Make FunctionResponse.TTL configurable

[alperencelik]

What problem are you facing?

Currently, there appears to be no way to persist the TTL set on a FunctionResponse across pipeline steps. This is causing conflicts when EnableBetaRealtimeCompositions is enabled.

As far as I understand, response.TTL corresponds to the requeueAfter time in the composite controller and I'd like to requeue it less frequently than the default value (1 min).

As an example, I have a Composition configured in Pipeline mode as shown below:

apiVersion: apiextensions.crossplane.io/v1
kind: Composition
...
  mode: Pipeline
  pipeline:
  - functionRef:
      name: my-function
    step:  my-function-step
  - functionRef:
      name: function-auto-ready
    step: auto-ready-composition

Even though I set a custom TTL in my-function the last step of the pipeline (function-auto-ready) seems to override the FunctionResponse, resetting the TTL to the default.

How could this Function help solve your problem?

I suggest making the TTL value configurable via DeploymentRuntimeConfig while keeping the current default value the same. This would allow users to override the default requeue interval when necessary.

[alperencelik]

I've created #171 to explain what I'm trying to say better. Tested it locally and it seemed to work for me.