This document discusses migrating from Drupal 6/7 to Drupal 8 using the Migrate module. It provides an overview of common migration tasks like planning, data mapping, and handling dependencies. It also explains the key components of migration - the source and destination plugins that provide and import data, and the various process plugins that can transform and map data as it flows from source to destination. The document demonstrates how to configure a basic migration using YAML definitions and run migrations via Drush or custom code.

1. Мигрируем на Drupal 8!
#dckiev14

2. About us
Andy Postnikov http://dgo.to/@andypost
Pavel Makhrinsky http://dgo.to/@gumanist

3. More then 2% of all sites
How many sites are running Drupal 6 and 7?

4. Latest stats

5. 10 Drupal myths
●Box product
●Lego
●Contrib - themes, modules, libraries
●Multilingual
●Platform
●Support
●Community
●Evolution

6. Go Drupal 8
●PHP 5.4 - 5.5, 5.6.2
●HTML 5
●Libraries - jQuery 2.1 (3.0)
●Modules
●CDN - REST
●Database

7. Common migration tasks
●Planning
oData mapping
oDependencies management
oData cleanup
●Chicken 'n Egg handling
●Continuous content lifecycle
●Progress monitoring
●Rollback results

8. What is the migrate module?
Source => Process => Destination

9. Migrate vs Feeds
Mostly indentical feature set:
●Since 2009 but FeedAPI 2007
●feeds is UI-oriented
●feeds_tamper vs custom code
●feeds has a lot of satelite modules

10. Migrate in Drupal 8 retrospective
Signed after 6 weeks away from feature freeze
https://www.drupal.org/node/1052692#comment-6620570
Initial patch was commited November 21, 2013
https://www.drupal.org/node/2125717#comment-8197259
Drupal 6 to Drupal 8 patch April 23, 2014
https://www.drupal.org/node/2121299#comment-8710315
Still in progress of polishing
https://groups.drupal.org/imp - weekly call

11. Processing

12. Mapping

13. Definition (yml-file)
id: migrate_example_people
source:
plugin: migrate_example_people
destination:
plugin: entity:user
md5_passwords: true
process:
name:
-
plugin: concat
delimiter: .
source:
- first_name
- last_name
-
plugin: callback
callable:
- 'DrupalComponentUtilityUnicode'
- strtolower
-
plugin: callback
callable: trim
-
plugin: dedupe_entity
entity_type: user
field: name
mail: email
pass: pass
roles:
-
plugin: explode
delimiter: ';'
source: groups

14. Chicken and egg
process:
tid: tid
vid:
plugin: migration
migration: d6_taxonomy_vocabulary
source: vid
parent:
-
plugin: skip_process_on_empty
source: parent
-
plugin: migration
migration: d6_taxonomy_term

15. Dependencies
migration_dependencies:
required:
- d6_filter_format
- d6_user_role
- d6_user_picture_entity_display
- d6_user_picture_entity_form_display
optional:
- d6_user_picture_file

16. Execution flow
class MigrateExecutable {
/** Performs an import operation - migrate items from source to destination. */
public function import() {
$source = $this->getSource();
$id_map = $this->migration->getIdMap();
$source->rewind();
while ($source->valid()) {
$row = $source->current();
$this->processRow($row);
$destination_id_values = $destination->import($row, $id_map-
>lookupDestinationId($this->sourceIdValues));
$id_map->saveIdMapping($row, $destination_id_values, $this-
>sourceRowStatus, $this->rollbackAction);
$source->next();
}
}

17. Source plugins
Provides source rows - mostly custom
1.getIterator(): iterator producing rows
2.prepareRow(): add more data to a row
3.There are hooks for prepareRow()
MigrateSourceInterface

18. Source example - core
/**
* Drupal 6 menu source from database.
*
* @MigrateSource(
* id = "d6_menu",
* source_provider = "menu"
* )
*/
class Menu extends DrupalSqlBase {
/**
* {@inheritdoc}
*/
public function query() {
$query = $this->select('menu_custom', 'm')
->fields('m', array('menu_name', 'title', 'description'));
return $query;
}

19. Source example - custom
public function count() {
if (is_array($this->getData())) {
return count($this->getData());
}
return 0;
}
public function getIterator() {
return new ArrayIterator($this->getData());
}
protected function getData() {
if (!isset($this->data)) {
$this->data = array();
foreach ($this->fetchDataFromYandexDirect() as $key => $value) {
$this->data[$key] = (array) $value;
}
}
return $this->data;
}

20. Process plugins
●Keys are destination properties
●Values are process pipelines
●Each pipeline is a series of process plugins +
configuration
●There are shorthands
MigrateProcessInterface::transform()

21. Process pipelines
process:
id:
-
plugin: machine_name
source: name
-
plugin: dedupe_entity
entity_type: user_role
field: id
-
plugin: user_update_8002 #custom

22. Process plugins shipped
Constant values
Plugins:
get
concat
dedupebase
iterator
skip_row_if_not_set
default_value
extract
flatten
iterator
migration
skip_process_on_empty
skip_row_on_empty
static map
machine_name
dedupe_entity
callback

23. Process plugin example
public function transform($value, MigrateExecutable
$migrate_executable, Row $row, $destination_property) {
$new_value = $this->getTransliteration()-
>transliterate($value,
LanguageInterface::LANGCODE_DEFAULT, '_');
$new_value = strtolower($new_value);
$new_value = preg_replace('/[^a-z0-9_]+/', '_',
$new_value);
return preg_replace('/_+/', '_', $new_value);
}

24. Destination plugins
●Does the actual import
●Almost always provided by migrate module
●Most common is entity:$entity_type
oentity:node
oentity:user
●If you are writing one, you are doing it wrong
MigrateDestinationInterface

25. Destination plugins shipped
●Config
●Entity
●Null
●for custom tables: url_alias, user_data…
destination:
plugin: config
config_name: user.mail

26. Destination plugin example
/**
* {@inheritdoc}
*/
public function import(Row $row, array $old_destination_id_values =
array()) {
$path = $this->aliasStorage->save(
$row->getDestinationProperty('source'),
$row->getDestinationProperty('alias'),
$row->getDestinationProperty('langcode'),
$old_destination_id_values ? $old_destination_id_values[0] : NULL
);
return array($path['pid']);
}

27. Demo
●Drush
●UI sandbox

28. Drush or custom code
Recommended way to execute - DRUSH
Custom code:
public function submitForm(array &$form, array &$form_state) {
/** @var $migration DrupalmigrateEntityMigrationInterface */
$migration = entity_load('migration', $form_state['values']['migration']);
$executable = new MigrateExecutable($migration, $this);
$executable->import();
// Display statistics.
$this->getStats($form, $form_state);
$form_state['rebuild'] = TRUE;
}

29. How to help
Document driven development
http://dgo.to/2127611
Open issues of migration system:
http://goo.gl/fmVNQl
Drupal groups http://dgo.to/g/imp
IRC: Freenode #drupal-migrate

30. Links
https://www.drupal.org/upgrade/migrate
https://www.drupal.org/node/2127611
https://groups.drupal.org/imp
IRC: Freenode #drupal-migrate

31. Questions & Discussions
Andy Postnikov http://dgo.to/@andypost
Pavel Makhrinsky http://dgo.to/@gumanist
Kiev 2014