Graceful Shutdown Handler

graceful is a Go package designed to help register and execute handlers that should be run during the shutdown of a Go application. It provides a convenient way to ensure that necessary cleanup operations are performed gracefully when the application is shutting down due to signals like SIGINT or SIGTERM.

Installation

To use graceful in your Go project, simply import it using:

go get github.com/dreson4/graceful/v2

Usage

In your main function

//initialize the graceful package before using it, add this to your main file init or start of main function
graceful.Initialize()

//blocking operation, it will block execution until app terminates, add this at the end of your main function
graceful.Wait()

Anywhere within the app register your handler which will be called when the app shuts down, could be a cleanup operation e.t.c

func cleanUp(){

}

graceful.OnShutdown(cleanUp)

Example

package main

import (
	"fmt"
	"time"

	"github.com/dreson4/graceful/v2"
)

func init(){
	graceful.Initialize()
}

func mySuperImportantFunction(){
	graceful.IncrementJobCounter()
	defer graceful.DecrementJobCounter()
	
	//do some important stuff that shouldn't be interrupted
}

func main() {
	fmt.Println("Starting application")

	// Register a sample shutdown handler
	graceful.OnShutdown(func() {
		fmt.Println("Cleanup operation started")
		time.Sleep(2 * time.Second)
		fmt.Println("Cleanup operation completed")
	})

	// Simulate application logic
	time.Sleep(5 * time.Second)
	
	mySuperImportantFunction()

	// Wait for graceful shutdown
	graceful.Wait()

	fmt.Println("Application shutdown")
}