Better syntax for ordered operations

[TheSpiritXIII]

Eschewed features

• This issue is not requesting templating, unstuctured edits, build-time side-effects from args or env vars, or any other eschewed feature.

What would you like to have added?

I want to apply transformers in order with a better UX.

Why is this needed?

For example, let's say I use labels to set all resources labels, but I want a few to be different. I want to use patches to modify the different labels, but sadly patches runs before labels.

It would be great if Kustomize supported some sort of operations field which let you list otherwise global fixed operations:

# These get applied in order.
operations:
- labels:
  - pairs:
      addonmanager.kubernetes.io/mode: Reconcile
- patchesStrategicMerge:
  - patch.yaml

Can you accomplish the motivating task without this feature, and if so, how?

I've been using transformers to accomplish this:

transformers
- |-
  apiVersion: builtin
  kind: LabelTransformer
  metadata:
    name: addonmanager
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
  fieldSpecs:
  - path: metadata/labels
    create: true
- |-
  apiVersion: builtin
  kind: PatchStrategicMergeTransformer
  metadata:
    name: labels
  paths:
  - patch.yaml

However, there's some downsides:

• Notice I use the deprecated patch merge transformer... yet no warning.
• No IDE support. Normally I get syntax highlighting and basic field validation except within the transformers.

What other solutions have you considered?

N/A

Anything else we should know?

No response

Feature ownership

• I am interested in contributing this feature myself! 🎉

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