Add namespace column for docker stack ls command while targeting Kubernetes orchestrator

Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>

cli/command/stack/kubernetes/list.go

@@ -16,12 +16,12 @@ func RunList(dockerCli *KubeCli, opts options.List) error {
 		return err
 	}
 	format := opts.Format
-	if len(format) == 0 {
-		format = formatter.TableFormatKey
+	if format == "" || format == formatter.TableFormatKey {
+		format = formatter.KubernetesStackTableFormat
 	}
 	stackCtx := formatter.Context{
 		Output: dockerCli.Out(),
-		Format: formatter.NewStackFormat(format),
+		Format: formatter.Format(format),
 	}
 	sort.Sort(byName(stacks))
 	return formatter.StackWrite(stackCtx, stacks)
@@ -51,6 +51,7 @@ func getStacks(kubeCli *KubeCli) ([]*formatter.Stack, error) {
 			Name:         stack.name,
 			Services:     len(stack.getServices()),
 			Orchestrator: "Kubernetes",
+			Namespace:    stack.namespace,
 		})
 	}
 	return formattedStacks, nil