builder/amazon-chroot: add mount_options configuration option

builder/amazon/chroot/builder.go

@@ -35,6 +35,7 @@ type Config struct {
 	MountPath      string     `mapstructure:"mount_path"`
 	SourceAmi      string     `mapstructure:"source_ami"`
 	RootVolumeSize int64      `mapstructure:"root_volume_size"`
+	MountOptions   []string   `mapstructure:"mount_options"`
 
 	ctx interpolate.Context
 }
@@ -165,7 +166,9 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		},
 		&StepAttachVolume{},
 		&StepEarlyUnflock{},
-		&StepMountDevice{},
+		&StepMountDevice{
+			MountOptions: b.config.MountOptions,
+		},
 		&StepMountExtra{},
 		&StepCopyFiles{},
 		&StepChrootProvision{},

builder/amazon/chroot/step_mount_device.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/mitchellh/multistep"
@@ -24,6 +25,7 @@ type mountPathData struct {
 //   mount_device_cleanup CleanupFunc - To perform early cleanup
 type StepMountDevice struct {
 	mountPath    string
+	MountOptions []string
 }
 
 func (s *StepMountDevice) Run(state multistep.StateBag) multistep.StepAction {
@@ -70,8 +72,15 @@ func (s *StepMountDevice) Run(state multistep.StateBag) multistep.StepAction {
 
 	ui.Say("Mounting the root device...")
 	stderr := new(bytes.Buffer)
+
+	// build mount options from mount_options config, usefull for nouuid options
+	// or other specific device type settings for mount
+	opts := ""
+	if len(s.MountOptions) > 0 {
+		opts = "-o " + strings.Join(s.MountOptions, " -o ")
+	}
 	mountCommand, err := wrappedCommand(
-		fmt.Sprintf("mount %s %s", deviceMount, mountPath))
+		fmt.Sprintf("mount %s %s %s", opts, deviceMount, mountPath))
 	if err != nil {
 		err := fmt.Errorf("Error creating mount command: %s", err)
 		state.Put("error", err)