Support specifying the transfer net by configmap

The k8s.v1.cni.cncf.org/networks annotation supports
a json value with a list of NetworkSelectionElements
that contain additional configuration for the secondary
network attachment. This change allows the user to
specify the transfer network by referencing a ConfigMap
that contains a NetworkSelectionElement.

Signed-off-by: Sam Lucidi <[email protected]>

pkg/controller/plan/kubevirt.go

@@ -2,6 +2,7 @@ package plan
 
 import (
 	"context"
+	"encoding/json"
 	"encoding/xml"
 	"errors"
 	"fmt"
@@ -53,7 +54,9 @@ import (
 
 // Annotations
 const (
-	// Transfer network annotation (value=network-attachment-definition name)
+	// Legacy transfer network annotation
+	AnnMultusDefaultNetwork = "v1.multus-cni.io/default-network"
+	// Transfer network annotation (value=[]NetworkSelectionElement)
 	AnnTransferNetwork = "k8s.v1.cni.cncf.io/networks"
 	// Contains validations for a Kubevirt VM. Needs to be removed when
 	// creating a VM from a template.
@@ -1227,8 +1230,10 @@ func (r *KubeVirt) dataVolumes(vm *plan.VMStatus, secret *core.Secret, configMap
 		annotations[planbase.AnnRetainAfterCompletion] = "true"
 	}
 	if r.Plan.Spec.TransferNetwork != nil {
-		annotations[AnnTransferNetwork] = path.Join(
-			r.Plan.Spec.TransferNetwork.Namespace, r.Plan.Spec.TransferNetwork.Name)
+		err = r.setTransferNetworkAnnotation(annotations)
+		if err != nil {
+			return
+		}
 	}
 	if r.Plan.Spec.Warm || !r.Destination.Provider.IsHost() || r.Plan.IsSourceProviderOCP() {
 		// Set annotation for WFFC storage classes. Note that we create data volumes while
@@ -1757,8 +1762,10 @@ func (r *KubeVirt) guestConversionPod(vm *plan.VMStatus, vmVolumes []cnv.Volume,
 	// pod annotations
 	annotations := map[string]string{}
 	if r.Plan.Spec.TransferNetwork != nil {
-		annotations[AnnTransferNetwork] = path.Join(
-			r.Plan.Spec.TransferNetwork.Namespace, r.Plan.Spec.TransferNetwork.Name)
+		err = r.setTransferNetworkAnnotation(annotations)
+		if err != nil {
+			return
+		}
 	}
 	// pod
 	pod = &core.Pod{
@@ -2351,6 +2358,46 @@ func (r *KubeVirt) vmAllButMigrationLabels(vmRef ref.Ref) (labels map[string]str
 	return
 }
 
+// Set the transfer network annotation (either the namespaced name of the NAD, or a NetworkSelectionElement)
+func (r *KubeVirt) setTransferNetworkAnnotation(annotations map[string]string) (err error) {
+	if r.Plan.Spec.TransferNetwork != nil {
+		switch r.Plan.Spec.TransferNetwork.Kind {
+		case ConfigMap:
+			var configMap *core.ConfigMap
+			configMap, err = r.getTransferNetworkConfigMap()
+			var bytes []byte
+			bytes, err = json.Marshal([]map[string]string{configMap.Data})
+			if err != nil {
+				err = liberr.Wrap(err)
+				return
+			}
+			annotations[AnnTransferNetwork] = fmt.Sprintf("%s", bytes)
+			if err != nil {
+				return
+			}
+		default:
+			annotations[AnnMultusDefaultNetwork] = path.Join(
+				r.Plan.Spec.TransferNetwork.Namespace, r.Plan.Spec.TransferNetwork.Name)
+		}
+	}
+	return
+}
+
+// Get the configMap containing the NetworkSelectionElement for the transfer network.
+func (r *KubeVirt) getTransferNetworkConfigMap() (configMap *core.ConfigMap, err error) {
+	configMap = &core.ConfigMap{}
+	err = r.Client.Get(
+		context.TODO(),
+		client.ObjectKey{Name: r.Plan.Spec.TransferNetwork.Name, Namespace: r.Plan.Spec.TransferNetwork.Namespace},
+		configMap,
+	)
+	if err != nil {
+		err = liberr.Wrap(err)
+		return
+	}
+	return
+}
+
 // Represents a CDI DataVolume, its associated PVC, and added behavior.
 type ExtendedDataVolume struct {
 	*cdi.DataVolume

pkg/controller/plan/validation.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/md5"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"path"
@@ -104,6 +105,11 @@ const (
 	False = libcnd.False
 )
 
+// Kinds
+const (
+	ConfigMap = "ConfigMap"
+)
+
 // Validate the plan resource.
 func (r *Reconciler) validate(plan *api.Plan) error {
 	// Provider.
@@ -628,29 +634,88 @@ func (r *Reconciler) validateVM(plan *api.Plan) error {
 	return nil
 }
 
-// Validate transfer network selection.
-func (r *Reconciler) validateTransferNetwork(plan *api.Plan) (err error) {
-	if plan.Spec.TransferNetwork == nil {
+// validateTransferNetworkConfigMap checks for the presence of a configMap matching the specified
+// namespace and name, checks that the content is a valid NetworkSelectionElement, and then ensures
+// that the NetworkAttachmentDefinition specified by the NSE exists.
+func (r *Reconciler) validateTransferNetworkConfigMap(plan *api.Plan, key client.ObjectKey) (err error) {
+	notFound := libcnd.Condition{
+		Type:     TransferNetNotValid,
+		Status:   True,
+		Category: Critical,
+		Reason:   NotFound,
+		Message:  "Transfer network ConfigMap could not be found.",
+	}
+	notValid := libcnd.Condition{
+		Type:     TransferNetNotValid,
+		Status:   True,
+		Category: Critical,
+		Reason:   NotValid,
+		Message:  "Transfer network ConfigMap not valid.",
+	}
+	configMap := &v1.ConfigMap{}
+	err = r.Get(context.TODO(), key, configMap)
+	if err != nil {
+		if k8serr.IsNotFound(err) {
+			err = nil
+			plan.Status.SetCondition(notFound)
+			return
+		}
+		return
+	}
+	var bytes []byte
+	bytes, err = json.Marshal(configMap.Data)
+	if err != nil {
+		err = nil
+		plan.Status.SetCondition(notValid)
 		return
 	}
+	var nse net.NetworkSelectionElement
+	err = json.Unmarshal(bytes, &nse)
+	if err != nil {
+		err = nil
+		plan.Status.SetCondition(notValid)
+		return
+	}
+	key.Namespace = nse.Namespace
+	key.Name = nse.Name
+	err = r.validateTransferNetworkAttachmentDefinition(plan, key)
+	return
+}
+
+func (r *Reconciler) validateTransferNetworkAttachmentDefinition(plan *api.Plan, key client.ObjectKey) (err error) {
 	notFound := libcnd.Condition{
 		Type:     TransferNetNotValid,
 		Status:   True,
 		Category: Critical,
 		Reason:   NotFound,
-		Message:  "Transfer network is not valid.",
-	}
-	key := client.ObjectKey{
-		Namespace: plan.Spec.TransferNetwork.Namespace,
-		Name:      plan.Spec.TransferNetwork.Name,
+		Message:  "Transfer network could not be found.",
 	}
 	netAttachDef := &net.NetworkAttachmentDefinition{}
 	err = r.Get(context.TODO(), key, netAttachDef)
 	if k8serr.IsNotFound(err) {
 		err = nil
 		plan.Status.SetCondition(notFound)
+	}
+	return
+}
+
+// Validate transfer network selection.
+func (r *Reconciler) validateTransferNetwork(plan *api.Plan) (err error) {
+	if plan.Spec.TransferNetwork == nil {
 		return
 	}
+
+	key := client.ObjectKey{
+		Namespace: plan.Spec.TransferNetwork.Namespace,
+		Name:      plan.Spec.TransferNetwork.Name,
+	}
+
+	switch plan.Spec.TransferNetwork.Kind {
+	case ConfigMap:
+		err = r.validateTransferNetworkConfigMap(plan, key)
+	default:
+		err = r.validateTransferNetworkAttachmentDefinition(plan, key)
+	}
 	if err != nil {
 		err = liberr.Wrap(err)
 	}