Add possibility to provider the desired size of the instance volume

It possible the situation when 16Gb is not enough, to run all needed workloads,
in this situatution the node will have DiskPressure condition and will start
to evict pods from it. We want to prevent such situations and make instance volume
size configurable.

pkg/apis/libvirtproviderconfig/v1beta1/libvirtmachineproviderconfig_types.go

@@ -2,6 +2,7 @@ package v1beta1
 
 import (
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -50,9 +51,10 @@ type CloudInit struct {
 
 // Volume contains the info for the actuator to create a volume
 type Volume struct {
-	PoolName     string `json:"poolName"`
-	BaseVolumeID string `json:"baseVolumeID"`
-	VolumeName   string `json:"volumeName"`
+	PoolName     string             `json:"poolName"`
+	BaseVolumeID string             `json:"baseVolumeID"`
+	VolumeName   string             `json:"volumeName"`
+	VolumeSize   *resource.Quantity `json:"volumeSize,omitempty"`
 }
 
 // LibvirtClusterProviderConfig is the type that will be embedded in a Cluster.Spec.ProviderSpec field.

pkg/cloud/libvirt/actuators/machine/actuator.go

@@ -257,6 +257,7 @@ func (a *Actuator) createVolumeAndDomain(machine *machinev1.Machine, machineProv
 			VolumeName:     domainName,
 			BaseVolumeName: machineProviderConfig.Volume.BaseVolumeID,
 			VolumeFormat:   "qcow2",
+			VolumeSize:     machineProviderConfig.Volume.VolumeSize,
 		}); err != nil {
 		return nil, a.handleMachineError(machine, apierrors.CreateMachine("error creating volume %v", err), createEventAction)
 	}

pkg/cloud/libvirt/client/client.go

@@ -8,6 +8,8 @@ import (
 	libvirt "github.com/libvirt/libvirt-go"
 	libvirtxml "github.com/libvirt/libvirt-go-xml"
 	providerconfigv1 "github.com/openshift/cluster-api-provider-libvirt/pkg/apis/libvirtproviderconfig/v1beta1"
+
+	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/client-go/kubernetes"
 )
 
@@ -77,6 +79,9 @@ type CreateVolumeInput struct {
 
 	// VolumeFormat as volume format
 	VolumeFormat string
+
+	// VolumeSize contains the size of the volume
+	VolumeSize *resource.Quantity
 }
 
 // LibvirtClientBuilderFuncType is function type for building aws client
@@ -404,11 +409,21 @@ func (client *libvirtClient) CreateVolume(input CreateVolumeInput) error {
 		if err != nil {
 			return fmt.Errorf("Can't retrieve volume info %s", input.BaseVolumeName)
 		}
-		if baseVolumeInfo.Capacity > uint64(defaultSize) {
+
+		var volumeSize uint64
+		if input.VolumeSize != nil {
+			size, _ := input.VolumeSize.AsInt64()
+			volumeSize = uint64(size)
+		} else {
+			volumeSize = uint64(defaultSize)
+		}
+
+		if baseVolumeInfo.Capacity > volumeSize {
 			volumeDef.Capacity.Value = baseVolumeInfo.Capacity
 		} else {
-			volumeDef.Capacity.Value = uint64(defaultSize)
+			volumeDef.Capacity.Value = volumeSize
 		}
+
 		backingStoreDef, err := newDefBackingStoreFromLibvirt(baseVolume)
 		if err != nil {
 			return fmt.Errorf("Could not retrieve backing store %s", input.BaseVolumeName)

pkg/cloud/libvirt/client/volume.go

@@ -4,18 +4,17 @@ import (
 	"encoding/xml"
 	"errors"
 	"fmt"
-	"github.com/golang/glog"
 	"io"
 	"strconv"
 	"strings"
 	"time"
 
+	"github.com/golang/glog"
 	libvirt "github.com/libvirt/libvirt-go"
 	libvirtxml "github.com/libvirt/libvirt-go-xml"
 )
 
 const (
-	// TODO: support size in the API
 	defaultSize = 17706254336
 )