I apologize for my limited english. I’m currently responsible for maintaining a multi-site Drupal 8. I have several instances already in production. They share the same code (core, themes and modules). But I’m still improving my site factory by adding new contents and modules to its “model”.

From times to times, I have to update the instances in production according to the model. To achieve that, I spread the updates manually, instance by instance. The process is tedious and error prone.

I’m looking for a semi-automatic way to do it. One key principle is that the factory is “monotonic”: the model will never remove content types or modules previously defined and/or installed. After trying the “Features” module, I discovered that some entities Drupal 8 considers as “content” are common to all instances. It means that they are “configuration” for me, and should be updated, when normal contents should not be. One example is the back-office menus for authors. At the opposite, some Drupal “configuration” entities (site name, instance specific module configuration) should be kept stable.

That’s why I changed my mind. Now, I’m looking for a way to backup all the “pure content” of an instance: pages, nodes, files,… After that, I will destroy the instance to update (files and database), Then, I will create a new one by cloning the new model, And I will restore the content into the new instance. Of course, the restore step must guarantee the validity of the links between the pages and the files. Thanks for any comment, or reference to module or tutorial that can help me. Best regards