Add disableVolumeMetrics flag for CSI Driver

If customer does not use Prometheus metrics of the volume, let
them disable it. The metrics execute statVolume and that is bit
expensive and causes load on Quobyte registry (client cache
can be configured to cache response via TTL to reduce the affect).

At the moment, there are efforts on registry side to improve
the statVolume call path, but if customer does not use the metric,
probing the stats is not useful.

csi-driver-templates/templates/pods/containers/_quobyte_csi_node_driver_container.tpl

@@ -24,6 +24,7 @@
     - "--quobyte_version={{ .Values.quobyte.version }}"
     - "--immediate_erase={{ .Values.quobyte.immediateErase }}"
     - "--use_k8s_namespace_as_tenant={{ .Values.quobyte.useK8SNamespaceAsTenant }}"
+    - "--disable_volume_metrics={{ .Values.quobyte.disableVolumeMetrics }}"
     - "--role=node_driver"
   env:
     - name: NODE_ID

csi-driver-templates/values.yaml

@@ -63,6 +63,10 @@ quobyte:
   # Name or UUID of the shared volume (UUIDs are preferred to avoid name collisions)
   sharedVolumesList: ""
 
+  # Set to 'true' if PVC/volume metrics (used/available/total bytes and inodes)
+  # are not required to be exported as Prometheus metrics.
+  disableVolumeMetrics: false
+
   podKiller:
     # To disable pod killer, uninstall current CSI driver (helm uninstall <chart-name>)
     # set enable: false and install CSI driver again

src/cmd/main.go

@@ -29,6 +29,7 @@ var (
 	driverVersion                = flag.String("driver_version", "", "Quobyte CSI driver version")
 	useNameSpaceAsTenant         = flag.Bool("use_k8s_namespace_as_tenant", false, "Uses k8s PVC.namespace as Quobyte tenant")
 	enableQuobyteAccessKeyMounts = flag.Bool("enable_access_key_mounts", false, "Enables use of Quobyte Access keys for mounting volumes")
+	disableVolumeMetrics         = flag.Bool("disable_volume_metrics", false, "Disables volume metrics (space and inodes) export")
 	immediateErase               = flag.Bool("immediate_erase", false, "Schedules erase volume task immediately (supported from Quobyte 3.x)")
 	quobyteVersion               = flag.Int("quobyte_version", 2, "Specify Quobyte major version (2 for Quobyte 2.x and 3 for Quobyte 3.x)")
 	sharedVolumes                = flag.String("shared_volumes_list", "", "Comma separated list of shared volumes (applicable only for Quobyte 2.x)")
@@ -93,7 +94,8 @@ func main() {
 		*useNameSpaceAsTenant,
 		*enableQuobyteAccessKeyMounts,
 		*immediateErase,
-		*quobyteVersion)
+		*quobyteVersion,
+		*disableVolumeMetrics)
 	err = qd.Run()
 	if err != nil {
 		klog.Errorf("Failed to start Quobyte CSI grpc server due to error: %v.", err)

src/driver/driver.go

@@ -27,6 +27,7 @@ type QuobyteDriver struct {
 	IsQuobyteAccessKeyMountsEnabled bool
 	ImmediateErase                  bool
 	QuobyteVersion                  int
+	disabledVolumeMetrics           bool
 	quoybteClientFactory QuobyteApiClientProvider
 	mounter                        Mounter
 }
@@ -42,7 +43,8 @@ func NewQuobyteDriver(
 	useNamespaceAsQuobyteTenant,
 	enableQuobyteAccessKeyMounts bool,
 	immediateErase bool,
-	quobyteVersion int) *QuobyteDriver {
+	quobyteVersion int,
+	disableVolumeMetrics bool) *QuobyteDriver {
 	return &QuobyteDriver{
 		driverName,
 		driverVersion,
@@ -55,6 +57,7 @@ func NewQuobyteDriver(
 		enableQuobyteAccessKeyMounts,
 		immediateErase,
 		quobyteVersion,
+		disableVolumeMetrics,
 		&QuobyteApiClientFactory{},
 		&LinuxMounter{},
 	}
@@ -103,11 +106,13 @@ func (d *QuobyteDriver) Run() error {
 		}
 		return resp, err
 	}
-	klog.Infof("Starting Quobyte-CSI Driver - driver: '%s' version: '%s'"+
-		"GRPC socket: '%s' mount point: '%s' API URL: '%s' "+
-		" MapNamespaceNameToQuobyteTenant: %t QuobyteAccesskeysEnabled: %t",
+	klog.Infof("Starting Quobyte-CSI Driver - driver: '%s' version: '%s'" +
+		"GRPC socket: '%s' mount point: '%s' API URL: '%s' " +
+		" MapNamespaceNameToQuobyteTenant: %t QuobyteAccesskeysEnabled: %t" +
+		" VolumeMetricsDisabled: %t",
 		d.Name, d.Version, d.endpoint, d.clientMountPoint, d.ApiURL,
-		d.UseK8SNamespaceAsQuobyteTenant, d.IsQuobyteAccessKeyMountsEnabled)
+		d.UseK8SNamespaceAsQuobyteTenant, d.IsQuobyteAccessKeyMountsEnabled,
+		d.disabledVolumeMetrics)
 	d.server = grpc.NewServer(grpc.UnaryInterceptor(errHandler))
 	csi.RegisterNodeServer(d.server, d)
 	csi.RegisterControllerServer(d.server, d)

src/driver/node.go

@@ -191,6 +191,9 @@ func (d *QuobyteDriver) NodeExpandVolume(ctx context.Context, req *csi.NodeExpan
 }
 
 func (d *QuobyteDriver) NodeGetVolumeStats(ctx context.Context, req *csi.NodeGetVolumeStatsRequest) (*csi.NodeGetVolumeStatsResponse, error) {
+	if d.disabledVolumeMetrics {
+		return nil, fmt.Errorf("volume/PVC metrics export is disabled for the Quobyte CSI Driver %s", d.Name);
+	}
 	volumePath := req.GetVolumePath()
 	if len(volumePath) <= 0 {
 		return nil, fmt.Errorf("volume path must not be empty")

src/driver/node_test.go

@@ -108,16 +108,24 @@ func TestNodeUnpublishVolume(t *testing.T) {
 	d.mounter = mounter
 	req = &csi.NodeUnpublishVolumeRequest{}
 	req.TargetPath = unmountPath
-	got, err = d.NodeUnpublishVolume(context.TODO(), req)
+	got, _ = d.NodeUnpublishVolume(context.TODO(), req)
 	wanted := &csi.NodeUnpublishVolumeResponse {}
 	assert.Equal(wanted, got);
 }
 
 func TestNodeGetVolumeStats(t *testing.T) {
+	driverName := "my.quobyte.csi.provisioner"
 	d := &QuobyteDriver{}
-	req := &csi.NodeGetVolumeStatsRequest{}
-	got, err := d.NodeGetVolumeStats(context.TODO(), req)
+	d.Name = driverName
+	d.disabledVolumeMetrics = true
+	got, err := d.NodeGetVolumeStats(context.TODO(), &csi.NodeGetVolumeStatsRequest{})
 	assert := assert.New(t)
+	assert.Nil(got);
+	assert.NotNil(err);
+	assert.Contains(err.Error(), "disabled for the Quobyte CSI Driver " + driverName)
+	d = &QuobyteDriver{}
+	req := &csi.NodeGetVolumeStatsRequest{}
+	got, err = d.NodeGetVolumeStats(context.TODO(), req)
 	assert.Nil(got)
 	assert.NotNil(err)
 	assert.True(strings.Contains(err.Error(), "volume path must not be empty"))
@@ -139,7 +147,7 @@ func TestNodeGetVolumeStats(t *testing.T) {
 	d.mounter = mounter
 	req = &csi.NodeGetVolumeStatsRequest{}
 	req.VolumePath = mountedPath
-	got, err = d.NodeGetVolumeStats(context.TODO(), req)
+	got, _ = d.NodeGetVolumeStats(context.TODO(), req)
 	wanted := &csi.NodeGetVolumeStatsResponse {
 		Usage: []*csi.VolumeUsage {
 			{