Issue #3231996: Ensure file system is writeable

src/Validator/WritableFileSystemValidator.php

@@ -7,13 +7,12 @@ use Drupal\automatic_updates\Event\UpdateEvent;
 use Drupal\automatic_updates\PathLocator;
 use Drupal\automatic_updates\Validation\ValidationResult;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
-use Drupal\Core\StringTranslation\TranslatableMarkup;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
- * Validates that important file system paths are writable.
+ * Checks that the file system is writable.
  */
-class WriteableFileSystemValidator implements EventSubscriberInterface {
+class WritableFileSystemValidator implements EventSubscriberInterface {
 
   use StringTranslationTrait;
 
@@ -25,51 +24,54 @@ class WriteableFileSystemValidator implements EventSubscriberInterface {
   protected $pathLocator;
 
   /**
-   * Constructs a WriteableFileSystemValidator object.
+   * The Drupal root.
+   *
+   * @var string
+   */
+  protected $appRoot;
+
+  /**
+   * Constructs a WritableFileSystemValidator object.
    *
    * @param \Drupal\automatic_updates\PathLocator $path_locator
    *   The path locator service.
+   * @param string $app_root
+   *   The Drupal root.
    */
-  public function __construct(PathLocator $path_locator) {
+  public function __construct(PathLocator $path_locator, string $app_root) {
     $this->pathLocator = $path_locator;
+    $this->appRoot = $app_root;
   }
 
   /**
-   * Validates that the file system is writable.
+   * Checks that the file system is writable.
    *
    * @param \Drupal\automatic_updates\Event\UpdateEvent $event
    *   The event object.
+   *
+   * @todo It might make sense to use a more sophisticated method of testing
+   *   writability than is_writable(), since it's not clear if that can return
+   *   false negatives/positives due to things like SELinux, exotic file
+   *   systems, and so forth.
    */
   public function checkPermissions(UpdateEvent $event): void {
-    $dir = $this->pathLocator->getProjectRoot();
-    $message = $this->t('The project directory "@dir" is not writable.', [
-      '@dir' => $dir,
-    ]);
-    $this->checkPath($dir, $event, $message);
+    $messages = [];
+
+    if (!is_writable($this->appRoot)) {
+      $messages[] = $this->t('The Drupal directory "@dir" is not writable.', [
+        '@dir' => $this->appRoot,
+      ]);
+    }
 
     $dir = $this->pathLocator->getVendorDirectory();
-    $message = $this->t('The vendor directory "@dir" is not writable.', [
-      '@dir' => $dir,
-    ]);
-    $this->checkPath($dir, $event, $message);
-  }
+    if (!is_writable($dir)) {
+      $messages[] = $this->t('The vendor directory "@dir" is not writable.', ['@dir' => $dir]);
+    }
 
-  /**
-   * Checks that a path is writable, and flags an error if it's not.
-   *
-   * @param string $path
-   *   The path to check.
-   * @param \Drupal\automatic_updates\Event\UpdateEvent $event
-   *   The event object.
-   * @param \Drupal\Core\StringTranslation\TranslatableMarkup $error_message
-   *   The translated error message if the path is not writeable.
-   */
-  protected function checkPath(string $path, UpdateEvent $event, TranslatableMarkup $error_message): void {
-    if (is_writable($path)) {
-      return;
+    if ($messages) {
+      $result = ValidationResult::createError($messages, $this->t('The file system is not writable.'));
+      $event->addValidationResult($result);
     }
-    $result = ValidationResult::createError([$error_message]);
-    $event->addValidationResult($result);
   }
 
   /**
@@ -78,6 +80,7 @@ class WriteableFileSystemValidator implements EventSubscriberInterface {
   public static function getSubscribedEvents() {
     return [
       AutomaticUpdatesEvents::READINESS_CHECK => 'checkPermissions',
+      AutomaticUpdatesEvents::PRE_START => 'checkPermissions',
     ];
   }