001-keepalived

编译安装keepalived：

yum -y install openssl openssl-devel

mkdir /usr/local/soft
cd soft
wget https://www.keepalived.org/software/keepalived-1.2.12.tar.gz
tar zxvf keepalived-1.2.12.tar.gz 
ln -s keepalived-1.2.12  keepalived
cd keepalived
./configure --sysconf=/etc
make
echo $?
make install
echo $?
cd /etc/keepalived/
cp keepalived.conf keepalived.conf.20190528

[root@node1 ~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived

#全局配置
global_defs {
   notification_email {
        root@node1
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_SERVER                              #设备在组中的标识，可以一样也可以不一样
}

vrrp_script chk_nginx {                              #nginx健康检查
    script "/etc/keepalived/nginx.sh"                #检查脚本
    interval 1                                       #检查频率.秒
    weight -5                                        #priority减5
    fall 2                                           #检测失败的最大次数，超过两次认为节点资源发生故障
    rise 1                                           #请求一次成功认为节点恢复正常


vrrp_instance VI_1 {                    #VI_1，实例名，两台路由器相同
    #state MASTER
    state BACKUP                        #主/从状态
    interface eth0                      #监控网卡
    virtual_router_id 72                #虚拟路由编号，主备要一致
    priority 95                         #优先级
    advert_int 1                        #心跳间隔
    nopreempt                           #设置为不抢夺VIP，主备都需要设置
    authentication {                    #密钥认证（1-8位）
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {                 #VIP
        192.168.174.130/24 dev eth0 scope global label eth0:1
    }
    track_script {                      #引用脚本
        chk_nginx
    }
    notify_master "/usr/bin/python /etc/keepalived/master.py"     #
    notify_backup "/usr/bin/python /etc/keepalived/backup.py"
}

[root@node2 ~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived 

global_defs {
   notification_email {
    root@host161
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_SERVER
}

vrrp_script chk_nginx {
    script "/etc/keepalived/nginx.sh"
    interval 1
    weight -5
    fall 2
    rise 1
}

vrrp_instance VI_1 {
    state BACKUP 
    interface eth0
    virtual_router_id 72
    priority 91
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    192.168.174.130/24 dev eth0 scope global label eth0:1
    }
   track_script {
    chk_nginx
    }
    notify_master "/usr/bin/python /etc/keepalived/master.py"
    notify_backup "/usr/bin/python /etc/keepalived/backup.py"
}

主备不一样的配置：
1、priority   优先级
2、state      MASTER/BACKUP

权重设置简单的标准：
weight 的绝对值 要大于MASTER和BACKUP的priority值之差

nopreempt   设置为不抢夺VIP，主备配置都需要设置，主备状态设置成 BACKUP

#主备上都需要添加监控脚本
cat /etc/keepalived/nginx.sh 
#!/bin/bash
#author:fansik
#description:check nginx service

run=`ps -C nginx --no-header | wc -l`
if [ $run -eq 0 ]
then
        service nginx start
        sleep 3
fi

发邮件脚本：主备的脚本就text上对应的master/back 不一样，其他相同
[root@node1 ~]# more /etc/keepalived/master.py 
#/usr/bin/python
# -*- coding: UTF-8 -*-
import smtplib
import string

import socket
hostname = socket.gethostname()
ipadd = socket.gethostbyname(socket.getfqdn(socket.gethostname()))

import time
localtime = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) 

 
HOST = "smtp.163.com"
SUBJECT = "[警告] keepalived by (%s) "% ipadd 
TO = "xxx@xxxxx.com.cn"
FROM = "15800xxxxx@163.com"
text = "时间:%s\nIP:%s\n主机名:%s\n事件:change to Master, VIP: 192.168.1.130" % (localtime, ipadd,  hostname)
BODY = string.join((
    "From: %s" %FROM,
    "TO: %s" %TO,
    "Subject: %s" %SUBJECT,
    "",
    text
    ),"\r\n")
server = smtplib.SMTP()
server.connect(HOST,"25")
server.login("15800xxxxxx@163.com","xxxxxx")
server.sendmail(FROM,[TO],BODY)
server.quit()

[root@node1 ~]# more /etc/keepalived/master.py 
#/usr/bin/python
# -*- coding: UTF-8 -*-
import smtplib
import string

import socket
hostname = socket.gethostname()
ipadd = socket.gethostbyname(socket.getfqdn(socket.gethostname()))

import time
localtime = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) 

 
HOST = "smtp.163.com"
SUBJECT = "[警告] keepalived by (%s) "% ipadd 
TO = "xxx@xxxxx.com.cn"
FROM = "15800xxxxxx@163.com"
text = "时间:%s\nIP:%s\n主机名:%s\n事件:change to Master, VIP: 192.168.1.130" % (localtime, ipadd,  hostname)
BODY = string.join((
    "From: %s" %FROM,
    "TO: %s" %TO,
    "Subject: %s" %SUBJECT,
    "",
    text
    ),"\r\n")
server = smtplib.SMTP()
server.connect(HOST,"25")
server.login("15800xxxxxx@163.com","xxxxxx")
server.sendmail(FROM,[TO],BODY)
server.quit()

nginx进程不在，尝试重启nginx，重启后还是起不来，就直接杀掉keepalived,让备机接管
如果用这个脚本，配置keepalived就不需要配置执行失败次数和成功次数的参数

#!/bin/bash 
while :
do
nginxpid=`ps -C nginx --no-header | wc -l`
if [ $nginxpid -eq 0 ];then
service nginx restart
sleep 5
nginxpid=`ps -C nginx --no-header | wc -l`
if [ $nginxpid -eq 0 ];then
service keepalived stop
fi
fi
sleep 5 
done