Golang : Logging with logrus

While researching for the previous tutorial on how to save log messages to file. I came across an interesting package for logging in Golang - the package Logrus basically simplified the entire logging process. This tutorial will cover basic usage and if you want more advance stuff.. please see https://github.com/Sirupsen/logrus .

Before running the examples below. Please :

>go get github.com/Sirupsen/logrus

first.

Here you go :

 package main

 import (
 "github.com/sirupsen/logrus"
 )

 var logger = logrus.New()

 func main() {
 // error, but not fatal
 logger.Error("Some error, but continue.")

 // just a warning, nothing to worry about ... yet
 logger.Warn("Warning....crash to ground imminent.")

 // this line WILL NOT appear because the default log.Level does not
 // log anything that is debug level
 // for debugging purpose...
 logger.Debug("Just debugging information.")

 // to enable debug
 logger.Level = logrus.DebugLevel

 // this LINE WILL APPEAR
 logger.Debug("Just debugging information.")

 // add fields to debug information
 logger.WithFields(logrus.Fields{
 "variable": "value",
 "username": "adam",
 }).Debug("Even useful debugging information.")

 // notice that debug as no color coding for fields...but not with Info!
 logger.WithFields(logrus.Fields{
 "variable": "value",
 "username": "adam",
 }).Info("Even useful debugging information.")

 // just for your information
 logger.Info("Oh, just FYI!")

 // Executes os.Exit(1) function after this line
 logger.Fatal("Abort!")

 // Executess panic() function after this line
 logger.Panic("Panic!")
 }

Sample output :

ERRO[0000] Some error, but continue.

WARN[0000] Warning....crash to ground imminent.

DEBU[0000] Just debugging information.

DEBU[0000] Even useful debugging information. username=adam variable=value

INFO[0000] Even useful debugging information. username=adam variable=value

INFO[0000] Oh, just FYI!

FATA[0000] Abort!

exit status 1

References :

https://github.com/Sirupsen/logrus

https://github.com/Sirupsen/logrus/tree/master/examples