vagrant builder: define source box and output box in Vagrantfile

builder/vagrant/builder.go

@@ -199,6 +199,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 		&StepCreateVagrantfile{
 			Template:     b.config.Template,
 			SyncedFolder: b.config.SyncedFolder,
+			SourceBox:    b.config.SourceBox,
 			BoxName:      b.config.BoxName,
 			OutputDir:    b.config.OutputDir,
 			GlobalID:     b.config.GlobalID,

builder/vagrant/step_create_vagrantfile.go

@@ -17,11 +17,18 @@ type StepCreateVagrantfile struct {
 	OutputDir    string
 	SyncedFolder string
 	GlobalID     string
+	SourceBox    string
 	BoxName      string
 }
 
 var DEFAULT_TEMPLATE = `Vagrant.configure("2") do |config|
-  config.vm.box = "{{.BoxName}}"
+  config.vm.define "source", autostart: false do |source|
+	source.vm.box = "{{.SourceBox}}"
+  end
+  config.vm.define "output" do |output|
+	output.vm.box = "{{.BoxName}}"
+	output.vm.box_url = "file://package.box"
+  end
   {{ if ne .SyncedFolder "" -}}
   		config.vm.synced_folder "{{.SyncedFolder}}", "/vagrant"
   {{- else -}}
@@ -31,6 +38,7 @@ end`
 
 type VagrantfileOptions struct {
 	SyncedFolder string
+	SourceBox    string
 	BoxName      string
 }
 
@@ -57,6 +65,7 @@ func (s *StepCreateVagrantfile) createVagrantfile() (string, error) {
 	opts := &VagrantfileOptions{
 		SyncedFolder: s.SyncedFolder,
 		BoxName:      s.BoxName,
+		SourceBox:    s.SourceBox,
 	}
 
 	err = tpl.Execute(templateFile, opts)

builder/vagrant/step_create_vagrantfile_test.go

@@ -20,6 +20,7 @@ func TestStepCreateVagrantfile_Impl(t *testing.T) {
 func TestCreateFile(t *testing.T) {
 	testy := StepCreateVagrantfile{
 		OutputDir: "./",
+		SourceBox: "apples",
 		BoxName:   "bananas",
 	}
 	templatePath, err := testy.createVagrantfile()
@@ -30,7 +31,13 @@ func TestCreateFile(t *testing.T) {
 	contents, err := ioutil.ReadFile(templatePath)
 	actual := string(contents)
 	expected := `Vagrant.configure("2") do |config|
-  config.vm.box = "bananas"
+  config.vm.define "source", autostart: false do |source|
+	source.vm.box = "apples"
+  end
+  config.vm.define "output" do |output|
+	output.vm.box = "bananas"
+	output.vm.box_url = "file://package.box"
+  end
   config.vm.synced_folder ".", "/vagrant", disabled: true
 end`
 	if ok := strings.Compare(actual, expected); ok != 0 {
@@ -51,7 +58,13 @@ func TestCreateFile_customSync(t *testing.T) {
 	contents, err := ioutil.ReadFile(templatePath)
 	actual := string(contents)
 	expected := `Vagrant.configure("2") do |config|
-  config.vm.box = ""
+  config.vm.define "source", autostart: false do |source|
+	source.vm.box = ""
+  end
+  config.vm.define "output" do |output|
+	output.vm.box = ""
+	output.vm.box_url = "file://package.box"
+  end
   config.vm.synced_folder "myfolder/foldertimes", "/vagrant"
 end`
 	if ok := strings.Compare(actual, expected); ok != 0 {

builder/vagrant/step_up.go

@@ -20,7 +20,8 @@ func (s *StepUp) Run(ctx context.Context, state multistep.StateBag) multistep.St
 
 	ui.Say("Calling Vagrant Up...")
 
-	var args []string
+	// start only the source box
+	args := []string{"source"}
 	if s.GlobalID != "" {
 		args = append(args, s.GlobalID)
 	}