mirror of https://github.com/k3s-io/k3s
234 lines
8.4 KiB
Go
234 lines
8.4 KiB
Go
/*
|
|
Copyright 2018 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package volumepathhandler
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"os"
|
|
"path"
|
|
"path/filepath"
|
|
|
|
"k8s.io/klog"
|
|
|
|
"k8s.io/apimachinery/pkg/types"
|
|
)
|
|
|
|
const (
|
|
losetupPath = "losetup"
|
|
ErrDeviceNotFound = "device not found"
|
|
ErrDeviceNotSupported = "device not supported"
|
|
)
|
|
|
|
// BlockVolumePathHandler defines a set of operations for handling block volume-related operations
|
|
type BlockVolumePathHandler interface {
|
|
// MapDevice creates a symbolic link to block device under specified map path
|
|
MapDevice(devicePath string, mapPath string, linkName string) error
|
|
// UnmapDevice removes a symbolic link to block device under specified map path
|
|
UnmapDevice(mapPath string, linkName string) error
|
|
// RemovePath removes a file or directory on specified map path
|
|
RemoveMapPath(mapPath string) error
|
|
// IsSymlinkExist retruns true if specified symbolic link exists
|
|
IsSymlinkExist(mapPath string) (bool, error)
|
|
// GetDeviceSymlinkRefs searches symbolic links under global map path
|
|
GetDeviceSymlinkRefs(devPath string, mapPath string) ([]string, error)
|
|
// FindGlobalMapPathUUIDFromPod finds {pod uuid} symbolic link under globalMapPath
|
|
// corresponding to map path symlink, and then return global map path with pod uuid.
|
|
FindGlobalMapPathUUIDFromPod(pluginDir, mapPath string, podUID types.UID) (string, error)
|
|
// AttachFileDevice takes a path to a regular file and makes it available as an
|
|
// attached block device.
|
|
AttachFileDevice(path string) (string, error)
|
|
// GetLoopDevice returns the full path to the loop device associated with the given path.
|
|
GetLoopDevice(path string) (string, error)
|
|
// RemoveLoopDevice removes specified loopback device
|
|
RemoveLoopDevice(device string) error
|
|
}
|
|
|
|
// NewBlockVolumePathHandler returns a new instance of BlockVolumeHandler.
|
|
func NewBlockVolumePathHandler() BlockVolumePathHandler {
|
|
var volumePathHandler VolumePathHandler
|
|
return volumePathHandler
|
|
}
|
|
|
|
// VolumePathHandler is path related operation handlers for block volume
|
|
type VolumePathHandler struct {
|
|
}
|
|
|
|
// MapDevice creates a symbolic link to block device under specified map path
|
|
func (v VolumePathHandler) MapDevice(devicePath string, mapPath string, linkName string) error {
|
|
// Example of global map path:
|
|
// globalMapPath/linkName: plugins/kubernetes.io/{PluginName}/{DefaultKubeletVolumeDevicesDirName}/{volumePluginDependentPath}/{podUid}
|
|
// linkName: {podUid}
|
|
//
|
|
// Example of pod device map path:
|
|
// podDeviceMapPath/linkName: pods/{podUid}/{DefaultKubeletVolumeDevicesDirName}/{escapeQualifiedPluginName}/{volumeName}
|
|
// linkName: {volumeName}
|
|
if len(devicePath) == 0 {
|
|
return fmt.Errorf("Failed to map device to map path. devicePath is empty")
|
|
}
|
|
if len(mapPath) == 0 {
|
|
return fmt.Errorf("Failed to map device to map path. mapPath is empty")
|
|
}
|
|
if !filepath.IsAbs(mapPath) {
|
|
return fmt.Errorf("The map path should be absolute: map path: %s", mapPath)
|
|
}
|
|
klog.V(5).Infof("MapDevice: devicePath %s", devicePath)
|
|
klog.V(5).Infof("MapDevice: mapPath %s", mapPath)
|
|
klog.V(5).Infof("MapDevice: linkName %s", linkName)
|
|
|
|
// Check and create mapPath
|
|
_, err := os.Stat(mapPath)
|
|
if err != nil && !os.IsNotExist(err) {
|
|
klog.Errorf("cannot validate map path: %s", mapPath)
|
|
return err
|
|
}
|
|
if err = os.MkdirAll(mapPath, 0750); err != nil {
|
|
return fmt.Errorf("Failed to mkdir %s, error %v", mapPath, err)
|
|
}
|
|
// Remove old symbolic link(or file) then create new one.
|
|
// This should be done because current symbolic link is
|
|
// stale across node reboot.
|
|
linkPath := path.Join(mapPath, string(linkName))
|
|
if err = os.Remove(linkPath); err != nil && !os.IsNotExist(err) {
|
|
return err
|
|
}
|
|
err = os.Symlink(devicePath, linkPath)
|
|
return err
|
|
}
|
|
|
|
// UnmapDevice removes a symbolic link associated to block device under specified map path
|
|
func (v VolumePathHandler) UnmapDevice(mapPath string, linkName string) error {
|
|
if len(mapPath) == 0 {
|
|
return fmt.Errorf("Failed to unmap device from map path. mapPath is empty")
|
|
}
|
|
klog.V(5).Infof("UnmapDevice: mapPath %s", mapPath)
|
|
klog.V(5).Infof("UnmapDevice: linkName %s", linkName)
|
|
|
|
// Check symbolic link exists
|
|
linkPath := path.Join(mapPath, string(linkName))
|
|
if islinkExist, checkErr := v.IsSymlinkExist(linkPath); checkErr != nil {
|
|
return checkErr
|
|
} else if !islinkExist {
|
|
klog.Warningf("Warning: Unmap skipped because symlink does not exist on the path: %v", linkPath)
|
|
return nil
|
|
}
|
|
err := os.Remove(linkPath)
|
|
return err
|
|
}
|
|
|
|
// RemoveMapPath removes a file or directory on specified map path
|
|
func (v VolumePathHandler) RemoveMapPath(mapPath string) error {
|
|
if len(mapPath) == 0 {
|
|
return fmt.Errorf("Failed to remove map path. mapPath is empty")
|
|
}
|
|
klog.V(5).Infof("RemoveMapPath: mapPath %s", mapPath)
|
|
err := os.RemoveAll(mapPath)
|
|
if err != nil && !os.IsNotExist(err) {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// IsSymlinkExist returns true if specified file exists and the type is symbolik link.
|
|
// If file doesn't exist, or file exists but not symbolick link, return false with no error.
|
|
// On other cases, return false with error from Lstat().
|
|
func (v VolumePathHandler) IsSymlinkExist(mapPath string) (bool, error) {
|
|
fi, err := os.Lstat(mapPath)
|
|
if err == nil {
|
|
// If file exits and it's symbolick link, return true and no error
|
|
if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
|
|
return true, nil
|
|
}
|
|
// If file exits but it's not symbolick link, return fale and no error
|
|
return false, nil
|
|
}
|
|
// If file doesn't exist, return false and no error
|
|
if os.IsNotExist(err) {
|
|
return false, nil
|
|
}
|
|
// Return error from Lstat()
|
|
return false, err
|
|
}
|
|
|
|
// GetDeviceSymlinkRefs searches symbolic links under global map path
|
|
func (v VolumePathHandler) GetDeviceSymlinkRefs(devPath string, mapPath string) ([]string, error) {
|
|
var refs []string
|
|
files, err := ioutil.ReadDir(mapPath)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("Directory cannot read %v", err)
|
|
}
|
|
for _, file := range files {
|
|
if file.Mode()&os.ModeSymlink != os.ModeSymlink {
|
|
continue
|
|
}
|
|
filename := file.Name()
|
|
filepath, err := os.Readlink(path.Join(mapPath, filename))
|
|
if err != nil {
|
|
return nil, fmt.Errorf("Symbolic link cannot be retrieved %v", err)
|
|
}
|
|
klog.V(5).Infof("GetDeviceSymlinkRefs: filepath: %v, devPath: %v", filepath, devPath)
|
|
if filepath == devPath {
|
|
refs = append(refs, path.Join(mapPath, filename))
|
|
}
|
|
}
|
|
klog.V(5).Infof("GetDeviceSymlinkRefs: refs %v", refs)
|
|
return refs, nil
|
|
}
|
|
|
|
// FindGlobalMapPathUUIDFromPod finds {pod uuid} symbolic link under globalMapPath
|
|
// corresponding to map path symlink, and then return global map path with pod uuid.
|
|
// ex. mapPath symlink: pods/{podUid}}/{DefaultKubeletVolumeDevicesDirName}/{escapeQualifiedPluginName}/{volumeName} -> /dev/sdX
|
|
// globalMapPath/{pod uuid}: plugins/kubernetes.io/{PluginName}/{DefaultKubeletVolumeDevicesDirName}/{volumePluginDependentPath}/{pod uuid} -> /dev/sdX
|
|
func (v VolumePathHandler) FindGlobalMapPathUUIDFromPod(pluginDir, mapPath string, podUID types.UID) (string, error) {
|
|
var globalMapPathUUID string
|
|
// Find symbolic link named pod uuid under plugin dir
|
|
err := filepath.Walk(pluginDir, func(path string, fi os.FileInfo, err error) error {
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if (fi.Mode()&os.ModeSymlink == os.ModeSymlink) && (fi.Name() == string(podUID)) {
|
|
klog.V(5).Infof("FindGlobalMapPathFromPod: path %s, mapPath %s", path, mapPath)
|
|
if res, err := compareSymlinks(path, mapPath); err == nil && res {
|
|
globalMapPathUUID = path
|
|
}
|
|
}
|
|
return nil
|
|
})
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
klog.V(5).Infof("FindGlobalMapPathFromPod: globalMapPathUUID %s", globalMapPathUUID)
|
|
// Return path contains global map path + {pod uuid}
|
|
return globalMapPathUUID, nil
|
|
}
|
|
|
|
func compareSymlinks(global, pod string) (bool, error) {
|
|
devGlobal, err := os.Readlink(global)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
devPod, err := os.Readlink(pod)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
klog.V(5).Infof("CompareSymlinks: devGloBal %s, devPod %s", devGlobal, devPod)
|
|
if devGlobal == devPod {
|
|
return true, nil
|
|
}
|
|
return false, nil
|
|
}
|