munianci / loki

Minimalist logger for Golang

Loki

Inspired by a popular NodeJS logger library: debug.

Feature

• zero configuration for most use cases.
• Colorful console output
• Enable logger by environment easily

Install

go get github.com/joway/loki@latest

API

Usage

Use root logger simply

It will not been affected by LOKI_ENV.

loki.SetLevel(loki.INFO)

loki.Info("x: %s", "hi")
loki.Debug("x: %s", "hi")
loki.Error("x: %s", "hi")

Create your logger

logger := loki.New("app:xxx")
logger.Info("x: %s", "hi")
logger.Debug("x: %s", "hi")
logger.Error("x: %s", "hi")

To enable the logger, just add env LOKI_ENV=app:xxx in your command, like: LOKI_ENV=app:xxx ./main.

You can also use LOKI_ENV=app:a,app:b,model:a to enable multiple logger.

LOKI_ENV=* can enable all loggers.

Use file handler

// "02 Jan 06 15:04 MST"
l := loki.New("app:xxx")
fp, err := os.OpenFile("test.log", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.ModePerm)
defer fp.Close()
flushIntervalMs := 1000
l.SetHandler(loki.NewFileHandler(fp, flushIntervalMs))

l.Info("x: %s", "hi")

Change time format

// "02 Jan 06 15:04 MST"
loki.SetTimeFormatter(time.RFC822)

// disable time output
loki.SetTimeFormatter("")

Use your custom logger formatter

type ErrFormatter struct {
	loki.Formatter
}

func (f ErrFormatter) format(a ...interface{}) string {
	err := a[0].(error)
	return fmt.Sprintf("Error %v", err)
}

logger := loki.New("app:xxx")
f := ErrFormatter{}
logger.SetFormatter(f)
logger.Debug(errors.New("test error"))