code: func validateResolveImageFlag(dockerCli command.Cli, opts *options.Deploy) error {
  	if opts.ResolveImage != ResolveImageAlways && opts.ResolveImage != ResolveImageChanged && opts.ResolveImage != ResolveImageNever {
  		return errors.Errorf("Invalid option %s for flag --resolve-image", opts.ResolveImage)
  	}
  	// client side image resolution should not be done when the supported
  	// server version is older than 1.30
  	if versions.LessThan(dockerCli.Client().ClientVersion(), "1.30") {
  		opts.ResolveImage = ResolveImageNever
  	}
  	return nil
  }
docs: // validateResolveImageFlag validates the opts.resolveImage command line option
  // and also turns image resolution off if the version is older than 1.30