support local volume with block source reconstruction

This commit is contained in:
Yecheng Fu 2019-10-22 20:22:49 +08:00
parent 9832418870
commit 36a54399a6
5 changed files with 140 additions and 49 deletions

View File

@ -353,10 +353,10 @@ type reconstructedVolume struct {
volumeSpec *volumepkg.Spec
outerVolumeSpecName string
pod *v1.Pod
attachablePlugin volumepkg.AttachableVolumePlugin
volumeGidValue string
devicePath string
mounter volumepkg.Mounter
deviceMounter volumepkg.DeviceMounter
blockVolumeMapper volumepkg.BlockVolumeMapper
}
@ -500,6 +500,7 @@ func (rc *reconciler) reconstructVolume(volume podVolume) (*reconstructedVolume,
var volumeMapper volumepkg.BlockVolumeMapper
var volumeMounter volumepkg.Mounter
var deviceMounter volumepkg.DeviceMounter
// Path to the mount or block device to check
var checkPath string
@ -537,6 +538,17 @@ func (rc *reconciler) reconstructVolume(volume podVolume) (*reconstructedVolume,
err)
}
checkPath = volumeMounter.GetPath()
if deviceMountablePlugin != nil {
deviceMounter, err = deviceMountablePlugin.NewDeviceMounter()
if err != nil {
return nil, fmt.Errorf("reconstructVolume.NewDeviceMounter failed for volume %q (spec.Name: %q) pod %q (UID: %q) with: %v",
uniqueVolumeName,
volumeSpec.Name(),
volume.podName,
pod.UID,
err)
}
}
}
// Check existence of mount point for filesystem volume or symbolic link for block volume
@ -558,7 +570,7 @@ func (rc *reconciler) reconstructVolume(volume podVolume) (*reconstructedVolume,
// TODO: in case pod is added back before reconciler starts to unmount, we can update this field from desired state information
outerVolumeSpecName: volume.volumeSpecName,
pod: pod,
attachablePlugin: attachablePlugin,
deviceMounter: deviceMounter,
volumeGidValue: "",
// devicePath is updated during updateStates() by checking node status's VolumesAttached data.
// TODO: get device path directly from the volume mount path.
@ -585,19 +597,18 @@ func (rc *reconciler) updateDevicePath(volumesNeedUpdate map[v1.UniqueVolumeName
}
}
// getDeviceMountPath returns device mount path for block volume which
// implements BlockVolumeMapper or filesystem volume which implements
// DeviceMounter
func getDeviceMountPath(volume *reconstructedVolume) (string, error) {
if volume.blockVolumeMapper != nil {
// for block volume, we return its global map path
return volume.blockVolumeMapper.GetGlobalMapPath(volume.volumeSpec)
} else if volume.attachablePlugin != nil {
// for filesystem volume, we return its device mount path if the plugin implements AttachableVolumePlugin
volumeAttacher, err := volume.attachablePlugin.NewAttacher()
if volumeAttacher == nil || err != nil {
return "", err
}
return volumeAttacher.GetDeviceMountPath(volume.volumeSpec)
} else if volume.deviceMounter != nil {
// for filesystem volume, we return its device mount path if the plugin implements DeviceMounter
return volume.deviceMounter.GetDeviceMountPath(volume.volumeSpec)
} else {
return "", fmt.Errorf("blockVolumeMapper or attachablePlugin required")
return "", fmt.Errorf("blockVolumeMapper or deviceMounter required")
}
}
@ -628,7 +639,7 @@ func (rc *reconciler) updateStates(volumesNeedUpdate map[v1.UniqueVolumeName]*re
}
klog.V(4).Infof("Volume: %s (pod UID %s) is marked as mounted and added into the actual state", volume.volumeName, volume.podName)
// If the volume has device to mount, we mark its device as mounted.
if volume.attachablePlugin != nil || volume.blockVolumeMapper != nil {
if volume.deviceMounter != nil || volume.blockVolumeMapper != nil {
deviceMountPath, err := getDeviceMountPath(volume)
if err != nil {
klog.Errorf("Could not find device mount path for volume %s", volume.volumeName)

View File

@ -48,7 +48,7 @@ type Interface interface {
// most notably linux bind mounts and symbolic link.
IsLikelyNotMountPoint(file string) (bool, error)
// GetMountRefs finds all mount references to the path, returns a
// list of paths. Path could be a mountpoint path, device or a normal
// list of paths. Path could be a mountpoint or a normal
// directory (for bind mount).
GetMountRefs(pathname string) ([]string, error)
}

View File

@ -238,7 +238,7 @@ func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error) {
}
// GetMountRefs finds all mount references to pathname, returns a
// list of paths. Path could be a mountpoint path, device or a normal
// list of paths. Path could be a mountpoint or a normal
// directory (for bind mount).
func (mounter *Mounter) GetMountRefs(pathname string) ([]string, error) {
pathExists, pathErr := PathExists(pathname)
@ -441,7 +441,8 @@ func parseProcMounts(content []byte) ([]MountPoint, error) {
// SearchMountPoints finds all mount references to the source, returns a list of
// mountpoints.
// This function assumes source cannot be device.
// The source can be a mount point or a normal directory (bind mount). We
// didn't support device because there is no use case by now.
// Some filesystems may share a source name, e.g. tmpfs. And for bind mounting,
// it's possible to mount a non-root path of a filesystem, so we need to use
// root path and major:minor to represent mount source uniquely.

View File

@ -191,6 +191,32 @@ func (plugin *localVolumePlugin) NewBlockVolumeUnmapper(volName string,
// TODO: check if no path and no topology constraints are ok
func (plugin *localVolumePlugin) ConstructVolumeSpec(volumeName, mountPath string) (*volume.Spec, error) {
fs := v1.PersistentVolumeFilesystem
// The main purpose of reconstructed volume is to clean unused mount points
// and directories.
// For filesystem volume with directory source, no global mount path is
// needed to clean. Empty path is ok.
// For filesystem volume with block source, we should resolve to its device
// path if global mount path exists.
var path string
mounter := plugin.host.GetMounter(plugin.GetPluginName())
refs, err := mounter.GetMountRefs(mountPath)
if err != nil {
return nil, err
}
baseMountPath := plugin.generateBlockDeviceBaseGlobalPath()
for _, ref := range refs {
if mount.PathWithinBase(ref, baseMountPath) {
// If the global mount for block device exists, the source is block
// device.
// The resolved device path may not be the exact same as path in
// local PV object if symbolic link is used. However, it's the true
// source and can be used in reconstructed volume.
path, _, err = mount.GetDeviceNameFromMount(mounter, ref)
if err != nil {
return nil, err
}
}
}
localVolume := &v1.PersistentVolume{
ObjectMeta: metav1.ObjectMeta{
Name: volumeName,
@ -198,7 +224,7 @@ func (plugin *localVolumePlugin) ConstructVolumeSpec(volumeName, mountPath strin
Spec: v1.PersistentVolumeSpec{
PersistentVolumeSource: v1.PersistentVolumeSource{
Local: &v1.LocalVolumeSource{
Path: "",
Path: path,
},
},
VolumeMode: &fs,

View File

@ -422,44 +422,97 @@ func testFSGroupMount(plug volume.VolumePlugin, pod *v1.Pod, tmpDir string, fsGr
}
func TestConstructVolumeSpec(t *testing.T) {
tmpDir, plug := getPlugin(t)
defer os.RemoveAll(tmpDir)
volPath := filepath.Join(tmpDir, testMountPath)
spec, err := plug.ConstructVolumeSpec(testPVName, volPath)
if err != nil {
t.Errorf("ConstructVolumeSpec() failed: %v", err)
}
if spec == nil {
t.Fatalf("ConstructVolumeSpec() returned nil")
tests := []struct {
name string
mountPoints []mount.MountPoint
expectedPath string
}{
{
name: "filesystem volume with directory source",
mountPoints: []mount.MountPoint{
{
Device: "/mnt/disk/ssd0",
Path: "pods/poduid/volumes/kubernetes.io~local-volume/pvA",
},
},
expectedPath: "",
},
{
name: "filesystem volume with block source",
mountPoints: []mount.MountPoint{
{
Device: "/dev/loop0",
Path: testMountPath,
},
{
Device: "/dev/loop0",
Path: testBlockFormattingToFSGlobalPath,
},
},
expectedPath: "/dev/loop0",
},
}
volName := spec.Name()
if volName != testPVName {
t.Errorf("Expected volume name %q, got %q", testPVName, volName)
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
tmpDir, err := utiltesting.MkTmpdir("localVolumeTest")
if err != nil {
t.Fatalf("can't make a temp dir: %v", err)
}
defer os.RemoveAll(tmpDir)
plug := &localVolumePlugin{
host: volumetest.NewFakeVolumeHost(tmpDir, nil, nil),
}
mounter := plug.host.GetMounter(plug.GetPluginName())
fakeMountPoints := []mount.MountPoint{}
for _, mp := range tt.mountPoints {
fakeMountPoint := mp
fakeMountPoint.Path = filepath.Join(tmpDir, mp.Path)
fakeMountPoints = append(fakeMountPoints, fakeMountPoint)
}
mounter.(*mount.FakeMounter).MountPoints = fakeMountPoints
volPath := filepath.Join(tmpDir, testMountPath)
spec, err := plug.ConstructVolumeSpec(testPVName, volPath)
if err != nil {
t.Errorf("ConstructVolumeSpec() failed: %v", err)
}
if spec == nil {
t.Fatalf("ConstructVolumeSpec() returned nil")
}
volName := spec.Name()
if volName != testPVName {
t.Errorf("Expected volume name %q, got %q", testPVName, volName)
}
if spec.Volume != nil {
t.Errorf("Volume object returned, expected nil")
}
pv := spec.PersistentVolume
if pv == nil {
t.Fatalf("PersistentVolume object nil")
}
if spec.PersistentVolume.Spec.VolumeMode == nil {
t.Fatalf("Volume mode has not been set.")
}
if *spec.PersistentVolume.Spec.VolumeMode != v1.PersistentVolumeFilesystem {
t.Errorf("Unexpected volume mode %q", *spec.PersistentVolume.Spec.VolumeMode)
}
ls := pv.Spec.PersistentVolumeSource.Local
if ls == nil {
t.Fatalf("LocalVolumeSource object nil")
}
if pv.Spec.PersistentVolumeSource.Local.Path != tt.expectedPath {
t.Fatalf("Unexpected path got %q, expected %q", pv.Spec.PersistentVolumeSource.Local.Path, tt.expectedPath)
}
})
}
if spec.Volume != nil {
t.Errorf("Volume object returned, expected nil")
}
pv := spec.PersistentVolume
if pv == nil {
t.Fatalf("PersistentVolume object nil")
}
if spec.PersistentVolume.Spec.VolumeMode == nil {
t.Fatalf("Volume mode has not been set.")
}
if *spec.PersistentVolume.Spec.VolumeMode != v1.PersistentVolumeFilesystem {
t.Errorf("Unexpected volume mode %q", *spec.PersistentVolume.Spec.VolumeMode)
}
ls := pv.Spec.PersistentVolumeSource.Local
if ls == nil {
t.Fatalf("LocalVolumeSource object nil")
}
}
func TestConstructBlockVolumeSpec(t *testing.T) {