metadata:
  name: web-canary
  annotations:
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "20"     # 20% 流量
    # 或按请求头：
    # nginx.ingress.kubernetes.io/canary-by-header: "x-canary"
spec:
  rules:
    - host: app.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: web-v2
                port:
                  number: 80

kubectl get ingress -n prod | grep canary
kubectl -n ingress-nginx logs deploy/ingress-nginx-controller --tail=100 | grep -i canary
# 验证 OK 后：把主 Ingress 指向 v2，删除金丝雀 Ingress