consider dry run

Author: Hidetatsu Yaginuma

printer/kubectl_apply.go

@@ -22,29 +22,64 @@ func (ap *ApplyPrinter) Print(r io.Reader, w io.Writer) {
 		applyActionCreated    = "created"
 		applyActionConfigured = "configured"
 		applyActionUnchanged  = "unchanged"
+
+		dryRunStr = "(dry run)"
 	)
 
-	colors := map[string]color.Color{
+	darkColors := map[string]color.Color{
+		applyActionCreated:    color.Green,
+		applyActionConfigured: color.Yellow,
+		applyActionUnchanged:  color.Magenta,
+		dryRunStr:             color.Cyan,
+	}
+	lightColors := map[string]color.Color{
 		applyActionCreated:    color.Green,
 		applyActionConfigured: color.Yellow,
 		applyActionUnchanged:  color.Magenta,
+		dryRunStr:             color.Blue,
 	}
 
-	colorize := func(line, action string, wr io.Writer) {
+	colors := func(action string, dark bool) color.Color {
+		if dark {
+			return darkColors[action]
+		}
+		return lightColors[action]
+	}
+
+	colorize := func(line, action string, dryRun bool, wr io.Writer) {
+		if dryRun {
+			arg := strings.TrimSuffix(line, fmt.Sprintf(" %s %s", action, dryRunStr))
+			fmt.Fprintf(w, "%s %s %s\n",
+				arg,
+				color.Apply(action, colors(action, ap.DarkBackground)),
+				color.Apply(dryRunStr, colors(dryRunStr, ap.DarkBackground)),
+			)
+			return
+		}
+
 		arg := strings.TrimSuffix(line, " "+action)
-		fmt.Fprintf(w, "%s %s\n", arg, color.Apply(action, colors[action]))
+		fmt.Fprintf(w, "%s %s\n", arg, color.Apply(action, colors(action, ap.DarkBackground)))
 	}
 
 	scanner := bufio.NewScanner(r)
 	for scanner.Scan() {
 		line := scanner.Text()
 		switch {
+		// on dry run cases, it shows "xxx created (dry run)"
+		case strings.HasSuffix(line, fmt.Sprintf(" %s %s", applyActionCreated, dryRunStr)):
+			colorize(line, applyActionCreated, true, w)
+		case strings.HasSuffix(line, fmt.Sprintf(" %s %s", applyActionConfigured, dryRunStr)):
+			colorize(line, applyActionConfigured, true, w)
+		case strings.HasSuffix(line, fmt.Sprintf(" %s %s", applyActionUnchanged, dryRunStr)):
+			colorize(line, applyActionUnchanged, true, w)
+
+		// not dry run cases, it shows "xxx created"
 		case strings.HasSuffix(line, " "+applyActionCreated):
-			colorize(line, applyActionCreated, w)
+			colorize(line, applyActionCreated, false, w)
 		case strings.HasSuffix(line, " "+applyActionConfigured):
-			colorize(line, applyActionConfigured, w)
+			colorize(line, applyActionConfigured, false, w)
 		case strings.HasSuffix(line, " "+applyActionUnchanged):
-			colorize(line, applyActionUnchanged, w)
+			colorize(line, applyActionUnchanged, false, w)
 		default:
 			fmt.Fprintf(w, "%s\n", color.Apply(line, color.Green))
 		}

printer/kubectl_apply_test.go

@@ -43,6 +43,15 @@ func Test_ApplyPrinter_Print(t *testing.T) {
 				deployment.apps/foo unchanged
 			`),
 		},
+		{
+			name:           "dry run",
+			darkBackground: true,
+			input: testutil.NewHereDoc(`
+				deployment.apps/foo unchanged (dry run)`),
+			expected: testutil.NewHereDoc(`
+				deployment.apps/foo unchanged (dry run)
+			`),
+		},
 		{
 			name:           "something else. This likely won't happen but fallbacks here just in case.",
 			darkBackground: true,