Issue #3032078 by jrglasgow, dagomar, Berdir, nikitagupta, catch,...

Issue #3032078 by jrglasgow, dagomar, Berdir, nikitagupta, catch, anmolgoyal74, technoveltyco, idebr, ndf, jonas139, nod_: Multiple webheads can cause infinite growth of Twig cache

(cherry picked from commit a59f4db3)

core/lib/Drupal/Core/DependencyInjection/Compiler/TwigExtensionPass.php

@@ -9,7 +9,7 @@
 /**
  * Adds the twig_extension_hash parameter to the container.
  *
- * Parameter twig_extension_hash is a hash of all extension mtimes for Twig
+ * Parameter twig_extension_hash is a crc32 hash of all extensions for Twig
  * template invalidation.
  */
 class TwigExtensionPass implements CompilerPassInterface {
@@ -23,8 +23,8 @@ public function process(ContainerBuilder $container) {
       $class_name = $container->getDefinition($service_id)->getClass();
       $reflection = new \ReflectionClass($class_name);
       // We use the class names as hash in order to invalidate on new extensions
-      // and mtime for every time we change an existing file.
-      $twig_extension_hash .= $class_name . filemtime($reflection->getFileName());
+      // and crc32 for every time we change an existing file.
+      $twig_extension_hash .= $class_name . hash_file('crc32', $reflection->getFileName());
     }
 
     $container->setParameter('twig_extension_hash', Crypt::hashBase64($twig_extension_hash));

core/tests/Drupal/KernelTests/Core/Theme/TwigEnvironmentTest.php

@@ -6,6 +6,7 @@
 use Drupal\Component\Utility\Html;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Core\Site\Settings;
+use Drupal\Core\Template\TwigEnvironment;
 use Drupal\Core\Template\TwigPhpStorageCache;
 use Drupal\KernelTests\KernelTestBase;
 use Symfony\Component\DependencyInjection\Definition;
@@ -229,4 +230,62 @@ public function testTemplateInvalidation() {
     $this->assertEquals($template_after, $output);
   }
 
+  /**
+   * Test twig file prefix change.
+   */
+  public function testTwigFilePrefixChange() {
+    /** @var \Drupal\Core\Template\TwigEnvironment $environment */
+    $environment = \Drupal::service('twig');
+    $cache_prefixes = [];
+    $cache_filenames = [];
+
+    // Assume this is the service container of webserver A.
+    $container_a = $this->container;
+
+    $template_name = 'core/modules/system/templates/container.html.twig';
+
+    // Request 1 handled by webserver A.
+    $cache_prefixes[] = \Drupal::state()->get(TwigEnvironment::CACHE_PREFIX_METADATA_KEY)['twig_cache_prefix'];
+    $cache_filenames[] = $environment->getCache()->generateKey($template_name, $environment->getTemplateClass($template_name));
+
+    // Assume this is the service container of webserver B.
+    // Assume that the files on the webserver B have a different mtime than
+    // webserver A.
+    touch('core/lib/Drupal/Core/Template/TwigExtension.php');
+    clearstatcache(TRUE, 'core/lib/Drupal/Core/Template/TwigExtension.php');
+    $container_b = \Drupal::service('kernel')->rebuildContainer();
+
+    // Request 2 handled by webserver B.
+    \Drupal::setContainer($container_b);
+    $environment = \Drupal::service('twig');
+    $cache_prefixes[] = \Drupal::state()->get(TwigEnvironment::CACHE_PREFIX_METADATA_KEY)['twig_cache_prefix'];
+    $cache_filenames[] = $environment->getCache()->generateKey($template_name, $environment->getTemplateClass($template_name));
+
+    // Request 3 handled by webserver A.
+    \Drupal::setContainer($container_a);
+    $container = \Drupal::getContainer();
+    // Emulate twig service reconstruct on new request.
+    $container->set('twig', NULL);
+    $environment = $container->get('twig');
+    $cache_prefixes[] = \Drupal::state()->get(TwigEnvironment::CACHE_PREFIX_METADATA_KEY)['twig_cache_prefix'];
+    $cache_filenames[] = $environment->getCache()->generateKey($template_name, $environment->getTemplateClass($template_name));
+
+    // Request 4 handled by webserver B.
+    \Drupal::setContainer($container_b);
+    $container = \Drupal::getContainer();
+    // Emulate twig service reconstruct on new request.
+    $container->set('twig', NULL);
+    $environment = $container->get('twig');
+    $cache_prefixes[] = \Drupal::state()->get(TwigEnvironment::CACHE_PREFIX_METADATA_KEY)['twig_cache_prefix'];
+    $cache_filenames[] = $environment->getCache()->generateKey($template_name, $environment->getTemplateClass($template_name));
+
+    // The cache prefix should not have been changed, as this is stored in
+    // state and thus shared between all (web)servers.
+    $this->assertEquals(count(array_unique($cache_prefixes)), 1);
+
+    // This also applies to twig's file cache resulting in an unlimited growth
+    // of the cache storage directory.
+    $this->assertEquals(count(array_unique($cache_filenames)), 1);
+  }
+
 }