假定我們在Kubernetes 指定兩個worker節點中部署了ingress nginx來為后端的pod做proxy，這時候我們就需要通過keepalived實現高可用，提供對外的VIP

首先我們要先確保有兩個worker節點部署了ingress nginx
在本實驗中，環境如下：

IP地址 主機名 描述
10.0.0.31 k8s-master01  
10.0.0.34 k8s-node02 ingress nginx、keepalived
10.0.0.35 k8s-node03 ingress nginx、keepalived

1、查看ingress nginx狀態

[root@k8s-master01 Ingress]# kubectl get pod -n ingress-nginx -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nginx-ingress-controller-85bd8789cd-8c4xh 1/1 Running 0 62s 10.0.0.34 k8s-node02 <none> <none> nginx-ingress-controller-85bd8789cd-mhd8n 0/1 Pending 0 3s <none> <none> <none> <none> nginx-ingress-controller-85ff8dfd88-vqkhx 1/1 Running 0 3m56s 10.0.0.35 k8s-node03 <none> <none>
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創建一個用於測試環境的namespace

 kubectl  create namespace test
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2、部署一個Deployment（用於測試）

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myweb-deploy
  # 部署在測試環境
  namespace: test
spec:
  replicas: 3
  selector:
    matchLabels:
      name: myweb
      type: test
  template:
    metadata:
      labels:
        name: myweb
        type: test
    spec:
      containers:
      - name: nginx
        image: nginx:1.13
        imagePullPolicy: IfNotPresent
        ports:
          - containerPort: 80
---
# service
apiVersion: v1
kind: Service
metadata:
  name: myweb-svc
spec:
  selector:
    name: myweb
    type: test
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
---
# ingress
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執行kubectl create 創建deployment

kubectl  create -f myweb-demo.yaml
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查看deployment是否部署成功

[root@k8s-master01 Project]# kubectl get pods -n test -o wide | grep "myweb" myweb-deploy-6d586d7db4-2g5ll 1/1 Running 0 23s 10.244.3.240 k8s-node02 <none> <none> myweb-deploy-6d586d7db4-cf7w7 1/1 Running 0 4m2s 10.244.1.132 k8s-node01 <none> <none> myweb-deploy-6d586d7db4-rp5zc 1/1 Running 0 3m59s 10.244.2.5 k8s-node03 <none> <none>
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3、在兩個worker節點部署keepalived
VIP：10.0.0.130，接口：eth0

1.安裝keepalived

yum -y install keepalived
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1.k8s-node03節點作為master配置keepalived

[root@k8s-node03 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email_from Alexandre.Cassen@firewall.loc router_id k8s-node03 vrrp_skip_check_adv_addr vrrp_strict vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 110 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.130/24 dev eth0 label eth0:1 } }
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2.k8s-node03節點作為配置keepalived

[root@k8s-node03 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id k8s-node03 vrrp_skip_check_adv_addr vrrp_strict vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 110 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.130/24 dev eth0 label eth0:1 } }
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3.k8s-node02節點配置keeplived

[root@k8s-node02 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { router_id k8s-node02 vrrp_skip_check_adv_addr vrrp_strict vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 10.0.0.130/24 dev eth0 label eth0:1 } }
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4.兩個節點啟動keepalived並加入開機啟動

systemctl start keepalived.service
systemctl enable keepalived.service
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啟動完成后檢查k8s-node03的IP地址是否已有VIP

[root@k8s-node03 ~]# ip add | grep "130" inet 10.0.0.130/24 scope global secondary eth0:1
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5.在宿主機上配置hosts文件，實現IP和域名的解析

10.0.0.130 myweb.app.com
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6.瀏覽器測試訪問

4.測試vip漂移
現在我將k8s-node03的keepalived進程關閉，那么vip就會漂移到k8s-node02

[root@k8s-node03 ~]# systemctl stop keepalived.service // 在k8s-node02上查看VIP [root@k8s-node02 ~]# ip add | grep "130" inet 10.0.0.130/24 scope global secondary eth0:1
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