Support Dapr pub/sub

[fgheysels]

In Arcus.Messaging, I like the concept of the message routers and I'm wondering if we could add support for Dapr Pub/Sub components in Arcus.Messaging.
This would allow us to use the Dapr pub/sub component to connect with a messaging system (be it Azure ServiceBus, an MQTT topic, .... ) and combine this with the message routing functionality that Arcus offers.

[stijnmoreels]

So a message pump that takes in messages from a Dapr subscription? Yes, that is similar to what we already have. How can we test this? Is this something we can run as a service during tests or is this available as an Azure resource?

If this Dapr pub/sub is already available as an Azure Functions trigger, you could already create a message router yourself that does the translation before we fully support this.

[fgheysels]

Dapr is mostly used in a Kubernetes environment.
So, suppose you have a worker that consumes messages from a servicebus, you could use Dapr Pub/Sub to read the messages from ServiceBus.
Dapr will inject a sidecar into your pod which is responsible for doing the communication with -in this case- servicebus, and sends the messages to your program. So in fact, Dapr offers an abstraction over the messaging technology that you're using.

I think it is a good idea to discuss this offline ?

[stijnmoreels]

Ah, okay, so an extra layer, indeed. If you feel like there are some more context you should give me, yes, let's take this offline.

If it uses the sidecar, I think we can re-use the functionality we've previously written for the Arcus Dapr secret provider.