Move around code for better clarity

pkg/util/util_linux.go

@@ -0,0 +1,125 @@
+// +build linux
+
+package util
+
+import (
+	"bufio"
+	"bytes"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/SvenDowideit/cpuid"
+	"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, target, fsType, options string) error {
+	if err := mountProc(); err != nil {
+		return nil
+	}
+
+	bindMount := false
+	for _, v := range strings.Split(options, ",") {
+		if v == "bind" {
+			bindMount = true
+			break
+		}
+	}
+
+	if bindMount {
+		deviceInfo, err := os.Stat(device)
+		if err != nil {
+			return err
+		}
+		mode := deviceInfo.Mode()
+
+		switch {
+		case mode.IsDir():
+			if err := os.MkdirAll(target, 0755); err != nil {
+				return err
+			}
+		case mode.IsRegular():
+			err := os.MkdirAll(filepath.Dir(target), 0755)
+			if err != nil {
+				return err
+			}
+			file, err := os.OpenFile(target, os.O_CREATE, mode&os.ModePerm)
+			if err != nil {
+				return err
+			}
+			if err := file.Close(); err != nil {
+				return err
+			}
+		default:
+			return os.ErrInvalid
+		}
+	} else {
+		err := os.MkdirAll(target, 0755)
+		if err != nil {
+			return err
+		}
+
+		if fsType == "auto" || fsType == "" {
+			inferredType, err := GetFsType(device)
+			if err != nil {
+				return err
+			}
+			fsType = inferredType
+		}
+	}
+
+	return mount.Mount(device, target, fsType, options)
+}
+
+func Unmount(target string) error {
+	return mount.Unmount(target)
+}
+
+func Blkid(label string) (deviceName, deviceType string, err error) {
+	// Not all blkid's have `blkid -L label (see busybox/alpine)
+	cmd := exec.Command("blkid")
+	cmd.Stderr = os.Stderr
+	out, err := cmd.Output()
+	if err != nil {
+		return
+	}
+	r := bytes.NewReader(out)
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		line := s.Text()
+		if !strings.Contains(line, `LABEL="`+label+`"`) {
+			continue
+		}
+		d := strings.Split(line, ":")
+		deviceName = d[0]
+
+		s1 := strings.Split(line, `TYPE="`)
+		s2 := strings.Split(s1[1], `"`)
+		deviceType = s2[0]
+		return
+	}
+	return
+}
+
+// GetHypervisor tries to detect if we're running in a VM, and returns a string for its type
+func GetHypervisor() string {
+	return cpuid.CPU.HypervisorName
+}