1. 配置Ingress规则

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  namespace: namespace1
spec:
  rules:
  - host: foo.example.com
    http:
      paths:
      - path: /bar
        pathType: Prefix
        backend:
          service:
            name: service1
            port:
              name: port1
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  namespace: namespace2
spec:
  rules:
  - host: bar.example.com
    http:
      paths:
      - path: /foo
        pathType: Prefix
        backend:
          service:
            name: service2
            port:
              name: port2

2. 配置Service

apiVersion: v1
kind: Service
metadata:
  name: service1
  namespace: namespace1
spec:
  selector:
    app: app1
  ports:
  - name: port1
    port: 80
    targetPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: service2
  namespace: namespace2
spec:
  selector:
    app: app2
  ports:
  - name: port2
    port: 80
    targetPort: 80

在不同的命名空间中定义两个不同的Ingress规则，并为每个命名空间中的服务定义一个Service。在此示例中，根据请求的host和路径，将请求路由到不同的服务。这个方案可以解决多个命名空间中存在多个Ingress规则的问题。