Laravel lifecycle

Laravel Application Lifecycle

Laravel follows a structured lifecycle when handling HTTP requests. Understanding this flow helps in debugging, performance optimization, and writing better middleware. Here's the complete breakdown:

1. Entry Point: public/index.php

All requests start here. This file:

• Loads Composer's autoloader

• Bootstraps the Laravel application

• Creates an instance of the application kernel (either HTTP or Console)

require __DIR__.'/../vendor/autoload.php';
$app = require_once __DIR__.'/../bootstrap/app.php';

2. Application Initialization

• The bootstrap/app.php file creates the application instance

• Registers base service providers

• Binds important interfaces (Kernel, ExceptionHandler)

$app = new Illuminate\Foundation\Application(
    dirname(__DIR__)
);

3. Kernel Handling

• For HTTP requests: App\Http\Kernel

• For console commands: App\Console\Kernel

The kernel:

• Loads environment variables

• Loads configuration

• Handles exceptions

• Runs bootstrap providers (error handling, logging, etc.)

4. Service Providers Registration

• All providers listed in config/app.php are registered

• The register() method of each provider is called

• Providers can register bindings in the service container

5. Service Providers Boot

• After registration, the boot() method is called for all providers

• This is where providers can perform initialization

6. Request Handling

• The request is converted to a Symfony Request instance

• Passes through middleware stack (global, route middleware)

• Middleware can modify requests/responses or short-circuit the process

7. Router Dispatch

• The router matches the request to a route

• Route parameters are resolved

• Controller/method is determined

8. Controller Execution

• If route uses a controller:

  • Controller is instantiated (via service container)

  • Method dependencies are injected

  • Method is executed

• If closure route, the closure is executed

9. Response Preparation

• Controller/closure returns a response

• Response passes back through middleware

• Final response is sent to client

10. Termination

• Any terminable middleware runs after response is sent

• Application performs cleanup

Key Components in the Lifecycle

1. Service Container: The heart of Laravel, manages class dependencies

2. Service Providers: Extend application functionality

3. Middleware: Filter HTTP requests entering your application

4. Request/Response: Symfony components handling HTTP messages

5. Router: Matches URLs to controller actions or closures

Visual Flow

Client Request
    ↓
public/index.php
    ↓
Bootstrap (app.php)
    ↓
HTTP Kernel / Console Kernel
    ↓
Service Providers (register → boot)
    ↓
Request → Middleware Pipeline
    ↓
Router → Controller/Closure
    ↓
Response ← Middleware
    ↓
Client Response
    ↓
Terminable Middleware