code: func (s *ServerRunOptions) DefaultAdvertiseAddress(secure *SecureServingOptions) error {
  	if secure == nil {
  		return nil
  	}
  
  	if s.AdvertiseAddress == nil || s.AdvertiseAddress.IsUnspecified() {
  		hostIP, err := secure.DefaultExternalAddress()
  		if err != nil {
  			return fmt.Errorf("Unable to find suitable network address.error='%v'. "+
  				"Try to set the AdvertiseAddress directly or provide a valid BindAddress to fix this.", err)
  		}
  		s.AdvertiseAddress = hostIP
  	}
  
  	return nil
  }
docs: // DefaultAdvertiseAddress sets the field AdvertiseAddress if unset. The field will be set based on the SecureServingOptions.