logger

logger

Simple go logger which can write logs to multiple backends.

Advantages:

1. Multiple backends with individual levels
2. Simple
3. Fast
4. Prints file, line
5. fmt.Print, fmt.Printf, fmt.Println like API
6. Slack integration (you can choose separate levels for different Slack channels)
7. Sentry integration

Format

[level] time_rfc3339 file:line > message

Example

package main

import "github.com/gofort/logger"

func main() {
	logger.SetLevel(logger.DebugLevel)
	logger.Debug("Debug information")
	logger.Infof("Info: %s", "some info here")
	logger.Warn("Warning here!")
	logger.Errorln("Error", "info!")
	logger.Fatal("Fatal ...")
}

Result:

[DEBUG] 2017-08-27T13:16:13+03:00 main.go:37 main > Debug information
[INFO] 2017-08-27T13:16:13+03:00 main.go:38 main > Info: some info here
[WARN] 2017-08-27T13:16:13+03:00 main.go:39 main > Warning here!
[ERROR] 2017-08-27T13:16:13+03:00 main.go:40 main > Error info!
[FATAL] 2017-08-27T13:16:13+03:00 main.go:41 main > Fatal ...

Multiple backends

package main

import (
	"fmt"
	"os"

	"github.com/gofort/logger"
)

func main() {

	f, err := os.OpenFile("./logs", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer f.Close()

	stderrBackend := logger.NewWriterBackend(os.Stderr, logger.DebugLevel, true, false, "") // colored output enabled via third param
	fileBackend := logger.NewWriterBackend(f, logger.InfoLevel, false, false, "") // no debug logs

	l := logger.NewLogger(stderrBackend, fileBackend)

	l.Debug("Debug information")
	l.Infof("Info: %s", "some info here")
	l.Warn("Warning here!")
	l.Errorln("Error", "info!")
}

Result:

$ go run example/main.go
[DEBUG] 2017-08-27T13:17:48+03:00 main.go:24 main > Debug information
[INFO] 2017-08-27T13:17:48+03:00 main.go:25 main > Info: some info here
[WARN] 2017-08-27T13:17:48+03:00 main.go:26 main > Warning here!
[ERROR] 2017-08-27T13:17:48+03:00 main.go:27 main > Error info!
$ cat logs
[INFO] 2017-08-27T13:17:48+03:00 main.go:25 main > Info: some info here
[WARN] 2017-08-27T13:17:48+03:00 main.go:26 main > Warning here!
[ERROR] 2017-08-27T13:17:48+03:00 main.go:27 main > Error info!

Levels

Currently implemented: Fatal, Error, Warn, Info, Debug.

If you set FatalLevel => only Fatal logs would appear.

If you set ErrorLevel => only Fatal and Error logs would appear.

If you set WarnLevel => only Fatal, Error and Warn logs would appear.

If you set InfoLevel => only Fatal, Error, Warn and Info logs would appear.

If you set DebugLevel => all logs would appear.

Fatal

Fatal works as in standart golang log package, it means that after log, os.Exit(1) called