Golang - Create custom logger to share on files and packages across app

Question

In my program there is a lot places where I should create logs like following

log.Println("[Build]: bla bla“)

log.Println(“[INFO]: bla bla“)

log.Printf(“[ERROR]: bla bla“)

log.Println(“[WARNING]: bla bla“)

I use it for all my logging in different packages inside the application and it's bit frustrating to copy this, is there a way to create some generic log which I can simple re-use it inside my program.

I read about logrus etc but they provide some way to do it but not provide some custom way or maybe I miss something.

My program is command line tool

Answer 1

It's best to use a more proper logger like zap or logrus . Also prefer passing the logger explicitly as an argument and avoid global loggers.

Yet if the exact logging workflow with the built-in one is needed, with the provided sample output, it's possible to define them with proper prefixes, instead of repeating the level in each string:

var (
    warnlog  = log.New(os.Stderr, "[ warn  ]", log.Ltime|log.Lshortfile)
    infolog  = log.New(os.Stderr, "[ info  ]", log.Ltime|log.Lshortfile)
    buildlog = log.New(os.Stderr, "[ build ]", log.Ltime|log.Lshortfile)
    errlog   = log.New(os.Stderr, "[ error ]", log.Ltime|log.Lshortfile)
)