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unclejackunclejack
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add pkg/chrootarchive and use it on the daemon
Docker-DCO-1.1-Signed-off-by: Cristian Staretu <[email protected]> (github: unclejack) Conflicts: builder/internals.go daemon/graphdriver/aufs/aufs.go daemon/volumes.go fixed conflicts in imports
1 parent fa1484d commit 1cb17f0

11 files changed

Lines changed: 176 additions & 13 deletions

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‎builder/internals.go‎

Lines changed: 7 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -24,6 +24,7 @@ import (
2424
"github.com/docker/docker/daemon"
2525
imagepkg "github.com/docker/docker/image"
2626
"github.com/docker/docker/pkg/archive"
27+
"github.com/docker/docker/pkg/chrootarchive"
2728
"github.com/docker/docker/pkg/parsers"
2829
"github.com/docker/docker/pkg/symlink"
2930
"github.com/docker/docker/pkg/system"
@@ -46,7 +47,9 @@ func (b *Builder) readContext(context io.Reader) error {
4647
if b.context, err = tarsum.NewTarSum(decompressedStream, true, tarsum.Version0); err != nil {
4748
return err
4849
}
49-
if err := archive.Untar(b.context, tmpdirPath, nil); err != nil {
50+
51+
os.MkdirAll(tmpdirPath, 0700)
52+
if err := chrootarchive.Untar(b.context, tmpdirPath, nil); err != nil {
5053
return err
5154
}
5255

@@ -627,7 +630,7 @@ func (b *Builder) addContext(container *daemon.Container, orig, dest string, dec
627630
}
628631

629632
// try to successfully untar the orig
630-
if err := archive.UntarPath(origPath, tarDest); err == nil {
633+
if err := chrootarchive.UntarPath(origPath, tarDest); err == nil {
631634
return nil
632635
} else if err != io.EOF {
633636
log.Debugf("Couldn't untar %s to %s: %s", origPath, tarDest, err)
@@ -637,7 +640,7 @@ func (b *Builder) addContext(container *daemon.Container, orig, dest string, dec
637640
if err := os.MkdirAll(path.Dir(destPath), 0755); err != nil {
638641
return err
639642
}
640-
if err := archive.CopyWithTar(origPath, destPath); err != nil {
643+
if err := chrootarchive.CopyWithTar(origPath, destPath); err != nil {
641644
return err
642645
}
643646

@@ -650,7 +653,7 @@ func (b *Builder) addContext(container *daemon.Container, orig, dest string, dec
650653
}
651654

652655
func copyAsDirectory(source, destination string, destinationExists bool) error {
653-
if err := archive.CopyWithTar(source, destination); err != nil {
656+
if err := chrootarchive.CopyWithTar(source, destination); err != nil {
654657
return err
655658
}
656659

‎daemon/graphdriver/aufs/aufs.go‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -33,6 +33,7 @@ import (
3333
log "github.com/Sirupsen/logrus"
3434
"github.com/docker/docker/daemon/graphdriver"
3535
"github.com/docker/docker/pkg/archive"
36+
"github.com/docker/docker/pkg/chrootarchive"
3637
mountpk "github.com/docker/docker/pkg/mount"
3738
"github.com/docker/docker/utils"
3839
"github.com/docker/libcontainer/label"
@@ -305,7 +306,7 @@ func (a *Driver) Diff(id, parent string) (archive.Archive, error) {
305306
}
306307

307308
func (a *Driver) applyDiff(id string, diff archive.ArchiveReader) error {
308-
return archive.Untar(diff, path.Join(a.rootPath(), "diff", id), nil)
309+
return chrootarchive.Untar(diff, path.Join(a.rootPath(), "diff", id), nil)
309310
}
310311

311312
// DiffSize calculates the changes between the specified id

‎daemon/graphdriver/fsdiff.go‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,6 +8,7 @@ import (
88

99
log "github.com/Sirupsen/logrus"
1010
"github.com/docker/docker/pkg/archive"
11+
"github.com/docker/docker/pkg/chrootarchive"
1112
"github.com/docker/docker/pkg/ioutils"
1213
"github.com/docker/docker/utils"
1314
)
@@ -122,7 +123,7 @@ func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveRea
122123

123124
start := time.Now().UTC()
124125
log.Debugf("Start untar layer")
125-
if err = archive.ApplyLayer(layerFs, diff); err != nil {
126+
if err = chrootarchive.ApplyLayer(layerFs, diff); err != nil {
126127
return
127128
}
128129
log.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())

‎daemon/graphdriver/vfs/driver.go‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@ import (
88
"path"
99

1010
"github.com/docker/docker/daemon/graphdriver"
11-
"github.com/docker/docker/pkg/archive"
11+
"github.com/docker/docker/pkg/chrootarchive"
1212
"github.com/docker/libcontainer/label"
1313
)
1414

@@ -66,7 +66,7 @@ func (d *Driver) Create(id, parent string) error {
6666
if err != nil {
6767
return fmt.Errorf("%s: %s", parent, err)
6868
}
69-
if err := archive.CopyWithTar(parentDir, dir); err != nil {
69+
if err := chrootarchive.CopyWithTar(parentDir, dir); err != nil {
7070
return err
7171
}
7272
return nil

‎daemon/volumes.go‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -12,7 +12,7 @@ import (
1212

1313
log "github.com/Sirupsen/logrus"
1414
"github.com/docker/docker/daemon/execdriver"
15-
"github.com/docker/docker/pkg/archive"
15+
"github.com/docker/docker/pkg/chrootarchive"
1616
"github.com/docker/docker/pkg/symlink"
1717
"github.com/docker/docker/volumes"
1818
)
@@ -320,7 +320,7 @@ func copyExistingContents(source, destination string) error {
320320

321321
if len(srcList) == 0 {
322322
// If the source volume is empty copy files from the root into the volume
323-
if err := archive.CopyWithTar(source, destination); err != nil {
323+
if err := chrootarchive.CopyWithTar(source, destination); err != nil {
324324
return err
325325
}
326326
}

‎pkg/chrootarchive/archive.go‎

Lines changed: 76 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,76 @@
1+
package chrootarchive
2+
3+
import (
4+
"flag"
5+
"fmt"
6+
"io"
7+
"os"
8+
"runtime"
9+
"syscall"
10+
11+
"github.com/docker/docker/pkg/archive"
12+
"github.com/docker/docker/pkg/reexec"
13+
)
14+
15+
func untar() {
16+
runtime.LockOSThread()
17+
flag.Parse()
18+
19+
if err := syscall.Chroot(flag.Arg(0)); err != nil {
20+
fatal(err)
21+
}
22+
if err := syscall.Chdir("/"); err != nil {
23+
fatal(err)
24+
}
25+
if err := archive.Untar(os.Stdin, "/", nil); err != nil {
26+
fatal(err)
27+
}
28+
os.Exit(0)
29+
}
30+
31+
var (
32+
chrootArchiver = &archive.Archiver{Untar}
33+
)
34+
35+
func Untar(archive io.Reader, dest string, options *archive.TarOptions) error {
36+
if _, err := os.Stat(dest); os.IsNotExist(err) {
37+
if err := os.MkdirAll(dest, 0777); err != nil {
38+
return err
39+
}
40+
}
41+
cmd := reexec.Command("docker-untar", dest)
42+
cmd.Stdin = archive
43+
out, err := cmd.CombinedOutput()
44+
if err != nil {
45+
return fmt.Errorf("Untar %s %s", err, out)
46+
}
47+
return nil
48+
}
49+
50+
func TarUntar(src, dst string) error {
51+
return chrootArchiver.TarUntar(src, dst)
52+
}
53+
54+
// CopyWithTar creates a tar archive of filesystem path `src`, and
55+
// unpacks it at filesystem path `dst`.
56+
// The archive is streamed directly with fixed buffering and no
57+
// intermediary disk IO.
58+
func CopyWithTar(src, dst string) error {
59+
return chrootArchiver.CopyWithTar(src, dst)
60+
}
61+
62+
// CopyFileWithTar emulates the behavior of the 'cp' command-line
63+
// for a single file. It copies a regular file from path `src` to
64+
// path `dst`, and preserves all its metadata.
65+
//
66+
// If `dst` ends with a trailing slash '/', the final destination path
67+
// will be `dst/base(src)`.
68+
func CopyFileWithTar(src, dst string) (err error) {
69+
return chrootArchiver.CopyFileWithTar(src, dst)
70+
}
71+
72+
// UntarPath is a convenience function which looks for an archive
73+
// at filesystem path `src`, and unpacks it at `dst`.
74+
func UntarPath(src, dst string) error {
75+
return chrootArchiver.UntarPath(src, dst)
76+
}

‎pkg/chrootarchive/diff.go‎

Lines changed: 38 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,38 @@
1+
package chrootarchive
2+
3+
import (
4+
"flag"
5+
"fmt"
6+
"os"
7+
"runtime"
8+
"syscall"
9+
10+
"github.com/docker/docker/pkg/archive"
11+
"github.com/docker/docker/pkg/reexec"
12+
)
13+
14+
func applyLayer() {
15+
runtime.LockOSThread()
16+
flag.Parse()
17+
18+
if err := syscall.Chroot(flag.Arg(0)); err != nil {
19+
fatal(err)
20+
}
21+
if err := syscall.Chdir("/"); err != nil {
22+
fatal(err)
23+
}
24+
if err := archive.ApplyLayer("/", os.Stdin); err != nil {
25+
fatal(err)
26+
}
27+
os.Exit(0)
28+
}
29+
30+
func ApplyLayer(dest string, layer archive.ArchiveReader) error {
31+
cmd := reexec.Command("docker-applyLayer", dest)
32+
cmd.Stdin = layer
33+
out, err := cmd.CombinedOutput()
34+
if err != nil {
35+
return fmt.Errorf("ApplyLayer %s %s", err, out)
36+
}
37+
return nil
38+
}

‎pkg/chrootarchive/init.go‎

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,18 @@
1+
package chrootarchive
2+
3+
import (
4+
"fmt"
5+
"os"
6+
7+
"github.com/docker/docker/pkg/reexec"
8+
)
9+
10+
func init() {
11+
reexec.Register("docker-untar", untar)
12+
reexec.Register("docker-applyLayer", applyLayer)
13+
}
14+
15+
func fatal(err error) {
16+
fmt.Fprint(os.Stderr, err)
17+
os.Exit(1)
18+
}

‎pkg/reexec/command_linux.go‎

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,18 @@
1+
// +build linux
2+
3+
package reexec
4+
5+
import (
6+
"os/exec"
7+
"syscall"
8+
)
9+
10+
func Command(args ...string) *exec.Cmd {
11+
return &exec.Cmd{
12+
Path: Self(),
13+
Args: args,
14+
SysProcAttr: &syscall.SysProcAttr{
15+
Pdeathsig: syscall.SIGTERM,
16+
},
17+
}
18+
}

‎pkg/reexec/command_unsupported.go‎

Lines changed: 11 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
// +build !linux
2+
3+
package reexec
4+
5+
import (
6+
"os/exec"
7+
)
8+
9+
func Command(args ...string) *exec.Cmd {
10+
return nil
11+
}

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