package logrus import ( "encoding/json" "fmt" ) type JSONFormatter struct { // TimestampFormat sets the format used for marshaling timestamps. TimestampFormat 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 } data["time"] = entry.Time.Format(timestampFormat) data["msg"] = entry.Message data["level"] = 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 }