Drupal 8 and distributions part 2: problems and prospects

This is part two of a series on configuration management challenges in Durpal 8. Part 1 looked at challenges for small sites and distriubtions.

What is the state of support for distributions in Drupal 8?

Trying to gauge the state of anything in Drupal 8 has its inherent pitfalls. The software itself is still changing rapidly, and efforts in the contributed extensions space have barely begun. That said, various initiatives are in process.

For background on configuration management in Drupal 8, see the documentation on managing configuration and the configuration API. Drupal 8 configuration is divided between a system for one-off simple configuration like module settings and configuration entities that store items you may have from zero to any number of, like content types and views. The Drupal 8 handbook pages on configuration are useful but not fully up to date.

Two recent blog post series that provide background and technical details are:

The challenges

Distributions in Drupal can be divided into two main types:

  • Starter-kit distributions like Bear are designed to get you started in building a site that you then take in your own direction.
  • Full-featured distributions like Open Atrium or Open Outreach are designed to fill a use case and support upgrades.

This distinction is important in light of the Drupal 8 assumption that sites, not modules, own configuration. Starter-kit distros will work fine with this assumption, but for full-featured distros it presents major challenges; see part 1 of this series.

Configuration management in Drupal 8 is built primarily around the single-site staging or deployment problem rather than the requirements of distributions. Back in 2012 a discussion tried to assess what was needed to make Drupal 8 distribution-friendly, but it didn't get far.

Two types of tools look to be needed to fill the gaps.

  • Developer tools. Managing configuration in distributions will require exporting it into feature-like modules. Because any extension (module, theme, installation profile) can include configuration, most of the needs of distribution authors are a subset of what any extension developer will need. For example, the built-in Drupal 8 configuration export functionality is designed only for use on a single site.
  • Site tools. Since Drupal core's single-site configuration management model conflicts with the requirements of updatable distributions, specialized modules will be needed to provide distribution-based sites with the ability to receive configuration updates.

Emerging solutions

  • Features 8.x
    Some of the first efforts to provide distribution-related functionality came in the form of sketches towards a Drupal 8 version of the Features module. The sandbox module contains a small collection of methods that can be called from the Drupal command line utility Drush for editing and reverting configuration modules.
  • Configuration Development
    Configuration Development provides automated import and export of configuration between the active configuration storage and exported modules.
  • Configuration Revert
    The sandbox Configuration Revert project provides a set of reports that allows you to see the differences between the configuration items provided by the current versions of your installed modules, themes, and install profile, and the configuration on your site. From these reports, you can also import new configuration provided by updates, and revert your site configuration to the provided values.
  • Configuration Packager
    Configuration Packager enables the packaging of site configuration into modules, like Features for Drupal 7. Rather than producing manually authored individual features, Configuration Packager analyzes the site configuration and automatically divides it up into configuration modules based on configured preferences.

Remaining work and coordinating efforts

See the drupal.org issue META: Required functionality for Drupal 8 distributions for an initial inventory of the work outstanding to prepare for Drupal 8 distributions.

As usual, the main challenges are probably not so much technical as strategic and organizational. To prepare the way for Drupal 8 distributions, we need to coordinate to understand barriers, explore solutions, and pool efforts.

Part of this work will be developing shared, generic tool sets. Already, there's a lot of work in modules like Features 8.x and Configuration Packager that isn't specific to features or packages of configuration and would better be merged into a more generic solution; see the issues #2383959, #2405015, and #2407609. Configuration Development is the most likely candidate (#2388253), though there are some outstanding issues.

Interested in helping? Please comment on and help flesh out the meta issue or the issues and projects referenced there.

Packaging configuration

My own efforts have been focused recently on taking a fresh approach to packaging configuration in Drupal 8 in the Configuration Packager module. In my next post in this series, I'll introduce that project.

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