feat: csi-cinder storage capacity

Available capacity of disk storage

Signed-off-by: Serge Logvinov <[email protected]>

Author: sergelogvinov

Diff for: pkg/csi/cinder/controllerserver.go

@@ -772,7 +772,16 @@ func (cs *controllerServer) ValidateVolumeCapabilities(ctx context.Context, req
 }
 
 func (cs *controllerServer) GetCapacity(ctx context.Context, req *csi.GetCapacityRequest) (*csi.GetCapacityResponse, error) {
-	return nil, status.Error(codes.Unimplemented, "GetCapacity is not yet implemented")
+	klog.V(4).Infof("GetCapacity: called with args %+v", protosanitizer.StripSecrets(*req))
+
+	availableCapacity, err := cs.Cloud.GetFreeCapacity()
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "GetCapacity: failed with error %v", err)
+	}
+
+	return &csi.GetCapacityResponse{
+		AvailableCapacity: int64(availableCapacity * 1024 * 1024 * 1024),
+	}, nil
 }
 
 func (cs *controllerServer) ControllerGetVolume(ctx context.Context, req *csi.ControllerGetVolumeRequest) (*csi.ControllerGetVolumeResponse, error) {

Diff for: pkg/csi/cinder/driver.go

@@ -93,6 +93,7 @@ func NewDriver(o *DriverOpts) *Driver {
 			csi.ControllerServiceCapability_RPC_PUBLISH_UNPUBLISH_VOLUME,
 			csi.ControllerServiceCapability_RPC_CREATE_DELETE_SNAPSHOT,
 			csi.ControllerServiceCapability_RPC_LIST_SNAPSHOTS,
+			csi.ControllerServiceCapability_RPC_GET_CAPACITY,
 			csi.ControllerServiceCapability_RPC_EXPAND_VOLUME,
 			csi.ControllerServiceCapability_RPC_CLONE_VOLUME,
 			csi.ControllerServiceCapability_RPC_LIST_VOLUMES_PUBLISHED_NODES,

Diff for: pkg/csi/cinder/openstack/openstack.go

@@ -70,6 +70,7 @@ type IOpenStack interface {
 	GetInstanceByID(instanceID string) (*servers.Server, error)
 	ExpandVolume(volumeID string, status string, size int) error
 	GetMaxVolLimit() int64
+	GetFreeCapacity() (int, error)
 	GetMetadataOpts() metadata.Opts
 	GetBlockStorageOpts() BlockStorageOpts
 }

Diff for: pkg/csi/cinder/openstack/openstack_mock.go

@@ -460,6 +460,10 @@ func (_m *OpenStackMock) GetMaxVolLimit() int64 {
 	return 256
 }
 
+func (_m *OpenStackMock) GetFreeCapacity() (int, error) {
+	return 100, nil
+}
+
 func (_m *OpenStackMock) BackupsAreEnabled() (bool, error) {
 	return true, nil
 }

Diff for: pkg/csi/cinder/openstack/openstack_volumes.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"github.com/gophercloud/gophercloud/openstack"
+	volumelimit "github.com/gophercloud/gophercloud/openstack/blockstorage/extensions/limits"
 	volumeexpand "github.com/gophercloud/gophercloud/openstack/blockstorage/extensions/volumeactions"
 	"github.com/gophercloud/gophercloud/openstack/blockstorage/v3/volumes"
 	"github.com/gophercloud/gophercloud/openstack/compute/v2/extensions/volumeattach"
@@ -396,6 +397,21 @@ func (os *OpenStack) GetMaxVolLimit() int64 {
 	return defaultMaxVolAttachLimit
 }
 
+// GetFreeCapacity returns free capacity of the block storage, in GB
+func (os *OpenStack) GetFreeCapacity() (int, error) {
+	res, err := volumelimit.Get(os.blockstorage).Extract()
+	if err != nil {
+		return 0, err
+	}
+
+	capacity := res.Absolute.MaxTotalVolumeGigabytes - res.Absolute.TotalGigabytesUsed
+	if capacity < 0 {
+		capacity = 0
+	}
+
+	return capacity, nil
+}
+
 // diskIsAttached queries if a volume is attached to a compute instance
 func (os *OpenStack) diskIsAttached(instanceID, volumeID string) (bool, error) {
 	volume, err := os.GetVolume(volumeID)

Diff for: tests/sanity/cinder/fakecloud.go

@@ -332,6 +332,10 @@ func (cloud *cloud) GetMaxVolLimit() int64 {
 	return 256
 }
 
+func (cloud *cloud) GetFreeCapacity() (int, error) {
+	return 100, nil
+}
+
 func (cloud *cloud) GetMetadataOpts() metadata.Opts {
 	var m metadata.Opts
 	m.SearchOrder = fmt.Sprintf("%s,%s", "configDrive", "metadataService")