Add support for Strimzi Topics in KameletBinding

[nicolaferraro]

PR #1602 introduces KameletBinding, which is a mechanism to bind a Kamelet to a source/sink and works currently with explicit URIs and Knative endpoints.

It would be really cool if also other kind of enpoint could be decoded from Kubernetes object references, such as Strimzi Topics.

The following binding may be used to send data from twitter to a Kafka topic:

apiVersion: camel.apache.org/v1alpha1
kind: KameletBinding
metadata:
  name: twitter-stream-binding
spec:
  source:
    ref:
      apiVersion: camel.apache.org/v1alpha1
      kind: Kamelet
      name: twitter-stream
    properties:
      keyword: Camel K
      secret: ...
  sink:
    ref:
      apiVersion: kafka.strimzi.io/v1beta1
      kind: KafkaTopic
      name: tweets

[heiko-braun]

What I don't yet see is where the integration logic (DSL) goes. This is just the binding, and I assume it will tacked onto a Kamelt? Is there docs to learn about more about this comes together at the end?

[nicolaferraro]

What I don't yet see is where the integration logic (DSL) goes. This is just the binding, and I assume it will tacked onto a Kamelt? Is there docs to learn about more about this comes together at the end?

Yes, the "twitter-stream" Kamelet will contain the code that allow getting the tweets (or any other data, from SaaS or enterprise services) into a generic sink. The sink here is strimzi, but the same Kamelet can also sink into a Knative channel by creating another binding.

I'm currently writing a "Kamelets" section for the Camel K documentation where I explain the mechanism.