Support Redis Pub/Sub as Message Broker

[JamieCressey]

Similar to Kafka and RabbitMQ. This is a feature request for first class support for using Redis Pub/Sub as a message broker in a Micronaut application

[cristian-com]

Hi there!

I've just started to write some groundwork for this ticket. I'm trying to keep it as similar as possible to the Kafka and Rabbit projects.

Here the draft (very simple POC of publishing/consuming flow): #278

I'm basically targeting a something like:

@RedisListener
class MessageChannelListener {
    @MessageChannel("individual_channel")
    public void handle(@MessageBody byte[] message) { ... }
}

• Listeners with multiple handler methods
• Handler methods supporting multiple channels/patterns with the same message body type.
• Basic wiring for custom subscribers lifecycle callbacks
• A simple publisher
• Json parsing ?
• Executors ?
• Connections configuration/management (both single/cluster and probably Redis events, but I'm not sure about the latter, at least for the first iteration).

I have only encountered one issue so far, and was using the Gradle plugin. I'm trying to mirror the way of including the messaging library (as it is in Kafka/Rabbit projects):

  // FIXME
  implementation 'io.micronaut:micronaut-messaging:3.3.4'
  **VS** 
  api mn.micronaut.messaging // mn is not found, I dont know if this is a plugin version kind of issue

It would be appreciated some help with that, so I don't use much time trying to figure out myself :v

Please advise me if the above makes sense, or if this ticket is even workable at all (I'm assuming so from the tag).