84 lines
1.3 KiB
Go
84 lines
1.3 KiB
Go
package main
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import (
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"archive/tar"
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"encoding/json"
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"fmt"
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"io"
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"os"
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)
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func main() {
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f, err := os.Open("image/cache.tar")
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if err != nil {
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fmt.Println(err)
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os.Exit(1)
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}
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defer f.Close()
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// gzf, err := gzip.NewReader(f)
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// if err != nil {
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// fmt.Println(err)
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// os.Exit(1)
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// }
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tarReader := tar.NewReader(f)
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targetName := "manifest.json"
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var m Manifest
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for {
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header, err := tarReader.Next()
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if err == io.EOF {
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break
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}
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if err != nil {
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fmt.Println(err)
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os.Exit(1)
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}
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name := header.Name
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if name == targetName {
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m = handleManifest(tarReader, header)
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}
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switch header.Typeflag {
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case tar.TypeDir:
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continue
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case tar.TypeReg:
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fmt.Println("File: ", name)
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// show the contents
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// io.Copy(os.Stdout, tarReader)
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default:
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fmt.Printf("%s : %c %s %s\n",
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"hmmm?",
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header.Typeflag,
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"in file",
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name,
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)
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}
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}
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fmt.Printf("%+v\n", m)
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}
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type Manifest struct {
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Config string
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RepoTags []string
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Layers []string
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}
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func handleManifest(r *tar.Reader, header *tar.Header) Manifest {
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size := header.Size
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manifestBytes := make([]byte, size)
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_, err := r.Read(manifestBytes)
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if err != nil {
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panic(err)
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}
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var m [1]Manifest
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err = json.Unmarshal(manifestBytes, &m)
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if err != nil {
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panic(err)
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}
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return m[0]
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}
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