builder/virtualbox: Upload version to a "virtualbox_version_file"

builder/virtualbox/builder.go

@@ -43,6 +43,7 @@ type config struct {
 	SSHPort         uint          `mapstructure:"ssh_port"`
 	SSHUser         string        `mapstructure:"ssh_username"`
 	SSHWaitTimeout  time.Duration ``
+	VBoxVersionFile string        `mapstructure:"virtualbox_version_file"`
 	VBoxManage      [][]string    `mapstructure:"vboxmanage"`
 	VMName          string        `mapstructure:"vm_name"`
 
@@ -99,6 +100,10 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		b.config.VBoxManage = make([][]string, 0)
 	}
 
+	if b.config.VBoxVersionFile == "" {
+		b.config.VBoxVersionFile = ".vbox_version"
+	}
+
 	if b.config.VMName == "" {
 		b.config.VMName = "packer"
 	}
@@ -213,6 +218,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		new(stepRun),
 		new(stepTypeBootCommand),
 		new(stepWaitForSSH),
+		new(stepUploadVersion),
 		new(stepProvision),
 		new(stepShutdown),
 		new(stepExport),

builder/virtualbox/builder_test.go

@@ -315,3 +315,31 @@ func TestBuilderPrepare_VBoxManage(t *testing.T) {
 		t.Fatalf("bad: %#v", b.config.VBoxManage)
 	}
 }
+
+func TestBuilderPrepare_VBoxVersionFile(t *testing.T) {
+	var b Builder
+	config := testConfig()
+
+	// Test empty
+	delete(config, "virtualbox_version_file")
+	err := b.Prepare(config)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if b.config.VBoxVersionFile != ".vbox_version" {
+		t.Fatalf("bad value: %s", b.config.VBoxVersionFile)
+	}
+
+	// Test with a good one
+	config["virtualbox_version_file"] = "foo"
+	b = Builder{}
+	err = b.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+
+	if b.config.VBoxVersionFile != "foo" {
+		t.Fatalf("bad value: %s", b.config.VBoxVersionFile)
+	}
+}

builder/virtualbox/driver.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os/exec"
+	"regexp"
 	"strings"
 	"time"
 )
@@ -29,6 +30,9 @@ type Driver interface {
 	// properly. If there is any indication the driver can't function,
 	// this will return an error.
 	Verify() error
+
+	// Version reads the version of VirtualBox that is installed.
+	Version() (string, error)
 }
 
 type VBox42Driver struct {
@@ -104,3 +108,21 @@ func (d *VBox42Driver) VBoxManage(args ...string) error {
 func (d *VBox42Driver) Verify() error {
 	return nil
 }
+
+func (d *VBox42Driver) Version() (string, error) {
+	var stdout bytes.Buffer
+
+	cmd := exec.Command(d.VBoxManagePath, "--version")
+	cmd.Stdout = &stdout
+	if err := cmd.Run(); err != nil {
+		return "", err
+	}
+
+	versionRe := regexp.MustCompile("[^.0-9]")
+	matches := versionRe.Split(stdout.String(), 2)
+	if len(matches) == 0 {
+		return "", fmt.Errorf("No version found: %s", stdout.String())
+	}
+
+	return matches[0], nil
+}

builder/virtualbox/step_upload_version.go

@@ -0,0 +1,37 @@
+package virtualbox
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/packer"
+)
+
+// This step uploads a file containing the VirtualBox version, which
+// can be useful for various provisioning reasons.
+type stepUploadVersion struct{}
+
+func (s *stepUploadVersion) Run(state map[string]interface{}) multistep.StepAction {
+	comm := state["communicator"].(packer.Communicator)
+	config := state["config"].(*config)
+	driver := state["driver"].(Driver)
+	ui := state["ui"].(packer.Ui)
+
+	version, err := driver.Version()
+	if err != nil {
+		state["error"] = fmt.Errorf("Error reading version for metadata upload: %s", err)
+		return multistep.ActionHalt
+	}
+
+	ui.Say(fmt.Sprintf("Uploading VirtualBox version info (%s)", version))
+	var data bytes.Buffer
+	data.WriteString(version)
+	if err := comm.Upload(config.VBoxVersionFile, &data); err != nil {
+		state["error"] = fmt.Errorf("Error uploading VirtualBox version: %s", err)
+		return multistep.ActionHalt
+	}
+
+	return multistep.ActionContinue
+}
+
+func (s *stepUploadVersion) Cleanup(state map[string]interface{}) {}