github.com/akerouanton/docker@v1.11.0-rc3/pkg/archive/example_changes.go (about)

     1  // +build ignore
     2  
     3  // Simple tool to create an archive stream from an old and new directory
     4  //
     5  // By default it will stream the comparison of two temporary directories with junk files
     6  package main
     7  
     8  import (
     9  	"flag"
    10  	"fmt"
    11  	"io"
    12  	"io/ioutil"
    13  	"os"
    14  	"path"
    15  
    16  	"github.com/Sirupsen/logrus"
    17  	"github.com/docker/docker/pkg/archive"
    18  )
    19  
    20  var (
    21  	flDebug  = flag.Bool("D", false, "debugging output")
    22  	flNewDir = flag.String("newdir", "", "")
    23  	flOldDir = flag.String("olddir", "", "")
    24  	log      = logrus.New()
    25  )
    26  
    27  func main() {
    28  	flag.Usage = func() {
    29  		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
    30  		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
    31  		flag.PrintDefaults()
    32  	}
    33  	flag.Parse()
    34  	log.Out = os.Stderr
    35  	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
    36  		logrus.SetLevel(logrus.DebugLevel)
    37  	}
    38  	var newDir, oldDir string
    39  
    40  	if len(*flNewDir) == 0 {
    41  		var err error
    42  		newDir, err = ioutil.TempDir("", "docker-test-newDir")
    43  		if err != nil {
    44  			log.Fatal(err)
    45  		}
    46  		defer os.RemoveAll(newDir)
    47  		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
    48  			log.Fatal(err)
    49  		}
    50  	} else {
    51  		newDir = *flNewDir
    52  	}
    53  
    54  	if len(*flOldDir) == 0 {
    55  		oldDir, err := ioutil.TempDir("", "docker-test-oldDir")
    56  		if err != nil {
    57  			log.Fatal(err)
    58  		}
    59  		defer os.RemoveAll(oldDir)
    60  	} else {
    61  		oldDir = *flOldDir
    62  	}
    63  
    64  	changes, err := archive.ChangesDirs(newDir, oldDir)
    65  	if err != nil {
    66  		log.Fatal(err)
    67  	}
    68  
    69  	a, err := archive.ExportChanges(newDir, changes)
    70  	if err != nil {
    71  		log.Fatal(err)
    72  	}
    73  	defer a.Close()
    74  
    75  	i, err := io.Copy(os.Stdout, a)
    76  	if err != nil && err != io.EOF {
    77  		log.Fatal(err)
    78  	}
    79  	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
    80  }
    81  
    82  func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
    83  	fileData := []byte("fooo")
    84  	for n := 0; n < numberOfFiles; n++ {
    85  		fileName := fmt.Sprintf("file-%d", n)
    86  		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
    87  			return 0, err
    88  		}
    89  		if makeLinks {
    90  			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
    91  				return 0, err
    92  			}
    93  		}
    94  	}
    95  	totalSize := numberOfFiles * len(fileData)
    96  	return totalSize, nil
    97  }