mirror of https://github.com/docker/docs.git
149 lines
3.3 KiB
Go
149 lines
3.3 KiB
Go
// +build linux
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package devmapper
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import (
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"fmt"
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"io/ioutil"
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"os"
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"path"
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"github.com/docker/docker/daemon/graphdriver"
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"github.com/docker/docker/pkg/log"
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"github.com/docker/docker/pkg/mount"
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"github.com/docker/docker/pkg/units"
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)
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func init() {
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graphdriver.Register("devicemapper", Init)
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}
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// Placeholder interfaces, to be replaced
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// at integration.
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// End of placeholder interfaces.
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type Driver struct {
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*DeviceSet
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home string
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}
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func Init(home string, options []string) (graphdriver.Driver, error) {
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deviceSet, err := NewDeviceSet(home, true, options)
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if err != nil {
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return nil, err
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}
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if err := graphdriver.MakePrivate(home); err != nil {
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return nil, err
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}
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d := &Driver{
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DeviceSet: deviceSet,
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home: home,
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}
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return d, nil
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}
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func (d *Driver) String() string {
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return "devicemapper"
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}
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func (d *Driver) Status() [][2]string {
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s := d.DeviceSet.Status()
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status := [][2]string{
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{"Pool Name", s.PoolName},
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{"Pool Blocksize", fmt.Sprintf("%s", units.HumanSize(int64(s.SectorSize)))},
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{"Data file", s.DataLoopback},
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{"Metadata file", s.MetadataLoopback},
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{"Data Space Used", fmt.Sprintf("%s", units.HumanSize(int64(s.Data.Used)))},
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{"Data Space Total", fmt.Sprintf("%s", units.HumanSize(int64(s.Data.Total)))},
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{"Metadata Space Used", fmt.Sprintf("%s", units.HumanSize(int64(s.Metadata.Used)))},
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{"Metadata Space Total", fmt.Sprintf("%s", units.HumanSize(int64(s.Metadata.Total)))},
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}
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return status
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}
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func (d *Driver) Cleanup() error {
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err := d.DeviceSet.Shutdown()
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if err2 := mount.Unmount(d.home); err == nil {
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err = err2
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}
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return err
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}
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func (d *Driver) Create(id, parent string) error {
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if err := d.DeviceSet.AddDevice(id, parent); err != nil {
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return err
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}
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return nil
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}
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func (d *Driver) Remove(id string) error {
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if !d.DeviceSet.HasDevice(id) {
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// Consider removing a non-existing device a no-op
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// This is useful to be able to progress on container removal
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// if the underlying device has gone away due to earlier errors
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return nil
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}
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// This assumes the device has been properly Get/Put:ed and thus is unmounted
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if err := d.DeviceSet.DeleteDevice(id); err != nil {
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return err
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}
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mp := path.Join(d.home, "mnt", id)
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if err := os.RemoveAll(mp); err != nil && !os.IsNotExist(err) {
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return err
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}
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return nil
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}
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func (d *Driver) Get(id, mountLabel string) (string, error) {
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mp := path.Join(d.home, "mnt", id)
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// Create the target directories if they don't exist
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if err := os.MkdirAll(mp, 0755); err != nil && !os.IsExist(err) {
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return "", err
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}
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// Mount the device
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if err := d.DeviceSet.MountDevice(id, mp, mountLabel); err != nil {
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return "", err
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}
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rootFs := path.Join(mp, "rootfs")
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if err := os.MkdirAll(rootFs, 0755); err != nil && !os.IsExist(err) {
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d.DeviceSet.UnmountDevice(id)
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return "", err
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}
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idFile := path.Join(mp, "id")
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if _, err := os.Stat(idFile); err != nil && os.IsNotExist(err) {
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// Create an "id" file with the container/image id in it to help reconscruct this in case
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// of later problems
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if err := ioutil.WriteFile(idFile, []byte(id), 0600); err != nil {
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d.DeviceSet.UnmountDevice(id)
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return "", err
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}
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}
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return rootFs, nil
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}
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func (d *Driver) Put(id string) {
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if err := d.DeviceSet.UnmountDevice(id); err != nil {
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log.Errorf("Warning: error unmounting device %s: %s", id, err)
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}
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}
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func (d *Driver) Exists(id string) bool {
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return d.DeviceSet.HasDevice(id)
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}
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