How to call a Kustomize patch after namespace transformation?

How to make kustomize run a patch after namespace transformation was done?

Example, to reproduce:

extensionconfig.yaml

apiVersion: runtime.cluster.x-k8s.io/v1alpha1
kind: ExtensionConfig
metadata:
  name: my-extensionconfig

kustomization.yaml

resources:
- extensionconfig.yaml

namespace: foooo

output:

❯ kubectl kustomize  .
apiVersion: runtime.cluster.x-k8s.io/v1alpha1
kind: ExtensionConfig
metadata:
  name: my-extensionconfig
  namespace: foooo

Now namespace "foooo" is set. Now I want to update this resource with the same kustomization.yaml file, and do an additional patch.

Related question: How to exclude a resource when using namespace in kustomization.yaml?

My answer is based on the solution of user larsks https://stackoverflow.com/a/79269650/633961

transformers are called after namespace transformers.

input: extensionconfig.yaml

apiVersion: runtime.cluster.x-k8s.io/v1alpha1
kind: ExtensionConfig
metadata:
  name: my-extensionconfig

kustomization.yaml:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: foo
resources:
- extensionconfig.yaml

transformers:
- patch.yaml

patch.yaml

apiVersion: builtin
jsonOp: |-
  - op: remove
    path: /metadata/namespace
kind: PatchJson6902Transformer
metadata:
  name: patch6902
target:
  name: my-extensionconfig

Result:

❯ kustomize build .          

apiVersion: runtime.cluster.x-k8s.io/v1alpha1
kind: ExtensionConfig
metadata:
  name: my-extensionconfig

--> no "namespace". Problem solved, I am happy.