Resource has finalizers foregroundDeletion when using background propagation policy

[tenevdev]

I'm quite confused by app deletion and decided to ask here before raising an issue in case I'm missing something. I'm using ArgoCD 2.0.4 for reference. I'm migrating a workload from being managed with helm install / uninstall to being an Argo CD application. When I try to delete the application with foreground (default) propagation, one of my custom resources is stuck in a loop (agones-dev/agones#540 (comment)) so I want to try using background propagation which looks to be what helm uninstall does by default and works fine for this workload. I tried setting Background when deleting from the Web UI and running argocd app delete my-app --cascade -p background but both of these look like they did the same as before (same as foreground). When I check the resources created in this application I see they all have

finalizers:
- foregroundDeletion

but I expected to see background deletion.

I tried to simplify my case and actually it seems to be a problem with something else. I use the application set project to create this application and it seems like the application set controller keeps it in sync so on the Application resource I see

finalizers:
- resources-finalizer.argocd.argoproj.io

which may be left-over from an earlier attempt to delete the application with foreground and it doesn't get removed or change to background when I sync the application.

There is clearly more that I need to learn about the lifecycle of applications in the context of an application set.

[tenevdev]

I raised argoproj/applicationset#288.