1. Proposed title of this feature request
Support ignoreDifferences as a resource annotation

2. What is the nature and description of the request?

Summary

It would be great if the Application spec ignoreDifferences could be supported at the individual resource level, perhaps as an annotation.

Motivation

I am converting my set up use an ApplicationSets whenever possible to reduce boilerplate. A few Applications require specific ignoreDifferences config. In my case, one app has a ConfigMap resource, and another app updates it with dynamic configuration settings.

Proposal

Ideally similarly to syncOptions can be applied to individual resources via the argocd.argoproj.io/sync-options annotation. So there could be an argocd.argoproj.io/ignore-differences annotation.
Since the annotation is applied to a specific resource, there is no need to define the kubernetes API group in the annotation. It could be further simplified by (initially) only supporting a single jsonPointers type.

https://github.com/argoproj/argo-cd/issues/12686

3. Why does the customer need this? (List the business requirements here)

Customer needs this to resolve the following issue.

Context: Application object is intentionally managed by a infra team to avoid apps pulling from unauthorized repositories and other security needs. At the same time application team need not go through the learning process of Argo-Application attributes. Customer intentionally does not want to use ApplicationSet.

4. List any affected packages or components.
Red Hat OpenShift GitOps
argocd.argoproj.io/ignore-differences annotation