Adding a root filesystem override for kubelet mounter

cmd/kube-proxy/app/conntrack.go

@@ -67,7 +67,7 @@ func (realConntracker) SetTCPEstablishedTimeout(seconds int) error {
 func isSysFSWritable() (bool, error) {
 	const permWritable = "rw"
 	const sysfsDevice = "sysfs"
-	m := mount.New("" /* default mount path */)
+	m := mount.New()
 	mountPoints, err := m.List()
 	if err != nil {
 		glog.Errorf("failed to list mount points: %v", err)

cmd/kubelet/app/options/options.go

@@ -198,6 +198,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVar(&s.ExitOnLockContention, "exit-on-lock-contention", s.ExitOnLockContention, "Whether kubelet should exit upon lock-file contention.")
 	fs.StringVar(&s.RktPath, "rkt-path", s.RktPath, "Path of rkt binary. Leave empty to use the first rkt in $PATH.  Only used if --container-runtime='rkt'.")
 	fs.StringVar(&s.ExperimentalMounterPath, "experimental-mounter-path", s.ExperimentalMounterPath, "[Experimental] Path of mounter binary. Leave empty to use the default mount.")
+	fs.StringVar(&s.ExperimentalMounterRootfsPath, "experimental-mounter-rootfs-path", s.ExperimentalMounterRootfsPath, "[Experimental] Absolute path to the root filesystem for the mounter binary.")
 	fs.StringVar(&s.RktAPIEndpoint, "rkt-api-endpoint", s.RktAPIEndpoint, "The endpoint of the rkt API service to communicate with. Only used if --container-runtime='rkt'.")
 	fs.StringVar(&s.RktStage1Image, "rkt-stage1-image", s.RktStage1Image, "image to use as stage1. Local paths and http/https URLs are supported. If empty, the 'stage1.aci' in the same directory as '--rkt-path' will be used.")
 	fs.MarkDeprecated("rkt-stage1-image", "Will be removed in a future version. The default stage1 image will be specified by the rkt configurations, see https://github.com/coreos/rkt/blob/master/Documentation/configuration.md for more details.")

cmd/kubelet/app/server.go

@@ -118,7 +118,7 @@ func UnsecuredKubeletDeps(s *options.KubeletServer) (*kubelet.KubeletDeps, error
 		return nil, err
 	}
 
-	mounter := mount.New(s.ExperimentalMounterPath)
+	mounter := mount.NewCustomMounter(s.ExperimentalMounterPath, s.ExperimentalMounterRootfsPath)
 	var writer kubeio.Writer = &kubeio.StdWriter{}
 	if s.Containerized {
 		glog.V(2).Info("Running kubelet in containerized mode (experimental)")

hack/verify-flags/known-flags.txt

@@ -188,6 +188,7 @@ experimental-allowed-unsafe-sysctls
 experimental-bootstrap-kubeconfig
 experimental-keystone-url
 experimental-mounter-path
+experimental-mounter-rootfs-path
 experimental-nvidia-gpus
 experimental-prefix
 experimental-runtime-integration-type

pkg/apis/componentconfig/types.go

@@ -319,6 +319,8 @@ type KubeletConfiguration struct {
 	RktPath string `json:"rktPath,omitempty"`
 	// experimentalMounterPath is the path of mounter binary. Leave empty to use the default mount path
 	ExperimentalMounterPath string `json:"experimentalMounterPath,omitempty"`
+	// experimentalMounterRootfsPath is the absolute path to root filesystem for the mounter binary.
+	ExperimentalMounterRootfsPath string `json:"experimentalMounterRootfsPath,omitempty"`
 	// rktApiEndpoint is the endpoint of the rkt API service to communicate with.
 	// +optional
 	RktAPIEndpoint string `json:"rktAPIEndpoint,omitempty"`

pkg/apis/componentconfig/v1alpha1/types.go

@@ -367,6 +367,8 @@ type KubeletConfiguration struct {
 	// experimentalMounterPath is the path to mounter binary. If not set, kubelet will attempt to use mount
 	// binary that is available via $PATH,
 	ExperimentalMounterPath string `json:"experimentalMounterPath,omitempty"`
+	// experimentalMounterRootfsPath is the absolute path to root filesystem for the mounter binary.
+	ExperimentalMounterRootfsPath string `json:"experimentalMounterRootfsPath,omitempty"`
 	// rktApiEndpoint is the endpoint of the rkt API service to communicate with.
 	RktAPIEndpoint string `json:"rktAPIEndpoint"`
 	// rktStage1Image is the image to use as stage1. Local paths and

pkg/apis/componentconfig/v1alpha1/zz_generated.conversion.go

@@ -335,6 +335,7 @@ func autoConvert_v1alpha1_KubeletConfiguration_To_componentconfig_KubeletConfigu
 	out.RuntimeRequestTimeout = in.RuntimeRequestTimeout
 	out.RktPath = in.RktPath
 	out.ExperimentalMounterPath = in.ExperimentalMounterPath
+	out.ExperimentalMounterRootfsPath = in.ExperimentalMounterRootfsPath
 	out.RktAPIEndpoint = in.RktAPIEndpoint
 	out.RktStage1Image = in.RktStage1Image
 	if err := api.Convert_Pointer_string_To_string(&in.LockFilePath, &out.LockFilePath, s); err != nil {
@@ -517,6 +518,7 @@ func autoConvert_componentconfig_KubeletConfiguration_To_v1alpha1_KubeletConfigu
 	out.RuntimeRequestTimeout = in.RuntimeRequestTimeout
 	out.RktPath = in.RktPath
 	out.ExperimentalMounterPath = in.ExperimentalMounterPath
+	out.ExperimentalMounterRootfsPath = in.ExperimentalMounterRootfsPath
 	out.RktAPIEndpoint = in.RktAPIEndpoint
 	out.RktStage1Image = in.RktStage1Image
 	if err := api.Convert_string_To_Pointer_string(&in.LockFilePath, &out.LockFilePath, s); err != nil {

pkg/apis/componentconfig/v1alpha1/zz_generated.deepcopy.go

@@ -314,6 +314,7 @@ func DeepCopy_v1alpha1_KubeletConfiguration(in interface{}, out interface{}, c *
 		out.RuntimeRequestTimeout = in.RuntimeRequestTimeout
 		out.RktPath = in.RktPath
 		out.ExperimentalMounterPath = in.ExperimentalMounterPath
+		out.ExperimentalMounterRootfsPath = in.ExperimentalMounterRootfsPath
 		out.RktAPIEndpoint = in.RktAPIEndpoint
 		out.RktStage1Image = in.RktStage1Image
 		if in.LockFilePath != nil {

pkg/apis/componentconfig/zz_generated.deepcopy.go

@@ -316,6 +316,7 @@ func DeepCopy_componentconfig_KubeletConfiguration(in interface{}, out interface
 		out.RuntimeRequestTimeout = in.RuntimeRequestTimeout
 		out.RktPath = in.RktPath
 		out.ExperimentalMounterPath = in.ExperimentalMounterPath
+		out.ExperimentalMounterRootfsPath = in.ExperimentalMounterRootfsPath
 		out.RktAPIEndpoint = in.RktAPIEndpoint
 		out.RktStage1Image = in.RktStage1Image
 		out.LockFilePath = in.LockFilePath

pkg/cloudprovider/providers/openstack/metadata.go

@@ -95,7 +95,7 @@ func getMetadataFromConfigDrive() (*Metadata, error) {
 
 	glog.V(4).Infof("Attempting to mount configdrive %s on %s", dev, mntdir)
 
-	mounter := mount.New("" /* default mount path */)
+	mounter := mount.New()
 	err = mounter.Mount(dev, mntdir, "iso9660", []string{"ro"})
 	if err != nil {
 		err = mounter.Mount(dev, mntdir, "vfat", []string{"ro"})

pkg/generated/openapi/zz_generated.openapi.go

@@ -2657,6 +2657,13 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 							Format:      "",
 						},
 					},
+					"experimentalMounterRootfsPath": {
+						SchemaProps: spec.SchemaProps{
+							Description: "experimentalMounterRootfsPath is the absolute path to root filesystem for the mounter binary.",
+							Type:        []string{"string"},
+							Format:      "",
+						},
+					},
 					"rktAPIEndpoint": {
 						SchemaProps: spec.SchemaProps{
 							Description: "rktApiEndpoint is the endpoint of the rkt API service to communicate with.",
@@ -2971,7 +2978,7 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 						},
 					},
 				},
-				Required: []string{"TypeMeta", "podManifestPath", "syncFrequency", "fileCheckFrequency", "httpCheckFrequency", "manifestURL", "manifestURLHeader", "enableServer", "address", "port", "readOnlyPort", "tlsCertFile", "tlsPrivateKeyFile", "certDirectory", "authentication", "authorization", "hostnameOverride", "podInfraContainerImage", "dockerEndpoint", "rootDirectory", "seccompProfileRoot", "allowPrivileged", "hostNetworkSources", "hostPIDSources", "hostIPCSources", "registryPullQPS", "registryBurst", "eventRecordQPS", "eventBurst", "enableDebuggingHandlers", "minimumGCAge", "maxPerPodContainerCount", "maxContainerCount", "cAdvisorPort", "healthzPort", "healthzBindAddress", "oomScoreAdj", "registerNode", "clusterDomain", "masterServiceNamespace", "clusterDNS", "streamingConnectionIdleTimeout", "nodeStatusUpdateFrequency", "imageMinimumGCAge", "imageGCHighThresholdPercent", "imageGCLowThresholdPercent", "lowDiskSpaceThresholdMB", "volumeStatsAggPeriod", "networkPluginName", "networkPluginMTU", "networkPluginDir", "cniConfDir", "cniBinDir", "volumePluginDir", "containerRuntime", "remoteRuntimeEndpoint", "remoteImageEndpoint", "experimentalMounterPath", "lockFilePath", "exitOnLockContention", "hairpinMode", "babysitDaemons", "maxPods", "nvidiaGPUs", "dockerExecHandlerName", "podCIDR", "resolvConf", "cpuCFSQuota", "containerized", "maxOpenFiles", "reconcileCIDR", "registerSchedulable", "contentType", "kubeAPIQPS", "kubeAPIBurst", "serializeImagePulls", "nodeLabels", "nonMasqueradeCIDR", "enableCustomMetrics", "podsPerCore", "enableControllerAttachDetach", "systemReserved", "kubeReserved", "protectKernelDefaults", "makeIPTablesUtilChains", "iptablesMasqueradeBit", "iptablesDropBit"},
+				Required: []string{"TypeMeta", "podManifestPath", "syncFrequency", "fileCheckFrequency", "httpCheckFrequency", "manifestURL", "manifestURLHeader", "enableServer", "address", "port", "readOnlyPort", "tlsCertFile", "tlsPrivateKeyFile", "certDirectory", "authentication", "authorization", "hostnameOverride", "podInfraContainerImage", "dockerEndpoint", "rootDirectory", "seccompProfileRoot", "allowPrivileged", "hostNetworkSources", "hostPIDSources", "hostIPCSources", "registryPullQPS", "registryBurst", "eventRecordQPS", "eventBurst", "enableDebuggingHandlers", "minimumGCAge", "maxPerPodContainerCount", "maxContainerCount", "cAdvisorPort", "healthzPort", "healthzBindAddress", "oomScoreAdj", "registerNode", "clusterDomain", "masterServiceNamespace", "clusterDNS", "streamingConnectionIdleTimeout", "nodeStatusUpdateFrequency", "imageMinimumGCAge", "imageGCHighThresholdPercent", "imageGCLowThresholdPercent", "lowDiskSpaceThresholdMB", "volumeStatsAggPeriod", "networkPluginName", "networkPluginMTU", "networkPluginDir", "cniConfDir", "cniBinDir", "volumePluginDir", "containerRuntime", "remoteRuntimeEndpoint", "remoteImageEndpoint", "experimentalMounterPath", "experimentalMounterRootfsPath", "lockFilePath", "exitOnLockContention", "hairpinMode", "babysitDaemons", "maxPods", "nvidiaGPUs", "dockerExecHandlerName", "podCIDR", "resolvConf", "cpuCFSQuota", "containerized", "maxOpenFiles", "reconcileCIDR", "registerSchedulable", "contentType", "kubeAPIQPS", "kubeAPIBurst", "serializeImagePulls", "nodeLabels", "nonMasqueradeCIDR", "enableCustomMetrics", "podsPerCore", "enableControllerAttachDetach", "systemReserved", "kubeReserved", "protectKernelDefaults", "makeIPTablesUtilChains", "iptablesMasqueradeBit", "iptablesDropBit"},
 			},
 		},
 		Dependencies: []string{
@@ -14320,6 +14327,13 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 							Format:      "",
 						},
 					},
+					"experimentalMounterRootfsPath": {
+						SchemaProps: spec.SchemaProps{
+							Description: "experimentalMounterRootfsPath is the absolute path to root filesystem for the mounter binary.",
+							Type:        []string{"string"},
+							Format:      "",
+						},
+					},
 					"rktAPIEndpoint": {
 						SchemaProps: spec.SchemaProps{
 							Description: "rktApiEndpoint is the endpoint of the rkt API service to communicate with.",
@@ -14634,7 +14648,7 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 						},
 					},
 				},
-				Required: []string{"TypeMeta", "podManifestPath", "syncFrequency", "fileCheckFrequency", "httpCheckFrequency", "manifestURL", "manifestURLHeader", "enableServer", "address", "port", "readOnlyPort", "tlsCertFile", "tlsPrivateKeyFile", "certDirectory", "authentication", "authorization", "hostnameOverride", "podInfraContainerImage", "dockerEndpoint", "rootDirectory", "seccompProfileRoot", "allowPrivileged", "hostNetworkSources", "hostPIDSources", "hostIPCSources", "registryPullQPS", "registryBurst", "eventRecordQPS", "eventBurst", "enableDebuggingHandlers", "minimumGCAge", "maxPerPodContainerCount", "maxContainerCount", "cAdvisorPort", "healthzPort", "healthzBindAddress", "oomScoreAdj", "registerNode", "clusterDomain", "masterServiceNamespace", "clusterDNS", "streamingConnectionIdleTimeout", "nodeStatusUpdateFrequency", "imageMinimumGCAge", "imageGCHighThresholdPercent", "imageGCLowThresholdPercent", "lowDiskSpaceThresholdMB", "volumeStatsAggPeriod", "networkPluginName", "networkPluginDir", "cniConfDir", "cniBinDir", "networkPluginMTU", "volumePluginDir", "cloudProvider", "cloudConfigFile", "kubeletCgroups", "runtimeCgroups", "systemCgroups", "cgroupRoot", "containerRuntime", "remoteRuntimeEndpoint", "remoteImageEndpoint", "runtimeRequestTimeout", "rktPath", "experimentalMounterPath", "rktAPIEndpoint", "rktStage1Image", "lockFilePath", "exitOnLockContention", "hairpinMode", "babysitDaemons", "maxPods", "nvidiaGPUs", "dockerExecHandlerName", "podCIDR", "resolvConf", "cpuCFSQuota", "containerized", "maxOpenFiles", "reconcileCIDR", "registerSchedulable", "contentType", "kubeAPIQPS", "kubeAPIBurst", "serializeImagePulls", "outOfDiskTransitionFrequency", "nodeIP", "nodeLabels", "nonMasqueradeCIDR", "enableCustomMetrics", "evictionHard", "evictionSoft", "evictionSoftGracePeriod", "evictionPressureTransitionPeriod", "evictionMaxPodGracePeriod", "evictionMinimumReclaim", "podsPerCore", "enableControllerAttachDetach", "systemReserved", "kubeReserved", "protectKernelDefaults", "makeIPTablesUtilChains", "iptablesMasqueradeBit", "iptablesDropBit"},
+				Required: []string{"TypeMeta", "podManifestPath", "syncFrequency", "fileCheckFrequency", "httpCheckFrequency", "manifestURL", "manifestURLHeader", "enableServer", "address", "port", "readOnlyPort", "tlsCertFile", "tlsPrivateKeyFile", "certDirectory", "authentication", "authorization", "hostnameOverride", "podInfraContainerImage", "dockerEndpoint", "rootDirectory", "seccompProfileRoot", "allowPrivileged", "hostNetworkSources", "hostPIDSources", "hostIPCSources", "registryPullQPS", "registryBurst", "eventRecordQPS", "eventBurst", "enableDebuggingHandlers", "minimumGCAge", "maxPerPodContainerCount", "maxContainerCount", "cAdvisorPort", "healthzPort", "healthzBindAddress", "oomScoreAdj", "registerNode", "clusterDomain", "masterServiceNamespace", "clusterDNS", "streamingConnectionIdleTimeout", "nodeStatusUpdateFrequency", "imageMinimumGCAge", "imageGCHighThresholdPercent", "imageGCLowThresholdPercent", "lowDiskSpaceThresholdMB", "volumeStatsAggPeriod", "networkPluginName", "networkPluginDir", "cniConfDir", "cniBinDir", "networkPluginMTU", "volumePluginDir", "cloudProvider", "cloudConfigFile", "kubeletCgroups", "runtimeCgroups", "systemCgroups", "cgroupRoot", "containerRuntime", "remoteRuntimeEndpoint", "remoteImageEndpoint", "runtimeRequestTimeout", "rktPath", "experimentalMounterPath", "experimentalMounterRootfsPath", "rktAPIEndpoint", "rktStage1Image", "lockFilePath", "exitOnLockContention", "hairpinMode", "babysitDaemons", "maxPods", "nvidiaGPUs", "dockerExecHandlerName", "podCIDR", "resolvConf", "cpuCFSQuota", "containerized", "maxOpenFiles", "reconcileCIDR", "registerSchedulable", "contentType", "kubeAPIQPS", "kubeAPIBurst", "serializeImagePulls", "outOfDiskTransitionFrequency", "nodeIP", "nodeLabels", "nonMasqueradeCIDR", "enableCustomMetrics", "evictionHard", "evictionSoft", "evictionSoftGracePeriod", "evictionPressureTransitionPeriod", "evictionMaxPodGracePeriod", "evictionMinimumReclaim", "podsPerCore", "enableControllerAttachDetach", "systemReserved", "kubeReserved", "protectKernelDefaults", "makeIPTablesUtilChains", "iptablesMasqueradeBit", "iptablesDropBit"},
 			},
 		},
 		Dependencies: []string{

pkg/kubemark/hollow_kubelet.go

@@ -72,7 +72,7 @@ func NewHollowKubelet(
 		TLSOptions:        nil,
 		OOMAdjuster:       oom.NewFakeOOMAdjuster(),
 		Writer:            &kubeio.StdWriter{},
-		Mounter:           mount.New("" /* default mount path */),
+		Mounter:           mount.New(),
 	}
 
 	return &HollowKubelet{

pkg/util/mount/mount.go

@@ -94,13 +94,25 @@ func (mounter *SafeFormatAndMount) FormatAndMount(source string, target string,
 }
 
 // New returns a mount.Interface for the current system.
-func New(mounterPath string) Interface {
+func New() Interface {
+	return &Mounter{}
+}
+
+// NewCustomMounter returns a mount.Interface for the current system.
+// It provides options to override the default mounter behavior.
+// mounterPath allows using an alternative to `/bin/mount` for mounting.
+// mounterRootfsPath allows specifying a custom root filesystem path for non default `mounterPath`.
+func NewCustomMounter(mounterPath, mounterRootfsPath string) Interface {
 	// If mounter-path flag is not set, use default mount path
-	if len(mounterPath) == 0 {
+	if mounterPath == "" {
 		mounterPath = mount
 	}
+	if mounterRootfsPath == "" {
+		mounterRootfsPath = "/"
+	}
 	return &Mounter{
-		mounterPath: mounterPath,
+		mounterPath:       mounterPath,
+		mounterRootfsPath: mounterRootfsPath,
 	}
 }
 

pkg/util/mount/mount_linux.go

@@ -25,6 +25,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"path"
 	"strconv"
 	"strings"
 	"syscall"
@@ -53,7 +54,8 @@ const (
 // for the linux platform.  This implementation assumes that the
 // kubelet is running in the host's root mount namespace.
 type Mounter struct {
-	mounterPath string
+	mounterPath       string
+	mounterRootfsPath string
 }
 
 // Mount mounts source to target as fstype with given options. 'source' and 'fstype' must
@@ -61,16 +63,17 @@ type Mounter struct {
 // type, where kernel handles fs type for you. The mount 'options' is a list of options,
 // currently come from mount(8), e.g. "ro", "remount", "bind", etc. If no more option is
 // required, call Mount with an empty string list or nil.
+// Update source path to include a root filesystem override to make a containerized mounter (specified via `mounterPath`) work.
 func (mounter *Mounter) Mount(source string, target string, fstype string, options []string) error {
 	bind, bindRemountOpts := isBind(options)
 	if bind {
-		err := doMount(mounter.mounterPath, source, target, fstype, []string{"bind"})
+		err := doMount(mounter.mounterPath, path.Join(mounter.mounterRootfsPath, source), target, fstype, []string{"bind"})
 		if err != nil {
 			return err
 		}
-		return doMount(mounter.mounterPath, source, target, fstype, bindRemountOpts)
+		return doMount(mounter.mounterPath, path.Join(mounter.mounterRootfsPath, source), target, fstype, bindRemountOpts)
 	} else {
-		return doMount(mounter.mounterPath, source, target, fstype, options)
+		return doMount(mounter.mounterPath, path.Join(mounter.mounterRootfsPath, source), target, fstype, options)
 	}
 }
 

test/e2e/framework/test_context.go

@@ -119,6 +119,8 @@ type NodeTestContextType struct {
 	ContainerRuntimeEndpoint string
 	// MounterPath is the path to the program to run to perform a mount
 	MounterPath string
+	// MounterRootfsPath is the path to the root filesystem for the program used to perform a mount in kubelet
+	MounterRootfsPath string
 }
 
 type CloudConfig struct {
@@ -216,6 +218,7 @@ func RegisterNodeFlags() {
 	flag.StringVar(&TestContext.RuntimeIntegrationType, "runtime-integration-type", "", "Choose the integration path for the container runtime, mainly used for CRI validation.")
 	flag.StringVar(&TestContext.ContainerRuntimeEndpoint, "container-runtime-endpoint", "", "The endpoint of remote container runtime grpc server, mainly used for Remote CRI validation.")
 	flag.StringVar(&TestContext.MounterPath, "experimental-mounter-path", "", "Path of mounter binary. Leave empty to use the default mount.")
+	flag.StringVar(&TestContext.MounterRootfsPath, "experimental-mounter-rootfs-path", "", "Absolute path to root filesystem for the mounter binary.")
 }
 
 // overwriteFlagsWithViperConfig finds and writes values to flags using viper as input.

test/e2e_node/remote/remote.go

@@ -42,9 +42,10 @@ var resultsDir = flag.String("results-dir", "/tmp/", "Directory to scp test resu
 var sshOptionsMap map[string]string
 
 const (
-	archiveName  = "e2e_node_test.tar.gz"
-	CNIRelease   = "07a8a28637e97b22eb8dfe710eeae1344f69d16e"
-	CNIDirectory = "cni"
+	archiveName              = "e2e_node_test.tar.gz"
+	CNIRelease               = "07a8a28637e97b22eb8dfe710eeae1344f69d16e"
+	CNIDirectory             = "cni"
+	mounterRootfsPath string = "/"
 )
 
 var CNIURL = fmt.Sprintf("https://storage.googleapis.com/kubernetes-release/network-plugins/cni-%s.tar.gz", CNIRelease)
@@ -263,7 +264,7 @@ func RunRemote(archive string, host string, cleanup bool, junitFilePrefix string
 		return "", false, fmt.Errorf("Issue detecting node's OS via node's /etc/os-release. Err: %v, Output:\n%s", err, output)
 	}
 	if strings.Contains(output, "ID=gci") {
-		glog.Infof("GCI node and GCI mounter both detected, modifying --experimental-mounter-path accordingly")
+		glog.Infof("GCI node and GCI mounter both detected, modifying --mounter-path & --experimental-mounter-rootfs-path accordingly")
 
 		// Note this implicitly requires the script to be where we expect in the tarball, so if that location changes the error
 		// here will tell us to update the remote test runner.
@@ -274,6 +275,7 @@ func RunRemote(archive string, host string, cleanup bool, junitFilePrefix string
 			return "", false, err
 		}
 		// Insert args at beginning of testArgs, so any values from command line take precedence
+		testArgs = fmt.Sprintf("--experimental-mounter-rootfs-path=%s ", mounterRootfsPath) + testArgs
 		testArgs = fmt.Sprintf("--experimental-mounter-path=%s ", mounterPath) + testArgs
 	}
 

test/e2e_node/services/services.go

@@ -212,6 +212,7 @@ func (e *E2EServices) startKubelet() (*server, error) {
 		"--feature-gates", framework.TestContext.FeatureGates,
 		"--v", LOG_VERBOSITY_LEVEL, "--logtostderr",
 		"--experimental-mounter-path", framework.TestContext.MounterPath,
+		"--experimental-mounter-rootfs-path", framework.TestContext.MounterRootfsPath,
 	)
 
 	if framework.TestContext.RuntimeIntegrationType != "" {