Add add_resource_on_condition method to only add nodes when certain conditions are satisfied

[pit1sIBM]

Is your feature request related to a problem? Please describe.

Not a major problem, right now I'm implementing a feature to ignore certain nodes that are annotated in a certain way. This looks roughly like

ignore_resource = False
obj = fetch_k8s_resource(session)
if obj is not None:
    if ANNOTATION_IGNORE in obj["metadata"]["annotations"]:
       log.warn("Annotation set, ignoring resource")
       ignore_resource = True

if not ignore_resource:
    self.add_resource("job", k8s.Job(...))


# repeat for each resource

Describe the solution you'd like

I'd love to be more clear on whether a resource has some condition that needs to be satisfied first. In my head this looks like

def add_resource(self, name: str, obj: Any):
    ...

def add_resource_on_condition(self, name: str, obj: Any, cond: bool):
    if cond:
        self.add_resource(name, obj)

which turns the above example into

obj = fetch_k8s_resource(session)
self.add_resource_on_condition(
    "job", 
    k8s.Job(...), 
    obj is not None and ANNOTATION_IGNORE in obj["metadata"]["annotations"]
)

# repeat for each resource

Describe alternatives you've considered

Could also enhance existing add_resource with an additional param, I suggested a separate method to be more clear

Additional context

Add any other context about the feature request here.

[gabe-l-hart]

This is a really interesting idea! In general, for this kind of thing, I've tended to do two things:

1. Prototype it in my own operator's base component class (you could probably do this now)
2. Add it to oper8.x.oper8x_component

In general, I've tried to avoid adding too many optional bells-and-whistles to the base Component, but since this would just wrap self.add_resource, it would be a natural fit for the "Component plus common patterns" base in oper8.x. I don't think you guys are using oper8.x though, are you? It also gets you other nice things like the deps_annotation to auto-rollover on mounted data changes.

[pit1sIBM]

Understood, that makes sense to me. I was in the middle of 1 prior to opening the issue, completely missed oper8.x. I'll dig more into that now as the deps_annotation was on my todo list as well. Thank you!