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package archive // import "github.com/docker/docker/pkg/archive"
import (
"os"
"path/filepath"
"syscall"
"testing"
"github.com/containerd/containerd/pkg/userns"
"github.com/docker/docker/pkg/system"
"golang.org/x/sys/unix"
"gotest.tools/v3/assert"
"gotest.tools/v3/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, userns.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 = os.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 = os.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) {
restore := overrideUmask(0)
defer restore()
src, err := os.MkdirTemp("", "docker-test-overlay-tar-src")
assert.NilError(t, err)
defer os.RemoveAll(src)
setupOverlayTestDir(t, src)
dst, err := os.MkdirTemp("", "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) {
restore := overrideUmask(0)
defer restore()
src, err := os.MkdirTemp("", "docker-test-overlay-tar-src")
assert.NilError(t, err)
defer os.RemoveAll(src)
setupOverlayTestDir(t, src)
dst, err := os.MkdirTemp("", "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)
}
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