luet/pkg/helpers/archive.go
2020-02-11 16:55:00 +01:00

133 lines
2.9 KiB
Go

// Copyright © 2019 Ettore Di Giacinto <mudler@gentoo.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, see <http://www.gnu.org/licenses/>.
package helpers
import (
"archive/tar"
"io"
"os"
"path/filepath"
"github.com/docker/docker/pkg/archive"
)
func Tar(src, dest string) error {
out, err := os.Create(dest)
if err != nil {
return err
}
defer out.Close()
fs, err := archive.Tar(src, archive.Uncompressed)
if err != nil {
return err
}
defer fs.Close()
_, err = io.Copy(out, fs)
if err != nil {
return err
}
err = out.Sync()
if err != nil {
return err
}
return err
}
// Untar just a wrapper around the docker functions
func Untar(src, dest string, sameOwner bool) error {
var ans error
in, err := os.Open(src)
if err != nil {
return err
}
defer in.Close()
if sameOwner {
// PRE: i have root privileged.
opts := &archive.TarOptions{
// NOTE: NoLchown boolean is used for chmod of the symlink
// Probably it's needed set this always to true.
NoLchown: true,
ExcludePatterns: []string{"dev/"}, // prevent 'operation not permitted'
}
ans = archive.Untar(in, dest, opts)
} else {
var fileReader io.ReadCloser = in
tr := tar.NewReader(fileReader)
for {
header, err := tr.Next()
switch {
case err == io.EOF:
goto tarEof
case err != nil:
return err
case header == nil:
continue
}
// the target location where the dir/file should be created
target := filepath.Join(dest, header.Name)
// Check the file type
switch header.Typeflag {
// if its a dir and it doesn't exist create it
case tar.TypeDir:
if _, err := os.Stat(target); err != nil {
if err := os.MkdirAll(target, 0755); err != nil {
return err
}
}
// handle creation of file
case tar.TypeReg:
f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
if err != nil {
return err
}
// copy over contents
if _, err := io.Copy(f, tr); err != nil {
return err
}
// manually close here after each file operation; defering would cause each
// file close to wait until all operations have completed.
f.Close()
case tar.TypeSymlink:
source := header.Linkname
err := os.Symlink(source, target)
if err != nil {
return err
}
}
}
tarEof:
}
return ans
}