envName := strings.Replace(strings.ToUpper(name), "-", "_", -1)
	// Note: we do not rely on istio env package to retrieve configuration. We relies on viper.
	// This is just to make sure the reference doc tool can generate doc with these vars as env variable at istio.io.
	env.Register(envName, defaultValue, usage)
	bindViper(name)
}

func bindViper(name string) {