builder/amazon/chroot: get rid of AttachedDevicePath

builder/amazon/chroot/builder.go

@@ -24,10 +24,10 @@ type Config struct {
 	common.PackerConfig    `mapstructure:",squash"`
 	awscommon.AccessConfig `mapstructure:",squash"`
 
-	AttachedDevicePath string     `mapstructure:"attached_device_path"`
 	ChrootMounts       [][]string `mapstructure:"chroot_mounts"`
 	CopyFiles          []string   `mapstructure:"copy_files"`
 	DevicePath         string     `mapstructure:"device_path"`
+	DevicePrefix       string     `mapstructure:"device_prefix"`
 	MountCommand       string     `mapstructure:"mount_command"`
 	MountPath          string     `mapstructure:"mount_path"`
 	SourceAmi          string     `mapstructure:"source_ami"`
@@ -72,10 +72,6 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		b.config.DevicePath = "/dev/sdh"
 	}
 
-	if b.config.AttachedDevicePath == "" {
-		b.config.AttachedDevicePath = "/dev/xvdh"
-	}
-
 	if b.config.MountCommand == "" {
 		b.config.MountCommand = "mount"
 	}

builder/amazon/chroot/step_attach_volume.go

@@ -70,7 +70,7 @@ func (s *StepAttachVolume) Run(state map[string]interface{}) multistep.StepActio
 		return multistep.ActionHalt
 	}
 
-	state["device"] = config.AttachedDevicePath
+	state["device"] = device
 	state["attach_cleanup"] = s
 	return multistep.ActionContinue
 }