Issue #2507509 by catch, dawehner: Service changes should not result in fatal errors between patch or minor releases

core/lib/Drupal/Core/DrupalKernel.php

@@ -712,7 +712,7 @@ class DrupalKernel implements DrupalKernelInterface, TerminableInterface {
    *   The class name.
    */
   protected function getClassName() {
-    $parts = array('service_container', $this->environment);
+    $parts = array('service_container', $this->environment, hash('crc32b', \Drupal::VERSION . Settings::get('deployment_identifier')));
     return implode('_', $parts);
   }
 

core/modules/system/src/Tests/DrupalKernel/ContainerRebuildWebTest.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\DrupalKernel\ContainerRebuildWebTest.
+ */
+
+namespace Drupal\system\Tests\DrupalKernel;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Ensures that the container rebuild works as expected.
+ *
+ * @group DrupalKernel
+ */
+class ContainerRebuildWebTest extends WebTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['service_provider_test'];
+
+  /**
+   * Sets a different deployment identifier.
+   */
+  public function testSetContainerRebuildWithDifferentDeploymentIdentifier() {
+    $this->drupalGet('<front>');
+    $this->assertHeader('container_rebuild_indicator', FALSE);
+
+    $this->writeSettings(['settings' => ['deployment_identifier' => (object) ['value' => 'new-identifier', 'required' => TRUE]]]);
+
+    $this->drupalGet('<front>');
+
+    $this->assertHeader('container_rebuild_indicator', 'new-identifier');
+  }
+
+}

core/modules/system/tests/modules/service_provider_test/service_provider_test.services.yml

@@ -4,4 +4,5 @@ services:
     tags:
       - { name: event_subscriber }
       - { name: needs_destruction }
+    parent: container.trait
     arguments: ['@state']

core/modules/system/tests/modules/service_provider_test/src/ServiceProviderTestServiceProvider.php

@@ -9,6 +9,7 @@ namespace Drupal\service_provider_test;
 
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\DependencyInjection\ServiceModifierInterface;
+use Drupal\Core\Site\Settings;
 
 class ServiceProviderTestServiceProvider implements ServiceModifierInterface {
 
@@ -21,5 +22,9 @@ class ServiceProviderTestServiceProvider implements ServiceModifierInterface {
       $definition = $container->getDefinition('file.usage');
       $definition->setClass('Drupal\service_provider_test\TestFileUsage');
     }
+
+    if ($indicator = Settings::get('deployment_identifier')) {
+      $container->setParameter('container_rebuild_indicator', $indicator);
+    }
   }
 }

core/modules/system/tests/modules/service_provider_test/src/TestClass.php

@@ -9,11 +9,16 @@ namespace Drupal\service_provider_test;
 
 use Drupal\Core\State\StateInterface;
 use Drupal\Core\DestructableInterface;
+use Symfony\Component\DependencyInjection\ContainerAwareInterface;
+use Symfony\Component\DependencyInjection\ContainerAwareTrait;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
 
-class TestClass implements EventSubscriberInterface, DestructableInterface {
+class TestClass implements EventSubscriberInterface, DestructableInterface, ContainerAwareInterface {
+
+  use ContainerAwareTrait;
 
   /**
    * The state keyvalue collection.
@@ -39,6 +44,15 @@ class TestClass implements EventSubscriberInterface, DestructableInterface {
     drupal_set_message(t('The service_provider_test event subscriber fired!'));
   }
 
+  /**
+   * Flags the response in case a rebuild indicator is used.
+   */
+  public function onKernelResponseTest(FilterResponseEvent $event) {
+    if ($this->container->hasParameter('container_rebuild_indicator')) {
+      $event->getResponse()->headers->set('container_rebuild_indicator', $this->container->getParameter('container_rebuild_indicator'));
+    }
+  }
+
   /**
    * Registers methods as kernel listeners.
    *
@@ -47,6 +61,7 @@ class TestClass implements EventSubscriberInterface, DestructableInterface {
    */
   static function getSubscribedEvents() {
     $events[KernelEvents::REQUEST][] = array('onKernelRequestTest');
+    $events[KernelEvents::RESPONSE][] = array('onKernelResponseTest');
     return $events;
   }
 

sites/default/default.settings.php

@@ -286,6 +286,16 @@ $config_directories = array();
  */
 $settings['hash_salt'] = '';
 
+/**
+ * Deployment identifier.
+ *
+ * Drupal's dependency injection container will be automatically invalidated and
+ * rebuilt when the Drupal core version changes. When updating contributed or
+ * custom code that changes the container, changing this identifier will also
+ * allow the container to be invalidated as soon as code is deployed.
+ */
+# $settings['deployment_identifier'] = \Drupal::VERSION;
+
 /**
  * Access control for update.php script.
  *