argocd app diff should support application in any namespace.

[mugioka]

Summary

Now argocd app diff does not support application in any namespace.
I execute argocd app diff in app any namespace environment, always returns diff like bellow.

-    argocd.argoproj.io/instance: NAMESPACE_APP_NAME
+    argocd.argoproj.io/instance: APP_NAME

This reason is that, created local object for diff does not have correct labels.
I executed bellow command.

app diff "${APP_NAME}" --exit-code=false \ 
  --port-forward \
  --port-forward-namespace "${NAMESPACE}"\
  --auth-token "${ARGOCD_TOKEN}" \
  --server-side-generate \
  --plaintext \
  --local "${PWD}" \
  --local-include "*.yaml"

Motivation

I use app in any namespace and comment diff(live/local) on GitHub PR, the diff will occur every time and become noise.

Proposal

We should use app.InstanceName(argoSettings.ControllerNamespace) instead of app.Name in groupObjsForDiff.

argo-cd/cmd/argocd/commands/app.go

Line 1038 in 330252d

items = groupObjsForDiff(resources, groupedObjs, items, argoSettings, app.Name)

argo-cd/cmd/argocd/commands/app.go

Line 1047 in 330252d

items = groupObjsForDiff(resources, groupedObjs, items, argoSettings, app.Name)