Golang : Logging with logrus



Tags : golang logrus error-messages logging

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

  See also : Golang : How to save log messages to file?



Tags : golang logrus error-messages logging

By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


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