Merge pull request #79 from yacn/feature/basevmdk

Adds config option to specify a base disk image for persistence partition

Author: riobard

cmds.go

@@ -121,10 +121,18 @@ func cmdInit() int {
 			return 1
 		}
 
-		if err := makeDiskImage(diskImg, B2D.DiskSize); err != nil {
-			logf("Failed to create disk image %q: %s", diskImg, err)
-			return 1
-		}
+    if B2D.VMDK != "" {
+      logf("Using %v as base VMDK", B2D.VMDK)
+      if err := copyDiskImage(diskImg, B2D.VMDK); err != nil {
+        logf("Failed to copy disk image %v from %v: %s", diskImg, B2D.VMDK, err)
+        return 1
+      }
+    } else {
+      if err := makeDiskImage(diskImg, B2D.DiskSize); err != nil {
+        logf("Failed to create disk image %q: %s", diskImg, err)
+        return 1
+      }
+    }
 	}
 
 	if err := m.AttachStorage("SATA", vbx.StorageMedium{Port: 1, Device: 0, DriveType: vbx.DriveHDD, Medium: diskImg}); err != nil {

config.go

@@ -28,6 +28,7 @@ var B2D struct {
 	VM       string // virtual machine name
 	Dir      string // boot2docker directory
 	ISO      string // boot2docker ISO image path
+	VMDK     string // base VMDK to use as persistent disk
 	DiskSize uint   // VM disk image size (MB)
 	Memory   uint   // VM memory size (MB)
 
@@ -106,6 +107,7 @@ func config() (*flag.FlagSet, error) {
 	flags.StringVar(&B2D.VM, "vm", "boot2docker-vm", "virtual machine name.")
 	flags.StringVarP(&B2D.Dir, "dir", "d", dir, "boot2docker config directory.")
 	flags.StringVar(&B2D.ISO, "iso", filepath.Join(dir, "boot2docker.iso"), "path to boot2docker ISO image.")
+	flags.StringVar(&B2D.VMDK, "basevmdk", "", "Path to VMDK to use as base for persistent partition")
 	vbm := "VBoxManage"
 	if p := os.Getenv("VBOX_INSTALL_PATH"); p != "" && runtime.GOOS == "windows" {
 		vbm = filepath.Join(p, "VBoxManage.exe")

vbm.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"io"
 	"os"
 	"path/filepath"
 
@@ -66,6 +67,33 @@ func getHostOnlyNetworkInterface() (string, error) {
 	return hostonlyNet.Name, nil
 }
 
+// Copy disk image from given source path to destination
+func copyDiskImage(dst, src string) (err error) {
+	// Open source disk image
+	srcImg, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	closeSrcImg := func() {
+		if ee := srcImg.Close(); ee != nil {
+			err = ee
+		}
+	}
+	defer closeSrcImg()
+	dstImg, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	closeDstImg := func() {
+		if ee := dstImg.Close(); ee != nil {
+			err = ee
+		}
+	}
+	defer closeDstImg()
+	_, err = io.Copy(dstImg, srcImg)
+	return err
+}
+
 // Make a boot2docker VM disk image with the given size (in MB).
 func makeDiskImage(dest string, size uint) error {
 	// Create the dest dir.