bugfix: populate volume error

Signed-off-by: Eric Li <[email protected]>

daemon/mgr/container_storage.go

@@ -5,14 +5,14 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path"
 	"path/filepath"
 	"regexp"
 	"strconv"
 
 	"github.com/alibaba/pouch/apis/opts"
 	"github.com/alibaba/pouch/apis/types"
+	"github.com/alibaba/pouch/pkg/archive"
 	"github.com/alibaba/pouch/pkg/errtypes"
 	"github.com/alibaba/pouch/pkg/randomid"
 	"github.com/alibaba/pouch/pkg/system"
@@ -672,15 +672,9 @@ func copyImageContent(source, destination string) error {
 			return err
 		}
 		if len(dstList) == 0 {
-			// TODO: refactor
-
-			// If the source volume is empty, copies files from the root into the volume
-			commandLine := fmt.Sprintf("cp -r %s/* %s", source, destination)
-
-			cmd := exec.Command("sh", "-c", commandLine)
-			out, err := cmd.CombinedOutput()
+			err := archive.CopyWithTar(source, destination)
 			if err != nil {
-				logrus.Errorf("copyImageContent: %s, %v", string(out), err)
+				logrus.Errorf("copyImageContent: %v", err)
 				return err
 			}
 		}

pkg/archive/archive.go

@@ -0,0 +1,116 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func tarFromDir(src string, writer io.Writer) error {
+	// ensure the src actually exists before trying to tar it
+	if _, err := os.Stat(src); err != nil {
+		return fmt.Errorf("failed to stat source file %s: %v", src, err)
+	}
+
+	tw := tar.NewWriter(writer)
+	defer tw.Close()
+
+	// walk path
+	return filepath.Walk(src, func(file string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// create a new dir/file header
+		header, err := tar.FileInfoHeader(fi, fi.Name())
+		if err != nil {
+			return err
+		}
+
+		// update the name to correctly reflect the desired destination when untaring
+		header.Name = strings.TrimPrefix(strings.Replace(file, src, "", 1), string(filepath.Separator))
+		// write the header
+		if err := tw.WriteHeader(header); err != nil {
+			return err
+		}
+
+		if !fi.Mode().IsRegular() {
+			return nil
+		}
+
+		// open files for taring
+		f, err := os.Open(file)
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+
+		// copy file data into tar writer
+		if _, err := io.Copy(tw, f); err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
+func untarToDir(dst string, r io.Reader) error {
+	tr := tar.NewReader(r)
+
+	for {
+		header, err := tr.Next()
+
+		switch {
+		case err == io.EOF:
+			return nil
+		case err != nil:
+			return err
+		case header == nil:
+			continue
+		}
+
+		// the target location where the dir/file should be created
+		target := filepath.Join(dst, header.Name)
+
+		// check the file type
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if _, err := os.Stat(target); err != nil {
+				if err := os.MkdirAll(target, 0755); err != nil {
+					return err
+				}
+			}
+		case tar.TypeReg:
+			f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+
+			if _, err := io.Copy(f, tr); err != nil {
+				return err
+			}
+		}
+	}
+}
+
+// CopyWithTar create a tar from src directory,
+// and untar it in dst directory.
+func CopyWithTar(src, dst string) error {
+	buf := new(bytes.Buffer)
+
+	if err := tarFromDir(src, buf); err != nil {
+		return err
+	}
+
+	if err := untarToDir(dst, buf); err != nil {
+		return err
+	}
+
+	return nil
+
+}