mirror of
https://github.com/moby/moby.git
synced 2022-11-09 12:21:53 -05:00
294 lines
8.8 KiB
Go
294 lines
8.8 KiB
Go
package archive // import "github.com/docker/docker/pkg/archive"
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"os"
|
|
"os/exec"
|
|
"path/filepath"
|
|
"syscall"
|
|
"testing"
|
|
|
|
"github.com/docker/docker/pkg/reexec"
|
|
"github.com/docker/docker/pkg/system"
|
|
rsystem "github.com/opencontainers/runc/libcontainer/system"
|
|
"github.com/pkg/errors"
|
|
"golang.org/x/sys/unix"
|
|
"gotest.tools/assert"
|
|
"gotest.tools/skip"
|
|
)
|
|
|
|
// setupOverlayTestDir creates files in a directory with overlay whiteouts
|
|
// Tree layout
|
|
// .
|
|
// ├── d1 # opaque, 0700
|
|
// │ └── f1 # empty file, 0600
|
|
// ├── d2 # opaque, 0750
|
|
// │ └── f1 # empty file, 0660
|
|
// └── d3 # 0700
|
|
// └── f1 # whiteout, 0644
|
|
func setupOverlayTestDir(t *testing.T, src string) {
|
|
skip.If(t, os.Getuid() != 0, "skipping test that requires root")
|
|
skip.If(t, rsystem.RunningInUserNS(), "skipping test that requires initial userns (trusted.overlay.opaque xattr cannot be set in userns, even with Ubuntu kernel)")
|
|
// Create opaque directory containing single file and permission 0700
|
|
err := os.Mkdir(filepath.Join(src, "d1"), 0700)
|
|
assert.NilError(t, err)
|
|
|
|
err = system.Lsetxattr(filepath.Join(src, "d1"), "trusted.overlay.opaque", []byte("y"), 0)
|
|
assert.NilError(t, err)
|
|
|
|
err = ioutil.WriteFile(filepath.Join(src, "d1", "f1"), []byte{}, 0600)
|
|
assert.NilError(t, err)
|
|
|
|
// Create another opaque directory containing single file but with permission 0750
|
|
err = os.Mkdir(filepath.Join(src, "d2"), 0750)
|
|
assert.NilError(t, err)
|
|
|
|
err = system.Lsetxattr(filepath.Join(src, "d2"), "trusted.overlay.opaque", []byte("y"), 0)
|
|
assert.NilError(t, err)
|
|
|
|
err = ioutil.WriteFile(filepath.Join(src, "d2", "f1"), []byte{}, 0660)
|
|
assert.NilError(t, err)
|
|
|
|
// Create regular directory with deleted file
|
|
err = os.Mkdir(filepath.Join(src, "d3"), 0700)
|
|
assert.NilError(t, err)
|
|
|
|
err = system.Mknod(filepath.Join(src, "d3", "f1"), unix.S_IFCHR, 0)
|
|
assert.NilError(t, err)
|
|
}
|
|
|
|
func checkOpaqueness(t *testing.T, path string, opaque string) {
|
|
xattrOpaque, err := system.Lgetxattr(path, "trusted.overlay.opaque")
|
|
assert.NilError(t, err)
|
|
|
|
if string(xattrOpaque) != opaque {
|
|
t.Fatalf("Unexpected opaque value: %q, expected %q", string(xattrOpaque), opaque)
|
|
}
|
|
|
|
}
|
|
|
|
func checkOverlayWhiteout(t *testing.T, path string) {
|
|
stat, err := os.Stat(path)
|
|
assert.NilError(t, err)
|
|
|
|
statT, ok := stat.Sys().(*syscall.Stat_t)
|
|
if !ok {
|
|
t.Fatalf("Unexpected type: %t, expected *syscall.Stat_t", stat.Sys())
|
|
}
|
|
if statT.Rdev != 0 {
|
|
t.Fatalf("Non-zero device number for whiteout")
|
|
}
|
|
}
|
|
|
|
func checkFileMode(t *testing.T, path string, perm os.FileMode) {
|
|
stat, err := os.Stat(path)
|
|
assert.NilError(t, err)
|
|
|
|
if stat.Mode() != perm {
|
|
t.Fatalf("Unexpected file mode for %s: %o, expected %o", path, stat.Mode(), perm)
|
|
}
|
|
}
|
|
|
|
func TestOverlayTarUntar(t *testing.T) {
|
|
oldmask, err := system.Umask(0)
|
|
assert.NilError(t, err)
|
|
defer system.Umask(oldmask)
|
|
|
|
src, err := ioutil.TempDir("", "docker-test-overlay-tar-src")
|
|
assert.NilError(t, err)
|
|
defer os.RemoveAll(src)
|
|
|
|
setupOverlayTestDir(t, src)
|
|
|
|
dst, err := ioutil.TempDir("", "docker-test-overlay-tar-dst")
|
|
assert.NilError(t, err)
|
|
defer os.RemoveAll(dst)
|
|
|
|
options := &TarOptions{
|
|
Compression: Uncompressed,
|
|
WhiteoutFormat: OverlayWhiteoutFormat,
|
|
}
|
|
archive, err := TarWithOptions(src, options)
|
|
assert.NilError(t, err)
|
|
defer archive.Close()
|
|
|
|
err = Untar(archive, dst, options)
|
|
assert.NilError(t, err)
|
|
|
|
checkFileMode(t, filepath.Join(dst, "d1"), 0700|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d2"), 0750|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d3"), 0700|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d1", "f1"), 0600)
|
|
checkFileMode(t, filepath.Join(dst, "d2", "f1"), 0660)
|
|
checkFileMode(t, filepath.Join(dst, "d3", "f1"), os.ModeCharDevice|os.ModeDevice)
|
|
|
|
checkOpaqueness(t, filepath.Join(dst, "d1"), "y")
|
|
checkOpaqueness(t, filepath.Join(dst, "d2"), "y")
|
|
checkOpaqueness(t, filepath.Join(dst, "d3"), "")
|
|
checkOverlayWhiteout(t, filepath.Join(dst, "d3", "f1"))
|
|
}
|
|
|
|
func TestOverlayTarAUFSUntar(t *testing.T) {
|
|
oldmask, err := system.Umask(0)
|
|
assert.NilError(t, err)
|
|
defer system.Umask(oldmask)
|
|
|
|
src, err := ioutil.TempDir("", "docker-test-overlay-tar-src")
|
|
assert.NilError(t, err)
|
|
defer os.RemoveAll(src)
|
|
|
|
setupOverlayTestDir(t, src)
|
|
|
|
dst, err := ioutil.TempDir("", "docker-test-overlay-tar-dst")
|
|
assert.NilError(t, err)
|
|
defer os.RemoveAll(dst)
|
|
|
|
archive, err := TarWithOptions(src, &TarOptions{
|
|
Compression: Uncompressed,
|
|
WhiteoutFormat: OverlayWhiteoutFormat,
|
|
})
|
|
assert.NilError(t, err)
|
|
defer archive.Close()
|
|
|
|
err = Untar(archive, dst, &TarOptions{
|
|
Compression: Uncompressed,
|
|
WhiteoutFormat: AUFSWhiteoutFormat,
|
|
})
|
|
assert.NilError(t, err)
|
|
|
|
checkFileMode(t, filepath.Join(dst, "d1"), 0700|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d1", WhiteoutOpaqueDir), 0700)
|
|
checkFileMode(t, filepath.Join(dst, "d2"), 0750|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d2", WhiteoutOpaqueDir), 0750)
|
|
checkFileMode(t, filepath.Join(dst, "d3"), 0700|os.ModeDir)
|
|
checkFileMode(t, filepath.Join(dst, "d1", "f1"), 0600)
|
|
checkFileMode(t, filepath.Join(dst, "d2", "f1"), 0660)
|
|
checkFileMode(t, filepath.Join(dst, "d3", WhiteoutPrefix+"f1"), 0600)
|
|
}
|
|
|
|
func unshareCmd(cmd *exec.Cmd) {
|
|
cmd.SysProcAttr = &syscall.SysProcAttr{
|
|
Cloneflags: syscall.CLONE_NEWUSER | syscall.CLONE_NEWNS,
|
|
UidMappings: []syscall.SysProcIDMap{
|
|
{
|
|
ContainerID: 0,
|
|
HostID: os.Geteuid(),
|
|
Size: 1,
|
|
},
|
|
},
|
|
GidMappings: []syscall.SysProcIDMap{
|
|
{
|
|
ContainerID: 0,
|
|
HostID: os.Getegid(),
|
|
Size: 1,
|
|
},
|
|
},
|
|
}
|
|
}
|
|
|
|
const (
|
|
reexecSupportsUserNSOverlay = "docker-test-supports-userns-overlay"
|
|
reexecMknodChar0 = "docker-test-userns-mknod-char0"
|
|
reexecSetOpaque = "docker-test-userns-set-opaque"
|
|
)
|
|
|
|
func supportsOverlay(dir string) error {
|
|
lower := filepath.Join(dir, "l")
|
|
upper := filepath.Join(dir, "u")
|
|
work := filepath.Join(dir, "w")
|
|
merged := filepath.Join(dir, "m")
|
|
for _, s := range []string{lower, upper, work, merged} {
|
|
if err := os.MkdirAll(s, 0700); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
mOpts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lower, upper, work)
|
|
if err := syscall.Mount("overlay", merged, "overlay", uintptr(0), mOpts); err != nil {
|
|
return errors.Wrapf(err, "failed to mount overlay (%s) on %s", mOpts, merged)
|
|
}
|
|
if err := syscall.Unmount(merged, 0); err != nil {
|
|
return errors.Wrapf(err, "failed to unmount %s", merged)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// supportsUserNSOverlay returns nil error if overlay is supported in userns.
|
|
// Only Ubuntu and a few distros support overlay in userns (by patching the kernel).
|
|
// https://lists.ubuntu.com/archives/kernel-team/2014-February/038091.html
|
|
// As of kernel 4.19, the patch is not merged to the upstream.
|
|
func supportsUserNSOverlay() error {
|
|
tmp, err := ioutil.TempDir("", "docker-test-supports-userns-overlay")
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer os.RemoveAll(tmp)
|
|
cmd := reexec.Command(reexecSupportsUserNSOverlay, tmp)
|
|
unshareCmd(cmd)
|
|
out, err := cmd.CombinedOutput()
|
|
if err != nil {
|
|
return errors.Wrapf(err, "output: %q", string(out))
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// isOpaque returns nil error if the dir has trusted.overlay.opaque=y.
|
|
// isOpaque needs to be called in the initial userns.
|
|
func isOpaque(dir string) error {
|
|
xattrOpaque, err := system.Lgetxattr(dir, "trusted.overlay.opaque")
|
|
if err != nil {
|
|
return errors.Wrapf(err, "failed to read opaque flag of %s", dir)
|
|
}
|
|
if string(xattrOpaque) != "y" {
|
|
return errors.Errorf("expected \"y\", got %q", string(xattrOpaque))
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func TestReexecUserNSOverlayWhiteoutConverter(t *testing.T) {
|
|
skip.If(t, os.Getuid() != 0, "skipping test that requires root")
|
|
skip.If(t, rsystem.RunningInUserNS(), "skipping test that requires initial userns")
|
|
if err := supportsUserNSOverlay(); err != nil {
|
|
t.Skipf("skipping test that requires kernel support for overlay-in-userns: %v", err)
|
|
}
|
|
tmp, err := ioutil.TempDir("", "docker-test-userns-overlay")
|
|
assert.NilError(t, err)
|
|
defer os.RemoveAll(tmp)
|
|
|
|
char0 := filepath.Join(tmp, "char0")
|
|
cmd := reexec.Command(reexecMknodChar0, char0)
|
|
unshareCmd(cmd)
|
|
out, err := cmd.CombinedOutput()
|
|
assert.NilError(t, err, string(out))
|
|
assert.NilError(t, isChar0(char0))
|
|
|
|
opaqueDir := filepath.Join(tmp, "opaquedir")
|
|
err = os.MkdirAll(opaqueDir, 0755)
|
|
assert.NilError(t, err, string(out))
|
|
cmd = reexec.Command(reexecSetOpaque, opaqueDir)
|
|
unshareCmd(cmd)
|
|
out, err = cmd.CombinedOutput()
|
|
assert.NilError(t, err, string(out))
|
|
assert.NilError(t, isOpaque(opaqueDir))
|
|
}
|
|
|
|
func init() {
|
|
reexec.Register(reexecSupportsUserNSOverlay, func() {
|
|
if err := supportsOverlay(os.Args[1]); err != nil {
|
|
panic(err)
|
|
}
|
|
})
|
|
reexec.Register(reexecMknodChar0, func() {
|
|
if err := mknodChar0Overlay(os.Args[1]); err != nil {
|
|
panic(err)
|
|
}
|
|
})
|
|
reexec.Register(reexecSetOpaque, func() {
|
|
if err := replaceDirWithOverlayOpaque(os.Args[1]); err != nil {
|
|
panic(err)
|
|
}
|
|
})
|
|
if reexec.Init() {
|
|
os.Exit(0)
|
|
}
|
|
}
|