configMapGenerator unable to replace ConfigMap from a Helm chart

[cjyar]

Describe the bug

Kustomize is unable to replace the contents of a ConfigMap if the ConfigMap comes from the Helm generator.

Files that can reproduce the issue

kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

helmCharts:
- name: vault
  namespace: vault
  releaseName: vault
  repo: https://helm.releases.hashicorp.com
  version: 0.22.0

configMapGenerator:
- behavior: replace
  literals:
  - thing=stuff
  name: vault-config
  namespace: vault
  options:
    disableNameSuffixHash: true

Expected output

It should generate manifests

Actual output

Error: merging from generator &{0xc00028a5b0 <nil>}: id resid.ResId{Gvk:resid.Gvk{Group:"", Version:"v1", Kind:"ConfigMap", isClusterScoped:false}, Name:"vault-config", Namespace:"vault"} does not exist; cannot merge or replace

If I remove behavior: replace then I get this instead:

Error: merging from generator &{0xc0000dc480 <nil>}: id resid.ResId{Gvk:resid.Gvk{Group:"", Version:"v1", Kind:"ConfigMap", isClusterScoped:false}, Name:"vault-config", Namespace:"vault"} exists; behavior must be merge or replace

Kustomize version

{Version:kustomize/v4.5.7 GitCommit:56d82a8378dfc8dc3b3b1085e5a6e67b82966bd7 BuildDate:2022-08-02T16:28:01Z GoOs:darwin GoArch:amd64}

Platform

macOS

[k8s-ci-robot]

@cjyar: This issue is currently awaiting triage.

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[annasong20]

Hi @cjyar, I see the same error running kustomize v4.5.7 on macOS using the given kustomization.yaml.

I don't believe this is a bug. Kustomize runs its built-in kustomization fields in a certain order; the helmCharts generator is ahead of configMapGenerator in that order. Therefore, when kustomize runs configMapGenerator, it has yet to generate the helm chart specified and hence, the error.

An easy workaround is to move the configMapGenerator, as a plugin, under generators because kustomize runs plugins after built-in fields. You'd run kustomize build --enable-helm on the setup below:
kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

helmCharts:
- name: vault
  namespace: vault
  releaseName: vault
  repo: https://helm.releases.hashicorp.com
  version: 0.22.0

generators:
- configmap-generator.yaml

configmap-generator.yaml

apiVersion: builtin
kind: ConfigMapGenerator
behavior: replace
metadata:
  name: vault-config
  namespace: vault
literals:
  - thing=stuff
options:
  disableNameSuffixHash: true

Hope this helps.

[KnVerey]

/kind support
/triage resolved
/close

Feel free to re-open with more detail if the proposed solution doesn't work for you.

[k8s-ci-robot]

@KnVerey: Closing this issue.

In response to this:

/kind support
/triage resolved
/close

Feel free to re-open with more detail if the proposed solution doesn't work for you.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[preetsindhal]

Is there any way i can achieve the same on fluxcd using helmrelease, I tired the generators: approach it didn't work :(

Thanks

[celonis-eg]

Just for anyone reading--the recommendation above doesn't seem to work with either the replace or the merge behavior.