本文介绍搭建K8S集群的高可用，保证在主master节点挂掉之后，node节点的kubelet还能访问到另一个主节点的apiserver等组件进行运作。

实验部署

单master部署查照（Kubernetes单master节点二进制部署）

master2 部署

（1）将master1上kubernetes工作目录拷贝到master2节点

[root@localhost ~]# scp -r /opt/kubernetes/ root@192.168.49.179:/opt

（2）在master1，将kube-scheduler.service、kube-apiserver.servic、kube-controller-manager.service三个服务启动脚本拷贝到master2节点

[root@localhost ~]# scp /usr/lib/systemd/system/{kube-scheduler,kube-apiserver,kube-controller-manager}.service root@192.168.49.179:/usr/lib/systemd/system/

（3）在master2修改kubernetes配置文件kube-apiserver

[root@localhost ~]# cd /opt/kubernetes/cfg
[root@localhost cfg]# vim kube-apiserver 

（4）将master1上的etcd证书复制到master2上面

[root@localhost ~]# scp -r /opt/etcd/ root@192.168.49.179:/opt

（5）启动master2上的服务，并设置开机自启动

systemctl start kube-apiserver
systemctl enable kube-apiserver.service
systemctl start kube-scheduler.service 
systemctl enable kube-scheduler.service 
systemctl start kube-controller-manager.service 
systemctl enable kube-controller-manager.service

（6）查看node节点状态

#设置环境变量
[root@localhost cfg]# vim /etc/profile
#在末行添加
export PATH=$PATH:/opt/kubernetes/bin

[root@localhost cfg]# source /etc/profile
#查看node节点状态
[root@localhost cfg]# kubectl get node

4、负载均衡部署
（1）配置nginx

#配置nginx的yum源
[root@localhost ~]# vim /etc/yum.repos.d/nginx.repo
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=0

[root@localhost ~]# yum list
#安装nginx服务
[root@localhost ~]# yum install nginx -y
#nginx添加四层转发
[root@localhost ~]# vim /etc/nginx/nginx.conf 
插入
stream {
   log_format  main  '$remote_addr $upstream_addr - [$time_local] $status $upstream_bytes_sent';
    access_log  /var/log/nginx/k8s-access.log  main;

upstream k8s-apiserver {
            server 192.168.49.209:6443;		//master01
            server 192.168.49.179:6443;		//master02
    }
    server {
                listen 6443;
                proxy_pass k8s-apiserver;
    }
}

#检查语法
[root@localhost ~]# nginx -t
#启动服务
[root@localhost ~]# systemctl start nginx
#测试nginx服务能否访问

（2）配置keepalived

#安装keepalived
[root@localhost ~]# yum install keepalived -y
#更改配置文件
[root@localhost ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   # 接收邮件地址
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   # 邮件发送地址
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id NGINX_MASTER
}

vrrp_script check_nginx {
    script "/etc/nginx/check_nginx.sh"
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID实例，每个实例是唯一的
    priority 100    # 优先级，备服务器设置 90
    advert_int 1    # 指定VRRP 心跳包通告间隔时间，默认1秒
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.49.99/24
    }
    track_script {
        check_nginx
    }
}

#编写nginx的监控脚本
[root@localhost ~]# vim /etc/nginx/check_nginx.sh
count=$(ps -ef |grep nginx |egrep -cv "grep|$$")
if [ "$count" -eq 0 ];then
    systemctl stop keepalived
fi

查看漂移地址（使用ip addr命令查看）

（4）故障转移测试

#停掉主服务器的nginx服务，查看keepalived服务状态
[root@localhost ~]# pkill nginx
[root@localhost ~]# systemctl status keepalived.service 
● keepalived.service - LVS and VRRP High Availability Monitor
   Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
   Active: inactive (dead)
#到backup节点上查看漂移地址，能看到漂移地址说明故障转移成功
[root@localhost ~]# ip addr

如果把主服务器的服务再次开起来，漂移地址会重新回到主服务器节点上面去，因为配置文件中主服务器的优先级比从服务器的优先级高，keepalived会优先选择优先级较高的服务器

（5）更改node节点配置文件，将访问master节点的apiserver地址更换为VIP地址

[root@localhost ~]# vim /opt/kubernetes/cfg/bootstrap.kubeconfig 
#更改地址为VIP
    server: https://192.168.49.99:6443
[root@localhost ~]# vim /opt/kubernetes/cfg/kubelet.kubeconfig 
#更改地址为VIP
server: https://192.168.49.99:6443
[root@localhost ~]# vim /opt/kubernetes/cfg/kube-proxy.kubeconfig 
#更改地址为VIP
    server: https://192.168.49.99:6443

[root@localhost ~]# grep 99 /opt/kubernetes/cfg/*

#重启kubelet.service 
[root@node01 bin]# systemctl restart kubelet.service 
#在负载均衡节点查看日志
[root@localhost ~]# tail /var/log/nginx/k8s-access.log