Cannot set nested value path via downward API

[mamachanko]

What steps did you take:

1. Create a package with a values schema
2. Set a nested value path via the downward API

#! package.yaml

---
apiVersion: data.packaging.carvel.dev/v1alpha1
kind: Package
metadata: 
  name: test.example.com.0.1.0
  namespace: default
spec: 
  refName: test.example.com
  version: 0.1.0
  template: 
    spec: 
      deploy: 
        - kapp: {}
      fetch: 
        - path: config
          inline: 
            paths: 
              config/schema.yaml: |
                #@data/values-schema
                ---
                #@schema/type any=True
                internal: null
              config/values.yaml: |
                #@data/values
                ---
                internal:
                  secret_message: hello cool
              config/config.yaml: |
                #@ load("@ytt:data", "data")
                #@ load("@ytt:yaml", "yaml")
                ---
                apiVersion: v1
                kind: ConfigMap
                metadata: 
                  name: test.example.com
                data: 
                  values: #@ yaml.encode(data.values)
      template: 
        - ytt: 
            paths: 
              - ./config
            valuesFrom: 
              - downwardAPI: 
                  items: 
                    - name: internal.version
                      fieldPath: "metadata.annotations['packaging\\.carvel\\.dev/package-version']"
                    - name: internal.kubernetes_version
                      kubernetesVersion: {}
                    - name: internal.kubernetes_gvs
                      kubernetesAPIs: {}

---
apiVersion: packaging.carvel.dev/v1alpha1
kind: PackageInstall
metadata: 
  name: test
  namespace: default
spec: 
  packageRef: 
    refName: test.example.com
    versionSelection: 
      constraints: "> 0.0.0"
  serviceAccountName: install-sa

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: install-sa
  namespace: default

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: install-admin
rules:
  - apiGroups:
      - '*'
    resources:
      - '*'
    verbs:
      - '*'

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: install-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: install-admin
subjects:
  - kind: ServiceAccount
    name: install-sa
    namespace: default

What happened:

The package fails to install:

ytt -f package.yaml | kapp d -c -y -f- -a test

Target cluster 'https://127.0.0.1:54182' (nodes: kind-cert-manager-control-plane)

# ...

8:14:17AM: ---- waiting on 1 changes [4/5 done] ----
8:14:20AM: fail: reconcile packageinstall/test (packaging.carvel.dev/v1alpha1) namespace: default
8:14:20AM:  ^ Reconcile failed:  (message: ytt: Error: Overlaying data values (in following order: config/values.yaml, additional data values):
One or more data values were invalid
====================================

Given data value is not declared in schema
downwardapi_1.yaml:
    |
  1 | internal.kubernetes_version: 1.29.2
    |

    = found: internal.kubernetes_version
    = expected: a map item with the key named "internal" (from config/schema.yaml:2)


)

kapp: Error: waiting on reconcile packageinstall/test (packaging.carvel.dev/v1alpha1) namespace: default:
  Finished unsuccessfully (Reconcile failed:  (message: ytt: Error: Overlaying data values (in following order: config/values.yaml, additional data values):
One or more data values were invalid
====================================

Given data value is not declared in schema
downwardapi_1.yaml:
    |
  1 | internal.kubernetes_version: 1.29.2
    |

    = found: internal.kubernetes_version
    = expected: a map item with the key named "internal" (from config/schema.yaml:2)


))

What did you expect:

The package install and the nested value paths are set as expected:

❯ k get cm test.example.com -oyaml | yq .data
values: |
  internal:
    secret_message: hello cool
    version: 0.1.0
    kubernetes_version: 1.29.2
    kubernetes_gvs:
    - v1
    - apiregistration.k8s.io/v1
    - apps/v1
    #! ...

Anything else you would like to add:

note: fieldpath is not affected. only kappControllerVersion, kubernetesVersion and kubernetesAPIs

When we omit the schema from the package we can see that values are set but not nested:

❯ k get cm test.example.com -oyaml | yq .data
values: |
  internal:
    secret_message: hello cool
    version: 0.1.0
  internal.kubernetes_version: 1.29.2
  internal.kubernetes_gvs:
  - v1
  - apiregistration.k8s.io/v1
  - apps/v1
  #! ...

That's because DownwardAPI.AsYAMLs() only handles nestedness for fieldPath but not the others. here

Environment:

• kapp Controller version v0.48.2

---

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[praveenrewar]

Thank you @mamachanko for reporting this issue. I think this was missed as kappControllerVersion, kubernetesVersion and kubernetesAPIs were added sometime after downwardAPI.
Thank you so much for creating the PR ❤️