Clone a node programmatically

Question

I am modifying the node content on hook_form_alter() as follows.

  $node = \Drupal\node\Entity\Node::load($nid);
  if ($node) {
    $node->field_p_frontip = $availableip[0];
    $node->save();
  }

I need to clone the node and save it in the hook_form_alter() submission. How could I do this?

UPDATE

---

In D6 the node was cloned using the function clone_node_save which uses the node id to clone as clone_node_save($nid,false);, what is the corresponding function in D8 ??

Answer 1

In Drupal 8, any entity can be cloned using EntityInterface::createDuplicate(). So in the case of your node object: $cloned_node = $node->createDuplicate(). Calling $cloned_node->save() will save a new node with a different ID.

Answer 2

<!-- The below solution works for me. (Drupal - 9.4.1)
1. It perfectly clones all paragraphs.
2. It does not clone files.
3. It does not clone terms. -->

$nid = 17; // Example node id
$node = Node::load($nid);

if (is_object($node)) {
  $clonednode = $node->createDuplicate();
  // Loop over entity fields and duplicate nested paragraphs.
  foreach ($clonednode->getFields() as $field) {
    if ($field->getFieldDefinition()->getType() == 'entity_reference_revisions') {
      if ($field->getFieldDefinition()->getFieldStorageDefinition()->getSetting('target_type') == "paragraph") {
        $paragraphs = [];
        foreach ($field as $item) {
          $paragraphs[] = $item->entity->createDuplicate();
        }
        $fieldname = $field->getFieldDefinition()->getName();
        $clonednode->$fieldname =  $paragraphs;
      }
    }
  }

  $clonednode->changed->value = time();

  // Append cloned in the title.
  $clonednode->set('title', 'Cloned - ' . $node->getTitle());

  // Cloned node should be unpublished.
  $clonednode->set('status', 0);

  $clonednode->save();
}