Create property to disable the default behaviour of listening to a message bus in digiwf-s3-integration-starter

[boal]

Is your feature request related to a problem? Please describe.
The digiwf digiwf-s3-integration-starter is listening as default via spring-cloud-stream to a message broker like kafka. With this feature it is possible to get a presigned-url over a message bus.

On the other hand, the digiwf-s3-integration-starter supports the creation of presigned urls via REST. If an application does not need the feature to connect to a message bus, the starter tries to connect to the bus anyway.

To solve this problem, the digiwf-s3-integration-starter should have a property to disable the default behaviour of listening to the message bus. As a result, an application can use the digiwf-s3-integration-starter without a message bus.

Describe the solution you'd like

Create a property to disable the default behaviour of listening to a message bus via spring-cloud-stream.

Describe alternatives you've considered

The exclusion of the spring-cloud-stream config classes has to be done by the application itself which is using the digiwf-s3-integration-starter. If this exclusion done by the user of the digiwf-s3-integration-starter itself is the prevered solution, the necessary procedure should be documented.

A hardcoded solution to disable the default behaviour with exclusion of specific auto-configuration classes on start up can be found down below.

...
import org.springframework.cloud.stream.config.BindingServiceConfiguration;
import org.springframework.cloud.stream.function.FunctionConfiguration;
...

/**
 * Application class for starting the micro-service.
 */
@SpringBootApplication(
        ...
        // Deactivating the Spring Cloud Stream functionality that is activated by default
        exclude = { BindingServiceConfiguration.class, FunctionConfiguration.class },
       ...
)

An alternative to the hard coded solution is to exclude the classes via the following spring property:

spring:
  autoconfigure:
    exclude:
      # Deactivating the Spring Cloud Stream functionality that is activated by default
      - org.springframework.cloud.stream.config.BindingServiceConfiguration
      - org.springframework.cloud.stream.function.FunctionConfiguration

Acceptance Criteria

• Alternative 1: Provide an Property to disable the default behaviour of listening to a message bus.
• Alternative 2: Provide a documentation to disable the default behaviour by the user of the s3 integration starter.

Additional context

n/a

[github-actions]

👋 Thanks for reporting! The maintainers have been notified and will get back to you.

[darenegade]

@boal We would be very happy to receive a code contribution if you have a need for this feature

[simonhir]

In my opinion one integration starter should not behave any differently than all the others.
The behaviour with the automatic connection setup is probably caused by the digiwf-message lib.
A cleaner way might be to move the message-starter from the s3-core to the s3-starter and build a second s3-starter just for REST.