Keepalived常用配置及脚本
keepalived配置文件路径：/etc/keepalived/keepalived.conf
更多keepalived介绍请参考：http://blog.csdn.net/huwh_/article/details/77113410
1. keepalived.conf
1.1. MASTER（主机配置）
global_defs {
router_id proxy-keepalived
}
vrrp_script check_nginx {
script "/etc/keepalived/scripts/check_nginx.sh"
interval 3
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface eth2
virtual_router_id 15
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass xxx
}
track_script {
check_nginx
}
virtual_ipaddress {
180.101.115.139
218.98.38.29
}
nopreempt
notify_master "/etc/keepalived/keepalived_notify.sh master"
notify_backup "/etc/keepalived/keepalived_notify.sh backup"
notify_fault "/etc/keepalived/keepalived_notify.sh fault"
notify_stop "/etc/keepalived/keepalived_notify.sh stop"
}
1.2. BACKUP（备机配置）
global_defs {
router_id proxy-keepalived
}
vrrp_script check_nginx {
script "/etc/keepalived/scripts/check_nginx.sh"
interval 3
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth2
virtual_router_id 15
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass xxx
}
track_script {
check_nginx
}
virtual_ipaddress {
180.101.115.139
218.98.38.29
}
nopreempt
notify_master "/etc/keepalived/keepalived_notify.sh master"
notify_backup "/etc/keepalived/keepalived_notify.sh backup"
notify_fault "/etc/keepalived/keepalived_notify.sh fault"
notify_stop "/etc/keepalived/keepalived_notify.sh stop"
}
1.3. 注意事项
1、指定Nginx健康检测脚本：/etc/keepalived/scripts/check_nginx.sh
2、主备配置差别主要为（建议这么配置）：
- 主机:(state MASTER;priority 100)
- 备机：(state BACKUP;priority 99)
- 非抢占：nopreempt
或者： - 主机:(state BACKUP;priority 100)
- 备机：(state BACKUP;priority 100)
- 默认抢占
3、指定VIP
virtual_ipaddress {
180.101.115.139
218.98.38.29
}
4、可以指定为非抢占：nopreempt，即priority高不会抢占已经绑定VIP的机器。
5、制定绑定IP的网卡： interface eth2
6、可以指定keepalived状态变化通知
notify_master "/etc/keepalived/keepalived_notify.sh master"
notify_backup "/etc/keepalived/keepalived_notify.sh backup"
notify_fault "/etc/keepalived/keepalived_notify.sh fault"
notify_stop "/etc/keepalived/keepalived_notify.sh stop"
7、virtual_router_id 15值，主备值一致，但建议不应与集群中其他Nginx机器上的相同
2. Nginx健康检测脚本
在Nginx配置目录下（/etc/nginx/conf.d/）增加health.conf的配置文件,该配置文件用于配置Nginx health的接口。
server {
listen 80 default_server;
server_name localhost;
default_type text/html;
return 200 'Health';
}
Nginx健康检测脚本：/etc/keepalived/scripts/check_nginx.sh
2.1. 检查接口调用是否为200
#!/bin/sh
set -x
timeout=30 #指定默认30秒没返回200则为非健康，该值可根据实际调整
if [ -n ${timeout} ];then
httpcode=`curl -sL -w %{http_code} -m ${timeout} http://localhost -o /dev/null`
else
httpcode=`curl -sL -w %{http_code} http://localhost -o /dev/null`
fi
if [ ${httpcode} -ne 200 ];then
echo `date`': nginx is not healthy, return http_code is '${httpcode} >> /etc/keeperalived/keepalived.log
killall keepalived
exit 1
else
exit 0
fi
2.2. 检查Nginx进程是否运行
#!/bin/sh
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
echo "$(date) nginx pid not found">>/etc/keepalived/keepalived.log
killall keepalived
fi
3. Keepalived状态通知脚本
#!/bin/bash
set -x
warn_receiver=$1
ip=$(cat /etc/server.info|grep IPS)
warningInfo="${ip}_keepalived_changed_status_to_$1"
warn-report --user admin --key=xxxx --target=${warn_receiver} ${warningInfo}
echo $(date) $1 >> /etc/keepalived/status
说明：
- ip获取本机IP，可换成其他脚本，本例中IP获取是基于特殊环境的配置文件，其他地方不适用。
- 告警工具根据自己指定。
4. keepalived 切 VIP
例如将 A 机器上的 VIP 迁移到B 机器上。
4.1. 停止keepalived服务
停止被迁移的机器（A机器）的keepalived服务。
systemctl stop keepalived
4.2. 查看日志
解绑 A机器 VIP的日志
Sep 19 14:28:09 localhost systemd: Stopping LVS and VRRP High Availability Monitor...
Sep 19 14:28:09 localhost Keepalived[45705]: Stopping
Sep 19 14:28:09 localhost Keepalived_vrrp[45707]: VRRP_Instance(twemproxy) sent 0 priority
Sep 19 14:28:09 localhost Keepalived_vrrp[45707]: VRRP_Instance(twemproxy) removing protocol VIPs.
Sep 19 14:28:09 localhost Keepalived_healthcheckers[45706]: Stopped
Sep 19 14:28:10 localhost Keepalived_vrrp[45707]: Stopped
Sep 19 14:28:10 localhost Keepalived[45705]: Stopped Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2
Sep 19 14:28:10 localhost systemd: Stopped LVS and VRRP High Availability Monitor.
Sep 19 14:28:10 localhost ntpd[1186]: Deleting interface #10 bond0, 192.168.99.9#123, interface stats: received=0, sent=0, dropped=0, active_time=6755768 secs
绑定 B 机器 VIP的日志
Sep 17 17:20:25 localhost systemd: Starting LVS and VRRP High Availability Monitor...
Sep 17 17:20:26 localhost Keepalived[34566]: Starting Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2
Sep 17 17:20:26 localhost Keepalived[34566]: Opening file '/etc/keepalived/keepalived.conf'.
Sep 17 17:20:26 localhost Keepalived[34568]: Starting Healthcheck child process, pid=34569
Sep 17 17:20:26 localhost Keepalived[34568]: Starting VRRP child process, pid=34570
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Registering Kernel netlink reflector
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Registering Kernel netlink command channel
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Registering gratuitous ARP shared channel
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Opening file '/etc/keepalived/keepalived.conf'.
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Truncating auth_pass to 8 characters
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: VRRP_Instance(twemproxy) removing protocol VIPs.
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: Using LinkWatch kernel netlink reflector...
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: VRRP_Instance(twemproxy) Entering BACKUP STATE
Sep 17 17:20:26 localhost Keepalived_vrrp[34570]: VRRP sockpool: [ifindex(4), proto(112), unicast(0), fd(10,11)]
Sep 17 17:20:26 localhost systemd: Started LVS and VRRP High Availability Monitor.
Sep 17 17:20:26 localhost kernel: IPVS: Registered protocols (TCP, UDP, SCTP, AH, ESP)
Sep 17 17:20:26 localhost kernel: IPVS: Connection hash table configured (size=4096, memory=64Kbytes)
Sep 17 17:20:26 localhost kernel: IPVS: Creating netns size=2192 id=0
Sep 17 17:20:26 localhost kernel: IPVS: Creating netns size=2192 id=1
Sep 17 17:20:26 localhost kernel: IPVS: ipvs loaded.
Sep 17 17:20:26 localhost Keepalived_healthcheckers[34569]: Opening file '/etc/keepalived/keepalived.conf'.