Logging and Monitoring in Go - Golang (Because Debugging Shouldn't Feel Like Detective Work!)

Golang

""Learning Golang is like learning to cook with a simple recipe but yielding maximum results—with clean syntax, fast performance, and multitasking capabilities through goroutines that make you feel like a master chef, handling multiple tasks at once without a hitch!""

Ever spent hours staring at a blank terminal wondering what went wrong? With logging and monitoring, you can catch bugs before they turn into nightmares! 

Why Logging Matters? (Because "It Works on My Machine" Isn't a Debugging Strategy!)

• Track Errors – Find bugs fast.
• Monitor Performance – Know when your app is slow.
• Audit Events – Keep logs of important actions.

Simple Logging with Go’s Built-in log Package (Because fmt.Println() is Not Logging!)

package main

import (
	"log"
)

func main() {
	log.Println("This is a log message!")
}

Why use log?

• Adds timestamps automatically.
• Can redirect logs to files.

Logging to a File:

file, err := os.OpenFile("app.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
if err != nil {
	log.Fatal(err)
}
log.SetOutput(file)
log.Println("Logging to a file now!")

Advanced Logging with logrus (Because You Deserve Pretty Logs!)

logrus is a popular structured logging package:

go get github.com/sirupsen/logrus

Example usage:

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

func main() {
	logrus.SetFormatter(&logrus.JSONFormatter{})
	logrus.WithFields(logrus.Fields{
		"user": "Alice",
		"action": "login",
	}).Info("User logged in!")
}

Why logrus?

• Supports JSON logs.
• Customizable log levels (Info, Warning, Error, etc.).

Monitoring with Prometheus (Because You Can’t Fix What You Can’t Measure!)

Step 1: Install Prometheus Client

go get github.com/prometheus/client_golang/prometheus

Step 2: Add a Metric

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"net/http"
)

var requestCount = prometheus.NewCounter(
	prometheus.CounterOpts{
		Name: "http_requests_total",
		Help: "Total number of HTTP requests",
	},
)

func main() {
	prometheus.MustRegister(requestCount)
	http.Handle("/metrics", promhttp.Handler())
	http.ListenAndServe(":8080", nil)
}

Open http://localhost:8080/metrics and see live stats!

Log Aggregation with Loki + Grafana (Because Logs Shouldn’t Be Scattered Everywhere!)

• Loki – Stores logs efficiently.
• Grafana – Visualizes logs beautifully.

Step 1: Run Loki & Grafana (Docker Version)

docker run -d --name=loki -p 3100:3100 grafana/loki:latest

docker run -d --name=grafana -p 3000:3000 grafana/grafana

Step 2: Add Logs to Loki

go get github.com/grafana/loki-client-go/loki

Use the client to push logs to Loki, then visualize them in Grafana!

Logging and monitoring aren’t just for production—they’re your superpowers for writing better software.