Add an example for overwrite individual sub-charts using private image registry

[Archer-Li]

According to the documentation, it is possible to overwrite the registry for sub-charts. However, the corresponding keys for overwriting from the top level are not mentioned. Including such code snippets in the documentation would be very helpful.

For example, to overwrite the image registry for kube-state-metrics, it would be beneficial to show the corresponding keys that need to be set in the top level values.yaml file.

[petewall]

So, you're looking for guidance on setting the registry for the individual subcharts, rather than globally?

[Archer-Li]

Correct.

Using kube-state-metrics as an example, the current behavior for globally overwriting the registry changes registry.k8s.io/kube-state-metrics/kube-state-metrics:v2.14.0 to my.registry.com/kube-state-metrics/kube-state-metrics:v2.14.0

I am looking for a solution to use my.registry.com/registry.k8s.io/kube-state-metrics/kube-state-metrics:v2.14.0. I believe that setting the registry for the individual subcharts should allow me to achieve this.

[petewall]

Awesome. OK, i'll try and write up some documentation for that and let you know.

in the meantime, here's how you can do it, just for KSM:

clusterMetrics:
  kube-state-metrics:
    image:
      registry: my.registry.com/registry.k8s.io

Which is just referencing how to use these values:
https://github.com/prometheus-community/helm-charts/blob/main/charts/kube-state-metrics/values.yaml#L3-L9