code: func (container *Container) readHostConfig() error {
  	container.HostConfig = &containertypes.HostConfig{}
  	// If the hostconfig file does not exist, do not read it.
  	// (We still have to initialize container.HostConfig,
  	// but that's OK, since we just did that above.)
  	pth, err := container.HostConfigPath()
  	if err != nil {
  		return err
  	}
  
  	f, err := os.Open(pth)
  	if err != nil {
  		if os.IsNotExist(err) {
  			return nil
  		}
  		return err
  	}
  	defer f.Close()
  
  	if err := json.NewDecoder(f).Decode(&container.HostConfig); err != nil {
  		return err
  	}
  
  	container.InitDNSHostConfig()
  
  	return nil
  }
docs: // readHostConfig reads the host configuration from disk for the container.