blob: ed2fa3b623b0ac5bbe62ff04e22efd7f9d17e4fe [file] [log] [blame]
// Copyright 2021 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !disable_events
// Package logrus provides a logrus Formatter for events.
// To use for the global logger:
// logrus.SetFormatter(elogrus.NewFormatter(exporter))
// logrus.SetOutput(io.Discard)
// and for a Logger instance:
// logger.SetFormatter(elogrus.NewFormatter(exporter))
// logger.SetOutput(io.Discard)
// If you call elogging.SetExporter, then you can pass nil
// for the exporter above and it will use the global one.
package logrus
import (
type formatter struct{}
func NewFormatter() logrus.Formatter {
return &formatter{}
var _ logrus.Formatter = (*formatter)(nil)
// Format writes an entry to an event.Exporter. It always returns nil (see below).
// If e.Context is non-nil, Format gets the exporter from the context. Otherwise
// it uses the default exporter.
// Logrus first calls the Formatter to get a []byte, then writes that to the
// output. That doesn't work for events, so we subvert it by having the
// Formatter export the event (and thereby write it). That is why the logrus
// Output io.Writer should be set to io.Discard.
func (f *formatter) Format(e *logrus.Entry) ([]byte, error) {
ctx := e.Context
if ctx == nil {
ctx = context.Background()
ev := event.New(ctx, event.LogKind)
if ev == nil {
return nil, nil
ev.At = e.Time
ev.Labels = append(ev.Labels, convertLevel(e.Level).Label())
for k, v := range e.Data {
ev.Labels = append(ev.Labels, event.Value(k, v))
ev.Labels = append(ev.Labels, event.String("msg", e.Message))
return nil, nil
func convertLevel(level logrus.Level) severity.Level {
switch level {
case logrus.PanicLevel:
return severity.Fatal + 1
case logrus.FatalLevel:
return severity.Fatal
case logrus.ErrorLevel:
return severity.Error
case logrus.WarnLevel:
return severity.Warning
case logrus.InfoLevel:
return severity.Info
case logrus.DebugLevel:
return severity.Debug
case logrus.TraceLevel:
return severity.Trace
return severity.Trace