volume/mounts/linux_parser.go
package mounts // import "github.com/docker/docker/volume/mounts"
import (
"errors"
"fmt"
"path"
"path/filepath"
"strings"
"github.com/docker/docker/api/types/mount"
"github.com/docker/docker/volume"
)
// NewLinuxParser creates a parser with Linux semantics.
func NewLinuxParser() Parser {
return &linuxParser{
fi: defaultFileInfoProvider{},
}
}
type linuxParser struct {
fi fileInfoProvider
}
func linuxValidateNotRoot(p string) error {
p = path.Clean(strings.ReplaceAll(p, `\`, `/`))
if p == "/" {
return ErrVolumeTargetIsRoot
}
return nil
}
func linuxValidateAbsolute(p string) error {
p = strings.ReplaceAll(p, `\`, `/`)
if path.IsAbs(p) {
return nil
}
return fmt.Errorf("invalid mount path: '%s' mount path must be absolute", p)
}
func (p *linuxParser) ValidateMountConfig(mnt *mount.Mount) error {
// there was something looking like a bug in existing codebase:
// - validateMountConfig on linux was called with options skipping bind source existence when calling ParseMountRaw
// - but not when calling ParseMountSpec directly... nor when the unit test called it directly
return p.validateMountConfigImpl(mnt, true)
}
func (p *linuxParser) validateMountConfigImpl(mnt *mount.Mount, validateBindSourceExists bool) error {
if len(mnt.Target) == 0 {
return &errMountConfig{mnt, errMissingField("Target")}
}
if err := linuxValidateNotRoot(mnt.Target); err != nil {
return &errMountConfig{mnt, err}
}
if err := linuxValidateAbsolute(mnt.Target); err != nil {
return &errMountConfig{mnt, err}
}
switch mnt.Type {
case mount.TypeBind:
if len(mnt.Source) == 0 {
return &errMountConfig{mnt, errMissingField("Source")}
}
// Don't error out just because the propagation mode is not supported on the platform
if opts := mnt.BindOptions; opts != nil {
if len(opts.Propagation) > 0 && len(linuxPropagationModes) > 0 {
if _, ok := linuxPropagationModes[opts.Propagation]; !ok {
return &errMountConfig{mnt, fmt.Errorf("invalid propagation mode: %s", opts.Propagation)}
}
}
}
if mnt.VolumeOptions != nil {
return &errMountConfig{mnt, errExtraField("VolumeOptions")}
}
if err := linuxValidateAbsolute(mnt.Source); err != nil {
return &errMountConfig{mnt, err}
}
if validateBindSourceExists {
exists, _, err := p.fi.fileInfo(mnt.Source)
if err != nil {
return &errMountConfig{mnt, err}
}
createMountpoint := mnt.BindOptions != nil && mnt.BindOptions.CreateMountpoint
if !exists && !createMountpoint {
return &errMountConfig{mnt, errBindSourceDoesNotExist(mnt.Source)}
}
}
case mount.TypeVolume:
if mnt.BindOptions != nil {
return &errMountConfig{mnt, errExtraField("BindOptions")}
}
anonymousVolume := len(mnt.Source) == 0
if mnt.VolumeOptions != nil && mnt.VolumeOptions.Subpath != "" {
if anonymousVolume {
return &errMountConfig{mnt, errAnonymousVolumeWithSubpath}
}
if !filepath.IsLocal(mnt.VolumeOptions.Subpath) {
return &errMountConfig{mnt, errInvalidSubpath}
}
}
if mnt.ReadOnly && anonymousVolume {
return &errMountConfig{mnt, fmt.Errorf("must not set ReadOnly mode when using anonymous volumes")}
}
case mount.TypeTmpfs:
if mnt.BindOptions != nil {
return &errMountConfig{mnt, errExtraField("BindOptions")}
}
if len(mnt.Source) != 0 {
return &errMountConfig{mnt, errExtraField("Source")}
}
if _, err := p.ConvertTmpfsOptions(mnt.TmpfsOptions, mnt.ReadOnly); err != nil {
return &errMountConfig{mnt, err}
}
default:
return &errMountConfig{mnt, errors.New("mount type unknown")}
}
return nil
}
// label modes
var linuxLabelModes = map[string]bool{
"Z": true,
"z": true,
}
// consistency modes
var linuxConsistencyModes = map[mount.Consistency]bool{
mount.ConsistencyFull: true,
mount.ConsistencyCached: true,
mount.ConsistencyDelegated: true,
}
var linuxPropagationModes = map[mount.Propagation]bool{
mount.PropagationPrivate: true,
mount.PropagationRPrivate: true,
mount.PropagationSlave: true,
mount.PropagationRSlave: true,
mount.PropagationShared: true,
mount.PropagationRShared: true,
}
const linuxDefaultPropagationMode = mount.PropagationRPrivate
func linuxGetPropagation(mode string) mount.Propagation {
for _, o := range strings.Split(mode, ",") {
prop := mount.Propagation(o)
if linuxPropagationModes[prop] {
return prop
}
}
return linuxDefaultPropagationMode
}
func linuxHasPropagation(mode string) bool {
for _, o := range strings.Split(mode, ",") {
if linuxPropagationModes[mount.Propagation(o)] {
return true
}
}
return false
}
func linuxValidMountMode(mode string) bool {
if mode == "" {
return true
}
rwModeCount := 0
labelModeCount := 0
propagationModeCount := 0
copyModeCount := 0
consistencyModeCount := 0
for _, o := range strings.Split(mode, ",") {
switch {
case rwModes[o]:
rwModeCount++
case linuxLabelModes[o]:
labelModeCount++
case linuxPropagationModes[mount.Propagation(o)]:
propagationModeCount++
case copyModeExists(o):
copyModeCount++
case linuxConsistencyModes[mount.Consistency(o)]:
consistencyModeCount++
default:
return false
}
}
// Only one string for each mode is allowed.
if rwModeCount > 1 || labelModeCount > 1 || propagationModeCount > 1 || copyModeCount > 1 || consistencyModeCount > 1 {
return false
}
return true
}
var validTmpfsOptions = map[string]bool{
"exec": true,
"noexec": true,
}
func validateTmpfsOptions(rawOptions [][]string) ([]string, error) {
var options []string
for _, opt := range rawOptions {
if len(opt) < 1 || len(opt) > 2 {
return nil, errors.New("invalid option array length")
}
if _, ok := validTmpfsOptions[opt[0]]; !ok {
return nil, errors.New("invalid option: " + opt[0])
}
if len(opt) == 1 {
options = append(options, opt[0])
} else {
options = append(options, fmt.Sprintf("%s=%s", opt[0], opt[1]))
}
}
return options, nil
}
func (p *linuxParser) ReadWrite(mode string) bool {
if !linuxValidMountMode(mode) {
return false
}
for _, o := range strings.Split(mode, ",") {
if o == "ro" {
return false
}
}
return true
}
func (p *linuxParser) ParseMountRaw(raw, volumeDriver string) (*MountPoint, error) {
arr := strings.SplitN(raw, ":", 4)
if arr[0] == "" {
return nil, errInvalidSpec(raw)
}
var spec mount.Mount
var mode string
switch len(arr) {
case 1:
// Just a destination path in the container
spec.Target = arr[0]
case 2:
if linuxValidMountMode(arr[1]) {
// Destination + Mode is not a valid volume - volumes
// cannot include a mode. e.g. /foo:rw
return nil, errInvalidSpec(raw)
}
// Host Source Path or Name + Destination
spec.Source = arr[0]
spec.Target = arr[1]
case 3:
// HostSourcePath+DestinationPath+Mode
spec.Source = arr[0]
spec.Target = arr[1]
mode = arr[2]
default:
return nil, errInvalidSpec(raw)
}
if !linuxValidMountMode(mode) {
return nil, errInvalidMode(mode)
}
if path.IsAbs(spec.Source) {
spec.Type = mount.TypeBind
} else {
spec.Type = mount.TypeVolume
}
spec.ReadOnly = !p.ReadWrite(mode)
// cannot assume that if a volume driver is passed in that we should set it
if volumeDriver != "" && spec.Type == mount.TypeVolume {
spec.VolumeOptions = &mount.VolumeOptions{
DriverConfig: &mount.Driver{Name: volumeDriver},
}
}
if copyData, isSet := getCopyMode(mode, p.DefaultCopyMode()); isSet {
if spec.VolumeOptions == nil {
spec.VolumeOptions = &mount.VolumeOptions{}
}
spec.VolumeOptions.NoCopy = !copyData
}
if linuxHasPropagation(mode) {
spec.BindOptions = &mount.BindOptions{
Propagation: linuxGetPropagation(mode),
}
}
mp, err := p.parseMountSpec(spec, false)
if mp != nil {
mp.Mode = mode
}
if err != nil {
err = fmt.Errorf("%v: %v", errInvalidSpec(raw), err)
}
return mp, err
}
func (p *linuxParser) ParseMountSpec(cfg mount.Mount) (*MountPoint, error) {
return p.parseMountSpec(cfg, true)
}
func (p *linuxParser) parseMountSpec(cfg mount.Mount, validateBindSourceExists bool) (*MountPoint, error) {
if err := p.validateMountConfigImpl(&cfg, validateBindSourceExists); err != nil {
return nil, err
}
mp := &MountPoint{
RW: !cfg.ReadOnly,
Destination: path.Clean(filepath.ToSlash(cfg.Target)),
Type: cfg.Type,
Spec: cfg,
}
switch cfg.Type {
case mount.TypeVolume:
if cfg.Source != "" {
// non-anonymous volume
mp.Name = cfg.Source
}
mp.CopyData = p.DefaultCopyMode()
if cfg.VolumeOptions != nil {
if cfg.VolumeOptions.DriverConfig != nil {
mp.Driver = cfg.VolumeOptions.DriverConfig.Name
}
if cfg.VolumeOptions.NoCopy {
mp.CopyData = false
}
}
case mount.TypeBind:
mp.Source = path.Clean(filepath.ToSlash(cfg.Source))
if cfg.BindOptions != nil && len(cfg.BindOptions.Propagation) > 0 {
mp.Propagation = cfg.BindOptions.Propagation
} else {
// If user did not specify a propagation mode, get
// default propagation mode.
mp.Propagation = linuxDefaultPropagationMode
}
case mount.TypeTmpfs:
// NOP
}
return mp, nil
}
func (p *linuxParser) ParseVolumesFrom(spec string) (string, string, error) {
if len(spec) == 0 {
return "", "", fmt.Errorf("volumes-from specification cannot be an empty string")
}
id, mode, _ := strings.Cut(spec, ":")
if mode == "" {
return id, "rw", nil
}
if !linuxValidMountMode(mode) {
return "", "", errInvalidMode(mode)
}
// For now don't allow propagation properties while importing
// volumes from data container. These volumes will inherit
// the same propagation property as of the original volume
// in data container. This probably can be relaxed in future.
if linuxHasPropagation(mode) {
return "", "", errInvalidMode(mode)
}
// Do not allow copy modes on volumes-from
if _, isSet := getCopyMode(mode, p.DefaultCopyMode()); isSet {
return "", "", errInvalidMode(mode)
}
return id, mode, nil
}
func (p *linuxParser) DefaultPropagationMode() mount.Propagation {
return linuxDefaultPropagationMode
}
func (p *linuxParser) ConvertTmpfsOptions(opt *mount.TmpfsOptions, readOnly bool) (string, error) {
var rawOpts []string
if readOnly {
rawOpts = append(rawOpts, "ro")
}
if opt != nil && opt.Mode != 0 {
rawOpts = append(rawOpts, fmt.Sprintf("mode=%o", opt.Mode))
}
if opt != nil && opt.SizeBytes != 0 {
// calculate suffix here, making this linux specific, but that is
// okay, since API is that way anyways.
// we do this by finding the suffix that divides evenly into the
// value, returning the value itself, with no suffix, if it fails.
//
// For the most part, we don't enforce any semantic to this values.
// The operating system will usually align this and enforce minimum
// and maximums.
var (
size = opt.SizeBytes
suffix string
)
for _, r := range []struct {
suffix string
divisor int64
}{
{"g", 1 << 30},
{"m", 1 << 20},
{"k", 1 << 10},
} {
if size%r.divisor == 0 {
size = size / r.divisor
suffix = r.suffix
break
}
}
rawOpts = append(rawOpts, fmt.Sprintf("size=%d%s", size, suffix))
}
if opt != nil && len(opt.Options) > 0 {
tmpfsOpts, err := validateTmpfsOptions(opt.Options)
if err != nil {
return "", err
}
rawOpts = append(rawOpts, tmpfsOpts...)
}
return strings.Join(rawOpts, ","), nil
}
func (p *linuxParser) DefaultCopyMode() bool {
return true
}
func (p *linuxParser) ValidateVolumeName(name string) error {
return nil
}
func (p *linuxParser) IsBackwardCompatible(m *MountPoint) bool {
return len(m.Source) > 0 || m.Driver == volume.DefaultDriverName
}
func (p *linuxParser) ValidateTmpfsMountDestination(dest string) error {
if err := linuxValidateNotRoot(dest); err != nil {
return err
}
return linuxValidateAbsolute(dest)
}