pack, unpack: New commands.

Signed-off-by: Matthieu Nottale <[email protected]>

Author: Matthieu Nottale

cmd/pack.go

@@ -0,0 +1,29 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/docker/lunchbox/packager"
+	"github.com/spf13/cobra"
+)
+
+var packCmd = &cobra.Command{
+	Use:   "pack <app-name> [-o output_file]",
+	Short: "Pack this app as a single file",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		err := packager.Pack(args[0], packOutputFile)
+		if err != nil {
+			fmt.Printf("%v\n", err)
+			os.Exit(1)
+		}
+	},
+}
+
+var packOutputFile string
+
+func init() {
+	rootCmd.AddCommand(packCmd)
+	packCmd.Flags().StringVarP(&packOutputFile, "output", "o", "-", "Output file (- for stdout)")
+}

cmd/unpack.go

@@ -0,0 +1,29 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/docker/lunchbox/packager"
+	"github.com/spf13/cobra"
+)
+
+var unpackCmd = &cobra.Command{
+	Use:   "unpack <app-name> [-o output_dir]",
+	Short: "Unpack the app to expose the content",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		err := packager.Unpack(args[0], unpackOutputDir)
+		if err != nil {
+			fmt.Printf("%v\n", err)
+			os.Exit(1)
+		}
+	},
+}
+
+var unpackOutputDir string
+
+func init() {
+	rootCmd.AddCommand(unpackCmd)
+	unpackCmd.Flags().StringVarP(&unpackOutputDir, "output", "o", ".", "Output directory (.)")
+}

packager/extract.go

@@ -27,35 +27,43 @@ func Extract(appname string) (string, func(), error) {
 		return appname, func() {}, nil
 	}
 	// not a dir: probably a tarball package, extract that in a temp dir
-	f, err := os.Open(appname)
+	tempDir, err := ioutil.TempDir("", "dockerapp")
 	if err != nil {
 		return "", func() {}, err
 	}
-	tempDir, err := ioutil.TempDir("", "dockerapp")
+	err = extract(appname, tempDir)
 	if err != nil {
 		return "", func() {}, err
 	}
+	return tempDir, func() { os.RemoveAll(tempDir) }, nil
+}
+
+func extract(appname, outputDir string) error {
+	f, err := os.Open(appname)
+	if err != nil {
+		return err
+	}
 	tarReader := tar.NewReader(f)
 	for {
 		header, err := tarReader.Next()
 		if err == io.EOF {
 			break
 		}
 		if err != nil {
-			return "", func() {}, err
+			return err
 		}
-		tempDir = tempDir + "/"
+		outputDir = outputDir + "/"
 		switch header.Typeflag {
 		case tar.TypeDir: // = directory
-			os.Mkdir(tempDir+header.Name, 0755)
+			os.Mkdir(outputDir+header.Name, 0755)
 		case tar.TypeReg: // = regular file
 			data := make([]byte, header.Size)
 			_, err := tarReader.Read(data)
 			if err != nil {
-				return "", func() {}, err
+				return err
 			}
-			ioutil.WriteFile(tempDir+header.Name, data, 0755)
+			ioutil.WriteFile(outputDir+header.Name, data, 0644)
 		}
 	}
-	return tempDir, func() { os.RemoveAll(tempDir) }, nil
+	return nil
 }

packager/packing.go

@@ -0,0 +1,77 @@
+package packager
+
+import (
+	"archive/tar"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/docker/lunchbox/utils"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+// Pack packs the app as a single file
+func Pack(appname, output string) error {
+	if output == "-" && terminal.IsTerminal(int(os.Stdout.Fd())) {
+		return fmt.Errorf("Refusing to output to a terminal, use a shell redirect or the '-o' option")
+	}
+	appname, cleanup, err := Extract(appname)
+	if err != nil {
+		return err
+	}
+	defer cleanup()
+	var target io.Writer
+	if output == "-" {
+		target = os.Stdout
+	} else {
+		target, err = os.Create(output)
+		if err != nil {
+			return err
+		}
+	}
+	tarout := tar.NewWriter(target)
+	files := []string{"metadata.yml", "services.yml", "settings.yml"}
+	for _, f := range files {
+		payload, err := ioutil.ReadFile(path.Join(appname, f))
+		if err != nil {
+			return err
+		}
+		h := &tar.Header{
+			Name: f,
+			Size: int64(len(payload)),
+		}
+		err = tarout.WriteHeader(h)
+		if err != nil {
+			return err
+		}
+		_, err = tarout.Write(payload)
+		if err != nil {
+			return err
+		}
+	}
+	return tarout.Close()
+}
+
+// Unpack extracts a packed app
+func Unpack(appname, targetDir string) error {
+	s, err := os.Stat(appname)
+	if err != nil {
+		// try appending our extension
+		appname = utils.DirNameFromAppName(appname)
+		s, err = os.Stat(appname)
+	}
+	if err != nil {
+		return err
+	}
+	if s.IsDir() {
+		return fmt.Errorf("app already extracted")
+	}
+	out := path.Join(targetDir, utils.AppNameFromDir(appname)+".docker-app")
+	err = os.Mkdir(out, 0755)
+	if err != nil {
+		return err
+	}
+	return extract(appname, out)
+}