[K8S] 쿠버네티스 YAML 파일에 변수 선언, 처리하는 방법

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  labels:
    app: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:$VER
        ports:
        - containerPort: 80

export VER=0.05
envsubst < deployment.yaml | kubectl apply -f -