Previously only unpack operations were supported with chroot.
This adds chroot support for packing operations.
This prevents potential breakouts when copying data from a container.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
pkg/chrootarchive/diff_unix.go erroneously calls flush on stdout, which tries to read from stdout returning an error.
This has been fixed by removing the call and by modifying flush to return errors and checking for these errors on calls to flush.
Signed-off-by: Amit Krishnan <krish.amit@gmail.com>
