configurable volume attachment limit (#141)

* configurable volume attachment limit * volumeAttchLimit as flag * change default * use os env variable * remove MaxAllowedVolumesPerNode * log statements

Author: shipra101

deploy/kubernetes/driver/kubernetes/manifests/config-map.yaml

@@ -74,3 +74,4 @@ data:
  BlockDriverMemoryLimit: "600Mi" #container:iks-vpc-block-driver, resource-type: memory-limit
  CSISnapshotterCPULimit: "80m" #container:csi-snapshotter, resource-type: cpu-limit
  CSISnapshotterMemoryLimit: "160Mi" #container:csi-snapshotter, resource-type: memory-limit
+ VolumeAttachmentLimit: "12" #Volume Attachment Limit per node

deploy/kubernetes/driver/kubernetes/manifests/node-server.yaml

@@ -47,6 +47,8 @@ spec:
  valueFrom:
  fieldRef:
  fieldPath: spec.nodeName
+ - name: VOLUME_ATTACHMENT_LIMIT
+ value: "{{kube-system.addon-vpc-block-csi-driver-configmap.VolumeAttachmentLimit}}{{^kube-system.addon-vpc-block-csi-driver-configmap.VolumeAttachmentLimit}}12{{/kube-system.addon-vpc-block-csi-driver-configmap.VolumeAttachmentLimit}}"
  resources:
  limits:
  cpu: "{{kube-system.addon-vpc-block-csi-driver-configmap.CSIDriverRegistrarCPULimit}}{{^kube-system.addon-vpc-block-csi-driver-configmap.CSIDriverRegistrarCPULimit}}40m{{/kube-system.addon-vpc-block-csi-driver-configmap.CSIDriverRegistrarCPULimit}}"

pkg/ibmcsidriver/ibm_csi_driver.go

@@ -35,10 +35,9 @@ type IBMCSIDriver struct {
 vendorVersion string
 logger *zap.Logger
 region string
-
-ids *CSIIdentityServer
-ns *CSINodeServer
-cs *CSIControllerServer
+ids *CSIIdentityServer
+ns *CSINodeServer
+cs *CSIControllerServer
 
 vcap []*csi.VolumeCapability_AccessMode
 cscap []*csi.ControllerServiceCapability

pkg/ibmcsidriver/ibm_csi_driver_test.go

@@ -18,9 +18,10 @@ limitations under the License.
 package ibmcsidriver
 
 import (
-testingexec "k8s.io/utils/exec/testing"
 "testing"
 
+testingexec "k8s.io/utils/exec/testing"
+
 cloudProvider "github.com/IBM/ibm-csi-common/pkg/ibmcloudprovider"
 nodeMetadata "github.com/IBM/ibm-csi-common/pkg/metadata"
 nodeInfo "github.com/IBM/ibm-csi-common/pkg/metadata/fake"

pkg/ibmcsidriver/node.go

@@ -21,7 +21,6 @@ import (
 "fmt"
 "os"
 "path/filepath"
-"runtime"
 "strconv"
 "strings"
 "sync"
@@ -79,10 +78,7 @@ func (su *VolumeStatUtils) FSInfo(path string) (int64, int64, int64, int64, int6
 
 const (
 // DefaultVolumesPerNode is the default number of volumes attachable to a node
-DefaultVolumesPerNode = 4
-
-// MaxVolumesPerNode is the maximum number of volumes attachable to a node
-MaxVolumesPerNode = 12
+DefaultVolumesPerNode = 12
 
 // MinimumCoresWithMaximumAttachableVolumes is the minimum cores required to have maximum number of attachable volumes, currently 4 as per the docs.
 MinimumCoresWithMaximumAttachableVolumes = 4
@@ -380,12 +376,20 @@ func (csiNS *CSINodeServer) NodeGetInfo(ctx context.Context, req *csi.NodeGetInf
 },
 }
 
-// maxVolumesPerNode is the maximum number of volumes attachable to a node; default is 4
-cores := runtime.NumCPU()
-if cores >= MinimumCoresWithMaximumAttachableVolumes {
-maxVolumesPerNode = MaxVolumesPerNode
+// If environment variable is set, use this value as maxVolumesPerNode
+value, ok := os.LookupEnv("VOLUME_ATTACHMENT_LIMIT")
+if !ok {
+ctxLogger.Warn("VOLUME_ATTACHMENT_LIMIT is not provided. Setting the default value:", zap.Reflect("MaxVolumesPerNode", maxVolumesPerNode))
+} else {
+volumeAttachmentLimit, err := strconv.ParseInt(value, 10, 64)
+if err != nil {
+ctxLogger.Warn("Invalid value for VOLUME_ATTACHMENT_LIMIT. Setting the default value:", zap.Reflect("MaxVolumesPerNode", maxVolumesPerNode))
+} else {
+maxVolumesPerNode = volumeAttachmentLimit
+}
 }
-ctxLogger.Info("Number of cores of the node and attachable volume limits.", zap.Reflect("Cores", cores), zap.Reflect("AttachableVolumeLimits", maxVolumesPerNode))
+
+ctxLogger.Info("Attachable volume limits", zap.Reflect("AttachableVolumeLimits", maxVolumesPerNode))
 
 resp := &csi.NodeGetInfoResponse{
 NodeId: csiNS.Metadata.GetWorkerID(),

pkg/ibmcsidriver/node_test.go

@@ -20,14 +20,14 @@ package ibmcsidriver
 import (
 "errors"
 "fmt"
-"k8s.io/utils/exec"
-testingexec "k8s.io/utils/exec/testing"
 "os"
 "reflect"
-"runtime"
 "strings"
 "testing"
 
+"k8s.io/utils/exec"
+testingexec "k8s.io/utils/exec/testing"
+
 "github.com/IBM/ibm-csi-common/pkg/utils"
 csi "github.com/container-storage-interface/spec/lib/go/csi"
 "github.com/stretchr/testify/assert"
@@ -471,11 +471,7 @@ func TestNodeGetCapabilities(t *testing.T) {
 }
 
 func TestNodeGetInfo(t *testing.T) {
-cores := runtime.NumCPU()
 var maxVolumesPerNode int64 = DefaultVolumesPerNode
-if cores >= MinimumCoresWithMaximumAttachableVolumes {
-maxVolumesPerNode = MaxVolumesPerNode
-}
 
 testCases := []struct {
 name string