Safely Removing an ApplicationSet While Preserving Managed Kubernetes Resources

Understanding preserveResourcesOnDeletion and Its Behavior in Argo CD

When decommissioning an ApplicationSet, you might want to preserve the underlying Kubernetes resources created by the Applications it generated.

Argo CD provides the preserveResourcesOnDeletion flag for this purpose.

Key Configuration

To ensure managed resources are not deleted when the ApplicationSet is removed, set this in your ApplicationSet:

spec:
syncPolicy:
preserveResourcesOnDeletion: true

This instructs Argo CD not to prune Kubernetes resources when the ApplicationSet is deleted.

Important Notes

✅ Kubernetes resources will be preserved
❌ Argo CD Applications will be removed (unless otherwise handled)
🚫 No need to set PrunePropagationPolicy=orphan
- This is used only during Application syncs, not AppSet deletion.
⚠️ Sync event is not triggered on AppSet deletion, so no additional sync logic applies.

Preserving Argo CD Applications

If you also want to retain the Argo CD Application resources, follow this guide:

📘 How to prevent deleting generated Applications

In short:

Set applicationsSync: create-update in .spec.syncPolicy of the ApplicationSet
Add the finalizer manually to each generated Application:
metadata:
finalizers:
- resources-finalizer.argocd.argoproj.io

You’re safe to delete the ApplicationSet if:

preserveResourcesOnDeletion: true is set ✅
You don’t need the Argo CD Application resources afterward

If you need to keep both the Applications and their managed resources, apply both the syncPolicy and finalizers as documented.