keepalived相关配置示例(一)

配置前提：

(1) 各节点时间必须同步

(2) 确保iptables及selinux不会成为阻碍

(3) 各节点之间可通过主机名互相通信（对KA并非必须）

        建议使用/etc/hosts文件实现

(4) 确保各节点的用于集群服务的接口支持MULTICAST通信

单主配置实例：  node1为主     node2为从

node1

[root@node1 ~]#ntpdate 172.16.0.1  各节点时间必须同步
[root@node1 ~]#vim /etc/chrony.conf

[root@node1 ~]#systemctl restart chronyd.service
[root@node1 ~]#systemctl enable chronyd.service 开机启动chronyd.service
[root@node1 ~]#vim /etc/hosts   各节点之间可通过主机名互相通信

[root@node1 ~]#ping node2
[root@node1 ~]#ip link set multicast on dev ens33    确保各节点的用于集群服务的接口支持MULTICAST通信
[root@node1 ~]#yum install keepalived -y
[root@node1 /etc/keepalived]#cp keepalived.conf{,.bak}
[root@node1 /etc/keepalived]#vim keepalived.conf

global_defs {
   notification_email {
        root@localhost  #设置报警邮件地址，可以设置多个，每行一个。需要开启sendmail服务。
   }    
   notification_email_from keepalived@localhost #设置邮件的发送地址
   smtp_server 127.0.0.1    #设置SMTP Server地址
   smtp_connect_timeout 30  #设置SMTP Server的超时时间
   router_id node1   #表示运行Keepalived服务器的一个标识。发邮件时显示大邮件主题中的信息
   vrrp_mcast_group4 224.1.101.33
}  
 
vrrp_instance VI_1 {    #vrrp 实例定义部分
    state MASTER    #指定Keepalived的角色，MASTER表示些主机是主服务器。BACKUP表示此主机是备用服务器
    interface ens33 #指定HA监测网络的接口
    virtual_router_id 33 #虚拟路由标识，这个标识是一个数字，同一个vrrp实例使用唯一的标识，即同一个vrrp_instance下MASTER与BACKUP必须是一致的
    priority 100    #定义优先级，数字越大，优先级越高
    advert_int 1
    authentication {
        auth_type PASS  #设置验证类型和密码，MASTER和BACKUP必须使用相同的密码才能正常通信
        auth_pass Nl9OliUQ  # openssl rand -base64 7  得出随机八位数
    }   
    virtual_ipaddress { #设置虚拟IP地址，可以设置多个虚拟IP地址，每行一个
        172.16.0.99/16 dev ens33 label ens33:0
    }
}   
[root@node1 /etc/keepalived]#scp keepalived.conf node2:/etc/keepalived/ 传到node2中
[root@node2 /etc/keepalived]#systemctl start keepalived.service 启动时，由于优先级高于node2，所以node2关闭
[root@node2 /etc/keepalived]#systemctl status keepalived.service 查看日志

node2
[root@node2 ~]#ntpdate 172.16.0.1   各节点时间必须同步
[root@node2 ~]#vim /etc/chrony.conf

[root@node2 ~]#systemctl restart chronyd.service
[root@node2 ~]#systemctl enable chronyd.service 开机启动chronyd.service
[root@node2 ~]#vim /etc/hosts   各节点之间可通过主机名互相通信

[root@node2 ~]#ping node1
[root@node2 ~]#ip link set multicast on dev ens33 确保各节点的用于集群服务的接口支持MULTICAST通信
[root@node2 ~]#yum install keepalived -y
[root@node2 /etc/keepalived]#vim keepalived.conf
global_defs {
   notification_email {
        root@localhost  #设置报警邮件地址，可以设置多个，每行一个。需要开启sendmail服务。
   }    
   notification_email_from keepalived@localhost #设置邮件的发送地址
   smtp_server 127.0.0.1    #设置SMTP Server地址
   smtp_connect_timeout 30  #设置SMTP Server的超时时间
   router_id node2   #表示运行Keepalived服务器的一个标识。发邮件时显示大邮件主题中的信息
   vrrp_mcast_group4 224.1.101.33
}  
 
vrrp_instance VI_1 {    #vrrp 实例定义部分
    state BACKUP    #指定Keepalived的角色，MASTER表示些主机是主服务器。BACKUP表示此主机是备用服务器
    interface ens33 #指定HA监测网络的接口
    virtual_router_id 33 #虚拟路由标识，这个标识是一个数字，同一个vrrp实例使用唯一的标识，即同一个vrrp_instance下MASTER与BACKUP必须是一致的
    priority 80 #定义优先级，数字越大，优先级越高
    advert_int 1
    authentication {
        auth_type PASS  #设置验证类型和密码，MASTER和BACKUP必须使用相同的密码才能正常通信
        auth_pass Nl9OliUQ  # openssl rand -base64 7  得出随机八位数
    }   
    virtual_ipaddress { #设置虚拟IP地址，可以设置多个虚拟IP地址，每行一个
        172.16.0.99/16 dev ens33 label ens33:0
    }
}   
测试：
[root@node2 /etc/keepalived]#systemctl start keepalived.service
[root@node2 /etc/keepalived]#systemctl status keepalived.service 查看日志
[root@node2 /etc/keepalived]#tcpdump -i ens33 -nn host 224.1.101.33 node1开启时
08:25:13.748659 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 100, authtype simple, intvl 1s, length 20
[root@node2 /etc/keepalived]#tcpdump -i ens33 -nn host 224.1.101.33 node1关闭时
08:26:20.811002 IP 172.16.252.245 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 80, authtype simple, intvl 1s, length 20

双主模型实例：

node1
[root@node1 /etc/keepalived]#vim keepalived.conf
vrrp_instance VI_1 {
    interface ens33
    authentication {
        auth_type PASS
        auth_pass NcxCHRPP
    }
    virtual_ipaddress {
        172.16.0.99/16 dev ens33
    }
}
 
vrrp_instance VI_2 {
    state BACKUP
    priority 90
    interface ens33
    virtual_router_id 34
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass AcxRHRQP
    }
    virtual_ipaddress {
        172.16.0.88/16 dev ens33
    }
}

node2
[root@node2 /etc/keepalived]#vim keepalived.conf
vrrp_instance VI_1 {
    state BACKUP
    priority 80
    interface ens33
    virtual_router_id 33
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass NcxCHRPP
    }   
    virtual_ipaddress {
        172.16.0.99/16 dev ens33
    }   
}   
 
vrrp_instance VI_2 {
    state MASTER
    priority 100
    interface ens33
    virtual_router_id 34
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass AcxRHRQP
    }   
    virtual_ipaddress {
        172.16.0.88/16 dev ens33
    }   
}   
测试：
[root@node1 /etc/keepalived]#systemctl stop keepalived.service
[root@node1 /etc/keepalived]#systemctl stop keepalived.service
[root@node1 /etc/keepalived]#systemctl start keepalived.service
[root@node2 /etc/keepalived]#systemctl start keepalived.service
[root@node2 ~]#tcpdump -i ens33 -nn host 224.1.101.33
09:07:18.318146 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 100, authtype simple, intvl 1s, length 20
09:07:18.725960 IP 172.16.252.245 > 224.1.101.33: VRRPv2, Advertisement, vrid 34, prio 100, authtype simple, intvl 1s, length 20
09:07:19.319033 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 100, authtype simple, intvl 1s, length 20
[root@node1 /etc/keepalived]#systemctl stop keepalived.service
09:09:58.514319 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 100, authtype simple, intvl 1s, length 20
09:09:58.969318 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 34, prio 96, authtype simple, intvl 1s, length 20
09:09:59.515444 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 33, prio 100, authtype simple, intvl 1s, length 20
09:09:59.970398 IP 172.16.250.149 > 224.1.101.33: VRRPv2, Advertisement, vrid 34, prio 96, authtype simple, intvl 1s, length 20

通知脚本的使用方式:

[root@node1 /etc/keepalived]#vim notify.sh
#!/bin/bash
#
contact='root@localhost'
notify() {
local mailsubject="$(hostname) to be $1, vip floating"
local mailbody="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
echo "$mailbody" | mail -s "$mailsubject" $contact
}
 
case $1 in
master)
notify master
;;
backup)
notify backup
;;
fault)
notify fault
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac
[root@node1 /etc/keepalived]#chmod +x notify.sh
[root@node1 /etc/keepalived]#bash -n notify.sh
[root@node1 /etc/keepalived]#bash -x notify.sh master 脚本调用
[root@node1 /etc/keepalived]#bash -x notify.sh backup 脚本调用
[root@node1 /etc/keepalived]#bash -x notify.sh fault 脚本调用
[root@node1 /etc/keepalived]#scp -p notify.sh node2:/etc/keepalived/ 保留权限复制到node2
[root@node1 /etc/keepalived]#cp keepalived.conf{,.dual}
[root@node1 /etc/keepalived]#vim keepalived.conf 将双主模型删除
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 33
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass r6SYByVN
    }
    virtual_ipaddress {
    172.16.0.99/16 dev ens33 lable ens33:0
    }
 
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}   
[root@node2 /etc/keepalived]#cp keepalived.conf{,.dual}
[root@node2 /etc/keepalived]#vim keepalived.conf 做node1同样的操作