Any examples for how to use transformer configuration for variable and namespace?

[soorena776]

Hi,

In transfomerconfigs README you have mentioned that it's possible to use a transformer to inject variables and namespaces. Any examples?

Thank you

[Liujingfang1]

Please take a look at the example in https://github.com/kubernetes-sigs/kustomize/tree/master/examples/transformerconfigs

[PacoDu]

Hi, I think the documentation about the namespace transformer configuration is missing: https://kubectl.docs.kubernetes.io/pages/reference/kustomize.html.

I couldn't find any mention of this feature in the documentation but it is possible to add the namespace option to kustomize configuration:

namespace:
  - kind: MyKind
    path: spec/my/crd/path/namespace

I found the solution looking at this builtin transformer configuration: https://github.com/kubernetes-sigs/kustomize/blob/master/api/konfig/builtinpluginconsts/namespace.go.

[ghost]

hate to reopen this, but I am hitting gaps in documentation regularly.
Maybe simple is not better, if not documented.

[DmitriGekhtman]

The namespace transformer is still undocumented.

[chobostar]

I spend a time to get working example, here the result:

$ cat default-input.yaml 
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: manager-rolebinding
subjects:
- kind: ServiceAccount
  name: default
  namespace: system
- kind: ServiceAccount
  name: service-account
  namespace: system
- kind: ServiceAccount
  name: another
  namespace: random
- kind: ServiceAccount
  name: without-namespace
- kind: Unrecognized
  name: no-namespace
- apiGroup: rbac.authorization.k8s.io
  kind: User
  name: alice@example.com
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: frontend-admins
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: system:serviceaccounts:qa

$ cat kustomization.yaml 
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
- default-input.yaml

transformers:
- |-
  apiVersion: builtin
  kind: NamespaceTransformer
  metadata:
    name: notImportantHere
    namespace: test
  setRoleBindingSubjects: allServiceAccounts
  fieldSpecs:
  - path: metadata/namespace
    create: true

$ kustomize version
{Version:kustomize/v4.5.7 GitCommit:56d82a8378dfc8dc3b3b1085e5a6e67b82966bd7 BuildDate:2022-08-02T16:35:54Z GoOs:linux GoArch:amd64}

$ kustomize build .
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: manager-rolebinding
subjects:
- kind: ServiceAccount
  name: default
  namespace: test
- kind: ServiceAccount
  name: service-account
  namespace: test
- kind: ServiceAccount
  name: another
  namespace: test
- kind: ServiceAccount
  name: without-namespace
  namespace: test
- kind: Unrecognized
  name: no-namespace
- apiGroup: rbac.authorization.k8s.io
  kind: User
  name: alice@example.com
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: frontend-admins
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: system:serviceaccounts:qa

I hope it will help you.

[revero-doug]

The namespace transformer is still undocumented.

still

[larsks]

I'm not sure why this was closed but I've just created a PR (#4906) that adds the missing documentation.