cloudflared-mirror/log/log.go

86 lines
2.1 KiB
Go

// this forks the logrus json formatter to rename msg -> message as that's the
// expected field. Ideally the logger should make it easier for us.
package log
import (
"encoding/json"
"fmt"
"runtime"
"time"
"github.com/mattn/go-colorable"
"github.com/sirupsen/logrus"
)
var (
DefaultTimestampFormat = time.RFC3339
)
type JSONFormatter struct {
// TimestampFormat sets the format used for marshaling timestamps.
TimestampFormat string
}
func CreateLogger() *logrus.Logger {
logger := logrus.New()
logger.Out = colorable.NewColorableStderr()
logger.Formatter = &logrus.TextFormatter{ForceColors: runtime.GOOS == "windows"}
return logger
}
func (f *JSONFormatter) Format(entry *logrus.Entry) ([]byte, error) {
data := make(logrus.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["message"] = 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
}
// This is to not silently overwrite `time`, `msg` and `level` fields when
// dumping it. If this code wasn't there doing:
//
// logrus.WithField("level", 1).Info("hello")
//
// Would just silently drop the user provided level. Instead with this code
// it'll logged as:
//
// {"level": "info", "fields.level": 1, "msg": "hello", "time": "..."}
//
// It's not exported because it's still using Data in an opinionated way. It's to
// avoid code duplication between the two default formatters.
func prefixFieldClashes(data logrus.Fields) {
if t, ok := data["time"]; ok {
data["fields.time"] = t
}
if m, ok := data["msg"]; ok {
data["fields.msg"] = m
}
if l, ok := data["level"]; ok {
data["fields.level"] = l
}
}