containerd/archive/tar_windows.go

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package archive
import (
"archive/tar"
"errors"
"fmt"
"os"
"strings"
"github.com/containerd/containerd/sys"
)
// tarName returns platform-specific filepath
// to canonical posix-style path for tar archival. p is relative
// path.
func tarName(p string) (string, error) {
// windows: convert windows style relative path with backslashes
// into forward slashes. Since windows does not allow '/' or '\'
// in file names, it is mostly safe to replace however we must
// check just in case
if strings.Contains(p, "/") {
return "", fmt.Errorf("Windows path contains forward slash: %s", p)
}
return strings.Replace(p, string(os.PathSeparator), "/", -1), nil
}
// chmodTarEntry is used to adjust the file permissions used in tar header based
// on the platform the archival is done.
func chmodTarEntry(perm os.FileMode) os.FileMode {
perm &= 0755
// Add the x bit: make everything +x from windows
perm |= 0111
return perm
}
func setHeaderForSpecialDevice(*tar.Header, string, os.FileInfo) error {
// do nothing. no notion of Rdev, Inode, Nlink in stat on Windows
return nil
}
func open(p string) (*os.File, error) {
// We use sys.OpenSequential to ensure we use sequential file
// access on Windows to avoid depleting the standby list.
return sys.OpenSequential(p)
}
func openFile(name string, flag int, perm os.FileMode) (*os.File, error) {
// Source is regular file. We use sys.OpenFileSequential to use sequential
// file access to avoid depleting the standby list on Windows.
return sys.OpenFileSequential(name, flag, perm)
}
func mkdirAll(path string, perm os.FileMode) error {
return sys.MkdirAll(path, perm)
}
func prepareApply() func() {
// No umask or filesystem changes needed before apply
return func() {}
}
func skipFile(hdr *tar.Header) bool {
// Windows does not support filenames with colons in them. Ignore
// these files. This is not a problem though (although it might
// appear that it is). Let's suppose a client is running docker pull.
// The daemon it points to is Windows. Would it make sense for the
// client to be doing a docker pull Ubuntu for example (which has files
// with colons in the name under /usr/share/man/man3)? No, absolutely
// not as it would really only make sense that they were pulling a
// Windows image. However, for development, it is necessary to be able
// to pull Linux images which are in the repository.
//
// TODO Windows. Once the registry is aware of what images are Windows-
// specific or Linux-specific, this warning should be changed to an error
// to cater for the situation where someone does manage to upload a Linux
// image but have it tagged as Windows inadvertently.
if strings.Contains(hdr.Name, ":") {
return true
}
return false
}
// handleTarTypeBlockCharFifo is an OS-specific helper function used by
// createTarFile to handle the following types of header: Block; Char; Fifo
func handleTarTypeBlockCharFifo(hdr *tar.Header, path string) error {
return nil
}
func handleLChmod(hdr *tar.Header, path string, hdrInfo os.FileInfo) error {
return nil
}
func getxattr(path, attr string) ([]byte, error) {
return nil, nil
}
func setxattr(path, key, value string) error {
// Return not support error, do not wrap underlying not supported
// since xattrs should not exist in windows diff archives
return errors.New("xattrs not supported on Windows")
}