首先需要明白我们准备使用keepalived来做什么，今天这里只是给大家简单安装和配置下keepalived实现vip对外服务，防止单点故障。keepalived是高可用高可用高可用 而非负载非负载非负载。
下面我将使用keepalived部署双主模模式，实现方式，利用脚本检测某个服务，当服务宕机的时候，停止keepalived，vip漂移到另一个主机上。
VIP1: 192.168.80.136 eth0:10.0.0.11 em1:10.0.0.67
VIP2: 192.168.80.139 eth1:10.0.0.12 em2:10.0.0.68 #vip/主机1网卡对应ip/主机2对应网卡ip
1.安装keepalived
yum install -y glibc openssl-devel wget http://www.keepalived.org/software/keepalived-1.2.24.tar.gz tar zxf keepalived-1.2.24.tar.gz cd keepalived-1.2.24 mkdir /usr/local/keepalived ./configure --prefix=/usr/local/keepalived && make && make install
2.将keepalived配置为系统服务
mkdir /etc/keepalived cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/keepalived cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived chmod +x /etc/init.d/keepalived ln /usr/local/keepalived/sbin/keepalived /usr/sbin/keepalived chkconfig --add keepalived
3.配置keepalived服务
cd /etc/keepalived/
cat keepalived.conf （主机1配置）
! Configuration File for keepalived
global_defs {
router_id NODE_B
}
vrrp_script checkALL {
script "/etc/keepalived/script/check_nginx.sh" #检测nginx服务脚本
interval 5
}
vrrp_instance VIP136 {
state MASTER #VIP1的master 主机2的时候改为BACKUP
interface eth0
mcast_src_ip 10.0.0.11
virtual_router_id 136 #虚拟路由id 2个主机需要一样
priority 100 #优先级 数值越大优先级越大，第二个主机设置比她它小
advert_int 1
authentication {
auth_type PASS
auth_pass masterbrian #双方认证使用的密码
}
virtual_ipaddress {
192.168.80.136 #vip1虚拟ip
}
track_script {
checkALL #检测脚本
}
notify_master "/etc/keepalived/script/notify.sh master 10.0.0.11 192.168.80.136" #变为主的时候触发的脚本
notify_backup "/etc/keepalived/script/notify.sh backup 10.0.0.11 192.168.80.136"
notify_fault "/etc/keepalived/script/notify.sh fault 10.0.0.11 192.168.80.136"
}
vrrp_instance VIP139 {
state BACKUP #VIP2的slave 主机改为MASTER
nopreempt #备机不抢占模式，当备机的优先级高于主机的时候不抢占
interface eth1
mcast_src_ip 10.0.0.12
virtual_router_id 139
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass masterrobinson
}
virtual_ipaddress {
192.168.80.139
}
track_script {
checkALL
}
notify_master "/etc/keepalived/script/notify.sh master 10.0.0.12 192.168.80.139"
notify_backup "/etc/keepalived/script/notify.sh backup 10.0.0.12 192.168.80.139"
notify_fault "/etc/keepalived/script/notify.sh fault 10.0.0.12 192.168.80.139"
}cat keepalived.conf （主机2配置）
! Configuration File for keepalived
global_defs {
router_id LVS_DEVEL
}
vrrp_script checkALL {
script "/etc/keepalived/script/check_nginx.sh"
interval 5
}
vrrp_instance VIP136 {
state BACKUP
interface em1
nopreempt
mcast_src_ip 10.0.0.67
virtual_router_id 136
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass masterbrian
}
virtual_ipaddress {
192.168.80.136
}
track_script {
checkALL
}
notify_master "/etc/keepalived/script/notify.sh master 10.0.0.67 192.168.80.136"
notify_backup "/etc/keepalived/script/notify.sh backup 10.0.0.67 192.168.80.136"
notify_fault "/etc/keepalived/script/notify.sh fault 10.0.0.67 192.168.80.136"
}
vrrp_instance VIP139 {
state MASTER
interface em2
mcast_src_ip 10.0.0.68
virtual_router_id 139
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass masterrobinson
}
virtual_ipaddress {
192.168.80.139
}
track_script {
checkALL
}
notify_master "/etc/keepalived/script/notify.sh master 10.0.0.68 192.168.80.139"
notify_backup "/etc/keepalived/script/notify.sh backup 10.0.0.68 192.168.80.139"
notify_fault "/etc/keepalived/script/notify.sh fault 10.0.0.68 192.168.80.139"
}4.使用到的其他脚本文件
4.1监控nginx服务脚本，当nginx服务不存在的时候停止keepalived服务
这个脚本可以根需要使用高可用的服务来做相应的调整。
cat /etc/keepalived/script/check_nginx.sh
#!/bin/bash
checknginx=$(ps -C nginx --no-header | wc -l)
checkkeepalived=$(ps -C keepalived --no-header | wc -l)
TIME=$(date +%Y-%m-%d\ %H:%M:%S)
if [ ${checknginx} -eq 0 ];then
service nginx restart
sleep 3
fi
checknginx_two=$(ps -C nginx --no-header | wc -l)
if [ ${checknginx_two} -eq 0 ];then
killall -TERM keepalived
fi4.2状态变化的时候的触发的脚本
cat /etc/keepalived/script/notify.sh
#!/bin/bash
status=${1}
hostip=${2}
vip=${3}
TIME=$(date +%Y-%m-%d\ %H:%M:%S)
HOST_NAME=$(hostname)
subject="${HOST_NAME} to be ${status}: ${vip} floating"
send_user="xxxxx"
send_contant="${TIME} ${HOST_NAME}[${hostip}] 主机keepalived的VIP:${vip} 状态改变为${status},请检查相关服务。"
python /etc/keepalived/script/send_mail.py "${send_user}" "${subject}" "${send_contant}"4.3 notify.sh中触发的发送邮件的python脚本
这个脚本最下面需要修改 用户名和密码，邮件服务器和收件人等相关信息
cat /etc/keepalived/script/send_mail.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
"""
纯文本文件发送
"""
import sys
import smtplib
from email.header import Header
from email.mime.text import MIMEText
from abc import abstractmethod
class Mail(object):
"""dohost, user_name, pwd, context, Subject, To, filename, file_path, port, nick_name, mail_adressring for Mail"""
def __init__(self, host, user_name, pwd, context, Subject, To, port, nick_name, mail_adress):
"""
:param host: 邮件服务器地址
:param user_name: 邮件登陆名
:param pwd: 邮箱登陆密码
:param context: 邮箱正文
:param Subject: 邮箱主题
:param To: 收件人
:param From: 发件人
"""
self.host=host
self.user_name=user_name
self.pwd=pwd
self.context=context
self.Subject=Subject
self.To=To
self.port=port
self.nick_name=nick_name
self.mail_adress=mail_adress
@abstractmethod
def send(self,**kwargs):
"""
send mail to account
:param file:
:return:
"""
pass
class TextMail(Mail):
"""
只有文本信息的邮件
"""
def __init__(self,**kwargs):
super(TextMail,self).__init__(**kwargs)
self.mail_type='TEXT'
@abstractmethod
def send(self):
#print("send_start")
server=smtplib.SMTP(self.host,self.port)
server.set_debuglevel(0)
server.login(self.user_name,self.pwd)
msg=MIMEText(self.context,'html','utf-8')
msg['From']='{0}<{1}>'.format(self.nick_name,self.mail_adress,'utf-8')
msg['Subject']=Header(self.Subject,'utf-8').encode()
msg['To']=','.join(self.To)
try:
server.sendmail(self.mail_adress,self.To,msg.as_string())
print("mail has been successfully")
except smtplib.SMTPException as e:
print('邮件发送失败')
print(e)
def send_mail(fromstmp,fromuser,frompwd,content,subject,touser):
host=fromstmp
fromuser=fromuser
pwd=frompwd
scontent=content
subject=subject
touser=touser
nick_name="运维监控"
b=TextMail(host=host,user_name=fromuser,pwd=pwd,context=content,Subject=subject,To=touser,port=25,nick_name=nick_name,mail_adress=fromuser)
b.send()
if __name__ == '__main__':
"""
设置发送邮箱信息
"""
fromuser="XXX" #发送邮箱的 123456@qq.com
frompwd="XXX" #邮箱密码 xxxx
fromstmp="XXX" #邮件服务stmp smtp.qq.com
touser = [str(sys.argv[1])] #传过来的第一个参数
subject = str(sys.argv[2]) #传过来的第二个参数
content = str(sys.argv[3]) #传过来的第三个参数
touser='xxx@126.com','xxxx@123.com' #收邮件的人
send_mail(fromstmp,fromuser,frompwd,content,subject,touser)
