code: func LogOutput() (logOutput io.Writer, err error) {
  	logOutput = ioutil.Discard
  
  	logLevel := LogLevel()
  	if logLevel == "" {
  		return
  	}
  
  	logOutput = os.Stderr
  	if logPath := os.Getenv(EnvLogFile); logPath != "" {
  		var err error
  		logOutput, err = os.OpenFile(logPath, syscall.O_CREAT|syscall.O_RDWR|syscall.O_APPEND, 0666)
  		if err != nil {
  			return nil, err
  		}
  	}
  
  	// This was the default since the beginning
  	logOutput = &logutils.LevelFilter{
  		Levels:   ValidLevels,
  		MinLevel: logutils.LogLevel(logLevel),
  		Writer:   logOutput,
  	}
  
  	return
  }
docs: // LogOutput determines where we should send logs (if anywhere) and the log level.