Upgrading to Drupal 9

For most Drupal Developers and users, the idea of moving a project from one major version of Drupal to another can be daunting, with modules and themes having to being changed significantly or rebuilt completely, and data being migrated from the old site to the new one.

This was no more so than the move from Drupal 7 to 8, but luckily this has changed for Drupal 9 and an upgrade can be done with minimal changes and not a data migration in sight!

In this talk, we'll look at some of the changes to Drupal's tools and processes that have made this possible, and how to move your Drupal site to Drupal 9.

https://www.oliverdavies.uk/talks/upgrading-your-site-drupal-9

Transcript

1. Upgrading to Drupal 9
   Oliver Davies, Inviqa
   

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2. @opdavies
   

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3. The D7 release cycle
   • One long-running branch
   • Minor versions for bug fixes (7.80, April 2021)
   • No big, new features
   • Long time for changes to get committed to core
   @opdavies
   

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4. The D8 release cycle
   • Semantic versioning for core
   • Minor release (new features) every 6 months
   • Patch release (bug fixes) every month
   • Multiple supported versions of core (8.9, 9.0, 9.1)
   @opdavies
   

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5. @opdavies
   

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6. Drupal 8 vs Drupal 9
   • No new functionality
   • Deprecated code removed
   • PHP required version increased
   • Major versions of dependencies updated
   @opdavies
   

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7. Previous upgrade issues
   • Lots of breaking changes
   • Core released, but contrib takes time to catch up
   @opdavies
   

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8. Contrib improvements
   • Minimal code changes required
   • Single release can support multiple versions of core
   • Semantic versioning enabled for contrib projects
   @opdavies
   

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9. @opdavies
   

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10. The difference is deprecated
    code
    @opdavies
    

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11. Deprecation example
    function drupal_set_message($message = NULL, $type = 'status', $repeat = FALSE) {
    @trigger_error('drupal_set_message() is deprecated in Drupal 8.5.0 and will
    be removed before Drupal 9.0.0. Use \Drupal\Core\Messenger\MessengerInterface
    ::addMessage() instead. See https://www.drupal.org/node/2774931',
    E_USER_DEPRECATED);
    $messenger = \Drupal::messenger();
    if (isset($message)) {
    $messenger->addMessage($message, $type, $repeat);
    }
    return $messenger->all();
    }
    @opdavies
    

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12. How do I find it?
    @opdavies
    

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13. Drupal Check
    • Developed by Matt Glaman
    • "Built on PHPStan, this static analysis tool will check for
    correctness (e.g. using a class that doesn't exist), deprecation
    errors, and more."
    • https://github.com/mglaman/drupal-check
    @opdavies
    

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14. composer global require
    mglaman/drupal-check
    @opdavies
    

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15. drupal-check web/modules/custom
    @opdavies
    

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16. @opdavies
    

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17. Upgrade Status module
    @opdavies
    

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18. @opdavies
    

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19. PHPUnit Bridge
    • Drupal 8 uses Symfony's PHPUnit Bridge
    • Includes a 'Deprecation Helper'
    • Displays deprecation notices in test output
    @opdavies
    

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20. @opdavies
    

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21. Fixing deprecations
    - drupal_set_message($text);
    + Drupal::messenger()->addMessage($text);
    @opdavies
    

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22. @opdavies
    

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23. Composer
    • Dependency management tool for PHP
    • My preferred way to manage Drupal codebases
    • composer.json lists your dependencies and version constraints
    • composer.lock stores the installed dependencies and versions
    • Separate packages for core-recommended, core-dev and
    core-composer-scaffold
    @opdavies
    

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24. composer require
    drupal/admin_toolbar:^2.0
    @opdavies
    

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25. composer install
    @opdavies
    

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26. composer update
    drupal/admin_toolbar
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27. Always add '--no-dev' in
    production
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28. An Example: Dransible
    https://github.com/opdavies/dransible
    @opdavies
    

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29. @opdavies
    

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30. Upgrading Dransible
    • Remove Drush (temporarily)
    • Update from Drupal 8.8 to 8.9
    • Add Upgrade Status module
    • Update contrib modules to D9 compatible versions
    • Remove incompatible contrib modules (if possible)
    • Fix deprecations in custom code
    • Upgrade from Drupal 8.9 to 9.0
    @opdavies
    

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31. composer update drupal/core-*
    --with-dependencies
    @opdavies
    

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32. composer require
    drupal/upgrade_status
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33. @opdavies
    

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34. @opdavies
    

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35. @opdavies
    

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36. @opdavies
    

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37. @opdavies
    

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38. @opdavies
    

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39. composer update drupal/core-*
    --with-dependencies
    @opdavies
    

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40. @opdavies
    

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41. @opdavies
    

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42. There were some autowiring
    gotchas...
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43. Error: Class 'Symfony\Component\Config\Resource\ClassE
    xistenceResource' not found in Symfony\Component\Depen
    dencyInjection\Compiler\AutowirePass->createTypeNotFou
    ndMessage()
    @opdavies
    

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44. composer require
    symfony/config:^4
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45. Cannot autowire service "Drupal\simple_message\Display
    SimpleMessage": argument "$messenger" of method "__con
    struct()" references interface "Drupal\Core\Messenger\
    MessengerInterface" but no such service exists. You sh
    ould maybe alias this interface to the existing "messe
    nger" service
    @opdavies
    

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46. Fixing autowiring
    services:
    Drupal\simple_message\DisplaySimpleMessage:
    autowire: true
    tags:
    - { name: event_subscriber }
    @opdavies
    

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47. Fixing autowiring
    services:
    + Drupal\Core\Messenger\MessengerInterface:
    + alias: messenger
    + private: true
    Drupal\simple_message\DisplaySimpleMessage:
    autowire: true
    tags:
    - { name: event_subscriber }
    @opdavies
    

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48. The big deal about Drupal 9 is... that it should not be a big
    deal
    Dries Buytaert
    @opdavies
    

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49. Drupal 10
    • Released around June 2022
    • Drupal 9 EOL around November 2023
    • Symfony 4 EOL in November 2023
    • Another easy upgrade
    @opdavies
    

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50. Thanks!
    References:
    • https://www.drupal.org/docs/understanding-drupal
    • https://dri.es/drupal-9-0-0-released
    • https://dri.es/drupal-10-target-release-date-and-drupal-9-end-of-life
    • https://github.com/opdavies/dransible
    Me:
    • https://www.oliverdavies.uk
    @opdavies
    

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