Initial commit

util/util.go

@@ -0,0 +1,96 @@
+package util
+
+import (
+	"archive/tar"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"syscall"
+
+	"github.com/docker/docker/pkg/mount"
+)
+
+func mountProc() error {
+	if _, err := os.Stat("/proc/self/mountinfo"); os.IsNotExist(err) {
+		if _, err := os.Stat("/proc"); os.IsNotExist(err) {
+			if err = os.Mkdir("/proc", 0755); err != nil {
+				return err
+			}
+		}
+
+		if err := syscall.Mount("none", "/proc", "proc", 0, ""); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func Mount(device, directory, fsType, options string) error {
+	if err := mountProc(); err != nil {
+		return nil
+	}
+
+	if _, err := os.Stat(directory); os.IsNotExist(err) {
+		err = os.MkdirAll(directory, 0755)
+		if err != nil {
+			return err
+		}
+	}
+
+	return mount.Mount(device, directory, fsType, options)
+}
+
+func Remount(directory, options string) error {
+	return mount.Mount("", directory, "", fmt.Sprintf("remount,%s", options))
+}
+
+func ExtractTar(archive string, dest string) error {
+	f, err := os.Open(archive)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	input := tar.NewReader(f)
+
+	for {
+		header, err := input.Next()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return err
+		}
+
+		if header == nil {
+			break
+		}
+
+		fileInfo := header.FileInfo()
+		fileName := path.Join(dest, header.Name)
+		if fileInfo.IsDir() {
+			//log.Debugf("DIR : %s", fileName)
+			err = os.MkdirAll(fileName, fileInfo.Mode())
+			if err != nil {
+				return err
+			}
+		} else {
+			//log.Debugf("FILE: %s", fileName)
+			destFile, err := os.OpenFile(fileName, os.O_RDWR|os.O_CREATE|os.O_TRUNC, fileInfo.Mode())
+			if err != nil {
+				return err
+			}
+
+			_, err = io.Copy(destFile, input)
+			// Not deferring, concerned about holding open too many files
+			destFile.Close()
+
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}