support customized host os

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

pkg/exposer/generic_restore.go

@@ -494,10 +494,14 @@ func (e *genericRestoreExposer) createRestorePod(
 	volumeName := string(ownerObject.UID)
 
 	if selectedNode != "" {
-		affinity = &kube.LoadAffinity{}
+		affinity = nil
 		e.log.Infof("Selected node for restore pod. Ignore affinity from the node-agent config.")
 	}
 
+	if affinity == nil {
+		affinity = &kube.LoadAffinity{}
+	}
+
 	podInfo, err := getInheritedPodInfo(ctx, e.kubeClient, ownerObject.Namespace, nodeOS)
 	if err != nil {
 		return nil, errors.Wrap(err, "error to get inherited pod info from node-agent")

pkg/install/daemonset.go

@@ -235,12 +235,28 @@ func DaemonSet(namespace string, opts ...podTemplateOption) *appsv1api.DaemonSet
 	if c.forWindows {
 		daemonSet.Spec.Template.Spec.SecurityContext = nil
 		daemonSet.Spec.Template.Spec.Containers[0].SecurityContext = nil
-		daemonSet.Spec.Template.Spec.NodeSelector = map[string]string{
-			"kubernetes.io/os": "windows",
-		}
 		daemonSet.Spec.Template.Spec.OS = &corev1api.PodOS{
 			Name: "windows",
 		}
+
+		daemonSet.Spec.Template.Spec.Affinity = &corev1api.Affinity{
+			NodeAffinity: &corev1api.NodeAffinity{
+				RequiredDuringSchedulingIgnoredDuringExecution: &corev1api.NodeSelector{
+					NodeSelectorTerms: []corev1api.NodeSelectorTerm{
+						{
+							MatchExpressions: []corev1api.NodeSelectorRequirement{
+								{
+									Key:      "kubernetes.io/os",
+									Values:   []string{"windows"},
+									Operator: corev1api.NodeSelectorOpIn,
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
 		daemonSet.Spec.Template.Spec.Tolerations = []corev1api.Toleration{
 			{
 				Key:      "os",

pkg/install/deployment.go

@@ -364,12 +364,26 @@ func Deployment(namespace string, opts ...podTemplateOption) *appsv1api.Deployme
 				Spec: corev1api.PodSpec{
 					RestartPolicy:      corev1api.RestartPolicyAlways,
 					ServiceAccountName: c.serviceAccountName,
-					NodeSelector: map[string]string{
-						"kubernetes.io/os": "linux",
-					},
 					OS: &corev1api.PodOS{
 						Name: "linux",
 					},
+					Affinity: &corev1api.Affinity{
+						NodeAffinity: &corev1api.NodeAffinity{
+							RequiredDuringSchedulingIgnoredDuringExecution: &corev1api.NodeSelector{
+								NodeSelectorTerms: []corev1api.NodeSelectorTerm{
+									{
+										MatchExpressions: []corev1api.NodeSelectorRequirement{
+											{
+												Key:      "kubernetes.io/os",
+												Values:   []string{"windows"},
+												Operator: corev1api.NodeSelectorOpNotIn,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
 					Containers: []corev1api.Container{
 						{
 							Name:            "velero",

pkg/util/kube/node.go

@@ -33,7 +33,7 @@ const (
 	NodeOSLabel   = "kubernetes.io/os"
 )
 
-var nodeOSMap map[string]string = map[string]string{
+var realNodeOSMap map[string]string = map[string]string{
 	"linux":   NodeOSLinux,
 	"windows": NodeOSWindows,
 }
@@ -129,7 +129,7 @@ func HasNodeWithOS(ctx context.Context, os string, nodeClient corev1client.CoreV
 }
 
 func getRealOS(osLabel string) string {
-	if os, found := nodeOSMap[osLabel]; !found {
+	if os, found := realNodeOSMap[osLabel]; !found {
 		return NodeOSLinux
 	} else {
 		return os