Overview of initialization and bootstrap

Initializes the error handler.

Creates the object manager and basic shared services that are used everywhere and are affected by the environment. The environment parameters are injected properly into these objects.

Asserts that maintenance mode is not enabled; otherwise, terminates.

Asserts that the Commerce application is installed; otherwise, terminates.

Starts the Commerce application.

Any uncaught exception during application launch is automatically passed back to Commerce in the catchException() method which you can use to handle the exception. The latter must return either true or false:

• If true: Commerce handled exception successfully. No need to do anything else.
• If false: (or any other empty result) Commerce did not handle the exception. The bootstrap object performs the default exception-handling subroutine.

Sends the response provided by the application object.

Sample entry point script that modifies the bootstrap object:

<?php
use Magento\Framework\App\Bootstrap;
require __DIR__ . '/app/bootstrap.php';

$params = $_SERVER;
$params[Bootstrap::PARAM_REQUIRE_MAINTENANCE] = true; // default false
$params[Bootstrap::PARAM_REQUIRE_IS_INSTALLED] = false; // default true
$bootstrap = Bootstrap::create(BP, $params);

/** @var \Magento\Framework\App\Http $app */
$app = $bootstrap->createApplication('Magento\Framework\App\Http');
$bootstrap->run($app);

Determines the application area.

Starts the front controller and routing systems in order to find and execute a controller action.

Uses an HTTP response object to return result obtained from the controller action.

Error handling (in the following priority order):

1. If you are using developer mode:

   • If the Commerce application is not installed, redirect to Setup Wizard.
   • If the Commerce application is installed, display an error and HTTP status code 500 (Internal Server Error).

2. If the Commerce application is in maintenance mode, display a user-friendly “Service Unavailable” landing page with HTTP status code 503 (Service Unavailable).

3. If the Commerce application is not installed, redirect to Setup Wizard.

4. If the session is invalid, redirect to the home page.

5. If there is any other application initialization error, display a user-friendly “Page Not Found” page with HTTP status code 404 (Not Found).

6. On any other error, display a user-friendly “Service Unavailable” page with HTTP response 503 and generate an error report and display its ID on the page.