code: func (container *Container) FullHostname() string {
  	fullHostname := container.Config.Hostname
  	if container.Config.Domainname != "" {
  		fullHostname = fmt.Sprintf("%s.%s", fullHostname, container.Config.Domainname)
  	}
  	return fullHostname
  }
docs: // FullHostname returns hostname and optional domain appended to it.