Kubernetes K8S在IPVS代理模式下Service服务的ClusterIP类型访问失败处理

Kubernetes K8S使用IPVS代理模式，当Service的类型为ClusterIP时，如何处理访问service却不能访问后端pod的情况。

背景现象

Kubernetes K8S使用IPVS代理模式，当Service的类型为ClusterIP时，出现访问service却不能访问后端pod的情况。

主机配置规划

服务器名称(hostname)	系统版本	配置	内网IP	外网IP(模拟)
k8s-master	CentOS7.7	2C/4G/20G	172.16.1.110	10.0.0.110
k8s-node01	CentOS7.7	2C/4G/20G	172.16.1.111	10.0.0.111
k8s-node02	CentOS7.7	2C/4G/20G	172.16.1.112	10.0.0.112

场景复现

Deployment的yaml信息

yaml文件

[root@k8s-master service]# pwd
/root/k8s_practice/service
[root@k8s-master service]# cat myapp-deploy.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deploy
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
      release: v1
  template:
    metadata:
      labels:
        app: myapp
        release: v1
        env: test
    spec:
      containers:
      - name: myapp
        image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
        imagePullPolicy: IfNotPresent
        ports:
        - name: http
          containerPort: 80

启动Deployment并查看状态

[root@k8s-master service]# kubectl apply -f myapp-deploy.yaml 
deployment.apps/myapp-deploy created
[root@k8s-master service]# 
[root@k8s-master service]# kubectl get deploy -o wide
NAME           READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
myapp-deploy   3/3     3            3           14s   myapp        registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,release=v1
[root@k8s-master service]# kubectl get rs -o wide
NAME                      DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
myapp-deploy-5695bb5658   3         3         3       21s   myapp        registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=5695bb5658,release&