前言

高可用与负载均衡是运维领域的常见架构。在K8s中也广泛应用，例如master节点，etcd数据库，harbor等。本文将介绍keepalived高可用与haproxy负载均衡。

环境准备

使用的系统为Ubuntu20.04，首先修改主机名：

sudo hostnamectl set-hostname ha1 ; bash
sudo hostnamectl set-hostname ha2 ; bash

默认系统安装了bash_completion，但没启用。将if井号注释删除，开启自动补全。

vim ~/.bashrc

if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
    . /etc/bash_completion
fi

source ~/.bashrc

修改程序安装镜像源为清华源：

vim /etc/apt/sources.list

deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-updates main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ focal-security main restricted universe multiverse

apt update

可选：安装apt-file，方便查看软件的安装路径，配置文件，帮助文件等。

apt install -y apt-file
sudo apt-file update

keepalived的安装配置

两台主机都安装上keepalived：

apt install -y keepalived

打开配置文件，只保留一个vrrp实例，按dG删除光标后全部内容。

cp /usr/share/doc/keepalived/samples/keepalived.conf.vrrp /etc/keepalived/keepalived.conf

root@ha1:~# vim /etc/keepalived/keepalived.conf
vrrp_instance VI_1 {
	...
    interface ens33
    ...
    priority 100
    ...
    virtual_ipaddress {
        192.168.100.150 dev ens33 label eth33:1
    }
}

root@ha2:~# vim /etc/keepalived/keepalived.conf
vrrp_instance VI_1 {
	...
    interface ens33
    ...
    priority 80
    ...
    virtual_ipaddress {
        192.168.100.150 dev ens33 label eth33:1
    }
}

重启服务后，可查看接口配置：

sudo systemctl restart keepalived ; sudo systemctl status keepalived

ifconfig
ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.100.150  netmask 255.255.255.255  broadcast 0.0.0.0
        ether 00:0c:29:7d:f2:10  txqueuelen 1000  (Ethernet)

找到第三台机子对VIP不间断ping，再依次关闭ha主机，一直能ping通则为高可用。

C:\WINDOWS\system32> ping 192.168.100.150 -t

root@ha1:~# poweroff
root@ha2:~# poweroff

haproxy的安装配置

参考kubeadm和containerd部署K8s master节点，先部署三台master节点。再用了haproxy对这个三节点做反向代理，实现负载均衡。

apt install -y haproxy

打开配置文件，按Go到文本最末尾，添加以下内容：

root@ha1:~# vim /etc/haproxy/haproxy.cfg 
listen web
  bind 192.168.100.146:80
  mode tcp
  server server1 192.168.100.141:80 check inter 3s fall 3 rise 5
  server server2 192.168.100.143:80 check inter 3s fall 3 rise 5
  server server3 192.168.100.145:80 check inter 3s fall 3 rise 5

root@ha2:~#vim /etc/haproxy/haproxy.cfg 
listen web
  bind 192.168.100.147:80
  mode tcp
  server server1 192.168.100.141:80 check inter 3s fall 3 rise 5
  server server2 192.168.100.143:80 check inter 3s fall 3 rise 5
  server server3 192.168.100.145:80 check inter 3s fall 3 rise 5

sudo systemctl restart haproxy.service