文章目录
1.keepalived简介
Keepalived 软件起初是专为LVS负载均衡软件设计的，用来管理并监控LVS集群系统中各个服务节点的状态，后来又加入了可以实现高可用的VRRP功能。因此，Keepalived除了能够管理LVS软件外，还可以作为其他服务（例如：Nginx、Haproxy、MySQL等）的高可用解决方案软件。
Keepalived软件主要是通过VRRP协议实现高可用功能的。VRRP是Virtual Router RedundancyProtocol(虚拟路由器冗余协议）的缩写，VRRP出现的目的就是为了解决静态路由单点故障问题的，它能够保证当个别节点宕机时，整个网络可以不间断地运行。
所以，Keepalived 一方面具有配置管理LVS的功能，同时还具有对LVS下面节点进行健康检查的功能，另一方面也可实现系统网络服务的高可用功能。
keepalived官网https://www.keepalived.org/
2.keepalived安装
2.1 配置主keepalived
//关闭防火墙与SELINUX
[root@master ~]# systemctl stop firewalld
[root@master ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@master ~]# setenforce 0
[root@master ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
//配置网络源
[root@master ~]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[root@master ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@master ~]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@master ~]# yum -y install epel-release vim wget gcc gcc-c++
安装过程略.....
//安装keepalived
[root@master ~]# yum -y install keepalived
//查看安装生成的文件
[root@master ~]# rpm -ql keepalived
/etc/keepalived //配置目录
/etc/keepalived/keepalived.conf //此为主配置文件
/etc/sysconfig/keepalived
/usr/bin/genhash
/usr/lib/systemd/system/keepalived.service //此为服务控制文件
/usr/libexec/keepalived
/usr/sbin/keepalived
......
2.2 配置备keepalived
//关闭防火墙与SELINUX
[root@slave ~]# systemctl stop firewalld
[root@slave ~]# systemctl disable firewalld
Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service.
Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service.
[root@slave ~]# setenforce 0
[root@slave ~]# sed -ri 's/^(SELINUX=).*/\1disabled/g' /etc/selinux/config
//配置网络源
[root@slave ~]# curl -o /etc/yum.repos.d/CentOS7-Base-163.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo
[root@slave ~]# sed -i 's/\$releasever/7/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@slave ~]# sed -i 's/^enabled=.*/enabled=1/g' /etc/yum.repos.d/CentOS7-Base-163.repo
[root@slave ~]# yum -y install epel-release vim wget gcc gcc-c++
安装过程略.....
//安装keepalived
[root@slave ~]# yum -y install keepalived
//查看安装生成的文件
[root@slave ~]# rpm -ql keepalived
/etc/keepalived //配置目录
/etc/keepalived/keepalived.conf //此为主配置文件
/etc/sysconfig/keepalived
/usr/bin/genhash
/usr/lib/systemd/system/keepalived.service //此为服务控制文件
/usr/libexec/keepalived
/usr/sbin/keepalived
3. 在主备机上分别安装nginx
3.1 在master上安装nginx
[root@master ~]# yum -y install nginx
[root@master ~]# cd /usr/share/nginx/html/
[root@master html]# ls
404.html 50x.html index.html nginx-logo.png poweredby.png
[root@master html]# mv index.html{,.bak}
[root@master html]# echo 'master' > index.html
[root@master html]# ls
404.html 50x.html index.html index.html.bak nginx-logo.png poweredby.png
[root@master html]# systemctl start nginx
[root@master html]# systemctl enable nginx
[root@master html]# ss -antl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:80 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
3.2 在slave上安装nginx
[root@slave ~]# yum -y install nginx
[root@slave ~]# cd /usr/share/nginx/html/
[root@slave html]# ls
404.html 50x.html index.html nginx-logo.png poweredby.png
[root@slave html]# mv index.html{,.bak}
[root@slave html]# echo 'slave' > index.html
[root@slave html]# ls
404.html 50x.html index.html index.html.bak nginx-logo.png poweredby.png
[root@slave html]# systemctl start nginx
[root@slave html]# systemctl enable nginx
4. 配置keepalived配置文件
4.1 配置主keepalived
[root@master ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_master
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass wangqing
}
virtual_ipaddress {
192.168.80.250 dev ens33
}
}
virtual_server 192.168.80.250 80 {
delay_loop 6
lvs_sched rr
lvs_method DR
persistence_timeout 50
protocol TCP
real_server 192.168.80.130 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@master ~]# systemctl restart keepalived //重启服务
4.2 配置备keepalived
[root@slave ~]# vim /etc/keepalived/keepalived.conf
[root@slave ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_slave
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 90
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass wangqing
}
virtual_ipaddress {
192.168.80.250 dev ens33
}
}
virtual_server 192.168.80.250 80 {
delay_loop 6
lvs_sched rr
lvs_method DR
persistence_timeout 50
protocol TCP
real_server 192.168.80.130 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@slave ~]# systemctl restart keepalived //重启服务
5. 编写脚本监控nginx负载均衡机
keepalived通过脚本来监控nginx负载均衡机的状态
5.1 编写主keepalived脚本
1.创建脚本存放目录
[root@master ~]# mkdir /scripts
[root@master ~]# cd /scripts/
2.编写监控nginx服务脚本
[root@master scripts]# vim check_n.sh
#!/bin/bash
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl stop keepalived
fi
[root@master scripts]# chmod +x check_n.sh //添加执行权限
[root@master scripts]# ll -d check_n.sh
-rwxr-xr-x. 1 root root 142 1月 10 12:53 check_n.sh
[root@master scripts]# vim notify.sh
#!/bin/bash
VIP=$2
sendmail (){
subject="${VIP}'s server keepalived state is translate"
content="`date +'%F %T'`: `hostname`'s state change to master"
echo $content | mail -s "$subject" [email protected]
}
case "$1" in
master)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl start nginx
fi
sendmail
;;
backup)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -gt 0 ];then
systemctl stop nginx
fi
;;
*)
echo "Usage:$0 master|backup VIP"
;;
esac
[root@slave scripts]# chmod +x notify.sh
[root@master scripts]# ll
总用量 8
-rwxr-xr-x. 1 root root 142 1月 10 12:53 check_n.sh
-rwxr-xr-x. 1 root root 662 1月 10 12:54 notify.sh
此处的脚本名称应避免与服务名相同，推荐用服务名的首字母代替，如check_n，不要给脚本起名check_nginx
5.2 编写备keepalived脚本
[root@slave scripts]# vim notify.sh
#!/bin/bash
VIP=$2
sendmail (){
subject="${VIP}'s server keepalived state is translate"
content="`date +'%F %T'`: `hostname`'s state change to master"
echo $content | mail -s "$subject" [email protected]
}
case "$1" in
master)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -lt 1 ];then
systemctl start nginx
fi
sendmail
;;
backup)
nginx_status=$(ps -ef|grep -Ev "grep|$0"|grep '\bnginx\b'|wc -l)
if [ $nginx_status -gt 0 ];then
systemctl stop nginx
fi
;;
*)
echo "Usage:$0 master|backup VIP"
;;
esac
[root@slave scripts]# chmod +x notify.sh
[root@slave scripts]# ll
总用量 4
-rwxr-xr-x. 1 root root 662 1月 10 12:55 notify.sh
6. 配置keepalived加入监控脚本的配置
6.1 配置主keepalived
[root@master ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_master
}
vrrp_script nginx_check {
script "/scripts/check_n.sh"
interval 1
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass wangqing
}
virtual_ipaddress {
192.168.80.250 dev ens33
}
track_script {
nginx_check
}
notify_master "/scripts/notify.sh master 192.168.80.250"
notify_backup "/scripts/notify.sh backup 192.168.80.250"
}
virtual_server 192.168.80.250 80 {
delay_loop 6
lvs_sched rr
lvs_method DR
persistence_timeout 50
protocol TCP
real_server 192.168.80.130 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@master ~]# systemctl restart keepalived //重启服务
6.2 配置备keepalived
backup无需检测nginx是否正常，当升级为MASTER时启动nginx，当降级为BACKUP时关闭
[root@slave ~]# vim /etc/keepalived/keepalived.conf
[root@slave ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_slave
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 90
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass wangqing
}
virtual_ipaddress {
192.168.80.250 dev ens33
}
notify_master "/scripts/notify.sh master 192.168.80.250"
notify_backup "/scripts/notify.sh backup 192.168.80.250"
}
virtual_server 192.168.80.250 80 {
delay_loop 6
lvs_sched rr
lvs_method DR
persistence_timeout 50
protocol TCP
real_server 192.168.80.130 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.128 80 {
weight 1
TCP_CHECK {
connect_port 80
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@slave ~]# systemctl restart keepalived //重启服务
