首先需要明白我們準備使用keepalived來做什麽，今天這裏只是給大家簡單安裝和配置下keepalived實現vip對外服務，防止單點故障。keepalived是高可用高可用高可用 而非負載非負載非負載。

下面我將使用keepalived部署雙主模模式，實現方式，利用腳本檢測某個服務，當服務宕機的時候，停止keepalived，vip漂移到另一個主機上。

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/主機1網卡對應ip/主機2對應網卡ip

1.安裝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.將keepalived配置為系統服務

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服務

cd /etc/keepalived/

cat keepalived.conf （主機1配置）

! Configuration File for keepalived
global_defs {
   router_id NODE_B
}
vrrp_script checkALL {
   script "/etc/keepalived/script/check_nginx.sh"  #檢測nginx服務腳本       
   interval 5
}
vrrp_instance VIP136 {
    state MASTER #VIP1的master 主機2的時候改為BACKUP
    interface eth0
    mcast_src_ip 10.0.0.11
    virtual_router_id 136  #虛擬路由id 2個主機需要一樣              
    priority 100  #優先級 數值越大優先級越大，第二個主機設置比她它小
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass masterbrian  #雙方認證使用的密碼
    }
    virtual_ipaddress {
        192.168.80.136  #vip1虛擬ip
    }
    track_script {
        checkALL #檢測腳本
}
    notify_master "/etc/keepalived/script/notify.sh master 10.0.0.11 192.168.80.136" #變為主的時候觸發的腳本
    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  主機改為MASTER
   nopreempt  #備機不搶占模式，當備機的優先級高於主機的時候不搶占
   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 （主機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.使用到的其他腳本文件

4.1監控nginx服務腳本，當nginx服務不存在的時候停止keepalived服務

這個腳本可以根需要使用高可用的服務來做相應的調整。

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
fi

4.2狀態變化的時候的觸發的腳本

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}] 主機keepalived的VIP:${vip} 狀態改變為${status},請檢查相關服務。"
python /etc/keepalived/script/send_mail.py "${send_user}" "${subject}" "${send_contant}"

4.3 notify.sh中觸發的發送郵件的python腳本

這個腳本最下面需要修改 用戶名和密碼，郵件服務器和收件人等相關信息

cat /etc/keepalived/script/send_mail.py

#!/usr/bin/env python 
# -*- coding:utf-8 -*-
"""
純文本文件發送
"""
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: 郵件服務器地址
        :param user_name: 郵件登陸名
        :param pwd: 郵箱登陸密碼
        :param context: 郵箱正文
        :param Subject: 郵箱主題
        :param To: 收件人
        :param From: 發件人
        """
        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):
    """
    只有文本信息的郵件
    """
    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(‘郵件發送失敗‘)
            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="運維監控"    
    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__‘:
    """
    設置發送郵箱信息
    """
    fromuser="XXX"  #發送郵箱的 [email protected]
    frompwd="XXX"   #郵箱密碼 xxxx
    fromstmp="XXX"  #郵件服務stmp smtp.qq.com
    touser = [str(sys.argv[1])]  #傳過來的第一個參數
    subject = str(sys.argv[2])  #傳過來的第二個參數
    content = str(sys.argv[3])  #傳過來的第三個參數
    touser=‘[email protected]‘,‘[email protected]‘ #收郵件的人
    send_mail(fromstmp,fromuser,frompwd,content,subject,touser)

本文出自 “Poor Wretch” 博客，請務必保留此出處http://youprince.blog.51cto.com/9272426/1975346

keepalived 安裝配置（高可用VIP）,雙主模式