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Nginx - keepalived快速配置及脚本

Nginx + keepalived

双机主从模式

Terminal window
! Configuration File for keepalived
global_defs {
notification_email {
agou-ops@foxmail.com
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id master
vrrp_mcast_group4 224.1.111.11
}
vrrp_script chk_down { # 声明定义脚本
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" # 执行脚本内容
weight -10 # 如果脚本失败则将其权重降低10
interval 1 # 检查间隔
fall 1 # 失败次数
rise 1 # 检测1次成功就算成功
}
vrrp_script chk_ngx {
script "killall -0 nginx && exit 0 || exit 1"
# script "/root/chk_ngx.sh"
weight -10
interval 1
fall 3
rise 2
}
vrrp_instance VI_1 {
state MASTER # ---备用主机更换为BACKUP
interface ens33
lvs_sync_daemon_inteface ens33
virtual_router_id 51
priority 100 # ---备用主机适当降低优先级
advert_int 1
authentication {
auth_type PASS
auth_pass GU6hbFS4
}
virtual_ipaddress {
192.168.174.99/32 dev ens33 label ens33:1 # LVS VIP地址
}
track_script { # 调用脚本
chk_down
chk_ngx
}
notify_master "/root/notify.sh master"
notify_backup "/root/notify.sh backup"
notify_fault "/root/notify.sh fault"
}

脚本一:通过通知脚本实现当 keepalived 节点变成主节点时启用 nginx, 变成备用节点时停用 nginx

notify.sh

#!/bin/bash
contact='agou-ops@foxmail.com'
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)
systemctl start nginx.service
notify master
;;
backup)
systemctl stop nginx.service
notify backup
;;
fault)
systemctl stop nginx.service
notify fault
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac

脚本二:检测 nginx 运行状态,当 nginx 异常退出时尝试重新启动,若仍然无法启动 nginx,则将该节点降为备用节点(BACKUP)

chk_ngx.sh

#!/bin/bash
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
/usr/local/bin/nginx
sleep 2
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
/etc/init.d/keepalived stop
fi
fi

参考链接