Skip migration check on single node cluster

pkg/internal/checkup/checkup.go

@@ -59,6 +59,7 @@ type kubeVirtStorageClient interface {
 	CreateDataVolume(ctx context.Context, namespace string, dv *cdiv1.DataVolume) (*cdiv1.DataVolume, error)
 	DeleteDataVolume(ctx context.Context, namespace, name string) error
 	DeletePersistentVolumeClaim(ctx context.Context, namespace, name string) error
+	ListNodes(ctx context.Context) (*corev1.NodeList, error)
 	ListNamespaces(ctx context.Context) (*corev1.NamespaceList, error)
 	ListStorageClasses(ctx context.Context) (*storagev1.StorageClassList, error)
 	ListStorageProfiles(ctx context.Context) (*cdiv1.StorageProfileList, error)
@@ -93,6 +94,7 @@ const (
 	ErrGoldenImageNoDataSource     = "dataSource has no PVC or Snapshot source"
 	MessageSkipNoGoldenImage       = "Skip check - no golden image PVC or Snapshot"
 	MessageSkipNoVMI               = "Skip check - no VMI"
+	MessageSkipSingleNode          = "Skip check - single node"
 
 	pollInterval = 5 * time.Second
 )
@@ -823,6 +825,16 @@ func (c *Checkup) checkVMILiveMigration(ctx context.Context, errStr *string) err
 		return nil
 	}
 
+	nodes, err := c.client.ListNodes(ctx)
+	if err != nil {
+		return err
+	}
+	if len(nodes.Items) == 1 {
+		log.Print(MessageSkipSingleNode)
+		c.results.VMLiveMigration = MessageSkipSingleNode
+		return nil
+	}
+
 	vmi, err := c.client.GetVirtualMachineInstance(ctx, c.namespace, c.vmUnderTest.Name)
 	if err != nil {
 		return err

pkg/internal/checkup/checkup_test.go

@@ -46,6 +46,7 @@ import (
 
 const (
 	testNamespace = "target-ns"
+	testNode      = "test-node"
 )
 
 var (
@@ -146,6 +147,11 @@ func TestCheckupShouldReturnErrorWhen(t *testing.T) {
 			expectedResults: map[string]string{reporter.VMLiveMigrationKey: "failed waiting for VMI \"%s\" migration completed: migration failed"},
 			expectedErr:     "migration failed",
 		},
+		"skipMigrationOnSingleNode": {
+			clientConfig:    clientConfig{singleNode: true},
+			expectedResults: map[string]string{reporter.VMLiveMigrationKey: "Skip check - single node"},
+			expectedErr:     "",
+		},
 	}
 
 	for name, tc := range tests {
@@ -247,6 +253,7 @@ type clientConfig struct {
 	expectNoVMI                   bool
 	cloneFallback                 bool
 	failMigration                 bool
+	singleNode                    bool
 }
 
 type clientStub struct {
@@ -403,6 +410,23 @@ func (cs *clientStub) DeletePersistentVolumeClaim(ctx context.Context, namespace
 	return nil
 }
 
+func (cs *clientStub) ListNodes(ctx context.Context) (*corev1.NodeList, error) {
+	nodeList := &corev1.NodeList{}
+	itemCount := 2
+	if cs.singleNode {
+		itemCount = 1
+	}
+	for i := 0; i < itemCount; i++ {
+		nodeList.Items = append(nodeList.Items, corev1.Node{
+			ObjectMeta: metav1.ObjectMeta{
+				Name: fmt.Sprintf("node-%d", i),
+			},
+		})
+	}
+
+	return nodeList, nil
+}
+
 func (cs *clientStub) ListNamespaces(ctx context.Context) (*corev1.NamespaceList, error) {
 	nsList := &corev1.NamespaceList{
 		Items: []corev1.Namespace{

pkg/internal/client/client.go

@@ -100,6 +100,10 @@ func (c *Client) DeletePersistentVolumeClaim(ctx context.Context, namespace, nam
 	return c.CoreV1().PersistentVolumeClaims(namespace).Delete(ctx, name, metav1.DeleteOptions{})
 }
 
+func (c *Client) ListNodes(ctx context.Context) (*corev1.NodeList, error) {
+	return c.CoreV1().Nodes().List(ctx, metav1.ListOptions{})
+}
+
 func (c *Client) ListNamespaces(ctx context.Context) (*corev1.NamespaceList, error) {
 	return c.CoreV1().Namespaces().List(ctx, metav1.ListOptions{})
 }