Upgrading from DKAN 2.x

Background

DKAN 2

DKAN 2 was a major rewrite of DKAN 7.x-1.x for Drupal 8, and we misinterpreted a few aspects of the newly-introduced conventions around object-oriented programming and PSR namespacing. Specifically, there was an assumption that submodules could inherit the namespace of their parent module, so that under Drupal\dkan we could have submodules like Drupal\dkan\harvest and Drupal\dkan\datastore. This was not the case, and we ended up with some very generic top-level namespaces like Drupal\harvest and Drupal\datastore.

Aside from the confusion and aesthetic issues this caused, we also started to encounter problems with collisions on the Drupal.org module registry. Even if one were not to install the drupal/datastore module, Drupal’s packaging tools caused issues when people tried to create DKAN extensions to release on Drupal.org that had dependencies on specific DKAN submodules.

Parallel to this, there has been a long-standing desire to release DKAN on Drupal.org. The 7.x-1.x version of DKAN did not meet the requirements to publish there, due to some licensing issues with some of its dependencies. We got into the habit of developing DKAN on GitHub and releasing via packagist, and this continued when we moved to DKAN 2 and Drupal 8, even though licensing was no longer an issue.

Getting it right in DKAN 4

In 2025 we decided to “rip the band-aid off” and rename our submodules to meet namespacing conventions. This is a much bigger change than it might initially sound like, as it requires:

Changing the namespaces in every use statement, touching almost every file
Designing a multi-step upgrade path so that at no point does Drupal expect a module that is no longer present.
Properly handling config from the old modules, and custom config on existing sites that depends on the renamed modules.

For this reason, we are jumping two major versions of DKAN at once.

DKAN 2.23 will introduce the new, renamed modules (they will not yet be functional)
DKAN 3.0 will move all the code from the old modules to the new, provide all the update functions to migrate existing sites, and deprecate the old modules. We do not plan to release any updates to 3.0, as it is intended purely as a transition to DKAN 4.0.
DKAN 4.0 will remove the legacy modules from the codebase. This will also be the first release on drupal.org, and the package name in composer will change from getdkan/dkan to drupal/dkan.

Soon after 4.0.0 is released we will wind down work on the 2.x branch. We will consider backports and especially security updates but expect most new bugfixes and new features exclusively on DKAN 4.x.

Detailed instructions

Summary

Due to limitations in how database and config updates are performed by Drupal, it will not be possible to upgrade directly from 2.23 to 4. It must be done in separate upgrades. The process as described here may seem intimidating. However, it is fairly straightforward:

Upgrade to latest 2.x
Upgrade to 3.0
Upgrade to latest 4.x

Caution

This process makes many non-recoverable changes to your database. Do at least one dry-run of this in a development environment before attempting in production. It is also highly recommended that you take backups at each step to ensure you can roll back if something goes wrong.

Deployment notes

In most workflows for a site in production, you will not be performing composer and git commands directly on your production server. Throughout these instructions, there are notes like this with additional considerations when performing these actions on a codebase you are editing locally but deploying to a production server.

Step 1: Get to latest 2.x

Before jumping a major version, make sure you are on the latest release of DKAN 2.23.x. Make sure your version constraint for getdkan/dkan is ~2.23.0, ^2, or something equivalent.

Run:

composer update getdkan/dkan
drush update:db

Commit the changes to composer.json and composer.lock if these are under version control.

Deployment notes

Under most workflows, you would deploy this latest release to production and run the database updates on your server if they go smoothly on your local copy. Depending on your setup, this may be something you have to do manually (for instance, by visiting /update.php or running drush @your_alias update:db), or it may be part of a post-deploy hook or script that runs automatically after any new code deployment.

Ensure that after deployment, the new transitional DKAN modules (for instance, dkan_metastore) are enabled. Note that if you automatically import configuration as part of your deployment (for instance, with an Acquia post-deploy cloud hook), you also need to export your core.extension and add it to the commit that upgrades DKAN to 2.23.x. Otherwise, the new DKAN modules that are enabled via the database updates will be disabled again when your old config is imported. If this happens, re-enable them manually on your production server before proceeding to the next step.

Step 2: Export configuration

It is highly recommended that before upgrading to DKAN 3.x, you export your site settings using the Drupal UI or the drush config:export command. If you are not familiar with this workflow, please read the configuration management section of the Drupal documentation.

Deployment notes

Usually, you will be exporting config in your local environment, but you want it to reflect the latest state of your production instance. Make sure you have a recent copy of the production database before your export, particularly one that reflects the updates from Step 1.

If you keep your configuration in version control, commit the changes.

Step 3: Get to DKAN 3.x

Now you should be ready to upgrade the DKAN module. Run:

composer require getdkan/dkan:~3.0.0 -W

Note that DKAN 3 also uses the now-standalone JSON Form Widget module, which had previously been included as a submodule of DKAN. Adding -W to the composer command ensures that this new dependency will also be added.

Deployment notes

Do not deploy these code changes to production until you have completed steps 4-7 or you may lose functionality on your live site.

As detailed in the deployment notes for step 1, ensure that the transitional namespaced DKAN modules are enabled before deploying DKAN 3. If they were disabled inadvertently during the upgrade to 2.23.x, reenable them manually or via config before deploying DKAN 3.

Step 4: Refactor custom code

If your site contains any custom modules or themes that have dependencies on DKAN, you will need to update their namespaces and any references to the old module names. For example, if you had custom code that used the old Drupal\harvest namespace, you would need to change it to Drupal\dkan_harvest.

Make sure to update YAML files like .info.yml and .services.yml as well. These may have references to either module names or class namespaces that need to be updated.

Step 5: Run updates

You now have a 3.x codebase but your database has not changed since 2.x. Run:

drush update:db

This will disable all the “legacy” modules (e.g. harvest, datastore, etc) and enable the new, renamed ones (e.g. dkan_harvest, dkan_datastore). It will also run all the necessary update hooks to migrate the old modules’ settings to the new modules.

The update hooks will also go through each role on your site and remove any permissions defined in the disabled modules. This prevents the roles from being deleted completely due to missing dependencies. If you have exported your config, these permissions should be re-added to the roles when you re-import your config (see next step).

Step 6: Re-import configuration

The correct modules should now be enabled and disabled, but your site config is now in a weird state. Likely, several configurations have been automatically removed because their dependencies on legacy modules are no longer met. Fortunately, your original configuration is preserved in your sync directory if you followed step 2.

Before you import, you can inspect the difference between your current site config and the sync directory by visiting the Drupal UI at /admin/config/development/configuration. You will possibly see a number of configuration items being added, because they were removed when the legacy modules were disabled.

DKAN 3.x includes an event subscriber that modifies config on import to attempt to re-map old module names to new ones. Unexpected changes to config you see in this UI screen may be a result of that subscriber modifying config items on import.

Step 7: Re-export configuration

It’s time to lock in your migrated config. Now run

drush config:export

…to re-export your config to the sync directory.

If you are managing your sync directory in version control (recommended), you have another opportunity to inspect what changed before committing.

Deployment notes

It is at this point we recommend committing your changes and deploying the new commit to production. Your updated DKAN version, refactored custom code, and updated configuration files will all hit at the same time. Hopefully, at this point your specific deployment workflow will run the database updates and re-import the updated site configuration (in that order!).

Also, you should have performed one or more local dry-runs before attempting this in production. Still, if anything goes wrong, be prepared to roll back both the code and the database to a previous tag and backup, respectively.

Step 8: DKAN 4

The newly namespaced modules are now enabled, the legacy modules disabled, and all config migrated. We can now upgrade to DKAN 4. Note that the vendor name must also be updated:

composer require drupal/dkan:~4.0.0
drush update:db

While there should be no pending database updates at this point, it is always a good idea to run drush update:db after any change to composer.json.

A note on DKAN 4.1

By the time you read this, DKAN 4.1 may already be out. You may wish to upgrade directly to 4.1 instead of 4.0. DKAN 4.1 introduces breaking changes to JSON validation, so make sure to read the release notes for that version before upgrading (they will be linked directly in a future version of this document). It is possible that you will need to make some minor adjustments to your metastore schemas to ensure they are compatible with JSON Schema draft-07 or later.

To upgrade to 4.1, simply change the composer command in step 8 to:

composer require drupal/dkan:~4.1.0

Or use a loser constraint like ^4 to allow for any 4.x release.