velero/pkg/archive/extractor.go

115 lines
2.5 KiB
Go

/*
Copyright 2019 the Velero contributors.
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.
*/
package archive
import (
"archive/tar"
"compress/gzip"
"io"
"path/filepath"
"github.com/sirupsen/logrus"
"github.com/vmware-tanzu/velero/pkg/util/filesystem"
)
// Extractor unzips/extracts a backup tarball to a local
// temp directory.
type Extractor struct {
log logrus.FieldLogger
fs filesystem.Interface
}
func NewExtractor(log logrus.FieldLogger, fs filesystem.Interface) *Extractor {
return &Extractor{
log: log,
fs: fs,
}
}
// UnzipAndExtractBackup extracts a reader on a gzipped tarball to a local temp directory
func (e *Extractor) UnzipAndExtractBackup(src io.Reader) (string, error) {
gzr, err := gzip.NewReader(src)
if err != nil {
e.log.Infof("error creating gzip reader: %v", err)
return "", err
}
defer gzr.Close()
return e.readBackup(tar.NewReader(gzr))
}
func (e *Extractor) writeFile(target string, tarRdr *tar.Reader) error {
file, err := e.fs.Create(target)
if err != nil {
return err
}
defer file.Close()
if _, err := io.Copy(file, tarRdr); err != nil {
return err
}
return nil
}
func (e *Extractor) readBackup(tarRdr *tar.Reader) (string, error) {
dir, err := e.fs.TempDir("", "")
if err != nil {
e.log.Infof("error creating temp dir: %v", err)
return "", err
}
for {
header, err := tarRdr.Next()
if err == io.EOF {
break
}
if err != nil {
e.log.Infof("error reading tar: %v", err)
return "", err
}
target := filepath.Join(dir, header.Name)
switch header.Typeflag {
case tar.TypeDir:
err := e.fs.MkdirAll(target, header.FileInfo().Mode())
if err != nil {
e.log.Infof("mkdirall error: %v", err)
return "", err
}
case tar.TypeReg:
// make sure we have the directory created
err := e.fs.MkdirAll(filepath.Dir(target), header.FileInfo().Mode())
if err != nil {
e.log.Infof("mkdirall error: %v", err)
return "", err
}
// create the file
if err := e.writeFile(target, tarRdr); err != nil {
e.log.Infof("error copying: %v", err)
return "", err
}
}
}
return dir, nil
}