Support multiple Docker Compose files

[dieter-medium]

At the moment, the configuration option spring.docker.compose.file supports only a single file. However, I am using Spring Boot together with DevContainers, and to get my setup up and running, I need to use two Docker Compose files:

../compose.yaml
./compose.override.yaml

It would be highly beneficial if spring.docker.compose.file could support multiple files, similar to how Docker Compose itself allows specifying multiple files using the -f option.

Benefits:

• Aligns with Docker Compose's native functionality, offering a more flexible and powerful configuration.
• Supports complex setups like development with DevContainers.
• Improves user experience by reducing the need for workaround solutions.

Additional Context:

Supporting multiple Docker Compose files is a common scenario in development environments where configurations are split for better manageability. Implementing this feature would make Spring Boot's Docker Compose support more robust and versatile.

Thank you for considering this enhancement!

[mhalbritter]

Thanks for that proposal, I think this makes sense. How configuration merging works is documented here: https://docs.docker.com/compose/multiple-compose-files/merge/