keepalived简述
简述
1集群类型
2keepalived 介绍
3安装keepalived（centos7自带是1.35版本，没有特殊需求可以使用此版本）
[root@keepalived1 ~]# yum -y install keepalived
[root@keepalived1 ~]# systemctl enable --now keepalived
编译安装
[root@keepalived1 ~]# yum -y install gcc curl openssl-devel libnl3-devel net-snmp-devel [root@keepalived1 ~]# wget https://keepalived.org/software/keepalived-2.0.20.tar.gz [root@keepalived1 ~]# tar xvf keepalived-2.0.20.tar.gz -C /usr/local/src [root@keepalived1 ~]# cd /usr/local/src/keepalived-2.0.20/ [root@keepalived1 ~]# ./configure --prefix=/usr/local/keepalived --disable-fwmark 防止生成iptables规则，无法访问vip [root@keepalived1 ~]# make && make install
[root@keepalived1 ~]# mkdir /etc/keepalived
[root@keepalived1 ~]#cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived
[root@keepalived1 ~]#systemctl enable --now keepalived.service
4配置简述
#/etc/keepalived/keepalived.conf
global_defs {
notification_email {
root@localhost #keepalived 发生故障切换时邮件发送的目标邮箱，可以按行区分写多个
}
notification_email_from keepalived@localhost #发邮件的地址
smtp_server 127.0.0.1 #邮件服务器地址
smtp_connect_timeout 30 #邮件服务器连接timeout
router_id ka1.example.com #每个keepalived主机唯一标识，建议使用当前主机名，但多节点重名
不影响
vrrp_skip_check_adv_addr #对所有通告报文都检查，会比较消耗性能，启用此配置后，如果收到的通告报文和上一个报文是同一个路由器，则跳过检查，默认值为全检查
vrrp_strict #严格遵守VRRP协议,启用此项后以下状况将无法启动服务:1.无VIP地址 2.配置了单播邻居 3.在VRRP版本2中有IPv6地址，开启动此项并且没有配置vrrp_iptables时会自动开启iptables防火
墙规则，默认导致VIP无法访问,建议不加此项配置
vrrp_garp_interval 0 #gratuitous ARP messages 报文发送延迟，0表示不延迟
vrrp_gna_interval 0 #unsolicited NA messages （不请自来）消息发送延迟
vrrp_mcast_group4 224.0.0.18 #指定组播IP地址范围：224.0.0.0到239.255.255.255,默认值：224.0.0.18
vrrp_iptables #此项和vrrp_strict同时开启时，则不会添加防火墙规则,如果无配置vrrp_strict项,则无需启用此项配置
}
5启用keepalived日志功能
[root@keepalived1 ~]#vim /etc/sysconfig/keepalived KEEPALIVED_OPTIONS="-D -S 6" [root@keepalived1 ~]#vim /etc/rsyslog.conf local6.* /var/log/keepalived.log [root@keepalived1 ~]#systemctl restart keepalived.service rsyslog.service
[root@keepalived1 ~]# ll /var/log/keeepalived.log
-rw------- 1 root root 4742 1Ղ 7 12:55 /var/log/keeepalived.log
6实现子配置文件
[root@keepalived1 ~]#mkdir /etc/keepalived/conf.d/ [root@keepalived1 ~]#vim /etc/keepalived/keepalived.conf
7 总结配置概览
主配置文件
[root@keepalived1 ~]# cat /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { acassen@firewall.loc xxxxx@xxxx.com } notification_email_from Alexandre.Cassen@firewall.loc smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id ka1 另一个节点为ka2 vrrp_skip_check_adv_addr # vrrp_strict vrrp_garp_interval 0 vrrp_gna_interval 0 } include /etc/keepalived/conf.d/*.conf
子配置文件
[root@keepalived1 ~]# cat /etc/keepalived/conf.d/v1.conf
vrrp_instance VI_1 {
state MASTER 另一个为BACKUP
interface ens33 网卡根据自己机器来
virtual_router_id 1 另一个节点也是1
priority 100 另一个节点为80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.10.200
}
unicast_src_ip 192.168.10.31 此机器地址为31，ka2配置就成32
unicast_peer {
192.168.10.32 另一个节点为32，ka2就配置成31
}
notify_master "/etc/keepalived/notify.sh master" keepalived节点状态切换脚本
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.10.200 80 {
delay_loop 3
lb_algo rr
lb_kind DR
protocol TCP
sorry_server 127.0.0.1 80
real_server 192.168.10.33 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 1
nb_get_retry 3
delay_before_retry 1
}
}
real_server 192.168.10.34 80 {
weight 1
TCP_CHECK {
connect_timeout 5
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
-------------------------------------------------------------------
[root@keepalived1 ~]# cat /etc/keepalived/notify.sh
#!/bin/bash
#
contact='xxx@xxxx' 和主配置的邮箱一致
notify() {
mailsubject="$(hostname) to be $1, vip floating"
mailbody="$(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
8实验环境
ka1（192.168.10.31）
ka2（192.168.10.32）
vip（192.168.10.200）
web1（192.168.10.33）
web2（192.168.10.34）
在web1和web2执行
[root@web1 ~]# cat lvs_dr_rs.sh #!/bin/bash vip=192.168.10.200 mask='255.255.255.255' dev=lo:1 rpm -q httpd &> /dev/null || yum -y install httpd &>/dev/null service httpd start &> /dev/null && echo "The httpd Server is Ready!" echo "<h1>`hostname`</h1>" > /var/www/html/index.html case $1 in start) echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce ifconfig $dev $vip netmask $mask #broadcast $vip up #route add -host $vip dev $dev echo "The RS Server is Ready!" ;; stop) ifconfig $dev down echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce echo "The RS Server is Canceled!" ;; *) echo "Usage: $(basename $0) start|stop" exit 1 ;; esac
看到后端都获得了vip
在ka1和ka2上把第七步的配置写入，进行测试。
1.所有节点都正常
结论：正常的轮询访问
2.ka1的keepalived服务停止，后端服务正常
结论：ka2接管vip，并正常提供服务，邮箱收到了ka2成为了master的信息
3后端服务器都宕机，ka1和ka2正常（这个页面由ka1和ka2提供，所以需要装个web服务）
4后端服务器都宕机，ka1也宕机，ka2正常
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