Keepalived
一、安装部署
- 下载地址:
点我下载 - 通过ftp工具上传到linux中,/home/software
- 解压
tar -zxvf keepalived-2.0.18.tar.gz
- 解压后进入到解压出来的目录,看到会有
configure
,那么就可以做配置了(配置安装和nginx一模一样) - 使用
configure
命令配置安装目录与核心配置文件所在位置:
./configure --prefix=/usr/local/keepalived --sysconf=/etc
- prefix:keepalived安装的位置
- sysconf:keepalived核心配置文件所在位置,固定位置,改成其他位置则keepalived启动不了,/var/log/messages中会报错
5.1. 配置过程中可能会出现警告信息,如下所示:
*** WARNING - this build will not support IPVS with IPv6. Please install libnl/libnl-3 dev libraries to support IPv6 with IPVS.
5.2. 安装libnl/libnl-3
依赖
yum -y install libnl libnl-devel
5.3. 重新configure
一下,此时OK。
- 安装keepalived
make && make install
- 进入到
/etc/keepalived
,该目录下为keepalived核心配置文件 - 如果忘记安装配置的目录,则通过如下命令找到:
二、配置 Keepalived - 主
1. 通过命令 vim keepalived.conf
打开配置文件
global_defs {
# 路由id:当前安装keepalived的节点主机标识符,保证全局唯一
router_id keep_171
}
vrrp_instance VI_1 {
# 表示状态是MASTER主机还是备用机BACKUP
state MASTER
# 该实例绑定的网卡
interface ens33
# 保证主备节点一致即可
virtual_router_id 51
# 权重,master权重一般高于backup,如果有多个,那就是选举,谁的权重高,谁就当选
priority 100
# 主备之间同步检查时间间隔,单位秒
advert_int 2
# 认证权限密码,防止非法节点进入
authentication {
auth_type PASS
auth_pass 1111
}
# 虚拟出来的ip,可以有多个(vip)
virtual_ipaddress {
192.168.1.161
}
}
附:查看网卡名称
2. 启动 Keepalived
在sbin目录中进行启动(同nginx),如下图:
3. 查看进程
ps -ef|grep keepalived
4. 查看vip
在网卡ens33下,多了一个192.168.1.161,这个就是虚拟ip
三、配置 Keepalived - 备
1. 通过命令 vim keepalived.conf
打开配置文件
global_defs {
router_id keep_172
}
vrrp_instance VI_1 {
# 备用机设置为BACKUP
state BACKUP
interface ens33
virtual_router_id 51
# 权重低于MASTER
priority 80
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
# 注意:主备两台的vip都是一样的,绑定到同一个vip
192.168.1.161
}
}
2. 启动 Keepalived
# 启动keepalived
systemctl start keepalived
# 停止keepalived
systemctl stop keepalived
# 重启keepalived
systemctl restart keepalived
3. 查看进程
ps -ef|grep keepalived
四、Keepalived配置Nginx自动重启
1. 增加Nginx重启检测脚本
vim /etc/keepalived/check_nginx_alive_or_not.sh
#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
# 判断nginx是否宕机,如果宕机了,尝试重启
if [ $A -eq 0 ];then
/usr/local/nginx/sbin/nginx
# 等待一小会再次检查nginx,如果没有启动成功,则停止keepalived,使其启动备用机
sleep 3
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
killall keepalived
fi
fi
- 增加运行权限
chmod +x /etc/keepalived/check_nginx_alive_or_not.sh
2. 配置keepalived监听nginx脚本
vrrp_script check_nginx_alive {
script "/etc/keepalived/check_nginx_alive_or_not.sh"
interval 2 # 每隔两秒运行上一行脚本
weight 10 # 如果脚本运行成功,则升级权重+10
# weight -10 # 如果脚本运行失败,则升级权重-10
}
3. 在vrrp_instance
中新增监控的脚本
track_script {
check_nginx_alive # 追踪 nginx 脚本
}
4. 重启Keepalived使得配置文件生效
systemctl restart keepalived
五、配置Keepalived双主热备
规则:以一个虚拟ip分组归为同一个路由
主节点配置:
global_defs {
router_id keep_171
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.161
}
}
vrrp_instance VI_2 {
state BACKUP
interface ens33
virtual_router_id 52
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.162
}
}
备用节点配置
global_defs {
router_id keep_172
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.161
}
}
vrrp_instance VI_2 {
state MASTER
interface ens33
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.162
}
}
别忘记分别重启两条Keepalived
# 重启Keepalived
systemctl restart keepalived