logrus/json_formatter.go

60 lines
1.2 KiB
Go

package logrus
import (
"encoding/json"
"fmt"
)
type JSONFormatter struct {
// TimestampFormat sets the format used for marshaling timestamps.
TimestampFormat string
MessageKey string
LevelKey string
TimeKey string
}
func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
data := make(Fields, len(entry.Data)+3)
for k, v := range entry.Data {
switch v := v.(type) {
case error:
// Otherwise errors are ignored by `encoding/json`
// https://github.com/Sirupsen/logrus/issues/137
data[k] = v.Error()
default:
data[k] = v
}
}
prefixFieldClashes(data)
timestampFormat := f.TimestampFormat
if timestampFormat == "" {
timestampFormat = DefaultTimestampFormat
}
timeKey := f.TimeKey
if timeKey == "" {
timeKey = "time"
}
messageKey := f.MessageKey
if messageKey == "" {
messageKey = "msg"
}
levelKey := f.LevelKey
if levelKey == "" {
levelKey = "level"
}
data[timeKey] = entry.Time.Format(timestampFormat)
data[messageKey] = entry.Message
data[levelKey] = entry.Level.String()
serialized, err := json.Marshal(data)
if err != nil {
return nil, fmt.Errorf("Failed to marshal fields to JSON, %v", err)
}
return append(serialized, '\n'), nil
}