}, {
+			str:        ".test.",
+			labelValue: "test",
+		}, {
+			str:        "-test-",
+			labelValue: "test",
+		}, {
+			str:        "_test_",
+			labelValue: "test",
+		}, {
+			str:        "_test_",
+			labelValue: "test",
+		}, {
+			str:        "!!! te st !!!",
+			labelValue: "te-st",
+		}, {
+			str:        "toolongtoolongtoolongtoolongtoolongtoolongtoolongtoolongtoolongtoolong",
+			labelValue: "toolongtoolongtoolongtoolongtoolongtoolongtoolongtoolongtoolong",
+		},
+	}
+
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			labelValue := ConvertToLabelValue(tc.str)
+			g.Expect(labelValue).To(gomega.Equal(tc.labelValue))
+		})
+	}
+}