服务器规划：
三台k8s-master 两台lvs
k8s01：10.20.31.157 lb01：10.20.31.184
k8s02：10.20.31.167 lb02：10.20.31.185
k8s03：10.20.31.186 vipIP：10.20.31.187
从构图中可以看到，所有节点都需要通过负载均衡器和API Server进行通信，负载均衡器就非常重要了。这里考虑负载均衡器的性能与高可用，我们选择了LVS + keepalived（LVS当然也可以部署在k8s的节点机器上，为了保证集群高可用，建议还是部署在单独的机器上。）。
lvs-master(10.20.31.184)
# 安装依赖
$ yum install -y ipvsadm wget curl gcc openssl-devel libnl3-devel net-snmp-devel libnfnetlink-devel
# 安装keepalived，centos7通过yum下载的版本有问题，会报一个叫【TCP socket bind failed. Rescheduling】的错误
$ wget http:///software/keepalived-1.4.5.tar.gz && tar -zxvf keepalived-1.4.5.tar.gz && cd keepalived-1.4.5 && ./configure && make && make install && cd .. && rm -f keepalived-1.4.5.tar.gz && rm -rf keepalived-1.4.5
################ keepalived负载均衡配置 ################
# 生成keepalived配置
$ cd /etc/keepalived && cat <<E0F > /etc/keepalived/keepalived.conf
global_defs {
router_id keepalived-master
}
vrrp_instance vip_1 {
state MASTER
! 注意这是网卡名称，使用ip a命令查看自己的局域网网卡名称
interface ens192
! keepalived主备router_id必须一致
virtual_router_id 88
! 优先级，keepalived主节点优先级要比备节点高
priority 100
advert_int 3
! 配置虚拟ip地址
virtual_ipaddress {
10.20.31.187
}
}
virtual_server 10.20.31.187 6443 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 0
protocol TCP
real_server 10.20.31.157 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
real_server 10.20.31.167 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
real_server 10.20.31.186 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
}
E0F
# 启动keepalived
$ systemctl enable keepalived && service keepalived start
# 检查keepalived状态
$ service keepalived status
# 查看日志
$ journalctl -f -u keepalived
# 查看虚拟ip
$ ip a
lvs-backup(10.20.31.185)
# 安装依赖
$ yum install -y ipvsadm wget curl gcc openssl-devel libnl3-devel net-snmp-devel libnfnetlink-devel
# 安装keepalived，centos7通过yum下载的版本有问题，会报一个叫【TCP socket bind failed. Rescheduling】的错误
$ wget http:///software/keepalived-1.4.5.tar.gz && tar -zxvf keepalived-1.4.5.tar.gz && cd keepalived-1.4.5 && ./configure && make && make install && cd .. && rm -f keepalived-1.4.5.tar.gz && rm -rf keepalived-1.4.5
################ keepalived负载均衡配置 ################
# 生成keepalived配置
$ mkdir -p /etc/keepalived && cd /etc/keepalived && cat <<E0F > /etc/keepalived/keepalived.conf
global_defs {
router_id keepalived-backup
}
vrrp_instance vip_1 {
state BACKUP
! 注意这是网卡名称，使用ip a命令查看自己的局域网网卡名称
interface ens192
! keepalived主备router_id必须一致
virtual_router_id 88
! 优先级，keepalived主节点优先级要比备节点高
priority 99
advert_int 3
! 配置虚拟ip地址
virtual_ipaddress {
10.20.31.187
}
}
virtual_server 10.20.31.187 6443 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 0
protocol TCP
real_server 10.20.31.157 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
real_server 10.20.31.167 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
real_server 10.20.31.186 6443 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 6443
}
}
}
E0F
# 启动keepalived
$ systemctl enable keepalived && service keepalived start
# 检查keepalived状态
$ service keepalived status
# 查看日志
$ journalctl -f -u keepalived
# 查看虚拟ip
$ ip a
real_server配置，也就是每个k8s Master节点机器
# 创建rs脚本
$ mkdir -p /opt/rs/ && cd /opt/rs && cat <<E0F > /opt/rs/rs.sh
#!/bin/bash
# 虚拟ip
vip=10.20.31.187
# 停止以前的lo:0
ifconfig lo:0 down
echo "1" > /proc/sys/net/ipv4/ip_forward
echo "0" > /proc/sys/net/ipv4/conf/all/arp_announce
# 启动一个回环地址并绑定给vip
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip dev lo:0
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
# ens33是主网卡名
echo "1" >/proc/sys/net/ipv4/conf/ens192/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/ens192/arp_announce
E0F
# 添加执行权限
$ chmod +x /opt/rs/rs.sh
# 执行rs脚本（如果出现错误，重新执行一遍即可）
$ ./rs.sh
# 添加到开机启动
$ echo '/opt/rs/rs.sh' >> /etc/rc.d/rc.local
# 在centos7中，/etc/rc.d/rc.local的权限被降低了，所以需要执行如下命令赋予其可执行权限
$ chmod +x /etc/rc.d/rc.local
