diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 4abbd40..2ab5ed1 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1,6 +1,7 @@
 <?php
 
 use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\DrupalKernel;
 use Drupal\Core\Database\Database;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Symfony\Component\ClassLoader\UniversalClassLoader;
@@ -128,39 +129,44 @@
 const DRUPAL_BOOTSTRAP_CONFIGURATION = 0;
 
 /**
- * Second bootstrap phase: try to serve a cached page.
+ * Second bootstrap phase, initalize a kernel.
  */
-const DRUPAL_BOOTSTRAP_PAGE_CACHE = 1;
+const DRUPAL_BOOTSTRAP_KERNEL = 1;
 
 /**
- * Third bootstrap phase: initialize database layer.
+ * Third bootstrap phase: try to serve a cached page.
  */
-const DRUPAL_BOOTSTRAP_DATABASE = 2;
+const DRUPAL_BOOTSTRAP_PAGE_CACHE = 2;
 
 /**
- * Fourth bootstrap phase: initialize the variable system.
+ * Fourth bootstrap phase: initialize database layer.
  */
-const DRUPAL_BOOTSTRAP_VARIABLES = 3;
+const DRUPAL_BOOTSTRAP_DATABASE = 3;
 
 /**
- * Fifth bootstrap phase: initialize session handling.
+ * Fifth bootstrap phase: initialize the variable system.
  */
-const DRUPAL_BOOTSTRAP_SESSION = 4;
+const DRUPAL_BOOTSTRAP_VARIABLES = 4;
 
 /**
- * Sixth bootstrap phase: set up the page header.
+ * Sixth bootstrap phase: initialize session handling.
  */
-const DRUPAL_BOOTSTRAP_PAGE_HEADER = 5;
+const DRUPAL_BOOTSTRAP_SESSION = 5;
 
 /**
- * Seventh bootstrap phase: load code for subsystems and modules.
+ * Seventh bootstrap phase: set up the page header.
  */
-const DRUPAL_BOOTSTRAP_CODE = 6;
+const DRUPAL_BOOTSTRAP_PAGE_HEADER = 6;
+
+/**
+ * Eighth bootstrap phase: load code for subsystems and modules.
+ */
+const DRUPAL_BOOTSTRAP_CODE = 7;
 
 /**
  * Final bootstrap phase: initialize language, path, theme, and modules.
  */
-const DRUPAL_BOOTSTRAP_FULL = 7;
+const DRUPAL_BOOTSTRAP_FULL = 8;
 
 /**
  * Role ID for anonymous users; should match what's in the "role" table.
@@ -2107,6 +2113,7 @@ function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
   // Not drupal_static(), because does not depend on any run-time information.
   static $phases = array(
     DRUPAL_BOOTSTRAP_CONFIGURATION,
+    DRUPAL_BOOTSTRAP_KERNEL,
     DRUPAL_BOOTSTRAP_PAGE_CACHE,
     DRUPAL_BOOTSTRAP_DATABASE,
     DRUPAL_BOOTSTRAP_VARIABLES,
@@ -2117,14 +2124,15 @@ function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
   );
   // Not drupal_static(), because the only legitimate API to control this is to
   // call drupal_bootstrap() with a new phase parameter.
-  static $final_phase;
+  static $final_phase = -1;
   // Not drupal_static(), because it's impossible to roll back to an earlier
   // bootstrap state.
   static $stored_phase = -1;
 
-  // When not recursing, store the phase name so it's not forgotten while
-  // recursing.
-  if ($new_phase) {
+  // When not recursing, store the phase name so it's not forgotten during
+  // recursion. Additionally, ensure that $final_phase is never rolled back to an
+  // earlier bootstrap state.
+  if ($new_phase && $phase > $final_phase) {
     $final_phase = $phase;
   }
   if (isset($phase)) {
@@ -2144,6 +2152,10 @@ function drupal_bootstrap($phase = NULL, $new_phase = TRUE) {
           _drupal_bootstrap_configuration();
           break;
 
+        case DRUPAL_BOOTSTRAP_KERNEL:
+          _drupal_bootstrap_kernel();
+          break;
+
         case DRUPAL_BOOTSTRAP_PAGE_CACHE:
           _drupal_bootstrap_page_cache();
           break;
@@ -2274,6 +2286,18 @@ function _drupal_bootstrap_configuration() {
 }
 
 /**
+ * Initialize the kernel / service container.
+ */
+function _drupal_bootstrap_kernel() {
+  // Normally, index.php puts a container in drupal_container() by creating a
+  // kernel. If there is no container yet, create one.
+  if (!drupal_container()) {
+    $kernel = new DrupalKernel('prod', FALSE, drupal_classloader());
+    $kernel->boot();
+  }
+}
+
+/**
  * Attempts to serve a page from the cache.
  */
 function _drupal_bootstrap_page_cache() {
@@ -2409,91 +2433,28 @@ function drupal_get_bootstrap_phase() {
 /**
  * Retrieves the Drupal Container to standardize object construction.
  *
- * On a normal page request the container is built by the kernel and passed in
- * to this function which stores it statically. Any full bootstrap outside of
- * the context of a page request will require a container with a minimal set of
- * services. If this function is called without the $rebuild parameter, and no
- * container object has been statically cached, it builds this minimal container,
- * registering the services that are required.
+ * The container is built by the kernel and passed in to this function which
+ * stores it statically. The container always contains the services from
+ * \Drupal\Core\CoreBundle, the bundles of enabled modules and any other
+ * bundles defined in $GLOBALS['conf']['container_bundles'].
  *
  * @see Drupal\Core\DrupalKernel
  *
  * @param Symfony\Component\DependencyInjection\Container $new_container
- *   A new container instance to replace the current.
- * @param bool $rebuild
- *   (optional) Internal use only. Whether to enforce a rebuild of the container.
- *   Used by the testing framework to inject a fresh container for unit tests.
+ *   (optional) A new container instance to replace the current.
  *
- * @return Symfony\Component\DependencyInjection\Container
+ * @return Symfony\Component\DependencyInjection\Container|bool
  *   The instance of the Container used to set up and maintain object
- *   instances.
+ *   instances or FALSE if none exist yet.
  */
-function drupal_container(Container $new_container = NULL, $rebuild = FALSE) {
+function drupal_container(Container $new_container = NULL) {
   // We do not use drupal_static() here because we do not have a mechanism by
   // which to reinitialize the stored objects, so a drupal_static_reset() call
   // would leave Drupal in a nonfunctional state.
-  static $container = NULL;
-  if ($rebuild) {
-    $container = NULL;
-  }
+  static $container = FALSE;
   if (isset($new_container)) {
     $container = $new_container;
   }
-  if (!isset($container)) {
-    // This is only ever used by the installer and by run-tests.sh.
-    // @todo Remove this entire section once these have been converted to use a
-    //   kernel.
-    $container = new ContainerBuilder();
-
-    // Register active configuration storage.
-    $container
-      ->register('config.cachedstorage.storage', 'Drupal\Core\Config\FileStorage')
-      ->addArgument(config_get_config_directory(CONFIG_ACTIVE_DIRECTORY));
-    // @todo Replace this with a cache.factory service plus 'config' argument.
-    $container
-      ->register('cache.config', 'Drupal\Core\Cache\CacheBackendInterface')
-      ->setFactoryClass('Drupal\Core\Cache\CacheFactory')
-      ->setFactoryMethod('get')
-      ->addArgument('config');
-
-    $container
-      ->register('config.storage', 'Drupal\Core\Config\CachedStorage')
-      ->addArgument(new Reference('config.cachedstorage.storage'))
-      ->addArgument(new Reference('cache.config'));
-
-    // Register configuration object factory.
-    $container->register('config.subscriber.globalconf', 'Drupal\Core\EventSubscriber\ConfigGlobalOverrideSubscriber');
-    $container->register('dispatcher', 'Symfony\Component\EventDispatcher\EventDispatcher')
-      ->addMethodCall('addSubscriber', array(new Reference('config.subscriber.globalconf')));
-    $container->register('config.factory', 'Drupal\Core\Config\ConfigFactory')
-      ->addArgument(new Reference('config.storage'))
-      ->addArgument(new Reference('dispatcher'));
-
-    // Register staging configuration storage.
-    $container
-      ->register('config.storage.staging', 'Drupal\Core\Config\FileStorage')
-      ->addArgument(config_get_config_directory(CONFIG_STAGING_DIRECTORY));
-
-    // Register the service for the default database connection.
-    $container->register('database', 'Drupal\Core\Database\Connection')
-      ->setFactoryClass('Drupal\Core\Database\Database')
-      ->setFactoryMethod('getConnection')
-      ->addArgument('default');
-    // Register the KeyValueStore factory.
-    $container
-      ->register('keyvalue', 'Drupal\Core\KeyValueStore\KeyValueFactory')
-      ->addArgument(new Reference('service_container'));
-    $container
-      ->register('keyvalue.database', 'Drupal\Core\KeyValueStore\KeyValueDatabaseFactory')
-      ->addArgument(new Reference('database'));
-
-    $container->register('path.alias_manager', 'Drupal\Core\Path\AliasManager')
-      ->addArgument(new Reference('database'))
-      ->addArgument(new Reference('keyvalue.database'));
-
-    // Register the EntityManager.
-    $container->register('plugin.manager.entity', 'Drupal\Core\Entity\EntityManager');
-  }
   return $container;
 }
 
diff --git a/core/includes/file.inc b/core/includes/file.inc
index 137dd0d..bcd3033 100644
--- a/core/includes/file.inc
+++ b/core/includes/file.inc
@@ -5,10 +5,12 @@
  * API for handling file uploads and server file management.
  */
 
+use Drupal\Core\StreamWrapper\LocalStream;
+use Drupal\Component\PhpStorage\MTimeProtectedFastFileStorage;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\HttpFoundation\StreamedResponse;
-use Drupal\Core\StreamWrapper\LocalStream;
+
 /**
  * Stream wrapper bit flags that are the basis for composite types.
  *
@@ -558,7 +560,7 @@ function file_save_htaccess($directory, $private = TRUE) {
 
   if ($private) {
     // Private .htaccess file.
-    $htaccess_lines = "SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006\nDeny from all\nOptions None\nOptions +FollowSymLinks";
+    $htaccess_lines = MTimeProtectedFastFileStorage::HTACCESS;
   }
   else {
     // Public .htaccess file.
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 24ceaf2..ecfe29e 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -288,6 +288,9 @@ function install_begin_request(&$install_state) {
 
   // Determine whether the configuration system is ready to operate.
   $install_state['config_verified'] = install_verify_config_directory(CONFIG_ACTIVE_DIRECTORY) && install_verify_config_directory(CONFIG_STAGING_DIRECTORY);
+  // Check existing settings.php.
+  $install_state['database_verified'] = install_verify_database_settings();
+  $install_state['settings_verified'] = $install_state['config_verified'] && $install_state['database_verified'];
 
   // If it is not, replace the configuration storage with the InstallStorage
   // implementation, for the following reasons:
@@ -312,7 +315,11 @@ function install_begin_request(&$install_state) {
   // This override is reverted as soon as the config directory has been set up
   // successfully.
   // @see drupal_install_config_directories()
-  if (!$install_state['config_verified']) {
+  if ($install_state['settings_verified']) {
+    $kernel = new DrupalKernel('install', FALSE, drupal_classloader(), FALSE);
+    $kernel->boot();
+  }
+  else {
     // @todo Move into a proper Drupal\Core\DependencyInjection\InstallContainerBuilder.
     $container = new ContainerBuilder();
 
@@ -362,10 +369,6 @@ function install_begin_request(&$install_state) {
   // accessing the database before it is set up yet.)
   drupal_maintenance_theme();
 
-  // Check existing settings.php.
-  $install_state['database_verified'] = install_verify_database_settings();
-  $install_state['settings_verified'] = $install_state['config_verified'] && $install_state['database_verified'];
-
   if ($install_state['database_verified']) {
     // Initialize the database system. Note that the connection
     // won't be initialized until it is actually requested.
@@ -1104,11 +1107,6 @@ function install_settings_form_submit($form, &$form_state) {
   // Add the config directories to settings.php.
   drupal_install_config_directories();
 
-  // We have valid configuration directories in settings.php.
-  // Reset the service container, so the config.storage service will use the
-  // actual active storage for installing configuration.
-  drupal_container(NULL, TRUE);
-
   // Indicate that the settings file has been verified, and check the database
   // for the last completed task, now that we have a valid connection. This
   // last step is important since we want to trigger an error if the new
@@ -1500,10 +1498,6 @@ function install_bootstrap_full(&$install_state) {
   // Clear the module list that was overriden earlier in the process.
   // This will allow all freshly installed modules to be loaded.
   module_list_reset();
-
-  // Instantiate the kernel.
-  $kernel = new DrupalKernel('prod', FALSE, drupal_classloader(), FALSE);
-  $kernel->boot();
   drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
 }
 
diff --git a/core/includes/install.inc b/core/includes/install.inc
index a2666ae..99cfcf6 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -6,6 +6,7 @@
  */
 
 use Drupal\Core\Database\Database;
+use Drupal\Core\DrupalKernel;
 use Drupal\locale\Gettext;
 
 /**
@@ -421,6 +422,9 @@ function drupal_verify_profile($install_state) {
 function drupal_install_system() {
   // Create tables.
   drupal_install_schema('system');
+  // Immediately boot a kernel to have real services ready.
+  $kernel = new DrupalKernel('install', FALSE, drupal_classloader(), FALSE);
+  $kernel->boot();
 
   $system_path = drupal_get_path('module', 'system');
   require_once DRUPAL_ROOT . '/' . $system_path . '/system.install';
diff --git a/core/lib/Drupal/Component/PhpStorage/FileStorage.php b/core/lib/Drupal/Component/PhpStorage/FileStorage.php
index a07c27e..fcbbb7b 100644
--- a/core/lib/Drupal/Component/PhpStorage/FileStorage.php
+++ b/core/lib/Drupal/Component/PhpStorage/FileStorage.php
@@ -83,6 +83,10 @@ function writeable() {
    * Implements Drupal\Component\PhpStorage\PhpStorageInterface::deleteAll().
    */
   function deleteAll() {
+    // @todo remove this to properly decouple this class from Drupal.
+    if (!function_exists('file_unmanaged_delete_recursive')) {
+      include_once DRUPAL_ROOT . '/core/includes/file.inc';
+    }
     return file_unmanaged_delete_recursive($this->directory, array(__CLASS__, 'filePreDeleteCallback'));
   }
 
diff --git a/core/lib/Drupal/Component/PhpStorage/MTimeProtectedFastFileStorage.php b/core/lib/Drupal/Component/PhpStorage/MTimeProtectedFastFileStorage.php
index 68a6205..908289a 100644
--- a/core/lib/Drupal/Component/PhpStorage/MTimeProtectedFastFileStorage.php
+++ b/core/lib/Drupal/Component/PhpStorage/MTimeProtectedFastFileStorage.php
@@ -40,6 +40,8 @@
  */
 class MTimeProtectedFastFileStorage extends FileStorage {
 
+  const HTACCESS="SetHandler Drupal_Security_Do_Not_Remove_See_SA_2006_006\nDeny from all\nOptions None\nOptions +FollowSymLinks";
+
   /**
    * The secret used in the HMAC.
    *
@@ -144,7 +146,10 @@ protected function ensureDirectory() {
       mkdir($this->directory, 0700, TRUE);
     }
     chmod($this->directory, 0700);
-    file_save_htaccess($this->directory);
+    $htaccess_path =  $this->directory . '/.htaccess';
+    if (!file_exists($htaccess_path) && file_put_contents($htaccess_path, self::HTACCESS)) {
+      @chmod($htaccess_path, 0444);
+    }
   }
 
   /**
diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index a5624d7..1bedc10 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -158,11 +158,6 @@ public function boot() {
     }
     $this->initializeContainer();
     $this->booted = TRUE;
-    // @todo Remove this once everything in the bootstrap has been converted to
-    //   services in the DIC.
-    drupal_bootstrap(DRUPAL_BOOTSTRAP_CODE);
-    // Now that full bootstrap is complete, we can dump the container if it
-    // was just rebuilt.
     if ($this->containerNeedsDumping && !$this->dumpDrupalContainer($this->container, $this->getContainerBaseClass())) {
       watchdog('DrupalKernel', 'Container cannot be written to disk');
     }
diff --git a/core/lib/Drupal/Core/HttpKernel.php b/core/lib/Drupal/Core/HttpKernel.php
index c1f7c5b..62d6b68 100644
--- a/core/lib/Drupal/Core/HttpKernel.php
+++ b/core/lib/Drupal/Core/HttpKernel.php
@@ -42,6 +42,9 @@ public function __construct(EventDispatcherInterface $dispatcher, ContainerInter
 
     public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
     {
+        // @todo Remove this once everything in the bootstrap has been
+        //   converted to services in the DIC.
+        drupal_bootstrap(DRUPAL_BOOTSTRAP_CODE);
         $request->headers->set('X-Php-Ob-Level', ob_get_level());
 
         $this->container->enterScope('request');
diff --git a/core/modules/forum/lib/Drupal/forum/Tests/ForumTest.php b/core/modules/forum/lib/Drupal/forum/Tests/ForumTest.php
index f56cfbb..a5e5eff 100644
--- a/core/modules/forum/lib/Drupal/forum/Tests/ForumTest.php
+++ b/core/modules/forum/lib/Drupal/forum/Tests/ForumTest.php
@@ -43,9 +43,9 @@ class ForumTest extends WebTestBase {
   protected $web_user;
 
   /**
-   * An array representing a container.
+   * An array representing a forum container.
    */
-  protected $container;
+  protected $forumContainer;
 
   /**
    * An array representing a forum.
@@ -259,15 +259,15 @@ private function doAdminTests($user) {
 
     // Edit forum taxonomy.
     // Restoration of the settings fails and causes subsequent tests to fail.
-    $this->container = $this->editForumTaxonomy();
+    $this->forumContainer = $this->editForumTaxonomy();
     // Create forum container.
-    $this->container = $this->createForum('container');
+    $this->forumContainer = $this->createForum('container');
     // Verify "edit container" link exists and functions correctly.
     $this->drupalGet('admin/structure/forum');
     $this->clickLink('edit container');
     $this->assertRaw('Edit container', 'Followed the link to edit the container');
     // Create forum inside the forum container.
-    $this->forum = $this->createForum('forum', $this->container['tid']);
+    $this->forum = $this->createForum('forum', $this->forumContainer['tid']);
     // Verify the "edit forum" link exists and functions correctly.
     $this->drupalGet('admin/structure/forum');
     $this->clickLink('edit forum');
@@ -275,7 +275,7 @@ private function doAdminTests($user) {
     // Navigate back to forum structure page.
     $this->drupalGet('admin/structure/forum');
     // Create second forum in container.
-    $this->delete_forum = $this->createForum('forum', $this->container['tid']);
+    $this->delete_forum = $this->createForum('forum', $this->forumContainer['tid']);
     // Save forum overview.
     $this->drupalPost('admin/structure/forum/', array(), t('Save'));
     $this->assertRaw(t('The configuration options have been saved.'));
@@ -290,7 +290,7 @@ private function doAdminTests($user) {
     $this->assertNoFieldByName('op', t('Delete'), 'Delete button not found.');
 
     // Test term edit form alterations.
-    $this->drupalGet('taxonomy/term/' . $this->container['tid'] . '/edit');
+    $this->drupalGet('taxonomy/term/' . $this->forumContainer['tid'] . '/edit');
     // Test parent field been hidden by forum module.
     $this->assertNoField('parent[]', 'Parent field not found.');
 
@@ -435,7 +435,7 @@ private function doBasicTests($user, $admin) {
     // Login the user.
     $this->drupalLogin($user);
     // Attempt to create forum topic under a container.
-    $this->createForumTopic($this->container, TRUE);
+    $this->createForumTopic($this->forumContainer, TRUE);
     // Create forum node.
     $node = $this->createForumTopic($this->forum, FALSE);
     // Verify the user has access to all the forum nodes.
@@ -516,9 +516,9 @@ private function verifyForums($node_user, Node $node, $admin, $response = 200) {
     }
 
     // View forum container page.
-    $this->verifyForumView($this->container);
+    $this->verifyForumView($this->forumContainer);
     // View forum page.
-    $this->verifyForumView($this->forum, $this->container);
+    $this->verifyForumView($this->forum, $this->forumContainer);
     // View root forum page.
     $this->verifyForumView($this->root_forum);
 
@@ -529,7 +529,7 @@ private function verifyForums($node_user, Node $node, $admin, $response = 200) {
     $breadcrumb = array(
       l(t('Home'), NULL),
       l(t('Forums'), 'forum'),
-      l($this->container['name'], 'forum/' . $this->container['tid']),
+      l($this->forumContainer['name'], 'forum/' . $this->forumContainer['tid']),
       l($this->forum['name'], 'forum/' . $this->forum['tid']),
     );
     $this->assertRaw(theme('breadcrumb', array('breadcrumb' => $breadcrumb)), 'Breadcrumbs were displayed');
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
index ac11b8f..bd11d53 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\simpletest;
 
 use Drupal\Core\DrupalKernel;
+use Symfony\Component\DependencyInjection\Reference;
 use Drupal\Core\Database\Database;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -128,6 +129,11 @@ public function containerBuild($container) {
     $conf['keyvalue_default'] = 'keyvalue.memory';
     $container
       ->register('keyvalue.memory', 'Drupal\Core\KeyValueStore\KeyValueMemoryFactory');
+    if (!$container->has('keyvalue')) {
+      $container
+        ->register('keyvalue', 'Drupal\Core\KeyValueStore\KeyValueFactory')
+        ->addArgument(new Reference('service_container'));
+    }
   }
 
   /**
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index 60a9a77..73fba95 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\simpletest;
 
 use Drupal\Core\Database\Database;
+use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Database\ConnectionNotDefinedException;
 use Drupal\Core\DrupalKernel;
 use ReflectionMethod;
@@ -819,7 +820,7 @@ protected function prepareEnvironment() {
     $this->originalContainer = clone drupal_container();
     $this->originalLanguage = $language_interface;
     $this->originalConfigDirectories = $GLOBALS['config_directories'];
-    $this->originalThemeKey = $GLOBALS['theme_key'];
+    $this->originalThemeKey = isset($GLOBALS['theme_key']) ? $GLOBALS['theme_key'] : NULL;
     $this->originalTheme = $GLOBALS['theme'];
 
     // Save further contextual information.
@@ -873,7 +874,8 @@ protected function prepareEnvironment() {
     }
 
     // Reset and create a new service container.
-    $this->container = drupal_container(NULL, TRUE);
+    $this->container = new ContainerBuilder();
+    drupal_container($this->container);
 
     // Unset globals.
     unset($GLOBALS['theme_key']);
@@ -906,9 +908,6 @@ protected function prepareEnvironment() {
    *   enabled modules to be immediately available in the same request.
    */
   protected function rebuildContainer() {
-    // DrupalKernel expects to merge a fresh bootstrap container, not remerge
-    // what is left over from a prior container build.
-    drupal_container(NULL, TRUE);
     // Create a new DrupalKernel for testing purposes, now that all required
     // modules have been enabled. This also stores a new dependency injection
     // container in drupal_container(). Drupal\simpletest\TestBase::tearDown()
@@ -966,11 +965,13 @@ protected function tearDown() {
     // In case a fatal error occurred that was not in the test process read the
     // log to pick up any fatal errors.
     simpletest_log_read($this->testId, $this->databasePrefix, get_class($this), TRUE);
-    $captured_emails = state()->get('system.test_email_collector') ?: array();
-    $emailCount = count($captured_emails);
-    if ($emailCount) {
-      $message = format_plural($emailCount, '1 e-mail was sent during this test.', '@count e-mails were sent during this test.');
-      $this->pass($message, t('E-mail'));
+    if (($container = drupal_container()) && $container->has('keyvalue')) {
+      $captured_emails = state()->get('system.test_email_collector') ?: array();
+      $emailCount = count($captured_emails);
+      if ($emailCount) {
+        $message = format_plural($emailCount, '1 e-mail was sent during this test.', '@count e-mails were sent during this test.');
+        $this->pass($message, t('E-mail'));
+      }
     }
 
     // Delete temporary files directory.
@@ -985,7 +986,9 @@ protected function tearDown() {
     $databases['default']['default'] = $connection_info['default'];
 
     // Restore original globals.
-    $GLOBALS['theme_key'] = $this->originalThemeKey;
+    if (isset($this->originalThemeKey)) {
+      $GLOBALS['theme_key'] = $this->originalThemeKey;
+    }
     $GLOBALS['theme'] = $this->originalTheme;
 
     // Reset all static variables.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/GetFilenameUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/GetFilenameUnitTest.php
index 32705bf..27ea1d7 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Bootstrap/GetFilenameUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Bootstrap/GetFilenameUnitTest.php
@@ -22,24 +22,13 @@ public static function getInfo() {
     );
   }
 
-  function setUp() {
-    parent::setUp();
-
-    // Remove the keyvalue service definition, since this test wants to verify
-    // the filesystem scan fallback of drupal_get_filename().
-    $this->keyvalue_definition = $this->container->getDefinition('keyvalue');
-    $this->container->removeDefinition('keyvalue');
-  }
-
-  function tearDown() {
-    $this->container->setDefinition('keyvalue', $this->keyvalue_definition);
-    parent::tearDown();
-  }
-
   /**
    * Tests that drupal_get_filename() works when the file is not in database.
    */
   function testDrupalGetFilename() {
+    // Assert that the test is meaningful by making sure the keyvalue service
+    // does not exist.
+    $this->assertFalse(drupal_container()->has('keyvalue'), 'The container has no keyvalue service.');
     // Retrieving the location of a module.
     $this->assertIdentical(drupal_get_filename('module', 'php'), 'core/modules/php/php.module', 'Retrieve module location.');
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php b/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
index c313d82..b859c16 100644
--- a/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/DrupalKernel/DrupalKernelTest.php
@@ -30,11 +30,6 @@ public static function getInfo() {
    * Tests DIC compilation.
    */
   function testCompileDIC() {
-    // Because we'll be instantiating a new kernel during this test, the
-    // container stored in drupal_container() will be updated as a side effect.
-    // We need to be able to restore it to the correct one at the end of this
-    // test.
-    $original_container = drupal_container();
     $classloader = drupal_classloader();
     global $conf;
     $conf['php_storage']['service_container']= array(
@@ -63,9 +58,6 @@ function testCompileDIC() {
       !$refClass->isSubclassOf('Symfony\Component\DependencyInjection\ContainerBuilder');
     $this->assertTrue($is_compiled_container);
 
-    // Reset the container.
-    drupal_container(NULL, TRUE);
-
     // Now use the read-only storage implementation, simulating a "production"
     // environment.
     $conf['php_storage']['service_container']['class'] = 'Drupal\Component\PhpStorage\FileReadOnlyStorage';
@@ -89,9 +81,6 @@ function testCompileDIC() {
     // modules.
     $this->assertFalse($container->has('bundle_test_class'));
 
-    // Reset the container.
-    drupal_container(NULL, TRUE);
-
     // Add another module so that we can test that the new module's bundle is
     // registered to the new container.
     $module_enabled['bundle_test'] = 'bundle_test';
@@ -113,8 +102,5 @@ function testCompileDIC() {
     $classloader = $container->get('class_loader');
     $refClass = new ReflectionClass($classloader);
     $this->assertTrue($refClass->hasMethod('getNamespaces'), 'Container has a classloader');
-
-    // Restore the original container.
-    drupal_container($original_container);
   }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php
index 21998e2..a62eb90 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/UpgradePathTestBase.php
@@ -134,6 +134,7 @@ protected function setUp() {
     $this->variable_set('site_mail', 'simpletest@example.com');
 
     drupal_set_time_limit($this->timeLimit);
+    $this->rebuildContainer();
     $this->setup = TRUE;
   }
 
diff --git a/core/update.php b/core/update.php
index 98296bb..7e5a3ac 100644
--- a/core/update.php
+++ b/core/update.php
@@ -448,20 +448,6 @@ function update_check_requirements($skip_warnings = FALSE) {
 drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
 drupal_maintenance_theme();
 
-// @todo Remove after converting update.php to use DrupalKernel.
-$container = drupal_container();
-$container->register('database', 'Drupal\Core\Database\Connection')
-  ->setFactoryClass('Drupal\Core\Database\Database')
-  ->setFactoryMethod('getConnection')
-  ->addArgument('default');
-$container->register('lock', 'Drupal\Core\Lock\DatabaseLockBackend');
-$container->register('router.dumper', '\Drupal\Core\Routing\MatcherDumper')
-  ->addArgument(new Reference('database'));
-$container->register('router.builder', 'Drupal\Core\Routing\RouteBuilder')
-  ->addArgument(new Reference('router.dumper'))
-  ->addArgument(new Reference('lock'))
-  ->addArgument(new Reference('dispatcher'));
-
 // Turn error reporting back on. From now on, only fatal errors (which are
 // not passed through the error handler) will cause a message to be printed.
 ini_set('display_errors', TRUE);