def key_helper(self):
        """ Generates a public key and a private key and stores them in the config. The public key will be applied to
        all the instances in the deployment later on when wait() is called.
        """
        if self.config['key_helper']:
            private_key, public_key = util.generate_rsa_keypair()
            self.config['ssh_private_key'] = private_key.decode()
            self.config['ssh_public_key'] = public_key.decode()