Decentralized migration scan package

[DanielSchiavo]

Issue reference

https://github.com/mongock/mongock/issues/704

Documentation PR reference

There are 2 commits
flamingock/mongock-docs#44

Description and context

This feature introduces multi-module support to Mongock, enabling modular projects to define and register their own migration packages independently.

Traditionally, Mongock required all migration packages to be configured centrally during builder setup. This approach can be limiting in large modular applications where each module should be able to manage its own database changes.

With this contribution:

Spring Boot modules can now annotate their configuration classes using @MongockScanPackage, and with this annotation, the package will be automatically added to the migration scan package.

For standalone applications, each module can implement a new MongockModuleConfig interface to programmatically register its own migration packages via builder.

This change improves decoupling, scalability, and maintainability in complex systems, especially microservices or monolithic applications split by modules.

Benefits

✅ Decentralized configuration of migration packages.

✅ Enables each module to independently define its migrations.

✅ Improves modularity and separation of concerns.

✅ Enhances flexibility for both Spring and Standalone runners.

✅ Maintains backward compatibility for centralized configuration.

✅ Provides a clean pattern for module-level migrations, both with annotations and builder-style setup.

Possible Drawbacks

I can't think of any

Checklist

• Unit tests provided
• Integration tests provided
• Documentation updated in documentation project
• Updated example in example projects

[DanielSchiavo]

I can't provide a example project in example projects until you guys merge the code

[DanielSchiavo]

Waiting for your feedback

[DanielSchiavo]

There is another feature that needs to be released for this to work well

[dieppa]

Hi @DanielSchiavo,

First of all, apologies for the delay in getting back to you — we’ve been working hard on our upcoming release, which will introduce many new features and mark a significant step forward in Mongock’s evolution.

Regarding your PR, thank you very much for the contribution — we really appreciate your effort. We believe this is a valuable improvement and are happy to move forward with merging it. That said, we have a few suggestions that might simplify the design and increase flexibility moving forward.

Although the current approach works, it might be more complex than necessary. What do you think about merging the concepts of Config and ScanPackage, and generalizing it to support additional properties in the future?

Here’s our proposed approach:

• Standalone runner
  Introduce a MongockModuleConfig interface with a method that returns a list of packages. The builder could then accept multiple MongockModuleConfig instances, offering a clean and extensible solution.

• Spring Boot integration
  Instead of using a custom annotation, it may be more user-friendly and consistent with the standalone approach to allow users to register any number of MongockModuleConfig beans. If I’m not mistaken (please confirm), Spring can inject a list of beans of the same type — we could leverage that to collect all registered configs into the builder.

Please let us know what you think. Once we agree on the best approach, I’m happy to assist with the final review and get this merged.

Thanks again!

[DanielSchiavo]

I'm glad you liked it @dieppa .

We can do it this way, I think it's a wise choice.

[dieppa]

Hello @DanielSchiavo, I am confused this is ready to review or you haven't got the change to update it as we discuss it? Let us know and we review it