关于Linux中Keepalived高可用热备自动化部署的一些笔记

傍晚时分,你坐在屋檐下,看着天慢慢地黑下去,心里寂寞而凄凉,感到自己的生命被剥夺了。当时我是个年轻人,但我害怕这样生活下去,衰老下去。在我看来,这是比死亡更可怕的事。——–王小波

写在前面


  • 今天和小伙伴们分享一些 Keepalived 相关笔记
  • 博文内容涉及:
    • vrrp 协议由来
    • Ansible 方式 Keepalived安装部署
    • Keepalived 脚本方式配置服务检查
    • Keepalived 自动化部署 Ansible 角色编写
  • 食用方式:
    • 需要 Linux 基础知识
    • 需要 Ansible 基础知识
  • 理解不足小伙伴帮忙指正

傍晚时分,你坐在屋檐下,看着天慢慢地黑下去,心里寂寞而凄凉,感到自己的生命被剥夺了。当时我是个年轻人,但我害怕这样生活下去,衰老下去。在我看来,这是比死亡更可怕的事。——–王小波


官网帮助文档:https://www.keepalived.org/manpage.html

关于keepalived是什么,在官网中这样描述:

Keepalived 是一个用 C 语言编写的路由软件。该项目的主要目标是为 Linux 系统和基于 Linux 的基础架构提供简单而强大的负载平衡高可用性设施

负载平衡框架依赖于众所周知且广泛使用的Linux 虚拟服务器 (IPVS) 内核模块,提供第 4 层负载平衡。Keepalived 实现了一组检查器,以根据其健康状况动态和自适应地维护和管理负载平衡的服务器池。(本文不涉及)

高可用性是通过 VRRP实现的协议。VRRP 是路由器故障转移的基础。此外,Keepalived 实现了一组与 VRRP 有限状态机的挂钩,提供低级和高速协议交互。为了提供最快的网络故障检测,Keepalived 实现了BFD协议。VRRP 状态转换可以考虑 BFD 提示来驱动快速状态转换。Keepalived 框架可以单独使用,也可以一起使用,以提供弹性基础架构

Keepalived 是免费软件;您可以根据自由软件基金会发布的 GNU 通用公共许可条款重新分发和/或修改它;许可证的第 2 版,或(由您选择)任何更高版本。

今天和小伙伴分享的主要是高可用热备部署,关于负载均衡方面的之后和小伙伴们分享,在部署keepalived之前,需要了解下VRRP协议

vrrp协议由来

当网关路由器出现故障时,本网段内以该设备为网关的主机都不能与 Internet 进行通信。所以需要进行容灾处理,但是通过部署多网关的方式实现网关的备份,存在一些问题:网关间IP地址冲突;主机会频繁切换网络出口。所以为解决网关路由的单点故障,有了VRRP协议。

VRRP即虚拟路由冗余协议,VRRP能够在不改变组网的情况下,从多台网关设备里产生一个虚拟路由器,通过配置虚拟路由器的IP地址为默认网关,实现网关的备份。

对外提供网关服务的是这个虚拟路由器。这样不管是真实路由器哪个出现问题,都不会影响整个网络的运行,提高了网络结构的稳定性。

在这里插入图片描述

VRRP配置方式:

  • 配置VRRP的成员;
  • 配置VRRP的优先级 (默认100);
  • 查看VRRP信息

VRRP协议通过一种竞选机制来将路由任务交给某个vrrp路由器的。

在VRRP物理结构中,有多个物理的VRRP路由器,其中有一台称为“master”(主节点路由器),其他的都是“backup”(备节点路由器)

在VRRP虚拟结构中,虚拟路由都是通过MAC+VRID的形式来标识的,如54-89-98-6F-3D-B5-{vrid}
只有master节点才会发送VRRP包(vrrp advertisement message)当master节点宕掉的时候,backup中优先级最高的VRRP设备会抢占并升级为master

下面为配置的简单Demo

三层交换机SW1上配置, 主路由器(Master)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
#三层交换机SW1上配置, 主路由器(Master)
<Huawei>system-view #进入系统视图
[Huawei]sysname SW1 #修改设备名字
[SW1]
[SW1]undo info-center enable #取消信息提示
#给vlan1配置网关
[SW1]interface Vlanif 1
[SW1-Vlanif1]ip address 192.168.1.252 255.255.255.0
#将三层交换机SW1配置为VRRP的成员,设置虚拟IP地址
[SW1-Vlanif1]vrrp vrid 1 virtual-ip 192.168.1.254
#配置VRRP的优先级,不写默认为100
[SW1-Vlanif1]vrrp vrid 1 priority 105
[SW1-Vlanif1]
#查看VRRP配置信息
[SW1-Vlanif1]display vrrp brief

三层交换机SW2上配置,,备用路由器(backup)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
#三层交换机SW2上配置,,备用路由器(backup)
<Huawei>system-view #进入系统视图
[Huawei]sysname SW2 #修改设备名字
[SW2]
[SW2]undo info-center enable #取消信息提示
#给vlan1配置网关
[SW2]interface Vlanif 1
[SW2-Vlanif1]ip address 192.168.1.253 255.255.255.0
#将三层交换机SW1配置为VRRP的成员,设置虚拟IP地址
[SW2-Vlanif1]vrrp vrid 1 virtual-ip 192.168.1.254
#不用设置优先级,默认为100
#查看VRRP配置信息
[SW2-Vlanif1]display vrrp brief

keepalived 安装部署

回到keepalived中,keepalived 通过VRRP(Virtual Router Redundancy Protocol)虚拟路由冗余协议来实现故障转移。keepalived正常工作时,主节点(master)会不断的发送心跳信息给备节点(backup)

1
2
3
4
5
6
7
8
9
10
11
12
13
┌──[root@vms153.liruilongs.github.io]-[~]
└─$tcpdump -i ens32 -nn host 224.0.0.18 #组播地址
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens32, link-type EN10MB (Ethernet), capture size 262144 bytes
23:27:36.149062 IP 192.168.26.153 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
23:27:37.150969 IP 192.168.26.153 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
23:27:38.152021 IP 192.168.26.153 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
^C
3 packets captured
3 packets received by filter
0 packets dropped by kernel
┌──[root@vms153.liruilongs.github.io]-[~]
└─$

当备节点在一定时间内没有收到主节点的心跳信息时,备节点会认为主节点宕了,就会接管主节点上的资源,并继续向外提供服务保证其可用性,当主节点恢复时,备节点会自动让出资源并再次自动成为备节点

这里我们通过 ansible 安装配置,下面的两台机器为我们要配置的机器,也就是node组,在master节点操作

  • 192.168.26.153
  • 192.168.26.154
1
2
3
4
5
6
7
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat inventory
[master]
192.168.26.152
[node]
192.168.26.153
192.168.26.154

安装web服务测试用

1
2
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible node -m shell -a "yum -y install httpd"

编写一个小剧本用于环境初始化,这个剧本实现对httpd服务的欢迎页进行内容填充,重启服务,设置防火墙域为trusted,即没有规则

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat httpd.yaml
---
- name: httpd init
hosts: node
tasks:
- name: httpd content
shell: "echo `hostname` > /var/www/html/index.html"
- name: Restart service httpd, in all cases
service:
name: httpd
state: restarted
- name: firewall
shell: firewall-cmd --set-default-zone=trusted
┌──[root@vms152.liruilongs.github.io]-[~]
└─$

执行剧本并测试填充结果测试

1
2
3
4
5
6
7
8
9
10
11
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible-playbook httpd.yaml
........
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible node -m shell -a 'hostname;cat /var/www/html/index.html'
192.168.26.154 | CHANGED | rc=0 >>
vms154.liruilongs.github.io
vms154.liruilongs.github.io
192.168.26.153 | CHANGED | rc=0 >>
vms153.liruilongs.github.io
vms153.liruilongs.github.io

安装 keepalived,我们使用的版本为:keepalived-1.3.5-19.el7.x86_64

1
2
3
4
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible node -m yum -a 'name=keepalived state=installed'
192.168.26.154 | SUCCESS => {
。。。。。。

编辑配置文件模板,把主备节点配置文件中不一样的,或者希望单独设置的内容做成变量

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepalived.conf.j2
! Configuration File for keepalived

global_defs {
router_id LVS_DEVEL #设置路由ID,可以和主机名相同,也可以随便定义
vrrp_iptables   #手动添加(禁止设置防火墙规则,keepalved每次启动都会自动添加防火墙拒绝所有的规则)
}

vrrp_instance VI_1 {
state {{ role }}
interface ens32 #定义网络接口,根据自己虚拟机上的网卡修改
virtual_router_id 51 #主备服务器VRID号必须保持一致
priority {{ priority }} #服务器优先级,优先级高则优先获得浮动IP
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.26.200
}
}

编写剧本,复制模板文件,然后重启keepalived服务,这里我们通过两个小剧本的方式传递不同的变量

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepalived.yaml
---
- name: vms153.liruilongs.github.io config
hosts: 192.168.26.153
tags:
- master
vars:
role: MASTER
priority: 100
tasks:
- name: copy keeplived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf

- name: restart keeplived
service:
name: keepalived
state: restarted


- name: vms154.liruilongs.github.io config
hosts: 192.168.26.154
tags:
- backup
vars:
role: BACKUP
priority: 50
tasks:
- name: copy keepalived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf

- name: restart keepalived
service:
name: keepalived
state: restarted

运行剧本并测试

1
2
3
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible-playbook keepalived.yaml
。。。。。。。。。。。

假设153机器应为某些原因,需要进行停机处理,我们可以直接把 keepalived 干掉,vip自动切到154

1
2
3
4
5
6
7
8
9
10
11
12
┌──[root@vms152.liruilongs.github.io]-[~]
└─$curl 192.168.26.200:80
vms153.liruilongs.github.io
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible 192.168.26.153 -m shell -a "systemctl stop keepalived"
192.168.26.153 | CHANGED | rc=0 >>

┌──[root@vms152.liruilongs.github.io]-[~]
└─$curl 192.168.26.200:80
vms154.liruilongs.github.io
┌──[root@vms152.liruilongs.github.io]-[~]
└─$

如果这个时候153机器恢复,那么我们可以重新拉起keepalived服务,vip回到153

1
2
3
4
5
6
7
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible 192.168.26.153 -m shell -a "systemctl start keepalived"
192.168.26.153 | CHANGED | rc=0 >>

┌──[root@vms152.liruilongs.github.io]-[~]
└─$curl 192.168.26.200:80
vms153.liruilongs.github.io

上面的操作,我们可以整合到一个剧本里

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepalived.yaml
---
- name: keepalived init
hosts: node
tasks:
- name: install
yum:
name:
- httpd
- keepalived
state: installed

- name: httpd content
shell: "echo `hostname` > /var/www/html/index.html"
- name: Restarted httpd
service:
name: httpd
state: restarted

- name: firewall clons
shell: firewall-cmd --set-default-zone=trusted
# 主机配置
- name: vms153.liruilongs.github.io config
hosts: 192.168.26.153
tags:
- master
vars:
role: MASTER
priority: 100
vip: 192.168.26.200
interface: ens32
tasks:
- name: copy keeplived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf
- name: restart keepalived
service:
name: keepalived
state: restarted
# 备机配置
- name: vms154.liruilongs.github.io config
hosts: 192.168.26.154
tags:
- backup
vars:
role: BACKUP
priority: 90
vip: 192.168.26.200
interface: ens32
tasks:
- name: copy keepalived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf
- name: restart keepalived
service:
name: keepalived
state: restarted

对于配置文件也可以更灵活一点

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepalived.conf.j2
! Configuration File for keepalived

global_defs {
router_id LVS_DEVEL #设置路由ID,可以和主机名相同,也可以随便定义
vrrp_iptables   #手动添加(禁止设置防火墙规则,keepalved每次启动都会自动添加防火墙拒绝所有的规则)
}

vrrp_instance VI_1 {
state {{ role }}
interface {{ interface }} #定义网络接口,根据自己虚拟机上的网卡修改
virtual_router_id 51 #主备服务器VRID号必须保持一致
priority {{ priority }} #服务器优先级,优先级高则优先获得浮动IP
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
{{ vip }}
}
}

有小伙伴会讲,这也太水了,每次故障都需要自己去进行主备切换,其实上面的配置为keepalived的最简单配置,没有使用keepalived 的检查配置,,告警等其他的功能。

如果是IPVS使用keepalived,可以对后端RealServer进行健康状况检查,支持网络层、传输层、应用层进行健康检查。

配置文件解析

熟悉下配置文件,keepalived的配置文件主要由3部分构造,ipvs配置,全局配置,VRRP配置。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
# 全局配置(全局配置有Global definitions和Static routes/address,全局定义和静态路由)
global_defs
{
...
}

# 配置vrrp实例(VRRP实例和VRRP同步组)
# vrrp instance # 虚拟路由器,VRRP实例
vrrp_instance NAME {
...
}
# vrrp synchronization group # VRRP同步组
vrrp_sync_group NAME {
...
}
# ipvs的相关配置
# LVS CONFIGURATION:
# 集群服务,服务内的RS
Virtual server groups
Virtual server #ipvs集群的vs和rs

下面为具体的参数解释

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
# 全局配置(全局配置有Global definitions和Static routes/address,全局定义和静态路由)
global_defs {
# 全局部分定义邮件报警系统,定义邮件发送目标,收件人邮箱地址
notification_email {
acassen@firewall.loc
failover@firewall.loc
sysadmin@firewall.loc
}
# 定义发件人邮箱地址
notification_email_from Alexandre.Cassen@firewall.loc
# 定义邮件发送服务器IP,本地发送写localhost
smtp_server 192.168.200.1
# 定义邮件服务器建立连接的超时时长
smtp_connect_timeout 30
# 标识keepalived服务器的字符串,物理节点的标识符;
router_id LVS_DEVEL
# 如果通告与接收的上一个通告来自相同的master路由器,则不执行检查
vrrp_skip_check_adv_addr
# 严格遵守VRRP协议,这一项最好关闭(加感叹号),若不关闭,可用vip无法被ping通
! vrrp_strict
# 在一个接口发送的两个免费ARP之间的延迟,可以精确到毫秒级(默认是0)
vrrp_garp_interval 0
vrrp_gna_interval 0
# IPV4多播地址,默认224.0.0.18
vrrp_mcast_group4 225.0.0.18
}

# 检查调用
vrrp_script <SCRIPT_NAME> { # 脚本名,后面要基于脚本名来进行调用
script "/etc/keepalived/chk_script.sh" # 执行的命令或脚本
interval INT # 每隔多少时间,这个监控脚本要执行一次
weight -INT # 失败了,当前节点的权重要减去多少,对于“weight”值的设置,有一个简单的标准,即“weight”值的绝对值要大于Master和Backup节点“priority”值之差
}


# 虚拟路由器,VRRP实例
vrrp_instance VI_1 {
# 定义实例的角色状态是master还是backup,在当前VRRP实例中此节点的初始状态
state MASTER
# 定义vrrp绑定的接口,即接收或发送心跳通告的接口,即HA监测接口
interface eth0
# 虚拟路由标识(VRID),同一实例该数值必须相同,即master和backup中该值要相同
virtual_router_id 51
# 该vrrp实例中本机的keepalived的优先级,优先级最高的为master(可用范围0-255)
# 该选项的优先级高于state选项,
# 即若state指定的是backup,但这里设置的值最高,则仍为master
priority 100
# 心跳信息发送和接收时间间隔,单位为秒
advert_int 1
# 认证方式,同一实例中这个配置必须完全一样才可通过认证,只建议使用PASS认证
authentication {
# 使用简单字符认证的方式
auth_type PASS
# 最多支持8字符,超过8字符将只取前8字符
auth_pass 1111
}
# 设置的VIP,当master出现故障后,VIP会故障转移到backup
virtual_ipaddress {
# 一般情况下我们只设置一个VIP地址,也可以设置多个
# 这些vip默认配置在interface指定的接口别名上,可使用dev选项来指定网卡: 192.168.200.19/24 dev eth1
# 使用ip add的方式添加,若要被ifconfig查看,在IP地址后加上label即可
192.168.200.16
192.168.200.17
192.168.200.18
}

# 调用检查
track_script {
chk_service
}

# 使用非抢占模式
nopreempt
#非抢占式:如果backup路由器工作在此模式下,则若Master路由器没有出现故障,backup即使随后被配置了更高的优先级也不会成为Master

# 使用延迟抢占模式
preempt_delay TIME
#抢占式:如果backup路由器工作在抢占方式下,当它收到VRRP报文后,会将主机的优先级与通告报文中的优先级进行比较,如果主机的优先级比当前的Master路由器的优先级高,就会主动抢占成为Master路由器,否则,将保持Backup状态

notify_master <STRING>|<QUOTED-STRING> # 当切换到master模式时,执行此脚本
notify_backup <STRING>|<QUOTED-STRING> # 当切换到backup模式时,执行此脚本
notify_fault <STRING>|<QUOTED-STRING> # 当切换到fault模式时,执行此脚本
notify <STRING>|<QUOTED-STRING>

}

服务检查

在上面的Demo的基础上,我们添加一个检查脚本,使用下面的检查策略。来检查httpd服务是否可用

1
2
3
4
5
6
7
8
9
10
11
12
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl status httpd > /dev/null
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$echo $?
0
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl stop httpd.service
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl status httpd > /dev/null
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$echo $?
3

也可以這樣

1
2
3
4
5
6
7
8
9
10
11
12
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl is-active httpd -q
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$echo $?
3
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl start httpd
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl is-active httpd -q
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$echo $?
0

或者這樣

1
2
3
4
5
6
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl show httpd -p ActiveState
ActiveState=active
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl show httpd -p ActiveState | sed 's/ActiveState=//g'
active

是否运行和是否活跃是两个概念,对于某些一次性服务可以使用下面的方式验证

1
2
3
4
5
6
7
8
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl show httpd -p ActiveState | cut -d'=' -f2
active
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$systemctl show httpd -p SubState | cut -d'=' -f2
running
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$

keepalived部署服务健康检查剧本

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepaliveds.yaml
---
- name: keepalived init
hosts: node
tasks:
- name: install
yum:
name:
- httpd
- keepalived
state: installed

- name: httpd content
shell: "echo `hostname` > /var/www/html/index.html"

- name: Restarted httpd
service:
name: httpd
state: restarted

- name: firewall clons
shell: firewall-cmd --set-default-zone=trusted
# 主机配置
- name: vms153.liruilongs.github.io config
hosts: 192.168.26.153
tags:
- master
vars:
role: MASTER
priority: 100
tasks:
- name: copy keeplived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf
- name: copy che_service
copy:
content: "#!/bin/sh\nsystemctl is-active httpd -q"
dest: /etc/keepalived/che_service.sh
backup: yes
mode: '0755'
- name: restart keepalived
service:
name: keepalived
state: restarted

# 备机配置
- name: vms154.liruilongs.github.io config
hosts: 192.168.26.154
tags:
- backup
vars:
role: BACKUP
priority: 90
tasks:
- name: copy keepalived config
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf
- name: copy che_service
copy:
content: "#!/bin/sh\nsystemctl is-active httpd -q"
dest: /etc/keepalived/che_service.sh
mode: '0755'
backup: yes
- name: restart keepalived
service:
name: keepalived
state: restarted

运行测试

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
┌──[root@vms152.liruilongs.github.io]-[~]
└─$curl 192.168.26.200
vms153.liruilongs.github.io
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible 192.168.26.153 -m service -a 'name=httpd state=stopped'
192.168.26.153 | CHANGED => {
"ansible_facts": {
"discovered_interpreter_python": "/usr/bin/python"
},
"changed": true,
"name": "httpd",
"state": "stopped",
.............
┌──[root@vms152.liruilongs.github.io]-[~]
└─$curl 192.168.26.200
vms154.liruilongs.github.io
┌──[root@vms152.liruilongs.github.io]-[~]
└─$

配置文件模板

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
┌──[root@vms152.liruilongs.github.io]-[~]
└─$cat keepalived.conf.j2
! Configuration File for keepalived

global_defs {
router_id LVS_DEVEL #设置路由ID,可以和主机名相同,也可以随便定义
vrrp_iptables   #手动添加(禁止设置防火墙规则,keepalved每次启动都会自动添加防火墙拒绝所有的规则)
}

vrrp_script chk_service {
script /etc/keepalived/che_service.sh
interval 2
}

vrrp_instance VI_1 {
state {{ role }}
interface ens32 #定义网络接口,根据自己虚拟机上的网卡修改
virtual_router_id 51 #主备服务器VRID号必须保持一致
priority {{ priority }} #服务器优先级,优先级高则优先获得浮动IP
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.26.200
}

track_script {
chk_service
}
}

这个剧本调了好些时间,需要注意的是,配置文件不能有其他的非空格的字符,检查脚本要记得授权,如果没有执行检查脚本,可以看下 /var/log/messages 日志文件

1
2
┌──[root@vms153.liruilongs.github.io]-[/etc/keepalived]
└─$cat /var/log/messages | grep -C 10 track

keepalived 角色编写

我们也可以把上面的剧本编写为角色,需要把handlers和和其他的东西抽出来

1
2
3
4
5
6
7
8
9
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible-galaxy init keepalived --init-path=./roles
- Role keepalived was created successfully
┌──[root@vms152.liruilongs.github.io]-[~]
└─$ansible-galaxy list
# /root/roles
- keepalived, (unknown version)
┌──[root@vms152.liruilongs.github.io]-[~]
└─$

编写task

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$cat tasks/main.yml
---
# tasks file for keepalived

# 安装 keepalived
- name: Install keepalived
yum:
name: keepalived
state: latest
tags: keepalived
notify: restart keepalived

# copy 配置文件
- name: Keepalived configuration
template:
src: keepalived.conf.j2
dest: /etc/keepalived/keepalived.conf
notify: restart keepalived
# copy 检查脚本
- when: check_service_name | default(False)
name: Install check script
copy:
content: "#!/bin/sh\nsystemctl is-active {{ check_service_name }} -q"
dest: /etc/keepalived/che_service.sh
backup: yes
mode: 0755
owner: root
group: root
notify: restart keepalived

# 启动 服务
- name: Start keepalived
service:
name: keepalived
state: started
enabled: yes

编写handlers

1
2
3
4
5
6
7
8
9
10
11
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$cat handlers/main.yml
---
# handlers file for keepalived

- name: restart keepalived
service:
name: keepalived
state: restarted
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$

编写template

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$cat templates/keepalived.conf.j2
! Configuration File for keepalived

global_defs {
router_id LVS_DEVEL #设置路由ID,可以和主机名相同,也可以随便定义
vrrp_iptables   #手动添加(禁止设置防火墙规则,keepalved每次启动都会自动添加防火墙拒绝所有的规则)
}

vrrp_script chk_service {
script /etc/keepalived/che_service.sh
interval 2
}

vrrp_instance VI_1 {
state {{ keep_role }}
interface {{ keep_interface }} #定义网络接口,根据自己虚拟机上的网卡修改
virtual_router_id 51 #主备服务器VRID号必须保持一致
{% if keep_role.lower() == 'master' %}
priority {{ keep_priority }}
{% else %}
priority {{ keep_backup_priority }}
{% endif %}
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
{{ virtual_ipaddress }} dev {{ keep_interface }}
}

track_script {
chk_service
}
}
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$

编写defaults变量

1
2
3
4
5
6
7
8
9
10
11
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$cat defaults/main.yaml
---

keep_role: "master"
keep_priority: 100
keep_backup_priority: 50
keep_interface: "ens32"
virtual_ipaddress: "192.168.26.200"
check_service_name: httpd

编写调用剧本

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$cat tests/test.yml
---
- hosts: 192.168.26.153
vars:
keep_role: MASTER
roles:
- keepalived

- hosts: 192.168.26.154
vars:
keep_role: BACKUP
roles:
- keepalived
┌──[root@vms152.liruilongs.github.io]-[~/roles/keepalived]
└─$

博文参考


https://www.keepalived.org/manpage.html

https://www.cnblogs.com/hgzero/p/13718516.html

https://unix.stackexchange.com/questions/396630/the-proper-way-to-test-if-a-service-is-running-in-a-script

https://github.com/tcomerma/ansible-keepalived/

https://github.com/demis-svenska/aws-echis/tree/master/src/commcare_cloud/ansible/roles/keepalived

发布于

2022-09-15

更新于

2023-06-21

许可协议

评论
Your browser is out-of-date!

Update your browser to view this website correctly.&npsb;Update my browser now

×