package main
import (
	"log"
	"os"
	"github.com/hashicorp/logutils"
)
func main() {
	filter := &logutils.LevelFilter{
		Levels: []logutils.LogLevel{"DEBUG", "WARN", "ERROR"},
		MinLevel: logutils.LogLevel("WARN"),
		Writer: os.Stderr,
	}
	log.SetOutput(filter)
	log.Print("[DEBUG] Debugging") // this will not print
	log.Print("[WARN] Warning") // this will
	log.Print("[ERROR] Erring") // and so will this
	log.Print("Message I haven't updated") // and so will this
}