v5.8.0 breaks basic reusable generator w/ namespace transformation

[Unveraenderbar]

What happened?

Please have a look into the attached tar file.
The kustomization in the overlay directory dehydrates fine with all kustomize versions up to v5.8.0 — but aborts when using the latter with error message

$ kustomize-v5.8.0 build overlay
Error: accumulating resources: accumulation err='accumulating resources from '../base': '/var/home/5.8-bug/base' must resolve to a file': recursed accumulation of path '/var/home/5.8-bug/base': merging from generator &{0xc0004a2270 <nil>}: id resid.ResId{Gvk:resid.Gvk{Group:"", Version:"v1", Kind:"ConfigMap", isClusterScoped:false}, Name:"general-environment", Namespace:"abc"} does not exist; cannot merge or replace

It seems that the namespace trafo is not applied to the CM generator resource.

This is at least a major break in kustomize's API, and IMHO a bug: to my knowledge, transformations should always applied after generators, i.e. the CM generated should have its namespace assigned, and be mergeable

What did you expect to happen?

The kustomization in the overlay subdirectory should dehydrate with v5.8.8 the same way it did with earlier versions

How can we reproduce it (as minimally and precisely as possible)?

Please see attached tar file, resp. comments above.

Expected output

$ kustomize build overlay
apiVersion: v1
data:
  BASE_LAYER_ENV: base
  OVERLAY_ENV: overlay
kind: ConfigMap
metadata:
  name: general-environment-826bch2dh9
  namespace: abc

Actual output

None, please see error message given above.

Kustomize version

v5.8.0

Operating system

Linux

[Unveraenderbar]

5.8-bug.tgz

[koba1t]

Due to security risks, please do not attach tar files.
Please include the YAML manifest here in Markdown comment format or publish it in public GitHub repository.

/triage not-reproducible

[Unveraenderbar]

Here you are

$ tree
.
├── base
│   ├── configuration
│   │   └── general
│   └── kustomization.yaml
├── cm-generator
│   ├── kustomization.yaml
│   └── resources
│       └── general.yaml
└── overlay
    ├── configuration
    │   └── general
    └── kustomization.yaml

7 directories, 6 files
$ find . -type f | xargs -rifile sh -c 'echo "# file"; cat file'
# ./overlay/kustomization.yaml
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: abc # if namespace trafo is disabled, dehydrating w/ v5.8.0 works fine - otherwise it fails, while both cases work fine w/ earlier releases!

generators:
- ../cm-generator

resources:
- ../base
# ./overlay/configuration/general
OVERLAY_ENV=overlay
# ./base/kustomization.yaml
---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

generators:
- ../cm-generator

configMapGenerator:
- name: general-environment
  behavior: create
# ./base/configuration/general
BASE_LAYER_ENV=base
# ./cm-generator/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

kustomization/#transformed-transformers)

resources:
- resources/general.yaml
# ./cm-generator/resources/general.yaml
---
apiVersion: builtin
kind: ConfigMapGenerator

metadata:
  name: general-environment

behavior: merge

envs:
- configuration/general
$ kustomize-v5.8.0 build overlay
Error: accumulating resources: accumulation err='accumulating resources from '../base': '/var/home/scd/5.8-bug/base' must resolve to a file': recursed accumulation of path '/var/home/scd/5.8-bug/base': merging from generator &{0xc0004c4270 <nil>}: id resid.ResId{Gvk:resid.Gvk{Group:"", Version:"v1", Kind:"ConfigMap", isClusterScoped:false}, Name:"general-environment", Namespace:"abc"} does not exist; cannot merge or replace
$ kustomize version
v5.7.1
$ kustomize build overlay
apiVersion: v1
data:
  BASE_LAYER_ENV: base
  OVERLAY_ENV: overlay
kind: ConfigMap
metadata:
  name: general-environment-826bch2dh9
  namespace: abc

[Unveraenderbar]

@koba1t this issue has still status "not reproducible" — could you please state what is missing?
As indicated in the headline, the bug described here renders v5.8.0 IMHO unusable for non-trivial applications.

If you see this differently, it would be great if you could describe a workaround for the failing namespace trafo.

Thanks!

[Unveraenderbar]

@koba1t as it turns out, a workaround is simple — just inject the namespace trafo in the transformers section of the kustomization in overlays explicitely (instead of the namespace shortcut statement), i.e.

#namespace: abc # if namespace trafo is disabled, dehydrating w/ v5.8.0 works fine - otherwise it fails, while both cases work fine w/ earlier releases!
transformers: # if the very same namespace trafo is given in full form, v5.8.0 dehydrates correctly!
- |-
  apiVersion: builtin
  kind: NamespaceTransformer
  metadata:
    name: notImportantHere
    namespace: abc

But IMHO this makes it even clearer that the implementation in v5.8.0 is a bug, as both forms should be evaluated equivalently (as implemented in kustomize < v5.8.0)

[barrydobson]

I can also confirm this behaviour. Using a helm chart inflator as a generator, namespace isn't applied to any of the generator resources. Reverting to 5.7.1 fixes the issue.

[koba1t]

/triage accepted