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Add user namespace (mapping) support to the Docker engine

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Adds support for the daemon to handle user namespace maps as a
per-daemon setting.

Support for handling uid/gid mapping is added to the builder,
archive/unarchive packages and functions, all graphdrivers (except
Windows), and the test suite is updated to handle user namespace daemon
rootgraph changes.

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
This commit is contained in:
Phil Estes 2015-10-08 11:51:41 -04:00
parent 5e8012caca
commit e118299052
14 changed files with 262 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

104
archive/archive.go
View file

@ -19,6 +19,7 @@ import (
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/fileutils"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/pools"
"github.com/docker/docker/pkg/promise"
"github.com/docker/docker/pkg/system"
@ -41,6 +42,8 @@ type (
ExcludePatterns []string
Compression Compression
NoLchown bool
UIDMaps []idtools.IDMap
GIDMaps []idtools.IDMap
ChownOpts *TarChownOptions
IncludeSourceDir bool
// When unpacking, specifies whether overwriting a directory with a
@ -52,9 +55,13 @@ type (
}
// Archiver allows the reuse of most utility functions of this package
// with a pluggable Untar function.
// with a pluggable Untar function. Also, to facilitate the passing of
// specific id mappings for untar, an archiver can be created with maps
// which will then be passed to Untar operations
Archiver struct {
Untar func(io.Reader, string, *TarOptions) error
Untar func(io.Reader, string, *TarOptions) error
UIDMaps []idtools.IDMap
GIDMaps []idtools.IDMap
}
// breakoutError is used to differentiate errors related to breaking out
@ -66,7 +73,7 @@ type (
var (
// ErrNotImplemented is the error message of function not implemented.
ErrNotImplemented = errors.New("Function not implemented")
defaultArchiver = &Archiver{Untar}
defaultArchiver = &Archiver{Untar: Untar, UIDMaps: nil, GIDMaps: nil}
)
const (
@ -194,6 +201,8 @@ type tarAppender struct {
// for hardlink mapping
SeenFiles map[uint64]string
UIDMaps []idtools.IDMap
GIDMaps []idtools.IDMap
}
// canonicalTarName provides a platform-independent and consistent posix-style
@ -261,6 +270,25 @@ func (ta *tarAppender) addTarFile(path, name string) error {
hdr.Xattrs["security.capability"] = string(capability)
}
//handle re-mapping container ID mappings back to host ID mappings before
//writing tar headers/files
if ta.UIDMaps != nil || ta.GIDMaps != nil {
uid, gid, err := getFileUIDGID(fi.Sys())
if err != nil {
return err
}
xUID, err := idtools.ToContainer(uid, ta.UIDMaps)
if err != nil {
return err
}
xGID, err := idtools.ToContainer(gid, ta.GIDMaps)
if err != nil {
return err
}
hdr.Uid = xUID
hdr.Gid = xGID
}
if err := ta.TarWriter.WriteHeader(hdr); err != nil {
return err
}
@ -427,6 +455,8 @@ func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error)
TarWriter: tar.NewWriter(compressWriter),
Buffer: pools.BufioWriter32KPool.Get(nil),
SeenFiles: make(map[uint64]string),
UIDMaps: options.UIDMaps,
GIDMaps: options.GIDMaps,
}
defer func() {
@ -554,6 +584,10 @@ func Unpack(decompressedArchive io.Reader, dest string, options *TarOptions) err
defer pools.BufioReader32KPool.Put(trBuf)
var dirs []*tar.Header
remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps)
if err != nil {
return err
}
// Iterate through the files in the archive.
loop:
@ -631,6 +665,28 @@ loop:
}
trBuf.Reset(tr)
// if the options contain a uid & gid maps, convert header uid/gid
// entries using the maps such that lchown sets the proper mapped
// uid/gid after writing the file. We only perform this mapping if
// the file isn't already owned by the remapped root UID or GID, as
// that specific uid/gid has no mapping from container -> host, and
// those files already have the proper ownership for inside the
// container.
if hdr.Uid != remappedRootUID {
xUID, err := idtools.ToHost(hdr.Uid, options.UIDMaps)
if err != nil {
return err
}
hdr.Uid = xUID
}
if hdr.Gid != remappedRootGID {
xGID, err := idtools.ToHost(hdr.Gid, options.GIDMaps)
if err != nil {
return err
}
hdr.Gid = xGID
}
if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown, options.ChownOpts); err != nil {
return err
}
@ -703,7 +759,15 @@ func (archiver *Archiver) TarUntar(src, dst string) error {
return err
}
defer archive.Close()
return archiver.Untar(archive, dst, nil)
var options *TarOptions
if archiver.UIDMaps != nil || archiver.GIDMaps != nil {
options = &TarOptions{
UIDMaps: archiver.UIDMaps,
GIDMaps: archiver.GIDMaps,
}
}
return archiver.Untar(archive, dst, options)
}
// TarUntar is a convenience function which calls Tar and Untar, with the output of one piped into the other.
@ -719,7 +783,14 @@ func (archiver *Archiver) UntarPath(src, dst string) error {
return err
}
defer archive.Close()
if err := archiver.Untar(archive, dst, nil); err != nil {
var options *TarOptions
if archiver.UIDMaps != nil || archiver.GIDMaps != nil {
options = &TarOptions{
UIDMaps: archiver.UIDMaps,
GIDMaps: archiver.GIDMaps,
}
}
if err := archiver.Untar(archive, dst, options); err != nil {
return err
}
return nil
@ -801,6 +872,28 @@ func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
hdr.Name = filepath.Base(dst)
hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))
remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(archiver.UIDMaps, archiver.GIDMaps)
if err != nil {
return err
}
// only perform mapping if the file being copied isn't already owned by the
// uid or gid of the remapped root in the container
if remappedRootUID != hdr.Uid {
xUID, err := idtools.ToHost(hdr.Uid, archiver.UIDMaps)
if err != nil {
return err
}
hdr.Uid = xUID
}
if remappedRootGID != hdr.Gid {
xGID, err := idtools.ToHost(hdr.Gid, archiver.GIDMaps)
if err != nil {
return err
}
hdr.Gid = xGID
}
tw := tar.NewWriter(w)
defer tw.Close()
if err := tw.WriteHeader(hdr); err != nil {
@ -816,6 +909,7 @@ func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
err = er
}
}()
return archiver.Untar(r, filepath.Dir(dst), nil)
}

9
archive/archive_unix.go
View file

@ -61,6 +61,15 @@ func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, st
return
}
func getFileUIDGID(stat interface{}) (int, int, error) {
s, ok := stat.(*syscall.Stat_t)
if !ok {
return -1, -1, errors.New("cannot convert stat value to syscall.Stat_t")
}
return int(s.Uid), int(s.Gid), nil
}
func major(device uint64) uint64 {
return (device >> 8) & 0xfff
}

5
archive/archive_windows.go
View file

@ -63,3 +63,8 @@ func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
return nil
}
func getFileUIDGID(stat interface{}) (int, int, error) {
// no notion of file ownership mapping yet on Windows
return 0, 0, nil
}

5
archive/changes.go
View file

@ -14,6 +14,7 @@ import (
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/pools"
"github.com/docker/docker/pkg/system"
)
@ -341,13 +342,15 @@ func ChangesSize(newDir string, changes []Change) int64 {
}
// ExportChanges produces an Archive from the provided changes, relative to dir.
func ExportChanges(dir string, changes []Change) (Archive, error) {
func ExportChanges(dir string, changes []Change, uidMaps, gidMaps []idtools.IDMap) (Archive, error) {
reader, writer := io.Pipe()
go func() {
ta := &tarAppender{
TarWriter: tar.NewWriter(writer),
Buffer: pools.BufioWriter32KPool.Get(nil),
SeenFiles: make(map[uint64]string),
UIDMaps: uidMaps,
GIDMaps: gidMaps,
}
// this buffer is needed for the duration of this piped stream
defer pools.BufioWriter32KPool.Put(ta.Buffer)

4
archive/changes_posix_test.go
View file

@ -61,7 +61,7 @@ func TestHardLinkOrder(t *testing.T) {
sort.Sort(changesByPath(changes))
// ExportChanges
ar, err := ExportChanges(dest, changes)
ar, err := ExportChanges(dest, changes, nil, nil)
if err != nil {
t.Fatal(err)
}
@ -73,7 +73,7 @@ func TestHardLinkOrder(t *testing.T) {
// reverse sort
sort.Sort(sort.Reverse(changesByPath(changes)))
// ExportChanges
arRev, err := ExportChanges(dest, changes)
arRev, err := ExportChanges(dest, changes, nil, nil)
if err != nil {
t.Fatal(err)
}

2
archive/changes_test.go
View file

@ -410,7 +410,7 @@ func TestApplyLayer(t *testing.T) {
t.Fatal(err)
}
layer, err := ExportChanges(dst, changes)
layer, err := ExportChanges(dst, changes, nil, nil)
if err != nil {
t.Fatal(err)
}

41
archive/diff.go
View file

@ -11,6 +11,7 @@ import (
"strings"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/idtools"
"github.com/docker/docker/pkg/pools"
"github.com/docker/docker/pkg/system"
)
@ -18,16 +19,23 @@ import (
// UnpackLayer unpack `layer` to a `dest`. The stream `layer` can be
// compressed or uncompressed.
// Returns the size in bytes of the contents of the layer.
func UnpackLayer(dest string, layer Reader) (size int64, err error) {
func UnpackLayer(dest string, layer Reader, options *TarOptions) (size int64, err error) {
tr := tar.NewReader(layer)
trBuf := pools.BufioReader32KPool.Get(tr)
defer pools.BufioReader32KPool.Put(trBuf)
var dirs []*tar.Header
remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps)
if err != nil {
return 0, err
}
aufsTempdir := ""
aufsHardlinks := make(map[string]*tar.Header)
if options == nil {
options = &TarOptions{}
}
// Iterate through the files in the archive.
for {
hdr, err := tr.Next()
@ -169,6 +177,27 @@ func UnpackLayer(dest string, layer Reader) (size int64, err error) {
srcData = tmpFile
}
// if the options contain a uid & gid maps, convert header uid/gid
// entries using the maps such that lchown sets the proper mapped
// uid/gid after writing the file. We only perform this mapping if
// the file isn't already owned by the remapped root UID or GID, as
// that specific uid/gid has no mapping from container -> host, and
// those files already have the proper ownership for inside the
// container.
if srcHdr.Uid != remappedRootUID {
xUID, err := idtools.ToHost(srcHdr.Uid, options.UIDMaps)
if err != nil {
return 0, err
}
srcHdr.Uid = xUID
}
if srcHdr.Gid != remappedRootGID {
xGID, err := idtools.ToHost(srcHdr.Gid, options.GIDMaps)
if err != nil {
return 0, err
}
srcHdr.Gid = xGID
}
if err := createTarFile(path, dest, srcHdr, srcData, true, nil); err != nil {
return 0, err
}
@ -196,19 +225,19 @@ func UnpackLayer(dest string, layer Reader) (size int64, err error) {
// compressed or uncompressed.
// Returns the size in bytes of the contents of the layer.
func ApplyLayer(dest string, layer Reader) (int64, error) {
return applyLayerHandler(dest, layer, true)
return applyLayerHandler(dest, layer, &TarOptions{}, true)
}
// ApplyUncompressedLayer parses a diff in the standard layer format from
// `layer`, and applies it to the directory `dest`. The stream `layer`
// can only be uncompressed.
// Returns the size in bytes of the contents of the layer.
func ApplyUncompressedLayer(dest string, layer Reader) (int64, error) {
return applyLayerHandler(dest, layer, false)
func ApplyUncompressedLayer(dest string, layer Reader, options *TarOptions) (int64, error) {
return applyLayerHandler(dest, layer, options, false)
}
// do the bulk load of ApplyLayer, but allow for not calling DecompressStream
func applyLayerHandler(dest string, layer Reader, decompress bool) (int64, error) {
func applyLayerHandler(dest string, layer Reader, options *TarOptions, decompress bool) (int64, error) {
dest = filepath.Clean(dest)
// We need to be able to set any perms
@ -224,5 +253,5 @@ func applyLayerHandler(dest string, layer Reader, decompress bool) (int64, error
return 0, err
}
}
return UnpackLayer(dest, layer)
return UnpackLayer(dest, layer, options)
}