ignoreDifferences for PVCs

[dan-m8t]

Hey,

I am in a situation where the live PVC manifest differs from the source (helm generated). This comes from a migration task I needed to do and that failed (use different StorageClass). Because I needed to rollback my changes I changed the PVC live inside the cluster and added the storageClassName and volumeName to the manifest. I figured out later that it can be done easier (set UID of PVC inside the PV definition), but now I am in a situation where I cannot edit the PVC (and so the sync fails) because PVCs are immutable.
My solution was to ignore those changes but I am not sure if I am doing that right.

I want to ignore both storageClassName and volumeName fields in the Application.

According to the documentation it should work like this:

spec:
  ignoreDifferences:
  - group: apps
    kind: Deployment
    name: guestbook
    namespace: default
    jsonPointers:
    - /spec/replicas

I configured my Application like this:

  ignoreDifferences:
  - group: core
    jsonPointers:
    - /spec/volumeName
    - /spec/storageClassName
    kind: PersistentVolumeClaim

Sadly this does not work and Argo CD still states these resources out of sync.

Did I something wrong here?

Thanks

[dan-m8t]

I solved that by myself, I omitted the - group: core part and it worked as expected.

So the solution is this:

  ignoreDifferences:
  - jsonPointers:
    - /spec/volumeName
    - /spec/storageClassName
    kind: PersistentVolumeClaim

[mhagnumdw]

Tks @dan-m8t !

Does anyone know why - group: core doesn't work?

Since, according to the documentation:

API group - The API Group being accessed (for resource requests only). An empty string designates the core API group.

[rumstead]

The API group is blank, eg "", not actually "core".

The core (also called legacy) group is found at REST path /api/v1. The core group is not specified as part of the apiVersion field, for example, apiVersion: v1.

https://kubernetes.io/docs/reference/using-api/#api-groups