Added basic version of quiet mode to service create command

pkg/kn/commands/service/create.go

@@ -148,7 +148,13 @@ func NewServiceCreateCommand(p *commands.KnParams) *cobra.Command {
 				return err
 			}
 
-			out := cmd.OutOrStdout()
+			var out io.Writer
+			if p.QuietMode {
+				out = io.Discard
+			} else {
+				out = cmd.OutOrStdout()
+			}
+
 			if serviceExists {
 				if !editFlags.ForceCreate {
 					return fmt.Errorf(

pkg/kn/commands/types.go

@@ -70,6 +70,8 @@ type KnParams struct {
 	// General global options
 	LogHTTP bool
 
+	QuietMode bool
+
 	// Set this if you want to nail down the namespace
 	fixedCurrentNamespace string
 }

pkg/kn/root/root.go

@@ -92,6 +92,7 @@ Find more information about Knative at: https://knative.dev`, rootName),
 	rootCmd.PersistentFlags().StringVar(&p.KubeAsUID, "as-uid", "", "uid to impersonate for the operation")
 	rootCmd.PersistentFlags().StringArrayVar(&p.KubeAsGroup, "as-group", []string{}, "group to impersonate for the operation, this flag can be repeated to specify multiple groups")
 	flags.AddBothBoolFlags(rootCmd.PersistentFlags(), &p.LogHTTP, "log-http", "", false, "log http traffic")
+	rootCmd.PersistentFlags().BoolVarP(&p.QuietMode, "quiet-mode", "q", false, "run commands in quiet mode")
 
 	// Grouped commands
 	groups := templates.CommandGroups{