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moby--moby/daemon/volumes.go
Ben Firshman f0d55cd081
Rename Remote API to Engine API
Implementation of https://github.com/docker/docker/issues/28319

Signed-off-by: Ben Firshman <ben@firshman.co.uk>
2016-11-22 12:49:38 +00:00

303 lines
8.1 KiB
Go

package daemon
import (
"errors"
"fmt"
"os"
"path/filepath"
"strings"
"github.com/Sirupsen/logrus"
dockererrors "github.com/docker/docker/api/errors"
"github.com/docker/docker/api/types"
containertypes "github.com/docker/docker/api/types/container"
mounttypes "github.com/docker/docker/api/types/mount"
"github.com/docker/docker/container"
"github.com/docker/docker/volume"
"github.com/docker/docker/volume/drivers"
"github.com/opencontainers/runc/libcontainer/label"
)
var (
// ErrVolumeReadonly is used to signal an error when trying to copy data into
// a volume mount that is not writable.
ErrVolumeReadonly = errors.New("mounted volume is marked read-only")
)
type mounts []container.Mount
// volumeToAPIType converts a volume.Volume to the type used by the Engine API
func volumeToAPIType(v volume.Volume) *types.Volume {
tv := &types.Volume{
Name: v.Name(),
Driver: v.DriverName(),
}
if v, ok := v.(volume.DetailedVolume); ok {
tv.Labels = v.Labels()
tv.Options = v.Options()
tv.Scope = v.Scope()
}
return tv
}
// Len returns the number of mounts. Used in sorting.
func (m mounts) Len() int {
return len(m)
}
// Less returns true if the number of parts (a/b/c would be 3 parts) in the
// mount indexed by parameter 1 is less than that of the mount indexed by
// parameter 2. Used in sorting.
func (m mounts) Less(i, j int) bool {
return m.parts(i) < m.parts(j)
}
// Swap swaps two items in an array of mounts. Used in sorting
func (m mounts) Swap(i, j int) {
m[i], m[j] = m[j], m[i]
}
// parts returns the number of parts in the destination of a mount. Used in sorting.
func (m mounts) parts(i int) int {
return strings.Count(filepath.Clean(m[i].Destination), string(os.PathSeparator))
}
// registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
// It follows the next sequence to decide what to mount in each final destination:
//
// 1. Select the previously configured mount points for the containers, if any.
// 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination.
// 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations.
// 4. Cleanup old volumes that are about to be reassigned.
func (daemon *Daemon) registerMountPoints(container *container.Container, hostConfig *containertypes.HostConfig) (retErr error) {
binds := map[string]bool{}
mountPoints := map[string]*volume.MountPoint{}
defer func() {
// clean up the container mountpoints once return with error
if retErr != nil {
for _, m := range mountPoints {
if m.Volume == nil {
continue
}
daemon.volumes.Dereference(m.Volume, container.ID)
}
}
}()
// 1. Read already configured mount points.
for destination, point := range container.MountPoints {
mountPoints[destination] = point
}
// 2. Read volumes from other containers.
for _, v := range hostConfig.VolumesFrom {
containerID, mode, err := volume.ParseVolumesFrom(v)
if err != nil {
return err
}
c, err := daemon.GetContainer(containerID)
if err != nil {
return err
}
for _, m := range c.MountPoints {
cp := &volume.MountPoint{
Name: m.Name,
Source: m.Source,
RW: m.RW && volume.ReadWrite(mode),
Driver: m.Driver,
Destination: m.Destination,
Propagation: m.Propagation,
Spec: m.Spec,
CopyData: false,
}
if len(cp.Source) == 0 {
v, err := daemon.volumes.GetWithRef(cp.Name, cp.Driver, container.ID)
if err != nil {
return err
}
cp.Volume = v
}
mountPoints[cp.Destination] = cp
}
}
// 3. Read bind mounts
for _, b := range hostConfig.Binds {
bind, err := volume.ParseMountRaw(b, hostConfig.VolumeDriver)
if err != nil {
return err
}
// #10618
_, tmpfsExists := hostConfig.Tmpfs[bind.Destination]
if binds[bind.Destination] || tmpfsExists {
return fmt.Errorf("Duplicate mount point '%s'", bind.Destination)
}
if bind.Type == mounttypes.TypeVolume {
// create the volume
v, err := daemon.volumes.CreateWithRef(bind.Name, bind.Driver, container.ID, nil, nil)
if err != nil {
return err
}
bind.Volume = v
bind.Source = v.Path()
// bind.Name is an already existing volume, we need to use that here
bind.Driver = v.DriverName()
if bind.Driver == volume.DefaultDriverName {
setBindModeIfNull(bind)
}
}
binds[bind.Destination] = true
mountPoints[bind.Destination] = bind
}
for _, cfg := range hostConfig.Mounts {
mp, err := volume.ParseMountSpec(cfg)
if err != nil {
return dockererrors.NewBadRequestError(err)
}
if binds[mp.Destination] {
return fmt.Errorf("Duplicate mount point '%s'", cfg.Target)
}
if mp.Type == mounttypes.TypeVolume {
var v volume.Volume
if cfg.VolumeOptions != nil {
var driverOpts map[string]string
if cfg.VolumeOptions.DriverConfig != nil {
driverOpts = cfg.VolumeOptions.DriverConfig.Options
}
v, err = daemon.volumes.CreateWithRef(mp.Name, mp.Driver, container.ID, driverOpts, cfg.VolumeOptions.Labels)
} else {
v, err = daemon.volumes.CreateWithRef(mp.Name, mp.Driver, container.ID, nil, nil)
}
if err != nil {
return err
}
if err := label.Relabel(mp.Source, container.MountLabel, false); err != nil {
return err
}
mp.Volume = v
mp.Name = v.Name()
mp.Driver = v.DriverName()
// only use the cached path here since getting the path is not necessary right now and calling `Path()` may be slow
if cv, ok := v.(interface {
CachedPath() string
}); ok {
mp.Source = cv.CachedPath()
}
}
binds[mp.Destination] = true
mountPoints[mp.Destination] = mp
}
container.Lock()
// 4. Cleanup old volumes that are about to be reassigned.
for _, m := range mountPoints {
if m.BackwardsCompatible() {
if mp, exists := container.MountPoints[m.Destination]; exists && mp.Volume != nil {
daemon.volumes.Dereference(mp.Volume, container.ID)
}
}
}
container.MountPoints = mountPoints
container.Unlock()
return nil
}
// lazyInitializeVolume initializes a mountpoint's volume if needed.
// This happens after a daemon restart.
func (daemon *Daemon) lazyInitializeVolume(containerID string, m *volume.MountPoint) error {
if len(m.Driver) > 0 && m.Volume == nil {
v, err := daemon.volumes.GetWithRef(m.Name, m.Driver, containerID)
if err != nil {
return err
}
m.Volume = v
}
return nil
}
func backportMountSpec(container *container.Container) error {
for target, m := range container.MountPoints {
if m.Spec.Type != "" {
// if type is set on even one mount, no need to migrate
return nil
}
if m.Name != "" {
m.Type = mounttypes.TypeVolume
m.Spec.Type = mounttypes.TypeVolume
// make sure this is not an anyonmous volume before setting the spec source
if _, exists := container.Config.Volumes[target]; !exists {
m.Spec.Source = m.Name
}
if container.HostConfig.VolumeDriver != "" {
m.Spec.VolumeOptions = &mounttypes.VolumeOptions{
DriverConfig: &mounttypes.Driver{Name: container.HostConfig.VolumeDriver},
}
}
if strings.Contains(m.Mode, "nocopy") {
if m.Spec.VolumeOptions == nil {
m.Spec.VolumeOptions = &mounttypes.VolumeOptions{}
}
m.Spec.VolumeOptions.NoCopy = true
}
} else {
m.Type = mounttypes.TypeBind
m.Spec.Type = mounttypes.TypeBind
m.Spec.Source = m.Source
if m.Propagation != "" {
m.Spec.BindOptions = &mounttypes.BindOptions{
Propagation: m.Propagation,
}
}
}
m.Spec.Target = m.Destination
if !m.RW {
m.Spec.ReadOnly = true
}
}
return container.ToDiskLocking()
}
func (daemon *Daemon) traverseLocalVolumes(fn func(volume.Volume) error) error {
localVolumeDriver, err := volumedrivers.GetDriver(volume.DefaultDriverName)
if err != nil {
return fmt.Errorf("can't retrieve local volume driver: %v", err)
}
vols, err := localVolumeDriver.List()
if err != nil {
return fmt.Errorf("can't retrieve local volumes: %v", err)
}
for _, v := range vols {
name := v.Name()
_, err := daemon.volumes.Get(name)
if err != nil {
logrus.Warnf("failed to retrieve volume %s from store: %v", name, err)
}
err = fn(v)
if err != nil {
return err
}
}
return nil
}