keealived安装

keealived安装

依赖
 yum install -y libnl*
 yum install -y libnfnetlink-devel zlib zlib-devel gcc gcc-c++ openssl openssl-devel openssh

1.上官网下载 .tar.gz任意版本压缩包
2.上传linux ，解压tar xvf keepalived-1.3.5.tar.gz
3.进入解压目录，./configure --prefix=/usr/local/keepalived  指定安装目录。然后make && make install
4. cp /解压目录/keepalived/etc/init.d/keepalived /etc/init.d/keepalived 赋值执行问脚本到service服务
5.mkdir /etc/keepalived  然后赋值配置文件到指定目录
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf

6.cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived

7.chkconfig keepalived on 设置开机启动

8.service keepalived start 启动

ps:
使用service keepalived start命令启动服务时，
默认会将/etc/sysconfig/keepalived文件中KEEPALIVED_OPTIONS参数作为keepalived服务启动时的参数，
并从/etc/keepalived/目录下加载keepalived.conf配置文件，或用-f参数指定配置文件的位置。或者修改启动脚本里的
keepalived=/usr/local/keepalived/sbin/keepalived 启动脚本
keepalived_config=/usr/local/keepalived/etc/keepalived/keepalived.conf 配置文件地址
keepalived_pid=/usr/local/keepalived/run/keepalived.pid pid没的说

配置如下：具体含义可以自己查
! Configuration File for keepalived

global_defs {
   #notification_email {
   # [e-mail]
   #[e-mail]
   #[e-mail]
   #} 不需要邮件发送
   #notification_email_from [e-mail]
   #smtp_server 192.168.200.1
   #smtp_connect_timeout 30
   router_id LVS_DEVEL
   #vrrp_skip_check_adv_addr
   #vrrp_strict   暂不需要这些参数
   #vrrp_garp_interval 0
   #vrrp_gna_interval 0
}
vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"         ##监控脚本
    interval 2                                      ##时间间隔，2秒
    weight -10                                        ##权重weight 为正时，脚本检测成功时此weight会加到priority上 ，weight为负时，脚本检测成功时此weight不影响priority，检测失败时priority – abs(weight)
    fall 2  
    rise 1
}

vrrp_instance VI_1 {
    state MASTER
    interface em1
    mcast_src_ip 192.168.17.32
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        check_nginx        #监控脚本
   }
    virtual_ipaddress {
        192.168.18.200
    }
}

备用节点修改mcast_src_ip为自己ip ，priority值小于主节点 99即可，注意跟权重的配合。
修改state=BACKUP

check_nginx.sh 最靠谱的方式应该检查某个url是否返回值
#!/bin/bash
# 如果进程中没有nginx则将keepalived进程kill掉
A=`ps -C nginx --no-header |wc -l`      ## 查看是否有 nginx进程 把值赋给变量A 
if [ $A -eq 0 ];then                    ## 如果没有进程值得为 零
       service keepalived stop          ## 则结束 keepalived 进程
fi

双主模式只需要再建一个vrrp_instance 将slave 变成master master里配置 slave即可。注意ip不能重复。