Default UUID key in ConfigEntityType

Just a rerole.

+++ b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.phpundefined
@@ -78,6 +78,10 @@ public function __construct($entity_type, array $entity_info, ConfigFactory $con
+    if (isset($this->entityInfo['entity_keys']['uuid'])) {
+      $this->uuidKey = $this->entityInfo['entity_keys']['uuid'];
+    }

+++ b/core/modules/config/config.moduleundefined
@@ -90,3 +90,19 @@ function config_menu() {
+
+/**
+ * Implements hook_entity_info().
+ */
+function config_entity_info(&$info) {
+  $config_entities = array_filter($info, function($entity_info) {
+    // Use the ConfigEntityBase class, and not ConfigEntityInterface. As the
+    // uuid key assumption is made in ConfigEntityBase.
+    return is_subclass_of($entity_info['class'], 'Drupal\Core\Config\Entity\ConfigEntityBase');
+  });
+
+  // Merge the 'uuid' key into all entity_keys data.
+  foreach (array_keys($config_entities) as $type) {
+    $info[$type]['entity_keys'] += array('uuid' => 'uuid');
+  }

I thought config module just provides the UI so we can't rely on that functionality here?

This would be easy to do in/after #2119905: Provide @ConfigEntityType and @ContentEntityType to have better defaults

Related #2182239: Improve ContentEntityBase::id() for better DX supposes that 'id' key works wrong for some config entities

This is certainly a better approach than the one I had in #2208285: Make ConfigEntityType::getKey() enforce the UUID key. However, this should also revert the relevant hunks that were introduced in #2198377: Enforce UUID key name in configuration entities, namely:

diff --git a/core/includes/entity.inc b/core/includes/entity.inc
index 0ade970..226d82a 100644
--- a/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -240,7 +240,12 @@ function entity_revision_delete($entity_type, $revision_id) {
  */
 function entity_load_by_uuid($entity_type_id, $uuid, $reset = FALSE) {
   $entity_type = \Drupal::entityManager()->getDefinition($entity_type_id);
-  if (!$uuid_key = $entity_type->getKey('uuid')) {
+
+  // Configuration entities do not use annotations to set the UUID key.
+  if ($entity_type->isSubclassOf('Drupal\Core\Config\Entity\ConfigEntityInterface')) {
+    $uuid_key = 'uuid';
+  }
+  elseif (!$uuid_key = $entity_type->getKey('uuid')) {
     throw new EntityStorageException("Entity type $entity_type_id does not support UUIDs.");
   }
 
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
index 42ad63e..87b43f7 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
@@ -174,7 +174,12 @@ public function isSyncing() {
    * {@inheritdoc}
    */
   public function createDuplicate() {
-    $duplicate = parent::createDuplicate();
+    $duplicate = clone $this;
+    $duplicate->set($this->getEntityType()->getKey('id'), NULL);
+
+    // @todo Inject the UUID service into the Entity class once possible.
+    $duplicate->set('uuid', \Drupal::service('uuid')->generate());
+
     // Prevent the new duplicate from being misinterpreted as a rename.
     $duplicate->setOriginalId(NULL);
     return $duplicate;

Awesome, looks great!

Less code++

Committed 0f35ae9 and pushed to 8.x. Thanks!