高可用篇之Keepalived （HAProxy+keepalived 搭建高可用负载均衡集群）

yum -y install keepalived

[root@haproxy-master network-scripts]# cp ifcfg-ens33 ifcfg-ens33:0
[root@haproxy-master network-scripts]# vim ifcfg-ens33:0
[root@haproxy-master network-scripts]# ifup ens33:0
[root@haproxy-master network-scripts]# ip a | grep -i ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 192.168.1.102/24 brd 192.168.1.255 scope global noprefixroute dynamic ens33
    inet 192.168.1.200/24 brd 192.168.1.255 scope global secondary ens33:0
[root@haproxy-master network-scripts]# cat ifcfg-ens33:0
TYPE=Ethernet
NAME=ens33:0
DEVICE=ens33:0
IPADDR=192.168.1.200  ##VIP
 NETMASK=255.255.255.0
ONBOOT=yes
[root@haproxy-master network-scripts]#

[root@haproxy-slave network-scripts]#  cp ifcfg-ens33 ifcfg-ens33:0
[root@haproxy-slave network-scripts]# vim ifcfg-ens33:0
[root@haproxy-slave network-scripts]# echo "" > ifcfg-ens33:0
[root@haproxy-slave network-scripts]# vim ifcfg-ens33:0
[root@haproxy-slave network-scripts]# cat ifcfg-ens33:0
TYPE=Ethernet
NAME=ens33:0
DEVICE=ens33:0
IPADDR=192.168.1.200   ##VIP
NETMASK=255.255.255.0
ONBOOT=yes

[root@haproxy-slave network-scripts]# ifup ens33:0
ERROR     : [/etc/sysconfig/network-scripts/ifup-eth] Error, some other host (00:0C:29:D4:BF:E8) already uses address 192.                                                                                                                   168.1.200.
[root@haproxy-slave network-scripts]# vim ifcfg-ens33:0
[root@haproxy-slave network-scripts]# ifup ens33:0
ERROR     : [/etc/sysconfig/network-scripts/ifup-eth] Error, some other host (00:0C:29:D4:BF:E8) already uses address 192.                                                                                                                   168.1.200.

vi /etc/sysconfig/network-scripts/ifup-eth

#if [ $? = 1 ]; then

#  ARPINGMAC=$(echo $ARPING | sed -ne 's/.*\[\(.*\)\].*/\1/p')

#  net_log $"Error, some other host ($ARPINGMAC) already uses address ${ipaddr[$idx]}."

#  exit 1

#fi

[root@haproxy-master scripts]# cat /etc/keepalived/keepalived.conf
global_defs {  ##全局定义， 还可以设置发送邮件等功能
   router_id haproxy-master  # 路由ID，标识本节点的字符串，邮件通知时会用到
}

# 自定义VRRP实例健康检查脚本 keepalived只能做到对自身问题和网络故障的监控，Script可以增加其他的监控来判定是否需要切换主备
vrrp_script chk_haproxy
{
     script "/etc/keepalived/scripts/haproxy_check.sh"  #心跳检测脚本，检测haproxy是否启动
     interval 2   #检测脚本执行的间隔，单位是秒
     timeout 2
     fall 3
}

# VRRP实例：定义对外提供服务的VIP区域及其相关属性
vrrp_instance haproxy {
state MASTER    #指定keepalived的角色，MASTER为主，BACKUP为备
    interface ens33   #节点固有IP(非VIP)的网卡，用来发VRRP包
    virtual_router_id 20     #虚拟路由编号，主从要一致
    priority  150    #优先级，数值越大，获取处理请求的优先级越高，主从之间最好差50
    authentication {         auth_type PASS         auth_pass 20     }  #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
    virtual_ipaddress {
192.168.1.200    #定义虚拟ip(VIP)
    }

# 自定义健康检查脚本
    track_script {
         chk_haproxy    # 配置上面自定义的vrrp脚本调用名
    }
    notify_master "/etc/keepalived/scripts/haproxy_master.sh"   #记录切换为主节点的信息
}
[root@haproxy-master scripts]#

[root@haproxy-slave scripts]# cat /etc/keepalived/keepalived.conf
global_defs {

router_id haproxy-slave
}

vrrp_script chk_haproxy
{
script "/etc/keepalived/scripts/haproxy_check.sh"
interval 2
timeout 2
fall 3
}
vrrp_instance haproxy {
state BACKUP
interface ens33
virtual_router_id 20
priority  100
authentication {         auth_type PASS         auth_pass 20     }
virtual_ipaddress {
192.168.1.200
}
track_script {
chk_haproxy
}
notify_master "/etc/keepalived/scripts/haproxy_master.sh"
}
[root@haproxy-slave scripts]#

#!/bin/bash
LOGFILE="/var/log/keepalived-haproxy-state.log"
date >> $LOGFILE
A=`ps -C haproxy --no-header | wc -l`
if [ $A -eq 0 ];then
echo "fail: check_haproxy status" >> $LOGFILE
echo "Try to start haproxy service" >> $LOGFILE
  systemctl start haproxy  #重启haproxy服务
  sleep 2
  if [ `ps -C haproxy --no-header | wc -l` -eq 0 ];then  #如果启动失败，就进行VIP 转移
echo "Can not start haproxy service, so will stop keepalived service" >> $LOGFILE
        killall keepalived
fi
else
echo "success: check_haproxy status" >> $LOGFILE
fi

[root@haproxy-master scripts]# cat haproxy_master.sh
#!/bin/bash
LOGFILE="/var/log/keepalived-haproxy-state.log"
echo "Being Master ..." >> $LOGFILE
[root@haproxy-master scripts]#

systemctl start keepalived