Let the ClusterFilter API to use a ConfigMap reference with namespace

[tobschli]

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

I am facing a problem where another Kubernetes API is interacting with the ClusterFilter API, specifically the ConfigMap reference of the Lua script that one can configure (ClusterFilter.spec.filters[].Lua.Script).

This is of type ConfigMapKeySelector, which in turn has a LocalObjectReference inside it.
According to documentation of this type:

LocalObjectReference contains enough information to let you locate the referenced object inside the same namespace.

The problem herein lies that the ClusterFilter API is a non-namespaced resource.
Therefore, other APIs do not know that the referenced ConfigMap is meant to be in the namespace of fluent-bit.

Describe the solution you'd like

It would be nice to not have any implicit namespace assumption, but use something like ObjectReference instead, enabling other APIs to also know where this ConfigMap lives.

Additional context

No response