实战：Keepalived 高可用LVS
关于LVS基础不多介绍直接操练起来。1.环境准备
首先准备4台机器（VM,Vbox...）
node1--> Director1 192.168.137.31 vip=192.168.137.10
node2--> Director2 192.168.137.32 vip=192.168.137.10
node3-->RServer1 192.168.137.33
node4-->RServer2 192.168.137.34
基于DR负载均衡模式，设置了一个VIP（Virtual IP）为192.168.137.10，用户只需要访问这个IP地址即可获得网页服务。其中，负载均衡MASTER-Server1 192.168.137.31，BACKUP-Server2 192.168.137.32 ;RServer1为192.168.137.33，RServer2为192.168..137.34
拓扑：
https://s2.运维网.com/oss/201711/13/da06433e34d6d452054013423da4b37c.jpg
2.RealServer 配置
RS1配置
# yum install -y httpd
# echo "The page from node3" > /var/www/html/index.html
# service httpd start 编写脚本setka.sh配置内核参数
# cat setka.sh
#!/bin/bash
vip=192.168.137.10
case $1 in
start)
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
;;
stop)
ifconfig lo:0 down
echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce
;;
esac# bash setka.sh start ##运行该脚本设置相关内核参数及VIP地址。
# cat /proc/sys/net/ipv4/conf/lo/arp_ignore ##内核参数设置成功
1
# cat /proc/sys/net/ipv4/conf/all/arp_announce
2
# ifconfig lo:0 ##VIP设置成功
lo:0 Link encap:Local Loopback
inet addr:192.168.137.10Mask:255.255.255.255
UP LOOPBACK RUNNINGMTU:65536Metric:1
# scp setka.sh root@192.168.137.33:/root ##拷贝一份给RS2
setka.sh 100%547 0.5KB/s 00:00
RS2配置
# yum install -y httpd
# echo "The page from node4" > /var/www/html/index.html
# service start httpd
# bash setka.sh ##执行脚本，检查设置是否生效
两台都准备妥当后。 3.Director 配置
在配置之前，先要把4机器的时间同步一下
以node1为ntp-server
# for i in 31 32 33 34;do ssh 192.168.137.$i 'date';done##提前给4台机器做了密钥认证
Wed Nov8 23:50:28 CST 2017
Wed Nov8 23:50:28 CST 2017
Wed Nov8 23:50:28 CST 2017
Wed Nov8 23:50:28 CST 2017
# yum install -y ipvsadm
# route add -host 192.168.137.10/32 dev eth0
添加IPVS规则
# ipvsadm -A -t 192.168.137.10:80 -s rr
# ipvsadm -a -t 1192.168.137.10:80 -r 192.168.137.37 -g -w 1
# ipvsadm -a -t 192.168.137.10:80 -r 192.168.137.37 -g -w 1
# ipvsadm -a -t 192.168.137.10:80 -r 192.168.137.33 -g -w 2
# ipvsadm -L -n
使用另一台Director访问VIP
curl http://192.168.137.10
# curl http://192.168.137.10
The page from node3
# curl http://192.168.137.10
The page from node4
# curl http://192.168.137.10 两台Director进行IPVS测试之后，清除ipvs规则删除route条目
# ipvsadm -C
# route del -host 192.168.137.10/32 dev eth0
开始给Director 配置keepalived
MASTER 配置（node1）
# yum install -y keepalivedhttpd
# echo "Sorry,Under maintances(31)." > /var/www/html/index.html##添加sorry_server页面
# service httpd start
# 编辑配置文件keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost#本地email地址
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_mcast_group4 224.0.1.118#配置VRRP组播域
}
#健康状态检测脚本检查
vrrp_script chk_mt {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -20
}
#实例
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 151#虚拟路由ID
priority 100 #权重100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.137.10/16 dev eth0 label eth0:1#虚拟IP地址这里建议使用16为掩码
}
track_script {#追踪健康状态脚本
chk_mt
}
notify_master "/etc/keepalived/notify.sh master"#配置通知脚本
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
#虚拟服务器及RealServer配置
virtual_server 192.168.137.10 80 {
delay_loop 6
lb_algo wrr #weighted rr （表示通过权重来轮询调度）
lb_kind DR #LVS DR 模型
nat_mask 255.255.255.0
protocol TCP
sorry_server 127.0.0.1 80#本地sorry_server服务器配置
real_server 192.168.137.33 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.137.34 80 {
weight 2
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
} 通知脚本(/etc/keepalived/notify.sh)：
#!/bin/bash
# Author: ljohnmail@foxmail.com
# description: An example of notify script
#
vip=192.168.137.10
contact='root@localhost'
notify() {
mailsubject="`hostname` to be $1: $vip floating"
mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"
echo $mailbody | mail -s "$mailsubject" $contact
}
case "$1" in
master)
notify master
exit 0
;;
backup)
notify backup
exit 0
;;
fault)
notify fault
exit 0
;;
*)
echo 'Usage: `basename $0` {master|backup|fault}'
exit 1
;;
esac
注：通知脚本需要拷一份至node2
scp notify.sh root@192.168.137.32:/etc/keepalived/ BACKUP配置（node2）
# yum install -y keepalived
# yum install -y httpd
# echo "Sorry,Under maintances(32)." > /var/www/html/index.html##添加sorry_server页面
# service httpd start
# 配置keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_mcast_group4 224.0.1.118
}
vrrp_script chk_mt {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -20
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 151
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.137.10/16 dev eth0 label eth0:1
}
track_script {
chk_mt
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.137.10 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
protocol TCP
sorry_server 127.0.0.1 80
real_server 192.168.137.33 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.137.34 80 {
weight 2
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
} 4.启动keepalived并测试功能
在node1上
1、启动keepalived
# service keepalived restart ; ssh 192.168.137.32 'service keepalived restart'
# ifconfig
# ifconfig ##可以看到eth0:1地址已经获取到
eth0 Link encap:EthernetHWaddr 00:0C:29:AA:09:30
inet addr:192.168.137.31Bcast:192.168.137.255Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:feaa:930/64 Scope:Link
UP BROADCAST RUNNING MULTICASTMTU:1500Metric:1
RX packets:46005 errors:0 dropped:0 overruns:0 frame:0
TX packets:59292 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5151611 (4.9 MiB)TX bytes:5965319 (5.6 MiB)
eth0:1 Link encap:EthernetHWaddr 00:0C:29:AA:09:30
inet addr:192.168.137.10Bcast:0.0.0.0Mask:255.255.0.0
UP BROADCAST RUNNING MULTICASTMTU:1500Metric:1 2、测试访问web
# curl http://192.168.137.10
The page from node3
# curl http://192.168.137.10
The page from node4 3、健康状态检测
手动在(MASTER)/etc/keepalived中新建一个down文件
# touch down
# 脚本检测到down文件存在权重减20，则vip会自动的floating 到BACKUP的主机上，删除down文件MASTER会将vip抢回来（处于主备的抢占模式下）。
测试如下：
# touch down
#
# ls
downkeepalived.confnotify.sh
在node2上发现VIP设置成功
# ifconfig eth0:1
eth0:1 Link encap:EthernetHWaddr 00:0C:29:CB:63:DF
inet addr:192.168.137.10Bcast:0.0.0.0Mask:255.255.0.0
UP BROADCAST RUNNING MULTICASTMTU:1500Metric:1
在看看mail，此处说明VIP漂至node2
U 10 root Wed Nov8 21:5019/723 "node2.localdomain to be master: 192.168.137.10 floating"
访问VIP：
# curl 192.168.137.10
The page from node4
# curl 192.168.137.10
The page from node3
删除node1keepalived上的down文件。
#rm -rf /etc/keepalived/down
# ifconfig eth0:1
eth0:1 Link encap:EthernetHWaddr 00:0C:29:AA:09:30
inet addr:192.168.137.10Bcast:0.0.0.0Mask:255.255.0.0
UP BROADCAST RUNNING MULTICASTMTU:1500Metric:1
mail邮件
>N9 root Wed Nov8 22:0118/713 "node1.localdomain to be master: 192.168.137.10 floating"
查看网站是否正常访问
# curl 192.168.137.10
The page from node4
# curl 192.168.137.10
The page from node3
这里可看到地址又被node1抢回来了（因为我们配置的是抢占模式），网站正常被调度，测试完毕！！！
4、Sorry_Server测试
在RealServer(node3)
停掉两台RealServer服务器
# service httpd stop ; ssh 192.168.137.34 'service httpd stop'
# curl http://192.168.137.10
Sorry,Under maintances(31).
注释：这里会用涉及到ntp时钟同步，Openssl的密钥的认证，
# ntpdate IP(ntp时钟服务器地址)
*/5 * * * * root /usr/sbin/ntpdate 192.168.137.31 &>/dev/null;hwclock -w
# ssh-keygen -t rsa -P '' -f "/root/.ssh/id_rsa"
# ssh-copy-id -i .ssh/id_rsa.pubmachine
至此keepalived+lvs_dr+healthcheck 高可用集群就这样部署完毕。
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