全リソースのnamespaceを設定したい

input.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: demo
  name: demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - image: ghcr.io/making/hello-tanzu
        name: hello-tanzu

overlay.yml

#@ load("@ytt:overlay", "overlay")

apiVersion: v1
kind: Namespace
metadata:
 name: demo

#@overlay/match by=overlay.not_op(overlay.subset({"kind":"Namespace"})),expects="1+"
---
metadata:
 #@overlay/match missing_ok=True
 namespace: demo