dynamically bound sources

[Shohou]

It seems strange to me that there is dynamically bound destinations, but no dynamically bound sources. Is there a reason for that?

It seems to be easy implementable by copying BinderAwareChannelResolver, BeanFactoryMessageChannelDestinationResolver, DynamicDestinationsBindable, renaming them and changing logic to create inputs instead of outputs

[viniciusccarvalho]

@Shohou How would a dynamic source work? For destinations the concept is to support routers so that messages with different payload/headers would map to different endpoints. Now for sources? What does that mean, how you switch sources? Based on what criteria?

There's a new story on allowing programmatically creation of sources instead of just relying on @StreamListener if this is what you meant, we are addressing this for 2.0

[Shohou]

@viniciusccarvalho Is there a way to define Input with channel name not hard coded into the application? Let's say I have the application which I want to deploy multiple times as multiple nodes of some service and attach each node to the different channel. Channel name must be configurable somehow, for example it could be based on spring.application.name plus some prefix. Is it possible right now? I couldn't find.

[artembilan]

@Shohou ,

Seems for me you are mixing MessageChannel bean in the application internals with the external destination. As far as I see you are saying that you "want to deploy multiple times", that sounds like you really have only one compiled code base. I really don't see reason to make the channel bean name dynamically determined - it is only for internal logic. See Spring Integration for more information.

Looks like what you need is called binding in Spring Cloud Stream. That is definitely an external destination, e.g. Kafka topic, to which we bind our internal message channel. And that is already indeed can be configured in the application.properties: https://docs.spring.io/spring-cloud-stream/docs/Ditmars.RELEASE/reference/htmlsingle/#binding-properties. Seek for the:

spring.cloud.stream.bindings.input.destination=ticktock

where input is a channel bean name, and ticktock is a destination in the target binder system - Kafka topic, RabbitMQ exchange, Hazelcast topic, AWS Kinesis stream etc.

Does it make sense to you?

[Shohou]

somehow i missed destination property... or well... its because of evolution of some ideas... anyway destination solves my problem

Thank you!