This uses a plain filepath.Walk + addTarFile to create a tar file,
optionially compressing it with gzip.
Unfortunately go only has gzip compression support, not bzip2 or xz.
However, this is not a regression, as docker currently uses *no*
compression for TarFilter(). The only compression of tarfiles
currently happens in utils/tarsum.go, and that manually does gzip
compression.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Upstream-commit: 5ea48aa7f8d3839877b869fdfcea2d5de0972fbf
Component: engine