command/*: colors on error messages (red)

command/cli_ui.go

@@ -0,0 +1,42 @@
+package command
+
+import (
+	"fmt"
+
+	"github.com/mitchellh/cli"
+	"github.com/mitchellh/colorstring"
+)
+
+// ColoredUi is a Ui implementation that colors its output according
+// to the given color schemes for the given type of output.
+type ColorizeUi struct {
+	Colorize    *colorstring.Colorize
+	OutputColor string
+	InfoColor   string
+	ErrorColor  string
+	Ui          cli.Ui
+}
+
+func (u *ColorizeUi) Ask(query string) (string, error) {
+	return u.Ui.Ask(u.colorize(query, u.OutputColor))
+}
+
+func (u *ColorizeUi) Output(message string) {
+	u.Ui.Output(u.colorize(message, u.OutputColor))
+}
+
+func (u *ColorizeUi) Info(message string) {
+	u.Ui.Info(u.colorize(message, u.InfoColor))
+}
+
+func (u *ColorizeUi) Error(message string) {
+	u.Ui.Error(u.colorize(message, u.ErrorColor))
+}
+
+func (u *ColorizeUi) colorize(message string, color string) string {
+	if color == "" {
+		return message
+	}
+
+	return u.Colorize.Color(fmt.Sprintf("%s%s[reset]", color, message))
+}

command/cli_ui_test.go

@@ -0,0 +1,11 @@
+package command
+
+import (
+	"testing"
+
+	"github.com/mitchellh/cli"
+)
+
+func TestColorizeUi_impl(t *testing.T) {
+	var _ cli.Ui = new(ColorizeUi)
+}

command/meta.go

@@ -15,6 +15,8 @@ type Meta struct {
 	Color       bool
 	ContextOpts *terraform.ContextOpts
 	Ui          cli.Ui
+
+	oldUi cli.Ui
 }
 
 // Colorize returns the colorization structure for a command.
@@ -104,15 +106,30 @@ func (m *Meta) contextOpts() *terraform.ContextOpts {
 // will potentially modify the args in-place. It will return the resulting
 // slice.
 func (m *Meta) process(args []string) []string {
-	m.Color = true
+	// We do this so that we retain the ability to technically call
+	// process multiple times, even if we have no plans to do so
+	if m.oldUi != nil {
+		m.Ui = m.oldUi
+	}
 
+	// Set colorization
+	m.Color = true
 	for i, v := range args {
 		if v == "-no-color" {
 			m.Color = false
-			return append(args[:i], args[i+1:]...)
+			args = append(args[:i], args[i+1:]...)
+			break
 		}
 	}
 
+	// Set the UI
+	m.oldUi = m.Ui
+	m.Ui = &ColorizeUi{
+		Colorize:   m.Colorize(),
+		ErrorColor: "[red]",
+		Ui:         m.oldUi,
+	}
+
 	return args
 }