Merge pull request #39311 from rkouj/refactor-tear-down-at

Automatic merge from submit-queue

Check if pathExists before performing Unmount

Unmount operation should not fail if path does not exist

Part two of: https://github.com/kubernetes/kubernetes/pull/38547
Plugins status captured here: https://github.com/kubernetes/kubernetes/issues/39251

cc: @saad-ali

pkg/volume/configmap/configmap.go

@@ -267,14 +267,7 @@ func (c *configMapVolumeUnmounter) TearDown() error {
 }
 
 func (c *configMapVolumeUnmounter) TearDownAt(dir string) error {
-	glog.V(3).Infof("Tearing down volume %v for pod %v at %v", c.volName, c.podUID, dir)
-
-	// Wrap EmptyDir, let it do the teardown.
-	wrapped, err := c.plugin.host.NewWrapperUnmounter(c.volName, wrappedVolumeSpec(), c.podUID)
-	if err != nil {
-		return err
-	}
-	return wrapped.TearDownAt(dir)
+	return volume.UnmountViaEmptyDir(dir, c.plugin.host, c.volName, wrappedVolumeSpec(), c.podUID)
 }
 
 func getVolumeSource(spec *volume.Spec) (*v1.ConfigMapVolumeSource, bool) {

pkg/volume/downwardapi/downwardapi.go

@@ -272,14 +272,7 @@ func (c *downwardAPIVolumeUnmounter) TearDown() error {
 }
 
 func (c *downwardAPIVolumeUnmounter) TearDownAt(dir string) error {
-	glog.V(3).Infof("Tearing down volume %v for pod %v at %v", c.volName, c.podUID, dir)
-
-	// Wrap EmptyDir, let it do the teardown.
-	wrapped, err := c.plugin.host.NewWrapperUnmounter(c.volName, wrappedVolumeSpec(), c.podUID)
-	if err != nil {
-		return err
-	}
-	return wrapped.TearDownAt(dir)
+	return volume.UnmountViaEmptyDir(dir, c.plugin.host, c.volName, wrappedVolumeSpec(), c.podUID)
 }
 
 func (b *downwardAPIVolumeMounter) getMetaDir() string {

pkg/volume/empty_dir/empty_dir.go

@@ -299,6 +299,13 @@ func (ed *emptyDir) TearDown() error {
 
 // TearDownAt simply discards everything in the directory.
 func (ed *emptyDir) TearDownAt(dir string) error {
+	if pathExists, pathErr := volumeutil.PathExists(dir); pathErr != nil {
+		return fmt.Errorf("Error checking if path exists: %v", pathErr)
+	} else if !pathExists {
+		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", dir)
+		return nil
+	}
+
 	// Figure out the medium.
 	medium, isMnt, err := ed.mountDetector.GetMountMedium(dir)
 	if err != nil {

pkg/volume/git_repo/git_repo.go

@@ -254,13 +254,7 @@ func (c *gitRepoVolumeUnmounter) TearDown() error {
 
 // TearDownAt simply deletes everything in the directory.
 func (c *gitRepoVolumeUnmounter) TearDownAt(dir string) error {
-
-	// Wrap EmptyDir, let it do the teardown.
-	wrapped, err := c.plugin.host.NewWrapperUnmounter(c.volName, wrappedVolumeSpec(), c.podUID)
-	if err != nil {
-		return err
-	}
-	return wrapped.TearDownAt(dir)
+	return volume.UnmountViaEmptyDir(dir, c.plugin.host, c.volName, wrappedVolumeSpec(), c.podUID)
 }
 
 func getVolumeSource(spec *volume.Spec) (*v1.GitRepoVolumeSource, bool) {

pkg/volume/secret/secret.go

@@ -294,14 +294,7 @@ func (c *secretVolumeUnmounter) TearDown() error {
 }
 
 func (c *secretVolumeUnmounter) TearDownAt(dir string) error {
-	glog.V(3).Infof("Tearing down volume %v for pod %v at %v", c.volName, c.podUID, dir)
-
-	// Wrap EmptyDir, let it do the teardown.
-	wrapped, err := c.plugin.host.NewWrapperUnmounter(c.volName, wrappedVolumeSpec(), c.podUID)
-	if err != nil {
-		return err
-	}
-	return wrapped.TearDownAt(dir)
+	return volume.UnmountViaEmptyDir(dir, c.plugin.host, c.volName, wrappedVolumeSpec(), c.podUID)
 }
 
 func getVolumeSource(spec *volume.Spec) (*v1.SecretVolumeSource, bool) {

pkg/volume/util.go

@@ -34,7 +34,9 @@ import (
 	"github.com/golang/glog"
 	"k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/types"
 	"k8s.io/kubernetes/pkg/util/sets"
+	volutil "k8s.io/kubernetes/pkg/volume/util"
 )
 
 type RecycleEventRecorder func(eventtype, message string)
@@ -332,3 +334,23 @@ func ChooseZoneForVolume(zones sets.String, pvcName string) string {
 	glog.V(2).Infof("Creating volume for PVC %q; chose zone=%q from zones=%q", pvcName, zone, zoneSlice)
 	return zone
 }
+
+// UnmountViaEmptyDir delegates the tear down operation for secret, configmap, git_repo and downwardapi
+// to empty_dir
+func UnmountViaEmptyDir(dir string, host VolumeHost, volName string, volSpec Spec, podUID types.UID) error {
+	glog.V(3).Infof("Tearing down volume %v for pod %v at %v", volName, podUID, dir)
+
+	if pathExists, pathErr := volutil.PathExists(dir); pathErr != nil {
+		return fmt.Errorf("Error checking if path exists: %v", pathErr)
+	} else if !pathExists {
+		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", dir)
+		return nil
+	}
+
+	// Wrap EmptyDir, let it do the teardown.
+	wrapped, err := host.NewWrapperUnmounter(volName, volSpec, podUID)
+	if err != nil {
+		return err
+	}
+	return wrapped.TearDownAt(dir)
+}

test/test_owners.csv

@@ -194,6 +194,7 @@ Garbage collector should orphan pods created by rc if deleteOptions.OrphanDepend
 "Generated release_1_5 clientset should create pods, delete pods, watch pods",rrati,0
 "Generated release_1_5 clientset should create v2alpha1 cronJobs, delete cronJobs, watch cronJobs",soltysh,1
 HA-master survive addition/removal replicas different zones,derekwaynecarr,0
+HA-master survive addition/removal replicas multizone workers,rkouj,0
 HA-master survive addition/removal replicas same zone,derekwaynecarr,0
 Hazelcast should create and scale hazelcast,mikedanese,1
 Horizontal pod autoscaling (scale resource: CPU) Deployment Should scale from 1 pod to 3 pods and from 3 to 5,jszczepkowski,0
@@ -697,7 +698,6 @@ k8s.io/kubernetes/pkg/kubelet/kuberuntime,yifan-gu,1
 k8s.io/kubernetes/pkg/kubelet/lifecycle,yujuhong,1
 k8s.io/kubernetes/pkg/kubelet/network,freehan,0
 k8s.io/kubernetes/pkg/kubelet/network/cni,freehan,0
-k8s.io/kubernetes/pkg/kubelet/network/exec,freehan,0
 k8s.io/kubernetes/pkg/kubelet/network/hairpin,freehan,0
 k8s.io/kubernetes/pkg/kubelet/network/hostport,erictune,1
 k8s.io/kubernetes/pkg/kubelet/network/kubenet,freehan,0