allow to use ISO images inplace v.s. copying them

builder/virtualbox/iso/builder.go

@@ -204,6 +204,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			ResultKey:    "iso_path",
 			TargetPath:   b.config.TargetPath,
 			Url:          b.config.ISOUrls,
+			Inplace:      b.config.InplaceISO,
 		},
 		&vboxcommon.StepOutputDir{
 			Force: b.config.PackerForce,

builder/vmware/iso/builder.go

@@ -291,6 +291,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			ResultKey:    "iso_path",
 			TargetPath:   b.config.TargetPath,
 			Url:          b.config.ISOUrls,
+			Inplace:      b.config.InplaceISO,
 		},
 		&vmwcommon.StepOutputDir{
 			Force: b.config.PackerForce,

common/download.go

@@ -154,10 +154,7 @@ func (d *DownloadClient) Get() (string, error) {
 		return "", fmt.Errorf("Unable to treat uri scheme %s as a Downloader. : %T", u.Scheme, d.downloader)
 	}
 
-	local, ok := d.downloader.(LocalDownloader)
-	if !ok && !d.config.CopyFile {
-		d.config.CopyFile = true
-	}
+	local, _ := d.downloader.(LocalDownloader)
 
 	// If we're copying the file, then just use the actual downloader
 	if d.config.CopyFile {

common/iso_config.go

@@ -24,6 +24,7 @@ type ISOConfig struct {
 	TargetPath      string   `mapstructure:"iso_target_path"`
 	TargetExtension string   `mapstructure:"iso_target_extension"`
 	RawSingleISOUrl string   `mapstructure:"iso_url"`
+	InplaceISO      bool     `mapstructure:"iso_inplace"`
 }
 
 func (c *ISOConfig) Prepare(ctx *interpolate.Context) (warnings []string, errs []error) {

common/step_download.go

@@ -45,6 +45,11 @@ type StepDownload struct {
 	// extension on the URL is used. Otherwise, this will be forced
 	// on the downloaded file for every URL.
 	Extension string
+
+	// Inplace indicates wether to copy file
+	// versus using it inplace.
+	// Inplace is only used when referencing local ISO files.
+	Inplace bool
 }
 
 func (s *StepDownload) Run(_ context.Context, state multistep.StateBag) multistep.StepAction {
@@ -89,7 +94,7 @@ func (s *StepDownload) Run(_ context.Context, state multistep.StateBag) multiste
 		config := &DownloadConfig{
 			Url:        url,
 			TargetPath: targetPath,
-			CopyFile:   false,
+			CopyFile:   !s.Inplace,
 			Hash:       HashForType(s.ChecksumType),
 			Checksum:   checksum,
 			UserAgent:  useragent.String(),