fail fs-backup for windows nodes

Signed-off-by: Lyndon-Li <lyonghui@vmware.com>

changelogs/unreleased/8518-Lyndon-Li

@@ -0,0 +1 @@
+Make fs-backup work on linux nodes with the new Velero deployment and disable fs-backup if the source/target pod is running in non-linux node (#8424)

pkg/cmd/server/server.go

@@ -82,6 +82,7 @@ import (
 	"github.com/vmware-tanzu/velero/pkg/restore"
 	"github.com/vmware-tanzu/velero/pkg/uploader"
 	"github.com/vmware-tanzu/velero/pkg/util/filesystem"
+	"github.com/vmware-tanzu/velero/pkg/util/kube"
 	"github.com/vmware-tanzu/velero/pkg/util/logging"
 )
 
@@ -454,10 +455,20 @@ func (s *server) veleroResourcesExist() error {
 
 func (s *server) checkNodeAgent() {
 	// warn if node agent does not exist
-	if err := nodeagent.IsRunning(s.ctx, s.kubeClient, s.namespace); err == nodeagent.ErrDaemonSetNotFound {
-		s.logger.Warn("Velero node agent not found; pod volume backups/restores will not work until it's created")
-	} else if err != nil {
-		s.logger.WithError(errors.WithStack(err)).Warn("Error checking for existence of velero node agent")
+	if kube.WithLinuxNode(s.ctx, s.crClient, s.logger) {
+		if err := nodeagent.IsRunningOnLinux(s.ctx, s.kubeClient, s.namespace); err == nodeagent.ErrDaemonSetNotFound {
+			s.logger.Warn("Velero node agent not found for linux nodes; pod volume backups/restores and data mover backups/restores will not work until it's created")
+		} else if err != nil {
+			s.logger.WithError(errors.WithStack(err)).Warn("Error checking for existence of velero node agent for linux nodes")
+		}
+	}
+
+	if kube.WithWindowsNode(s.ctx, s.crClient, s.logger) {
+		if err := nodeagent.IsRunningOnWindows(s.ctx, s.kubeClient, s.namespace); err == nodeagent.ErrDaemonSetNotFound {
+			s.logger.Warn("Velero node agent not found for Windows nodes; pod volume backups/restores and data mover backups/restores will not work until it's created")
+		} else if err != nil {
+			s.logger.WithError(errors.WithStack(err)).Warn("Error checking for existence of velero node agent for Windows nodes")
+		}
 	}
 }
 

pkg/exposer/csi_snapshot_test.go

@@ -1146,7 +1146,7 @@ func Test_csiSnapshotExposer_DiagnoseExpose(t *testing.T) {
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: velerov1.DefaultNamespace,
 			Name:      "node-agent-pod-1",
-			Labels:    map[string]string{"name": "node-agent"},
+			Labels:    map[string]string{"role": "node-agent"},
 		},
 		Spec: corev1.PodSpec{
 			NodeName: "fake-node",

pkg/exposer/generic_restore_test.go

@@ -627,7 +627,7 @@ func Test_ReastoreDiagnoseExpose(t *testing.T) {
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: velerov1.DefaultNamespace,
 			Name:      "node-agent-pod-1",
-			Labels:    map[string]string{"name": "node-agent"},
+			Labels:    map[string]string{"role": "node-agent"},
 		},
 		Spec: corev1.PodSpec{
 			NodeName: "fake-node",

pkg/nodeagent/node_agent.go

@@ -33,8 +33,14 @@ import (
 )
 
 const (
-	// daemonSet is the name of the Velero node agent daemonset.
+	// daemonSet is the name of the Velero node agent daemonset on linux nodes.
 	daemonSet = "node-agent"
+
+	// daemonsetWindows is the name of the Velero node agent daemonset on Windows nodes.
+	daemonsetWindows = "node-agent-windows"
+
+	// nodeAgentRole marks pods with node-agent role on all nodes.
+	nodeAgentRole = "node-agent"
 )
 
 var (
@@ -89,9 +95,16 @@ type Configs struct {
 	PodResources *kube.PodResources `json:"podResources,omitempty"`
 }
 
-// IsRunning checks if the node agent daemonset is running properly. If not, return the error found
-func IsRunning(ctx context.Context, kubeClient kubernetes.Interface, namespace string) error {
-	if _, err := kubeClient.AppsV1().DaemonSets(namespace).Get(ctx, daemonSet, metav1.GetOptions{}); apierrors.IsNotFound(err) {
+func IsRunningOnLinux(ctx context.Context, kubeClient kubernetes.Interface, namespace string) error {
+	return isRunning(ctx, kubeClient, namespace, daemonSet)
+}
+
+func IsRunningOnWindows(ctx context.Context, kubeClient kubernetes.Interface, namespace string) error {
+	return isRunning(ctx, kubeClient, namespace, daemonsetWindows)
+}
+
+func isRunning(ctx context.Context, kubeClient kubernetes.Interface, namespace string, daemonset string) error {
+	if _, err := kubeClient.AppsV1().DaemonSets(namespace).Get(ctx, daemonset, metav1.GetOptions{}); apierrors.IsNotFound(err) {
 		return ErrDaemonSetNotFound
 	} else if err != nil {
 		return err
@@ -116,7 +129,7 @@ func isRunningInNode(ctx context.Context, namespace string, nodeName string, crC
 	}
 
 	pods := new(v1.PodList)
-	parsedSelector, err := labels.Parse(fmt.Sprintf("name=%s", daemonSet))
+	parsedSelector, err := labels.Parse(fmt.Sprintf("role=%s", nodeAgentRole))
 	if err != nil {
 		return errors.Wrap(err, "fail to parse selector")
 	}
@@ -128,7 +141,7 @@ func isRunningInNode(ctx context.Context, namespace string, nodeName string, crC
 	}
 
 	if err != nil {
-		return errors.Wrap(err, "failed to list daemonset pods")
+		return errors.Wrap(err, "failed to list node-agent pods")
 	}
 
 	for i := range pods.Items {

pkg/nodeagent/node_agent_test.go

@@ -40,7 +40,7 @@ type reactor struct {
 }
 
 func TestIsRunning(t *testing.T) {
-	daemonSet := &appsv1.DaemonSet{
+	ds := &appsv1.DaemonSet{
 		ObjectMeta: metav1.ObjectMeta{
 			Namespace: "fake-ns",
 			Name:      "node-agent",
@@ -80,7 +80,7 @@ func TestIsRunning(t *testing.T) {
 			name:      "succeed",
 			namespace: "fake-ns",
 			kubeClientObj: []runtime.Object{
-				daemonSet,
+				ds,
 			},
 		},
 	}
@@ -93,7 +93,7 @@ func TestIsRunning(t *testing.T) {
 				fakeKubeClient.Fake.PrependReactor(reactor.verb, reactor.resource, reactor.reactorFunc)
 			}
 
-			err := IsRunning(context.TODO(), fakeKubeClient, test.namespace)
+			err := isRunning(context.TODO(), fakeKubeClient, test.namespace, daemonSet)
 			if test.expectErr == "" {
 				assert.NoError(t, err)
 			} else {
@@ -108,11 +108,11 @@ func TestIsRunningInNode(t *testing.T) {
 	corev1.AddToScheme(scheme)
 
 	nonNodeAgentPod := builder.ForPod("fake-ns", "fake-pod").Result()
-	nodeAgentPodNotRunning := builder.ForPod("fake-ns", "fake-pod").Labels(map[string]string{"name": "node-agent"}).Result()
-	nodeAgentPodRunning1 := builder.ForPod("fake-ns", "fake-pod-1").Labels(map[string]string{"name": "node-agent"}).Phase(corev1.PodRunning).Result()
-	nodeAgentPodRunning2 := builder.ForPod("fake-ns", "fake-pod-2").Labels(map[string]string{"name": "node-agent"}).Phase(corev1.PodRunning).Result()
+	nodeAgentPodNotRunning := builder.ForPod("fake-ns", "fake-pod").Labels(map[string]string{"role": "node-agent"}).Result()
+	nodeAgentPodRunning1 := builder.ForPod("fake-ns", "fake-pod-1").Labels(map[string]string{"role": "node-agent"}).Phase(corev1.PodRunning).Result()
+	nodeAgentPodRunning2 := builder.ForPod("fake-ns", "fake-pod-2").Labels(map[string]string{"role": "node-agent"}).Phase(corev1.PodRunning).Result()
 	nodeAgentPodRunning3 := builder.ForPod("fake-ns", "fake-pod-3").
-		Labels(map[string]string{"name": "node-agent"}).
+		Labels(map[string]string{"role": "node-agent"}).
 		Phase(corev1.PodRunning).
 		NodeName("fake-node").
 		Result()

pkg/podvolume/backupper.go

@@ -206,6 +206,12 @@ func (b *backupper) BackupPodVolumes(backup *velerov1api.Backup, pod *corev1api.
 		return nil, pvcSummary, nil
 	}
 
+	if err := kube.IsLinuxNode(b.ctx, pod.Spec.NodeName, b.crClient); err != nil {
+		err := errors.Wrapf(err, "Pod %s/%s is not running in linux node(%s), skip", pod.Namespace, pod.Name, pod.Spec.NodeName)
+		skipAllPodVolumes(pod, volumesToBackup, err, pvcSummary, log)
+		return nil, pvcSummary, []error{err}
+	}
+
 	err := nodeagent.IsRunningInNode(b.ctx, backup.Namespace, pod.Spec.NodeName, b.crClient)
 	if err != nil {
 		skipAllPodVolumes(pod, volumesToBackup, err, pvcSummary, log)

pkg/podvolume/backupper_test.go

@@ -260,7 +260,7 @@ func createPodObj(running bool, withVolume bool, withVolumeMounted bool, volumeN
 
 func createNodeAgentPodObj(running bool) *corev1api.Pod {
 	podObj := builder.ForPod(velerov1api.DefaultNamespace, "fake-node-agent").Result()
-	podObj.Labels = map[string]string{"name": "node-agent"}
+	podObj.Labels = map[string]string{"role": "node-agent"}
 
 	if running {
 		podObj.Status.Phase = corev1api.PodRunning
@@ -303,6 +303,14 @@ func createPVBObj(fail bool, withSnapshot bool, index int, uploaderType string)
 	return pvbObj
 }
 
+func createNodeObj() *corev1api.Node {
+	return builder.ForNode("fake-node-name").Labels(map[string]string{"kubernetes.io/os": "linux"}).Result()
+}
+
+func createWindowsNodeObj() *corev1api.Node {
+	return builder.ForNode("fake-node-name").Labels(map[string]string{"kubernetes.io/os": "windows"}).Result()
+}
+
 func TestBackupPodVolumes(t *testing.T) {
 	scheme := runtime.NewScheme()
 	velerov1api.AddToScheme(scheme)
@@ -358,13 +366,32 @@ func TestBackupPodVolumes(t *testing.T) {
 			uploaderType:  "kopia",
 			bsl:           "fake-bsl",
 		},
+		{
+			name: "pod is not running on Linux node",
+			volumes: []string{
+				"fake-volume-1",
+				"fake-volume-2",
+			},
+			kubeClientObj: []runtime.Object{
+				createNodeAgentPodObj(true),
+				createWindowsNodeObj(),
+			},
+			sourcePod:    createPodObj(false, false, false, 2),
+			uploaderType: "kopia",
+			errs: []string{
+				"Pod fake-ns/fake-pod is not running in linux node(fake-node-name), skip",
+			},
+		},
 		{
 			name: "node-agent pod is not running in node",
 			volumes: []string{
 				"fake-volume-1",
 				"fake-volume-2",
 			},
-			sourcePod:    createPodObj(true, false, false, 2),
+			sourcePod: createPodObj(true, false, false, 2),
+			kubeClientObj: []runtime.Object{
+				createNodeObj(),
+			},
 			uploaderType: "kopia",
 			errs: []string{
 				"daemonset pod not found in running state in node fake-node-name",
@@ -379,6 +406,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, false, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 			},
 			uploaderType:          "kopia",
 			mockGetRepositoryType: true,
@@ -395,6 +423,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, false, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 			},
 			uploaderType: "kopia",
 			errs: []string{
@@ -410,6 +439,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, false, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 			},
 			ctlClientObj: []runtime.Object{
 				createBackupRepoObj(),
@@ -427,6 +457,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, true, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 			},
 			ctlClientObj: []runtime.Object{
 				createBackupRepoObj(),
@@ -448,6 +479,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, true, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 				createPVCObj(1),
 				createPVCObj(2),
 			},
@@ -471,6 +503,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, true, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 				createPVCObj(1),
 				createPVCObj(2),
 				createPVObj(1, true),
@@ -482,6 +515,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			runtimeScheme: scheme,
 			uploaderType:  "kopia",
 			bsl:           "fake-bsl",
+			errs:          []string{},
 		},
 		{
 			name: "volume not mounted by pod should be skipped",
@@ -492,6 +526,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, true, false, 2),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 				createPVCObj(1),
 				createPVCObj(2),
 				createPVObj(1, false),
@@ -503,6 +538,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			runtimeScheme: scheme,
 			uploaderType:  "kopia",
 			bsl:           "fake-bsl",
+			errs:          []string{},
 		},
 		{
 			name: "return completed pvbs",
@@ -512,6 +548,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			sourcePod: createPodObj(true, true, true, 1),
 			kubeClientObj: []runtime.Object{
 				createNodeAgentPodObj(true),
+				createNodeObj(),
 				createPVCObj(1),
 				createPVObj(1, false),
 			},
@@ -522,6 +559,7 @@ func TestBackupPodVolumes(t *testing.T) {
 			uploaderType:  "kopia",
 			bsl:           "fake-bsl",
 			pvbs:          1,
+			errs:          []string{},
 		},
 	}
 	// TODO add more verification around PVCBackupSummary returned by "BackupPodVolumes"
@@ -568,8 +606,8 @@ func TestBackupPodVolumes(t *testing.T) {
 
 			pvbs, _, errs := bp.BackupPodVolumes(backupObj, test.sourcePod, test.volumes, nil, velerotest.NewLogger())
 
-			if errs == nil {
-				assert.Nil(t, test.errs)
+			if test.errs == nil {
+				assert.NoError(t, err)
 			} else {
 				for i := 0; i < len(errs); i++ {
 					assert.EqualError(t, errs[i], test.errs[i])

pkg/podvolume/restorer.go

@@ -122,7 +122,7 @@ func (r *restorer) RestorePodVolumes(data RestoreData, tracker *volume.RestoreVo
 		return nil
 	}
 
-	if err := nodeagent.IsRunning(r.ctx, r.kubeClient, data.Restore.Namespace); err != nil {
+	if err := nodeagent.IsRunningOnLinux(r.ctx, r.kubeClient, data.Restore.Namespace); err != nil {
 		return []error{errors.Wrapf(err, "error to check node agent status")}
 	}
 
@@ -213,6 +213,12 @@ func (r *restorer) RestorePodVolumes(data RestoreData, tracker *volume.RestoreVo
 		} else if err != nil {
 			r.log.WithError(err).Error("Failed to check node-agent pod status, disengage")
 		} else {
+			if err := kube.IsLinuxNode(checkCtx, nodeName, r.crClient); err != nil {
+				r.log.WithField("node", nodeName).WithError(err).Error("Restored pod is not running in linux node")
+				r.nodeAgentCheck <- errors.Wrapf(err, "restored pod %s/%s is not running in linux node(%s)", data.Pod.Namespace, data.Pod.Name, nodeName)
+				return
+			}
+
 			err = nodeagent.IsRunningInNode(checkCtx, data.Restore.Namespace, nodeName, r.crClient)
 			if err != nil {
 				r.log.WithField("node", nodeName).WithError(err).Error("node-agent pod is not running in node, abort the restore")

pkg/podvolume/restorer_test.go

@@ -33,7 +33,6 @@ import (
 	"k8s.io/client-go/kubernetes"
 	kubefake "k8s.io/client-go/kubernetes/fake"
 	"k8s.io/client-go/tools/cache"
-	ctrlfake "sigs.k8s.io/controller-runtime/pkg/client/fake"
 
 	"github.com/vmware-tanzu/velero/internal/volume"
 	velerov1api "github.com/vmware-tanzu/velero/pkg/apis/velero/v1"
@@ -314,6 +313,30 @@ func TestRestorePodVolumes(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "pod is not running on linux nodes",
+			pvbs: []*velerov1api.PodVolumeBackup{
+				createPVBObj(true, true, 1, "kopia"),
+			},
+			kubeClientObj: []runtime.Object{
+				createNodeAgentDaemonset(),
+				createWindowsNodeObj(),
+				createPVCObj(1),
+				createPodObj(true, true, true, 1),
+			},
+			ctlClientObj: []runtime.Object{
+				createBackupRepoObj(),
+			},
+			restoredPod:     createPodObj(true, true, true, 1),
+			sourceNamespace: "fake-ns",
+			bsl:             "fake-bsl",
+			runtimeScheme:   scheme,
+			errs: []expectError{
+				{
+					err: "restored pod fake-ns/fake-pod is not running in linux node(fake-node-name): os type windows for node fake-node-name is not linux",
+				},
+			},
+		},
 		{
 			name: "node-agent pod is not running",
 			pvbs: []*velerov1api.PodVolumeBackup{
@@ -321,6 +344,7 @@ func TestRestorePodVolumes(t *testing.T) {
 			},
 			kubeClientObj: []runtime.Object{
 				createNodeAgentDaemonset(),
+				createNodeObj(),
 				createPVCObj(1),
 				createPodObj(true, true, true, 1),
 			},
@@ -344,6 +368,7 @@ func TestRestorePodVolumes(t *testing.T) {
 			},
 			kubeClientObj: []runtime.Object{
 				createNodeAgentDaemonset(),
+				createNodeObj(),
 				createPVCObj(1),
 				createPodObj(true, true, true, 1),
 				createNodeAgentPodObj(true),
@@ -368,11 +393,6 @@ func TestRestorePodVolumes(t *testing.T) {
 				ctx = test.ctx
 			}
 
-			fakeClientBuilder := ctrlfake.NewClientBuilder()
-			if test.runtimeScheme != nil {
-				fakeClientBuilder = fakeClientBuilder.WithScheme(test.runtimeScheme)
-			}
-
 			objClient := append(test.ctlClientObj, test.kubeClientObj...)
 			objClient = append(objClient, test.veleroClientObj...)
 
@@ -438,7 +458,8 @@ func TestRestorePodVolumes(t *testing.T) {
 						for i := 0; i < len(errs); i++ {
 							j := 0
 							for ; j < len(test.errs); j++ {
-								if errs[i].Error() == test.errs[j].err {
+								err := errs[i].Error()
+								if err == test.errs[j].err {
 									break
 								}
 							}

pkg/util/kube/node.go

@@ -0,0 +1,67 @@
+/*
+Copyright The Velero Contributors.
+
+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 kube
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	corev1api "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+func IsLinuxNode(ctx context.Context, nodeName string, client client.Client) error {
+	node := &corev1api.Node{}
+	if err := client.Get(ctx, types.NamespacedName{Name: nodeName}, node); err != nil {
+		return errors.Wrapf(err, "error getting node %s", nodeName)
+	}
+
+	if os, found := node.Labels["kubernetes.io/os"]; !found {
+		return errors.Errorf("no os type label for node %s", nodeName)
+	} else if os != "linux" {
+		return errors.Errorf("os type %s for node %s is not linux", os, nodeName)
+	} else {
+		return nil
+	}
+}
+
+func WithLinuxNode(ctx context.Context, client client.Client, log logrus.FieldLogger) bool {
+	return withOSNode(ctx, client, "linux", log)
+}
+
+func WithWindowsNode(ctx context.Context, client client.Client, log logrus.FieldLogger) bool {
+	return withOSNode(ctx, client, "windows", log)
+}
+
+func withOSNode(ctx context.Context, client client.Client, osType string, log logrus.FieldLogger) bool {
+	nodeList := new(corev1api.NodeList)
+	if err := client.List(ctx, nodeList); err != nil {
+		log.Warn("Failed to list nodes, cannot decide existence of windows nodes")
+		return false
+	}
+
+	for _, node := range nodeList.Items {
+		if os, found := node.Labels["kubernetes.io/os"]; !found {
+			log.Warnf("Node %s doesn't have os type label, cannot decide existence of windows nodes")
+		} else if os == osType {
+			return true
+		}
+	}
+
+	return false
+}

pkg/util/kube/node_test.go

@@ -0,0 +1,132 @@
+/*
+Copyright The Velero Contributors.
+
+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 kube
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+
+	"github.com/vmware-tanzu/velero/pkg/builder"
+
+	clientFake "sigs.k8s.io/controller-runtime/pkg/client/fake"
+
+	velerotest "github.com/vmware-tanzu/velero/pkg/test"
+)
+
+func TestIsLinuxNode(t *testing.T) {
+	nodeNoOSLabel := builder.ForNode("fake-node").Result()
+	nodeWindows := builder.ForNode("fake-node").Labels(map[string]string{"kubernetes.io/os": "windows"}).Result()
+	nodeLinux := builder.ForNode("fake-node").Labels(map[string]string{"kubernetes.io/os": "linux"}).Result()
+
+	scheme := runtime.NewScheme()
+	corev1.AddToScheme(scheme)
+
+	tests := []struct {
+		name          string
+		kubeClientObj []runtime.Object
+		err           string
+	}{
+		{
+			name: "error getting node",
+			err:  "error getting node fake-node: nodes \"fake-node\" not found",
+		},
+		{
+			name: "no os label",
+			kubeClientObj: []runtime.Object{
+				nodeNoOSLabel,
+			},
+			err: "no os type label for node fake-node",
+		},
+		{
+			name: "os label does not match",
+			kubeClientObj: []runtime.Object{
+				nodeWindows,
+			},
+			err: "os type windows for node fake-node is not linux",
+		},
+		{
+			name: "succeed",
+			kubeClientObj: []runtime.Object{
+				nodeLinux,
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			fakeClientBuilder := clientFake.NewClientBuilder()
+			fakeClientBuilder = fakeClientBuilder.WithScheme(scheme)
+
+			fakeClient := fakeClientBuilder.WithRuntimeObjects(test.kubeClientObj...).Build()
+
+			err := IsLinuxNode(context.TODO(), "fake-node", fakeClient)
+			if err != nil {
+				assert.EqualError(t, err, test.err)
+			} else {
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestWithLinuxNode(t *testing.T) {
+	nodeWindows := builder.ForNode("fake-node-1").Labels(map[string]string{"kubernetes.io/os": "windows"}).Result()
+	nodeLinux := builder.ForNode("fake-node-2").Labels(map[string]string{"kubernetes.io/os": "linux"}).Result()
+
+	scheme := runtime.NewScheme()
+	corev1.AddToScheme(scheme)
+
+	tests := []struct {
+		name          string
+		kubeClientObj []runtime.Object
+		result        bool
+	}{
+		{
+			name: "error listing node",
+		},
+		{
+			name: "with node of other type",
+			kubeClientObj: []runtime.Object{
+				nodeWindows,
+			},
+		},
+		{
+			name: "with node of the same type",
+			kubeClientObj: []runtime.Object{
+				nodeWindows,
+				nodeLinux,
+			},
+			result: true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			fakeClientBuilder := clientFake.NewClientBuilder()
+			fakeClientBuilder = fakeClientBuilder.WithScheme(scheme)
+
+			fakeClient := fakeClientBuilder.WithRuntimeObjects(test.kubeClientObj...).Build()
+
+			result := withOSNode(context.TODO(), fakeClient, "linux", velerotest.NewLogger())
+			assert.Equal(t, test.result, result)
+		})
+	}
+}