Migrating from Drupal 7 to Drupal 10 Using the Migration Suite

Upgrading your Drupal site from version 7 to 10 can be a complex process, but with Drupal's powerful Migration Suite, the process can be made much more manageable. This guide will walk you through the steps to migrate a Drupal 7 site to Drupal 10, complete with detailed code examples.

Why Migrate to Drupal 10?

Drupal 10 brings numerous improvements, including enhanced performance, better security, a modernized user interface, and improved developer experience. By upgrading to Drupal 10, you can take advantage of the latest features and ensure long-term support for your site.

Prerequisites

Before you begin, ensure you have the following:

• A Drupal 10 installation.
• Composer installed on your local machine.
• Drush (Drupal Shell) installed.

Step-by-Step Migration Guide

1. Set Up Your Drupal 10 Environment

First, ensure your Drupal 10 environment is set up. Install the necessary migration modules using Composer:

composer require drupal/migrate_tools drupal/migrate_plus drupal/migrate_upgrade        

Enable the modules:

drush en migrate_tools migrate_plus migrate_upgrade        

2. Prepare Your Drupal 7 Site

Ensure your Drupal 7 site is accessible and that you have database credentials ready. You may need to enable additional modules on your Drupal 7 site to facilitate the migration.

3. Generate the Migration Configuration

Use Drush to generate the migration configuration files. Run the following command on your Drupal 10 site:

drush migrate-upgrade --legacy-db-url=mysql://username:password@localhost/dbname --legacy-root=https://example.com --configure-only
        

Replace username, password, localhost, dbname, and https://example.com with your actual Drupal 7 database credentials and site URL.

This command will generate a set of migration configuration files in your config/sync directory.

4. Review and Customize Migration Configurations

Review the generated configuration files in config/sync. You may need to customize these files to suit your specific migration needs.

Example of a Node Migration Configuration

migrate_plus.migration.migrate_nodes.yml:

id: migrate_nodes
label: 'Migrate Nodes'
migration_group: migrate_drupal_7
source:
  plugin: d7_node
  node_type: 'article'
process:
  type:
    plugin: default_value
    default_value: 'article'
  title: title
  body/value: body
  body/format:
    plugin: static_map
    source: body_format
    map:
      1: basic_html
  created: created
  changed: changed
  uid: uid
destination:
  plugin: 'entity:node'
  default_bundle: article
migration_dependencies:
  required: {  }
  optional: {  }
        

5. Run the Migration

After reviewing and customizing the migration configurations, run the migration using Drush:

drush migrate-import --all        

This command will execute all configured migrations. You can also run specific migrations by specifying their IDs:

drush migrate-import migrate_nodes        

6. Verify the Migration

Once the migration is complete, verify that all content has been migrated correctly. Check nodes, users, taxonomy terms, and any other entities to ensure they appear as expected on your Drupal 10 site.

7. Handle Custom Entities and Fields

If you have custom entities or fields in your Drupal 7 site, you may need to create custom migration plugins to handle these. Here's an example of how to create a custom migration plugin for a custom field:

Create a Custom Module: Create a directory for your custom module, e.g., modules/custom/custom_migration.

custom_migration.info.yml:

name: 'Custom Migration'
type: module
description: 'Custom migrations for Drupal 7 to Drupal 10.'
core_version_requirement: ^10
package: Custom
dependencies:
  - migrate_tools
  - migrate_plus
  - migrate_upgrade
        

Define the Custom Migration Plugin:

src/Plugin/migrate/source/CustomField.php:

<?php

namespace Drupal\custom_migration\Plugin\migrate\source;

use Drupal\migrate\Plugin\migrate\source\SqlBase;

/**
 * Source plugin for custom field migration.
 *
 * @MigrateSource(
 *   id = "custom_field"
 * )
 */
class CustomField extends SqlBase {

  /**
   * {@inheritdoc}
   */
  public function query() {
    $query = $this->select('field_data_custom_field', 'c')
      ->fields('c', ['entity_id', 'custom_field_value']);
    return $query;
  }

  /**
   * {@inheritdoc}
   */
  public function fields() {
    return [
      'entity_id' => $this->t('Entity ID'),
      'custom_field_value' => $this->t('Custom Field Value'),
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function getIds() {
    return [
      'entity_id' => [
        'type' => 'integer',
        'alias' => 'c',
      ],
    ];
  }
}
        

Define the Migration Configuration:

migrate_plus.migration.custom_field_migration.yml:

id: custom_field_migration
label: 'Custom Field Migration'
migration_group: migrate_drupal_7
source:
  plugin: custom_field
process:
  field_custom_field:
    plugin: get
    source: custom_field_value
destination:
  plugin: 'entity:node'
  default_bundle: article
migration_dependencies:
  required: {  }
  optional: {  }
        

Run the custom migration:

drush migrate-import custom_field_migration        

Conclusion

Migrating from Drupal 7 to Drupal 10 using the Migration Suite is a detailed process, but it provides a structured approach to ensure data integrity and consistency. By following these steps and leveraging the power of Drush and custom migration plugins, you can efficiently upgrade your site to take advantage of Drupal 10's features.

Feel free to reach out if you have any questions or need further assistance with your Drupal migration projects.

By sharing this comprehensive guide, you can help others in the LinkedIn community understand the migration process and leverage Drupal's capabilities to their fullest potential.