登录文件时如何禁用日志中的字段名称

Question

I am using logrus in golang to log to file. Right now, logrus is logging to file with field name.

ie

time="26-03-2017 03:37:58" level=error msg="Not fatal. An error. Won't stop execution"

How do I remove the field names so that the log entry becomes

ERRO 26-03-2017 03:37:58 Not fatal. An error. Won't stop execution

like how it behaves in case of stderr?

Answer 1

You need to write a custom formatter that emits only the fields you want to see.

There is an example in the logrus readme:

type MyJSONFormatter struct {
}

log.SetFormatter(new(MyJSONFormatter))

func (f *MyJSONFormatter) Format(entry *Entry) ([]byte, error) {
  // Note this doesn't include Time, Level and Message which are available on
  // the Entry. Consult `godoc` on information about those fields or read the
  // source of the official loggers.
  serialized, err := json.Marshal(entry.Data)
    if err != nil {
      return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
    }
  return append(serialized, '
'), nil
}