为什么Kubernetes Ingress不收流量？

我正在尝试在Kubernetes上设置一个简单的HTTP Web服务器，并使用临时外部IP公开它。但是，当尝试访问x.x.x.x /something时，我得到：

Error: Server Error
The server encountered a temporary error and could not complete your request.
Please try again in 30 seconds.

我的配置很简单：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: web
  labels:
    app: web
spec:
  replicas: 1
  selector:
    matchLabels:
      app: web
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
      - name: web
        image: gcr.io/my-repo-name
        ports:
        - containerPort: 8080
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
        readinessProbe:
          initialDelaySeconds: 10
          httpGet:
            path: /healthz
            port: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: web-balancer-service
spec:
  selector:
    app: web
  type: NodePort
  ports:
  - protocol: TCP
    port: 8080
    targetPort: 32111
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: my-ingress-app
spec:
  backend:
    serviceName: web-balancer-service
    servicePort: 8080

如果我describe ingress，我会看到后端是“Unknown”。 我的spec有问题吗？

Name:             my-ingress-app
Namespace:        default
Address:          x.x.x.x
Default backend:  web-balancer-service:8080 (10.60.0.57:32111)
Rules:
  Host  Path  Backends
  ----  ----  --------
  *     *     web-balancer-service:8080 (10.60.0.57:32111)
Annotations:
  ingress.kubernetes.io/backends:         {"k8s-be-30330--f4bbd8cbe40f4567":"Unknown"}
  ingress.kubernetes.io/forwarding-rule:  k8s-fw-default-my-ingress-app--f4bbd8cbe40f4567
  ingress.kubernetes.io/target-proxy:     k8s-tp-default-my-ingress-app--f4bbd8cbe40f4567
  ingress.kubernetes.io/url-map:          k8s-um-default-my-ingress-app--f4bbd8cbe40f4567
Events:
  Type    Reason  Age    From                     Message
  ----    ------  ----   ----                     -------
  Normal  ADD     7m18s  loadbalancer-controller  default/my-ingress-app
  Normal  CREATE  6m12s  loadbalancer-controller  ip: x.x.x.x