piyuesh23/d8_articles

Drupal 8 CMI

Separating config from content & being able to export config in code has always been a concern with Drupal. Solution to this started with the invent of features back in the days of Drupal 7 and has now become an integral part of Drupal 8.

Drupal 8 allows us to export configuration as YAML files. These can later be imported into another Drupal 8 instance with an easy to use interface. In this article, we will be talkig about:

• How to import/export single configuration?
• How to perform a bulk export of all the configurations on a site?
• How to synchronize configuration in a dev > stage > prod workflow?
• Running Drupal 8 with the configuration on file rather than Database.

Enabling the module:

The first step to get started with CMI is to enable the Configuration Manager module that bundles with Drupal 8 core.


Exporting/Importing Configuration:

The CMI interface gives us following 2 options for exporting the configuration:

• Exporting YAML files per component
• Exporting a config tarball of all the components

How to synchronize configuration in a dev > stage > prod workflow?

P.S. To move configuration across instances, its necessary for the components to have the same UUID. Dev/Stage/Prod instances need to be clones of each other.

CMI is not built for synchronizing a component from qed42.com to example.com.

To understand the process, lets assume we need to create an image style test it on dev & then push it across to both stage & prod. In a world without CMI, the process would be to create it on dev, test it & then recreate it again over the other instances(stage & prod). With CMI, the steps would be as follows:

• Create the sync directory to hold all the configurations. mkdir sites/defalult/files/sync
• Configure the same under config_directories array in settings.php.

$config_directories = array(
    CONFIG_SYNC_DIRECTORY => __DIR__ . '/files/sync'
);

• Create the image style on dev instance & test it.(Lets say we created an image style to scale images to 100X200 & named it as 100 x 200)
• Browse to /admin/config/development/configuration/full/export & click on export button. This will download a tarball of all the configurations in the system. Alternatively, we can use drush config commands to do the same: drush cex
• Extract the tarball exported into the sync directory created in 1st step. If using drush, only the updated or new configurations will be exported into sync directory automatically.
• Push the changes to version control system in use(GIT, SVN etc.).
• Pull the changes on staging server. If the configuration is exported for the first time, there will be a lot of configuration files getting pulled in, else it will be only the updated or new configurations.
• Browse to admin/config/development/configuration. An error message is displayed in case the UUIDs don't match. Otherwise,