Migrate Your Way
to Drupal 8 Greatness

Bring in content from older Drupal sites, other databases, or HTML files

etherpad.net/p/d8migrate

@mlncn
agaric.com

drush migrate-upgrade --legacy-root=http://data.agaric.com --configure-only
  
  drush mr --all
  
George Pankewytch, 16 Months after Sandy
Wil Carraway, Pile of Junk

  1 * #Entities
+ 2 * #Fields
= Migration Complexity

You're not going to migrate in your schema that you had in Drupal 7 or 6 or Joomla...
disco insolence, Solvognen’s Tangle Of Wires
...you'll build it exactly as you want it in Drupal 8.Les Lim


Migrate module is using a more general process called extract, transform, and load, or ETL.Brad Lowry



Migration is an Extract, Transform, Load (ETL) process. For historical reasons, in the Drupal migration tool the extract phase is called "source", the transform phase is called "process", and the load phase is called "destination". Migration API
Attrib, ""
In a file agaric_migrate.info.yml:
type: module
name: Agaric Migrate
description: "Migrate from Agaric's Drupal 7 site to its new Agaric 8 site."
package: Migrate
core: 8.x
dependencies:
  - migrate
  - migrate_plus
  

For more complex processing, you can add process plugins.

In a file like src/Plugin/migrate/process/NerdUserRoles.php

You start out with:

namespace Drupal\nerdcustom\Plugin\migrate\process;
use Drupal\migrate\ProcessPluginBase;
use Drupal\migrate\MigrateExecutableInterface;
use Drupal\migrate\Row;
github.com/stevector/nerdologues-d8
/**
 * This plugin maps old roles to new roles.
 *
 * @MigrateProcessPlugin(
 *   id = "nerd_user_roles"
 * )
 */
class NerdUserRoles extends ProcessPluginBase {
  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if ($value == 3) {
      return 'administrator';
    }
    elseif ($value == 4) {
      return 'content_administrator';
    }
  }
}
earthtimes.org, Loggerhead turtle migration mystery solved

etherpad.net/p/d8migrate

ben@agaric.com
@mlncn

Reading & Resources

.

IndyDina, ""
Cory Doctorow, "The coming civil war over general purpose computing"