本文采用Keepalived+HAProxy的方式构建高可用集群。
当你如果你有硬件负载均衡设备当然更好了。
准备环境：
| 主机 | ip |
|---|---|
| k8s-master01 | 192.168.10.4 |
| k8s-master02 | 192.168.10.5 |
| k8s-master03 | 192.168.10.6 |
| VIP | 192.168.10.150 |
架构图
注意：master集群采用奇数台数，3、5、7…
所有节点都进行hosts文件解析
tail -3 /etc/hosts
192.168.10.4 k8s-master01
192.168.10.5 k8s-master02
192.168.10.6 k8s-master03
所有节点都要安装keepalived和haproxy软件
yum -y install haproxy keepalived
修改haproxy配置文件（所有节点配置相同）
最好选择2.x版本，当然这个版本也不影响使用，只是功能没有2.x版本多
vim /etc/haproxy/haproxy.cfg
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
listen stats
bind *:8006
mode http
stats enable
stats hide-version
stats uri /stats
stats refresh 30s
stats realm Haproxy\ Statistics
stats auth admin:admin
frontend k8s-master
bind 0.0.0.0:16443
bind 127.0.0.1:16443
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-master01 192.168.10.4:6443 check
server k8s-master02 192.168.10.5:6443 check
server k8s-master03 192.168.10.6:6443 check
master01节点修改keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
script "/etc/keepalived/check_apiserver.sh"
interval 2
weight -5
fall 3
rise 2
}
vrrp_instance VI_1 {
state MASTER
interface eth0
mcast_src_ip 192.168.10.4
virtual_router_id 51
priority 100
advert_int 2
authentication {
auth_type PASS
auth_pass K8SHA_KA_AUTH
}
virtual_ipaddress {
192.168.10.150/24
}
track_script {
chk_apiserver
}
master02节点修改keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
script "/etc/keepalived/check_apiserver.sh"
interval 2
weight -5
fall 3
rise 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
mcast_src_ip 192.168.10.5
virtual_router_id 51
priority 50
advert_int 2
authentication {
auth_type PASS
auth_pass K8SHA_KA_AUTH
}
virtual_ipaddress {
192.168.10.150/24
}
track_script {
chk_apiserver
}
}
master03节点修改keepalived配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
}
vrrp_script chk_apiserver {
script "/etc/keepalived/check_apiserver.sh"
interval 2
weight -5
fall 3
rise 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
mcast_src_ip 192.168.10.6
virtual_router_id 51
priority 50
advert_int 2
authentication {
auth_type PASS
auth_pass K8SHA_KA_AUTH
}
virtual_ipaddress {
192.168.10.150/24
}
track_script {
chk_apiserver
}
}
所有节点创建健康检查脚本
vim /etc/keepalived/check_apiserver.sh
#!/bin/bash
err=0
for k in $(seq 1 5)
do
check_code=$(pgrep haproxy)
if [[ $check_code == "" ]]; then
err=$(expr $err + 1)
sleep 5
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
启动haproxy与keepalived服务
systemctl daemon-reload
systemctl enable --now haproxy
systemctl enable --now keepalived
可以用ping和telnet命令测试一下vip的可用性
ping 192.168.10.150
PING 192.168.10.150 (192.168.10.150) 56(84) bytes of data.
64 bytes from 192.168.10.150: icmp_seq=1 ttl=64 time=1.60 ms
64 bytes from 192.168.10.150: icmp_seq=2 ttl=64 time=0.519 ms
64 bytes from 192.168.10.150: icmp_seq=3 ttl=64 time=0.874 ms
64 bytes from 192.168.10.150: icmp_seq=4 ttl=64 time=0.786 ms
^C
--- 192.168.10.150 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3009ms
rtt min/avg/max/mdev = 0.519/0.946/1.606/0.403 ms
telnet 192.168.10.150 16443
Trying 192.168.10.150...
Connected to 192.168.10.150.
Escape character is '^]'.
Connection closed by foreign host.
再尝试一下断开vip所在节点的keepalived，看ip是否漂移，如果vip漂移至另一节点则代表成功
可能难免有地方出错，如果出错可以留言哈
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