How to catch and handle signals (e.g., SIGINT, SIGTERM) gracefully using runtime.Notify()?

To catch and handle signals gracefully using runtime.Notify() in Go, you need to follow these steps:

Import the necessary packages:

import (
   "os"
   "os/signal"
   "syscall"
)

Create a channel to receive the signals:

quit := make(chan os.Signal, 1)

signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)

Start a goroutine to listen for the signal:

go func() {
   sig := <-quit
   // Custom handling of the signal
   // ...
}()

Perform any necessary cleanup or shutdown tasks in the goroutine to handle the signal gracefully.

Here's an example illustrating the complete process:

package main

import (
   "fmt"
   "os"
   "os/signal"
   "syscall"
   "time"
)

func main() {
   quit := make(chan os.Signal, 1)

   signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)

   go func() {
      sig := <-quit
      fmt.Printf("\nSignal %s received. Gracefully shutting down...\n", sig)
      // Custom handling of the signal
      time.Sleep(2 * time.Second) // Simulating cleanup or shutdown tasks
      os.Exit(0)
   }()

   fmt.Println("Waiting for signals...")
   <-make(chan struct{}) // Blocking main goroutine indefinitely
}

In this example, we catch the SIGINT and SIGTERM signals, perform custom handling inside the goroutine, and gracefully shut down the application after a simulated cleanup or shutdown process.