Linux安装Keepalived
一、卸载Keepalived
# 查看安装版本
rpm -qi keepalived
# yum卸载
yum remove keepalived
# 找出残留的配置文件
find / -name keepalived
/etc/selinux/targeted/tmp/modules/100/keepalived
/etc/selinux/targeted/active/modules/100/keepalived
# 删除配置文件
rm -rf /etc/selinux/targeted/tmp/modules/100/keepalived
rm -rf /etc/selinux/targeted/active/modules/100/keepalived二、安装Keepalived
yum -y install keepalived
Last metadata expiration check: 0:41:09 ago on Wed 09 Nov 2022 02:13:14 PM CST.
Dependencies resolved.
=================================================================================================================================================================================================================================================
Package Architecture Version Repository Size
=================================================================================================================================================================================================================================================
Installing:
keepalived x86_64 2.1.5-8.el8 ol8_appstream 536 k
Installing dependencies:
mariadb-connector-c x86_64 3.1.11-2.el8_3 ol8_appstream 200 k
mariadb-connector-c-config noarch 3.1.11-2.el8_3 ol8_appstream 15 k
net-snmp-agent-libs x86_64 1:5.8-25.el8 ol8_appstream 748 k
net-snmp-libs x86_64 1:5.8-25.el8 ol8_baseos_latest 827 k
Transaction Summary
=================================================================================================================================================================================================================================================
Install 5 Packages
Total download size: 2.3 M
Installed size: 7.3 M
Downloading Packages:
(1/5): mariadb-connector-c-3.1.11-2.el8_3.x86_64.rpm 16 kB/s | 200 kB 00:12
(2/5): mariadb-connector-c-config-3.1.11-2.el8_3.noarch.rpm 17 kB/s | 15 kB 00:00
(3/5): net-snmp-agent-libs-5.8-25.el8.x86_64.rpm 91 kB/s | 748 kB 00:08
(4/5): keepalived-2.1.5-8.el8.x86_64.rpm 20 kB/s | 536 kB 00:26
(5/5): net-snmp-libs-5.8-25.el8.x86_64.rpm 30 kB/s | 827 kB 00:27
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 84 kB/s | 2.3 MB 00:27
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : net-snmp-libs-1:5.8-25.el8.x86_64 1/5
Installing : mariadb-connector-c-config-3.1.11-2.el8_3.noarch 2/5
Installing : mariadb-connector-c-3.1.11-2.el8_3.x86_64 3/5
Installing : net-snmp-agent-libs-1:5.8-25.el8.x86_64 4/5
Installing : keepalived-2.1.5-8.el8.x86_64 5/5
Running scriptlet: keepalived-2.1.5-8.el8.x86_64 5/5
Verifying : net-snmp-libs-1:5.8-25.el8.x86_64 1/5
Verifying : keepalived-2.1.5-8.el8.x86_64 2/5
Verifying : mariadb-connector-c-3.1.11-2.el8_3.x86_64 3/5
Verifying : mariadb-connector-c-config-3.1.11-2.el8_3.noarch 4/5
Verifying : net-snmp-agent-libs-1:5.8-25.el8.x86_64 5/5
Installed:
keepalived-2.1.5-8.el8.x86_64 mariadb-connector-c-3.1.11-2.el8_3.x86_64 mariadb-connector-c-config-3.1.11-2.el8_3.noarch net-snmp-agent-libs-1:5.8-25.el8.x86_64 net-snmp-libs-1:5.8-25.el8.x86_64
Complete!Keepalived基础命令：
# 启动 keepalived
systemctl start keepalived
# 加入开机启动 keepalived
systemctl enable keepalived
# 重新启动 keepalived
systemctl restart keepalived
# 查看 keepalived 状态
systemctl status keepalived 三、配置Haproxy验证脚本
cat check_haproxy.sh
#!/usr/bin/env bash
if [ $(pgrep haproxy|wc -l) -eq 0 ];then
sudo systemctl start haproxy
sleep 3
if [ $(pgrep haproxy|wc -l) -eq 0 ];then
sudo systemctl stop keepalived
fi
fi四、配置Keepalived
1、MASTER
global_defs {
router_id haproxy
script_user root
enable_script_security
}
vrrp_script chk_haproxy {
script "/etc/keepalived/check_haproxy.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
state MASTER
interface ens32
virtual_router_id 55
mcast_src_ip 10.95.34.38
nopreempt
priority 89
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.95.34.65
}
track_script {
chk_haproxy
}
}2、BACKUP
global_defs {
router_id haproxy
script_user root
enable_script_security
}
vrrp_script chk_haproxy {
script "/etc/keepalived/check_haproxy.sh"
interval 2
weight -20
}
vrrp_instance VI_1 {
state BACKUP
interface ens32
virtual_router_id 55
nopreempt
mcast_src_ip 10.95.34.37
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.95.34.65
}
track_script {
chk_haproxy
}
}
3、启动Keepalived
ip addr
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens32: mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:0c:29:be:d4:61 brd ff:ff:ff:ff:ff:ff
inet 10.95.34.37/24 brd 10.95.34.255 scope global noprefixroute ens32
valid_lft forever preferred_lft forever
inet 10.95.34.65/32 scope global ens32
valid_lft forever preferred_lft forever 可以看到，多出来一条虚拟ip的记录。当node1的节点宕机或者keepalived挂了的时候，就会自动切换到节点2上面，可以在节点2看到这一条记录信息。
五、验证
六、安装异常情况（暂未完全实践）
1、keepalived执行后日志狂刷，2.脚本并没有执行(down.sh)，具体情况就是haproxy挂掉后，keeplived并没有自杀，导致vip漂移失败，但是手动关闭keeplived后会实现漂移，原因就在于down脚本没有得到执行。
很纠结，经过排查，原因是ip_vs模块系统默认没有自动加载，执行命令:
查看
lsmod | grep ip_vs
(如果没有任何输出则表示ip_vs模块并没有被内核加载)
手动加载
modprobe ip_vs
modprobe ip_vs_wrr