dive-zfs/tar-read.go
Will Murphy ea88892839 WIP
2018-05-24 19:41:03 -04:00

148 lines
2.4 KiB
Go

package main
import (
"archive/tar"
"bytes"
"crypto/md5"
"encoding/json"
"fmt"
"hash"
"io"
"os"
"strings"
)
func main() {
f, err := os.Open("image/cache.tar")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer f.Close()
// gzf, err := gzip.NewReader(f)
// if err != nil {
// fmt.Println(err)
// os.Exit(1)
// }
tarReader := tar.NewReader(f)
targetName := "manifest.json"
var m Manifest
for {
header, err := tarReader.Next()
if err == io.EOF {
break
}
if err != nil {
fmt.Println(err)
os.Exit(1)
}
name := header.Name
if name == targetName {
m = handleManifest(tarReader, header)
}
switch header.Typeflag {
case tar.TypeDir:
continue
case tar.TypeReg:
fmt.Println("File: ", name)
if strings.HasSuffix(name, "layer.tar") {
fmt.Println("Containing:")
printFilesInTar(tarReader, header)
}
// show the contents
// io.Copy(os.Stdout, tarReader)
default:
fmt.Printf("%s : %c %s %s\n",
"hmmm?",
header.Typeflag,
"in file",
name,
)
}
}
fmt.Printf("%+v\n", m)
}
func printFilesInTar(parentReader *tar.Reader, h *tar.Header) {
hasher := md5.New
size := h.Size
tarredBytes := make([]byte, size)
_, err := parentReader.Read(tarredBytes)
if err != nil {
panic(err)
}
r := bytes.NewReader(tarredBytes)
tarReader := tar.NewReader(r)
for {
header, err := tarReader.Next()
if err == io.EOF {
break
}
if err != nil {
fmt.Println(err)
os.Exit(1)
}
name := header.Name
switch header.Typeflag {
case tar.TypeDir:
fmt.Println(" Directory: ", name)
continue
case tar.TypeReg:
fmt.Println(" File: ", name)
// show the contents
// io.Copy(os.Stdout, tarReader)
case tar.TypeSymlink:
fmt.Println(" SymLink", name)
default:
fmt.Printf("%s : %c %s %s\n",
"hmmm?",
header.Typeflag,
"in file",
name,
)
}
}
}
func makeEntry(r *tar.Reader, h *tar.Header, hasher *hash.Hash) FileChangeInfo {
fileBytes := make([]byte, h.Size)
}
type FileChangeInfo struct {
fileName string
typeflag int
md5sum [16]byte
}
type Manifest struct {
Config string
RepoTags []string
Layers []string
}
func handleManifest(r *tar.Reader, header *tar.Header) Manifest {
size := header.Size
manifestBytes := make([]byte, size)
_, err := r.Read(manifestBytes)
if err != nil {
panic(err)
}
var m [1]Manifest
err = json.Unmarshal(manifestBytes, &m)
if err != nil {
panic(err)
}
return m[0]
}