Support explicit source/target in knative endpoint

[nicolaferraro]

Currently Camel K 1.0.0-M2 has a pre-baked list of allowed endpoints that can be used as start or end of a route.

E.g.

from('knative:channel/xx`)

The Knative trait looks for:

• eventing.knative.dev/v1alpha1 -> Channel
• messaging.knative.dev/v1alpha1 -> Channel
• messaging.knative.dev/v1alpha1 -> InMemoryChannel
• messaging.knative.dev/v1alpha1 -> KafkaChannel
• ...

A similar thing happen for the knative/endpoint.

It would be better if a user can explicitly set the target, like:

from('knative:channel/xx?kind=InMemoryChannel')

or even:

from('knative:channel/xx?kind=InMemoryChannel&apiVersion=messaging.knative.dev/v1')

Same also for endpoint. In the case of channel, the operator creates also a subscription.

The resolution of the apiVersion and kind will happen at operator level, but those properties need to be accepted by the runtime.

Wdyt @lburgazzoli ?

[lburgazzoli]

A simple solution would be to make the endpoint to allow unknown options, would that be ok ?

[nicolaferraro]

Not sure.. I'm worried about @valdar making typos at next conference and not getting an error back :)

[lburgazzoli]

So I will add such info even if we throw them away :)