mappings cannot target metadata

[Luke Bond]

consider the following ResourceSync, taken from our current system:

apiVersion: sinker.influxdata.io/v1alpha1
kind: ResourceSync
metadata:
  name: cluster-0001-kustomization-status
  namespace: customer-0001
spec:
  mappings:
  - fromFieldPath: status
    toFieldPath: spec
  - fromFieldPath: metadata.labels
    toFieldPath: metadata.labels
  source:
    cluster:
      kubeConfig:
        secretRef:
          key: value
          name: cluster-0001-kubeconfig
      namespace: iox
    resourceRef:
      apiVersion: kustomize.toolkit.fluxcd.io/v1beta2
      kind: Kustomization
      name: iox-manifests
  target:
    resourceRef:
      apiVersion: tubernetes.influxdata.io/v1beta2
      kind: FluxcdKustomizationStatus
      name: iox-manifests

note that it has a mapping to copy the labels from source to target.

this doesn't work because on this line it is root.data that is passed into the set_field_path function: https://github.com/influxdata/sinker/blob/main/src/controller.rs#L168

root.data contains { spec: {...}, status: {...} }, the metadata is kept outside of the data object.

the result is that there results in two .metadata objects! somewhere one gets dropped.

i have a failing test for this, will work on a fix.

[Cannon Palms]

Nice find. Something that comes to mind as I read this issue is that it is important that sinker only take ownership of the labels it sets, not all labels, assuming it uses SSA. Do you think that is achievable? Written as a general feature, "sinker should take ownership of only leaf nodes of the jsonpath graph."

[Luke Bond]

assuming it uses SSA

it does

Do you think that is achievable?

i don't know :/ i'll make the change and see what it does to managed fields and report back. solvitur ambulando!

[Luke Bond]

okay so i fixed the bug and checked what it did to managedFields:

    managedFields:
    - apiVersion: tubernetes.influxdata.io/v1beta2
      fieldsType: FieldsV1
      fieldsV1:
        f:metadata:
          f:labels: {}
        f:spec:
          f:conditions: {}
          f:inventory:
            f:entries: {}
          f:lastAppliedRevision: {}
          f:lastAttemptedRevision: {}
          f:observedGeneration: {}
      manager: sinker.influxdata.io
      operation: Apply
      time: "2023-04-12T13:00:53Z"

not very helpful, because this ResourceSync is modifying the spec and the labels. i would have to test it on a mapping that modifies only labels to be sure, but it looks like it will own the whole labels object.

here is another where it is copying to spec and to labels, but labels actually existed:

    managedFields:
    - apiVersion: tubernetes.influxdata.io/v1
      fieldsType: FieldsV1
      fieldsV1:
        f:metadata:
          f:labels:
            f:app: {}
            f:idpe.influxdata.io/component: {}
            f:influxdata.io/owner: {}
            f:kustomize.toolkit.fluxcd.io/name: {}
            f:kustomize.toolkit.fluxcd.io/namespace: {}
        f:spec:
          f:loadBalancer:
            f:ingress: {}

looks like it will own only the labels it sets?

[Cannon Palms]

Nice, that's promising. Thanks for checking.