containerd/archive/tarheader/tarheader_unix.go
Akihiro Suda d26587c725
archive: disable looking up usernames and groupnames on the host
These strings were resolved using the user information on the host
filesystem and were decreasing reproducibility.

For moby/buildkit issue 3688

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
2023-03-08 02:04:40 +09:00

60 lines
1.5 KiB
Go

//go:build !windows
/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/*
Portions from https://github.com/moby/moby/blob/v23.0.1/pkg/archive/archive_unix.go#L52-L70
Copyright (C) Docker/Moby authors.
Licensed under the Apache License, Version 2.0
NOTICE: https://github.com/moby/moby/blob/v23.0.1/NOTICE
*/
package tarheader
import (
"archive/tar"
"os"
"syscall"
"golang.org/x/sys/unix"
)
func init() {
sysStat = statUnix
}
// statUnix populates hdr from system-dependent fields of fi without performing
// any OS lookups.
// From https://github.com/moby/moby/blob/v23.0.1/pkg/archive/archive_unix.go#L52-L70
func statUnix(fi os.FileInfo, hdr *tar.Header) error {
s, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
return nil
}
hdr.Uid = int(s.Uid)
hdr.Gid = int(s.Gid)
if s.Mode&unix.S_IFBLK != 0 ||
s.Mode&unix.S_IFCHR != 0 {
hdr.Devmajor = int64(unix.Major(uint64(s.Rdev)))
hdr.Devminor = int64(unix.Minor(uint64(s.Rdev)))
}
return nil
}