packer: Add Message method to Ui

command/build/command.go

@@ -63,6 +63,7 @@ func (c Command) Run(env packer.Environment, args []string) int {
 	for _, b := range builds {
 		buildUis[b.Name()] = &packer.PrefixedUi{
 			fmt.Sprintf("==> %s", b.Name()),
+			fmt.Sprintf("--> %s", b.Name()),
 			env.Ui(),
 		}
 	}

packer/rpc/ui.go

@@ -23,6 +23,12 @@ func (u *Ui) Error(message string) {
 	}
 }
 
+func (u *Ui) Message(message string) {
+	if err := u.client.Call("Ui.Message", message, new(interface{})); err != nil {
+		panic(err)
+	}
+}
+
 func (u *Ui) Say(message string) {
 	if err := u.client.Call("Ui.Say", message, new(interface{})); err != nil {
 		panic(err)
@@ -36,6 +42,12 @@ func (u *UiServer) Error(message *string, reply *interface{}) error {
 	return nil
 }
 
+func (u *UiServer) Message(message *string, reply *interface{}) error {
+	u.ui.Message(*message)
+	*reply = nil
+	return nil
+}
+
 func (u *UiServer) Say(message *string, reply *interface{}) error {
 	u.ui.Say(*message)
 

packer/rpc/ui_test.go

@@ -7,10 +7,12 @@ import (
 )
 
 type testUi struct {
-	errorCalled  bool
+	errorCalled    bool
-	errorMessage string
+	errorMessage   string
-	sayCalled    bool
+	messageCalled  bool
-	sayMessage   string
+	messageMessage string
+	sayCalled      bool
+	sayMessage     string
 }
 
 func (u *testUi) Error(message string) {
@@ -18,6 +20,11 @@ func (u *testUi) Error(message string) {
 	u.errorMessage = message
 }
 
+func (u *testUi) Message(message string) {
+	u.messageCalled = true
+	u.messageMessage = message
+}
+
 func (u *testUi) Say(message string) {
 	u.sayCalled = true
 	u.sayMessage = message
@@ -46,6 +53,9 @@ func TestUiRPC(t *testing.T) {
 	uiClient.Error("message")
 	assert.Equal(ui.errorMessage, "message", "message should be correct")
 
+	uiClient.Message("message")
+	assert.Equal(ui.messageMessage, "message", "message should be correct")
+
 	uiClient.Say("message")
 	assert.Equal(ui.sayMessage, "message", "message should be correct")
 }

packer/ui.go

@@ -11,14 +11,16 @@ import (
 // is formatted and various levels of output.
 type Ui interface {
 	Say(string)
+	Message(string)
 	Error(string)
 }
 
 // PrefixedUi is a UI that wraps another UI implementation and adds a
 // prefix to all the messages going out.
 type PrefixedUi struct {
-	Prefix string
+	SayPrefix     string
-	Ui     Ui
+	MessagePrefix string
+	Ui            Ui
 }
 
 // The ReaderWriterUi is a UI that writes and reads from standard Go
@@ -29,11 +31,15 @@ type ReaderWriterUi struct {
 }
 
 func (u *PrefixedUi) Say(message string) {
-	u.Ui.Say(fmt.Sprintf("%s: %s", u.Prefix, message))
+	u.Ui.Say(fmt.Sprintf("%s: %s", u.SayPrefix, message))
+}
+
+func (u *PrefixedUi) Message(message string) {
+	u.Ui.Say(fmt.Sprintf("%s: %s", u.MessagePrefix, message))
 }
 
 func (u *PrefixedUi) Error(message string) {
-	u.Ui.Error(fmt.Sprintf("%s: %s", u.Prefix, message))
+	u.Ui.Error(fmt.Sprintf("%s: %s", u.SayPrefix, message))
 }
 
 func (rw *ReaderWriterUi) Say(message string) {
@@ -44,6 +50,14 @@ func (rw *ReaderWriterUi) Say(message string) {
 	}
 }
 
+func (rw *ReaderWriterUi) Message(message string) {
+	log.Printf("ui: %s", message)
+	_, err := fmt.Fprintf(rw.Writer, message+"\n")
+	if err != nil {
+		panic(err)
+	}
+}
+
 func (rw *ReaderWriterUi) Error(message string) {
 	log.Printf("ui error: %s", message)
 	_, err := fmt.Fprint(rw.Writer, message+"\n")

packer/ui_test.go

@@ -17,11 +17,14 @@ func TestPrefixedUi(t *testing.T) {
 	assert := asserts.NewTestingAsserts(t, true)
 
 	bufferUi := testUi()
-	prefixUi := &PrefixedUi{"mitchell", bufferUi}
+	prefixUi := &PrefixedUi{"mitchell", "bar", bufferUi}
 
 	prefixUi.Say("foo")
 	assert.Equal(readWriter(bufferUi), "mitchell: foo\n", "should have prefix")
 
+	prefixUi.Message("foo")
+	assert.Equal(readWriter(bufferUi), "bar: foo\n", "should have prefix")
+
 	prefixUi.Error("bar")
 	assert.Equal(readWriter(bufferUi), "mitchell: bar\n", "should have prefix")
 }