ArgoCD rollback command to support `kubectl undo`

[ozooxo]

Summary

We would like to support using kubectl rollout undo deploy <name> --to-revision=1 and kubectl argo collouts undo <name> when we rollback.

Motivation

Looks like right now rollback is part of appStateManager.SyncAppState() (by this else condition). As it finally goes to syncContext.Sync(), there will be no difference on sync in the argoproj/gitops-engine level and it will always be a kubectl replace.

We wonder if there's a possibility for rollback to support a different path other than sync, so we can actually use kubectl commands like kubectl rollout undo deploy <name> --to-revision=1 or kubectl argo collouts undo <name> when we rollback?

Proposal

I think we'll need to expand argoproj/gitops-engine to support those kubectl * undo commands, and in ArgoCD controller to redirect rollback to a different path.

[jessesuen]

What is wrong with the existing rollback mechanism?

[ozooxo]

@jessesuen From reading your src, I think your rollback calls appStateManager.SyncAppState() (by this else condition) and it finally goes to kubectl replace with an old SHA (not the GitOps repo HEAD), but not kubectl undo. No?