在每一台master节点操作

安装keepalived和haproxy服务

yum install keepalived haproxy -y

haproxy配置(当然你也可以用nginx)

cp /etc/haproxy/haproxy.cfg /etc/haproxy/haproxy.cfg.bak

cat >/etc/haproxy/haproxy.cfg<<"EOF"
global
 maxconn 2000
 ulimit-n 16384
 log 127.0.0.1 local0 err
 stats timeout 30s
 
defaults
 log global
 mode http
 option httplog
 timeout connect 5000
 timeout client 50000
 timeout server 50000
 timeout http-request 15s
 timeout http-keep-alive 15s
 
frontend monitor-in
 bind *:33305
 mode http
 option httplog
 monitor-uri /monitor
 
frontend k8s-master
 bind 0.0.0.0:8443
 bind 127.0.0.1:8443
 mode tcp
 option tcplog
 tcp-request inspect-delay 5s
 default_backend k8s-master
 
backend k8s-master
 mode tcp
 option tcplog
 option tcp-check
 balance roundrobin
 default-server inter 10s downinter 5s rise 2 fall 2 slowstart 60s maxconn 250 maxqueue 256 weight 100
 server  k8s.master.01 192.168.230.100:6443 check
 server  k8s.master.02 192.168.230.101:6443 check
EOF

keepalived配置

健康检查脚本 check_apiserver.sh(在每一台master节点执行)

cat >  /etc/keepalived/check_apiserver.sh << EOF
#!/bin/bash
err=0
for k in \$(seq 1 3)
do
    check_code=\$(pgrep haproxy)
    if [[ \$check_code == "" ]]; then
        err=\$(expr \$err + 1)
        sleep 1
        continue
    else
        err=0
        break
    fi
done
 
if [[ \$err != "0" ]]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
else
    exit 0
fi
EOF

# 别忘了给脚本赋予执行权限
chmod +x /etc/keepalived/check_apiserver.sh

配置keepalived master节点(这个在master1节点操作)

cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
 
cat > /etc/keepalived/keepalived.conf << EOF
! Configuration File for keepalived
 
global_defs {
    router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5 
    weight -5
    fall 2
    rise 1
}
vrrp_instance VI_1 {
    state MASTER
    # 注意网卡名, 可以通过 ip a 命令查看
    interface ens32 
    mcast_src_ip 192.168.230.100
    virtual_router_id 51
    priority 100
    nopreempt
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    # 这个VIP就是之前网络规划的时候定下
    virtual_ipaddress {
        192.168.230.66
    }
    track_script {
      chk_apiserver 
} }
EOF

配置keepalived backup节点(这个在其他master节点操作, 记得IP得改过来)

cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
 
cat > /etc/keepalived/keepalived.conf << EOF
! Configuration File for keepalived
 
global_defs {
    router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5 
    weight -5
    fall 2
    rise 1
 
}
vrrp_instance VI_1 {
    state BACKUP
    # 注意网卡名, 可以通过 ip a 命令查看
    interface ens32
    mcast_src_ip 192.168.230.101
    virtual_router_id 51
    priority 50
    nopreempt
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
     # 这个VIP就是之前网络规划的时候定下
    virtual_ipaddress {
        192.168.230.66
    }
    track_script {
      chk_apiserver 
} }
EOF

# 别忘了给脚本赋予执行权限
chmod +x /etc/keepalived/check_apiserver.sh

启动keepalived和haproxy服务(在每一台master节点执行)

systemctl daemon-reload
systemctl enable --now haproxy
systemctl enable --now keepalived

测试是否生效

test ping vip

ping 192.168.230.66

test telnet vip

## 如果没有telnet命令就执行安装
# yum install telnet -y
telnet 192.168.230.66 8443

关闭主节点(即master1节点)，看vip是否漂移到备节点

没断网之前, vip落在master1节点上

将master1节点断网, 如下图，vip落在master2节点上，说明keepalived高可用至此配置完毕

service network stop

将master1节点的网打开

service network start