LVS DR模式搭建 keepalived + LVS

Posted 2020-12-03

一、LVS DR模式搭建

修改两台rs1和rs2机器的网关为之前的网关：192.168.238.2
#vi /etc/sysconfig/network-scripts/ifcfg-ens33
#systemctl restart network

dir机器上也需要编写一个脚本，加入如下内容：
[[email protected] ~]# vim /usr/local/sbin/lvs_dr.sh
#! /bin/bash
echo 1 > /proc/sys/net/ipv4/ip_forward
ipv=/usr/sbin/ipvsadm
vip=192.168.238.200
rs1=192.168.238.130
rs2=192.168.238.131
#注意这里的网卡名字
ifdown ens33
ifup ens33
ifconfig ens33:2 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip dev ens33:2
$ipv -C
$ipv -A -t $vip:80 -s rr
$ipv -a -t $vip:80 -r $rs1:80 -g -w 1
$ipv -a -t $vip:80 -r $rs2:80 -g -w 1
//脚本解释:
echo 1 > /proc/sys/net/ipv4/ip_forward 打开端口转发；
ipv=/usr/sbin/ipvsadm 变量；
ifdown ens33
ifup ens33 重启下网卡，再次执行这个脚本时不需要重复设置这个IP
ifconfig ens33:2 设置虚拟网卡名称为ens33:2；
route add -host $vip dev ens33:2 添加网关；
$ipv -C 是清空规则；
$ipv -a -t $vip:80 -r $rs1:80 -g -w 1 其中-g是getway，就是DR模式
[[email protected] ~]# sh /usr/local/sbin/lvs_dr.sh //执行脚本

两台rs机器上分别编写脚本，内容如下：
[[email protected] ~]# vim /usr/local/sbin/lvs_rs.sh
#/bin/bash
vip=192.168.238.200
#把vip绑定在lo上，是为了实现rs直接把结果返回给客户端
ifdown lo
ifup lo
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip lo:0
#以下操作为更改arp内核参数，目的是为了让rs顺利发送mac地址给客户端
#参考文档www.cnblogs.com/lgfeng/archive/2012/10/16/2726308.html
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
[[email protected] ~]# sh /usr/local/sbin/lvs_rs.sh //执行脚本

在rs2机器上同样编写/usr/local/sbin/lvs_rs.sh脚本，写入如上脚本内容
[[email protected] ~]# vim /usr/local/sbin/lvs_rs.sh
#/bin/bash
vip=192.168.238.200
#把vip绑定在lo上，是为了实现rs直接把结果返回给客户端
ifdown lo
ifup lo
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip lo:0
#以下操作为更改arp内核参数，目的是为了让rs顺利发送mac地址给客户端
#参考文档www.cnblogs.com/lgfeng/archive/2012/10/16/2726308.html
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
[[email protected] ~]# sh /usr/local/sbin/lvs_rs.sh //执行脚本
[[email protected] ~]# route -n
[[email protected] ~]# ip add
[[email protected] ~]# ip add
[[email protected] ~]# ip add //分别查看三台机器的网卡信息是否设置了vip=192.168.238.200
打开浏览器访问：192.168.238.200
[[email protected] ~]# iptables -t nat -F //清空防火墙规则
[[email protected] ~]# ipvsadm -ln

二、keepalived + LVS

[[email protected] ~]# ipvsadm -ln

[[email protected] ~]# vim /etc/keepalived/keepalived.conf
//配置文件内容请到https://coding.net/u/aminglinux/p/aminglinux-book/git/blob/master/D21Z/lvs_keepalived.conf获取，内容如下：
vrrp_instance VI_1 {
#备用服务器上为 BACKUP
state MASTER
#绑定vip的网卡为ens33，你的网卡和阿铭的可能不一样，这里需要你改一下
interface ens33
virtual_router_id 51
#备用服务器上为90
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass aminglinux
}
virtual_ipaddress {
192.168.238.200
}
}
virtual_server 192.168.238.200 80 {
#(每隔10秒查询realserver状态)
delay_loop 10
#(lvs 算法)
lb_algo wlc
#(DR模式)
lb_kind DR
#(同一IP的连接60秒内被分配到同一台realserver)
persistence_timeout 60
#(用TCP协议检查realserver状态)
protocol TCP

real_server 192.168.238.130 80 {
    #(权重)
    weight 100
    TCP_CHECK {
    #(10秒无响应超时)
    connect_timeout 10
    nb_get_retry 3
    delay_before_retry 3
    connect_port 80
    }
}
real_server 192.168.238.131 80 {
    weight 100
    TCP_CHECK {
    connect_timeout 10
    nb_get_retry 3
    delay_before_retry 3
    connect_port 80
    }
 }

}
配置完keepalived.conf配置文件，启动keepalived服务
[[email protected]x-01 ~]# systemctl start keepalived
[[email protected] ~]# ps aux |grep keep //查看keepalived进程
[[email protected] ~]# ipvsadm -ln
[[email protected] ~]# systemctl stop keepalived
[[email protected] ~]# systemctl start nginx //启动rs2的nginx
[[email protected] ~]# ip add //关掉原来的虚拟IP
[[email protected] ~]# ipvsadm -ln //再次查看已经没有规则了
[[email protected] ~]# systemctl start keepalived //再次启动keepalived
[[email protected] ~]# ipvsadm -ln //查看有两个规则了
说明keepalived有自动把宕机的rs剔除的功能
需要注意在两台rs机器上依然要执行/usr/local/sbin/lvs_rs.sh脚本