Interactive golang cli with promptui

main.go

package main

import (
	"fmt"
	"log"
	"os"

	"github.com/go-ozzo/ozzo-validation"
	"github.com/go-ozzo/ozzo-validation/is"
	"github.com/manifoldco/promptui"
	"github.com/urfave/cli"
)

func promptUsername() (string, error) {
	usernameValidate :=
		func(input string) error {
			return validation.Validate(input,
				validation.Required, // not empty
				is.Email,            // is a valid Email
			)
		}

	userNamePrompt := promptui.Prompt{
		Label:    "Username",
		Validate: usernameValidate,
	}

	return userNamePrompt.Run()
}

func promptPassword() (string, error) {
	passwordValidate :=
		func(input string) error {
			return validation.Validate(input,
				validation.Required,       // not empty
				validation.Length(5, 100), // length between 5 and 100
			)
		}

	passwordPrompt := promptui.Prompt{
		Label:    "Password",
		Validate: passwordValidate,
	}
	return passwordPrompt.Run()
}

func main() {
	app := cli.NewApp()
	app.Name = "interactive-cli"
	app.Usage = "An interactive cli to type credentials"
	app.Action = func(c *cli.Context) error {
		fmt.Println("Login with a authorized user!")
		name, err := promptUsername()
		if err != nil {
			fmt.Printf("Invalid Username %v \n", err)
		}

		pw, err := promptPassword()
		if err != nil {
			fmt.Printf("Invalid Password %v \n", err)
		}
		fmt.Printf("Sweet! %s, pw %s", name, pw)

		return nil
	}

	err := app.Run(os.Args)
	if err != nil {
		log.Fatal(err)
	}
}