Merge pull request #1374 from amshinde/k8s-empty-dir

volumes: Handle k8s empty-dirs of "default" medium type

pkg/katautils/create_test.go

@@ -16,6 +16,7 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"syscall"
 	"testing"
 
 	vc "github.com/kata-containers/runtime/virtcontainers"
@@ -177,12 +178,30 @@ func findLastParam(key string, params []vc.Param) (string, error) {
 }
 
 func TestSetEphemeralStorageType(t *testing.T) {
+	if os.Geteuid() != 0 {
+		t.Skip(testDisabledNeedRoot)
+	}
+
 	assert := assert.New(t)
 
+	dir, err := ioutil.TempDir(testDir, "foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	ephePath := filepath.Join(dir, k8sEmptyDir, "tmp-volume")
+	err = os.MkdirAll(ephePath, testDirMode)
+	assert.Nil(err)
+
+	err = syscall.Mount("tmpfs", ephePath, "tmpfs", 0, "")
+	assert.Nil(err)
+	defer syscall.Unmount(ephePath, 0)
+
 	ociSpec := oci.CompatOCISpec{}
 	var ociMounts []specs.Mount
 	mount := specs.Mount{
-		Source: "/var/lib/kubelet/pods/366c3a77-4869-11e8-b479-507b9ddd5ce4/volumes/kubernetes.io~empty-dir/cache-volume",
+		Source: ephePath,
 	}
 
 	ociMounts = append(ociMounts, mount)

pkg/katautils/utils.go

@@ -14,6 +14,8 @@ import (
 	"path/filepath"
 	"strings"
 	"syscall"
+
+	vc "github.com/kata-containers/runtime/virtcontainers"
 )
 
 const (
@@ -43,7 +45,9 @@ func IsEphemeralStorage(path string) bool {
 	if len(splitSourceSlice) > 1 {
 		storageType := splitSourceSlice[len(splitSourceSlice)-2]
 		if storageType == k8sEmptyDir {
-			return true
+			if _, fsType, _ := vc.GetDevicePathAndFsType(path); fsType == "tmpfs" {
+				return true
+			}
 		}
 	}
 	return false

pkg/katautils/utils_test.go

@@ -368,7 +368,24 @@ func TestGetFileContents(t *testing.T) {
 }
 
 func TestIsEphemeralStorage(t *testing.T) {
-	sampleEphePath := "/var/lib/kubelet/pods/366c3a75-4869-11e8-b479-507b9ddd5ce4/volumes/kubernetes.io~empty-dir/cache-volume"
+	if os.Geteuid() != 0 {
+		t.Skip(testDisabledNeedRoot)
+	}
+
+	dir, err := ioutil.TempDir(testDir, "foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	sampleEphePath := filepath.Join(dir, k8sEmptyDir, "tmp-volume")
+	err = os.MkdirAll(sampleEphePath, testDirMode)
+	assert.Nil(t, err)
+
+	err = syscall.Mount("tmpfs", sampleEphePath, "tmpfs", 0, "")
+	assert.Nil(t, err)
+	defer syscall.Unmount(sampleEphePath, 0)
+
 	isEphe := IsEphemeralStorage(sampleEphePath)
 	if !isEphe {
 		t.Fatalf("Unable to correctly determine volume type")

virtcontainers/container.go

@@ -1138,7 +1138,7 @@ func (c *Container) hotplugDrive() error {
 	}
 
 	// If device mapper device, then fetch the full path of the device
-	devicePath, fsType, err := getDevicePathAndFsType(dev.mountPoint)
+	devicePath, fsType, err := GetDevicePathAndFsType(dev.mountPoint)
 	if err != nil {
 		return err
 	}

virtcontainers/mount.go

@@ -164,7 +164,9 @@ const (
 	procTypeIndex
 )
 
-func getDevicePathAndFsType(mountPoint string) (devicePath, fsType string, err error) {
+// GetDevicePathAndFsType gets the device for the mount point and the file system type
+// of the mount.
+func GetDevicePathAndFsType(mountPoint string) (devicePath, fsType string, err error) {
 	if mountPoint == "" {
 		err = fmt.Errorf("Mount point cannot be empty")
 		return

virtcontainers/mount_test.go

@@ -238,7 +238,7 @@ func TestGetDeviceForPathBindMount(t *testing.T) {
 }
 
 func TestGetDevicePathAndFsTypeEmptyMount(t *testing.T) {
-	_, _, err := getDevicePathAndFsType("")
+	_, _, err := GetDevicePathAndFsType("")
 
 	if err == nil {
 		t.Fatal()
@@ -246,7 +246,7 @@ func TestGetDevicePathAndFsTypeEmptyMount(t *testing.T) {
 }
 
 func TestGetDevicePathAndFsTypeSuccessful(t *testing.T) {
-	path, fstype, err := getDevicePathAndFsType("/proc")
+	path, fstype, err := GetDevicePathAndFsType("/proc")
 
 	if err != nil {
 		t.Fatal(err)