Kustomization variable substitution type issue

[netthier]

I'm attempting to use the variable substitution feature in Flux's Kustomizations, but I'm getting weird issues with ambiguous strings (e.g. "20220802.5"):

Kustomization/my-namespace/my-ks dry-run failed, error: failed to create typed patch object (my-namespace/my-ks dry-run; kustomize.toolkit.fluxcd.io/v1beta2, Kind=Kustomization): .spec.postBuild.substitute.dd_tag: expected string, got &value.valueUnstructured{Value:2.02208025e+07}

I quoted each occurrence of ${dd_tag}, but that doesnt seem to help.

EDIT:
For more context, this error is being thrown by this Kustomization:

apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
kind: Kustomization
metadata:
  name: other-namespace
  namespace: other-ks
spec:
  path: "./apps/some/path/dev"
  targetNamespace: my-namespace
  prune: true
  interval: 5m
  sourceRef:
    kind: GitRepository
    name: flux-system
    namespace: flux-system
  postBuild:
    substitute:
      namespace: "my-namespace"
      dd_commit: "bba2c2d53adeed14b838efd256c55c47490bb10e"
      dd_tag: "20220802.5"

where ./apps/some/path/dev contains the Kustomization my-ks, which looks more or less like this:

apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
kind: Kustomization
metadata:
  name: my-ks
spec:
  targetNamespace: ${namespace}
  path: "./apps/some/path/base"
  prune: true
  interval: 5m
  sourceRef:
    kind: GitRepository
    name: flux-system
    namespace: flux-system
  postBuild:
    substitute:
      namespace: "${namespace}"
      dd_commit: "${dd_commit:=main}"
      dd_tag: "${dd_tag:=latest}"
  patches:
  # etc.

So the variable in question is actually passing through two Kustomizations before being applied to resources in ./apps/some/path/base

Changing the value of dd_tag such that it's not ambiguous anymore (string/float) fully fixes this issue, but is undesirable.

[somtochiama]

@netthier you can quote it w single quotes first like dd_tag: "'20220802.5'"

[applike-ss]

This does actually not seem to work when you pass this down more levels to other kustomization resources.

Any suggestion for this case?

[Sierra1011]

I'm getting the same issue creating Kustomizations to work around cross-resource dependencies.

Top level Kustomization has variable to replace multiple directories per environment, e.g. postBuild.substitute.var: "foo".
Created Kustomization does not inherit the variables, so I specify them in the created Kustomization the inherited value by using postBuild.substitute.var: ${foo}
I've tried to pass them through with a few combinations of single and double quotes, and I've given up because it just creates type errors on the second level Kustomization.

[netthier]

I've since given up on Flux+Kustomize and am currently using kluctl for GitOps and templating.
Handles float-like strings correctly as well, no matter the amount of layers :^)

[svengreb]

Why should directly defined variables be passed down when there is substituteFrom instead which can be used to share values across resources? You can define your values as ConfigMap in the “root“ KS and simply reference it in other KS.

Switching from official CNCF projects (and official tooling like Kustomize) to a more or less homebrewed single-men solution is like switching to a horse just for simple reasons like a cars color 😜

Without reproducible code it is hard to help because words can‘t explain a situation or setup that well.

[stefanprodan]

Docs on how to use numbers and booleans in post build substitutions are here: fluxcd/kustomize-controller#1129