LVS+Keepalived+dns高可用项目架构

一、搭建DNS服务

配置主服务器

1.修改核心配置文件

[root@DNS-master ~]# vim /etc/named.conf 

options {
        listen-on port 53 { 192.168.111.107;192.168.111.100; };
        directory       "/var/named";
};

zone "haha.com" IN {
        type master;
        file "haha.com";
        allow-transfer { 192.168.111.108; };
};
zone "111.168.192.in-addr.arpa" IN {
        type master;
        file "haha.fanxiang";
        allow-transfer { 192.168.111.108; };
};
 

2.编写正向区域数据文件

[root@DNS-master ~]# cat /var/named/haha.com 
$TTL   1D
@    IN    SOA    ns1.haha.com. root.haha.com (0 1H 1H 1H 2D)
        IN    NS      ns1
        IN    NS    ns2
ns1   IN    A    192.168.111.107
ns2    IN    A    192.168.111.108
www  IN    A    192.168.111.200
txt      IN    TXT     "AaBbCcDdEeFf"
 

3.编写反向区域数据文件

[root@DNS-master ~]# cat /var/named/haha.fanxiang 
$TTL    1D
@    IN    SOA    ns1.haha.com.    root.haha.com. (0 1H 1H 1H 2D)
        IN    NS    ns1
         IN    NS    ns2
ns1   IN    A    192.168.111.107
ns2   IN    A    192.168.111.108
200   IN    PTR    www.haha.com.
txt     IN    TXT    "AaBbCcDdEeFf"
 

4.功能测试

[root@DNS-master ~]# dig -t A www.haha.com @192.168.111.107

; <<>> DiG 9.16.23-RH <<>> -t A www.haha.com @192.168.111.107
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13434
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 89b0d8539659c6b70100000067fa382166d0738782ee7997 (good)
;; QUESTION SECTION:
;www.haha.com.            IN    A

;; ANSWER SECTION:
www.haha.com.        86400    IN    A    192.168.111.200

;; Query time: 2 msec
;; SERVER: 192.168.111.107#53(192.168.111.107)
;; WHEN: Sat Apr 12 17:53:37 CST 2025
;; MSG SIZE  rcvd: 85

配置从服务器

1.修改核心配置文件

[root@DNS-slave ~]# cat /etc/named.conf 
options {
    listen-on port 53 { 192.168.111.108;192.168.111.100; };
    directory     "/var/named";
};
zone "haha.com" IN {
    type slave;
    file "slaves/haha.com";
    masters { 192.168.111.107; };
    allow-transfer { none; };
};

zone  "111.168.192.in-addr.arpa" IN {
    type slave;
    file "slaves/haha.fanxiang";
    masters { 192.168.111.107; };
    allow-transfer { none; };
};
 

2.功能测试

[root@DNS-slave ~]# systemctl restart named

[root@DNS-slave ~]# dig -t A www.haha.com @192.168.111.108

; <<>> DiG 9.16.23-RH <<>> -t A www.haha.com @192.168.111.108
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53862
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 98940855eb1f6e400100000067fa385dd1f147c06a630f38 (good)
;; QUESTION SECTION:
;www.haha.com.            IN    A

;; ANSWER SECTION:
www.haha.com.        86400    IN    A    192.168.111.200

;; Query time: 1 msec
;; SERVER: 192.168.111.108#53(192.168.111.108)
;; WHEN: Sat Apr 12 17:54:37 CST 2025
;; MSG SIZE  rcvd: 85

二、搭建 Web服务器

1、配置nginx

[root@web01 ~]# cat /etc/nginx/conf.d/haha.conf 
server{
    listen 80;
    server_name www.haha.com;
    root /usr/share/nginx/html;
    access_log /var/log/nginx/haha_access.log;
    error_log /var/log/nginx/haha_error.log;
}
 

2、修改DNS

[root@web01 ~]# nmcli c modify ens160 ipv4.dns 192.168.111.100
[root@web01 ~]# nmcli c up ens160 
Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/3)
 

3、编写欢迎页面

[root@web01 ~]# echo "welcome web01" > /usr/share/nginx/html/index.html

4、测试服务

[root@web01 ~]# curl 192.168.111.201
welcome web01

5、复制配置文件到web02和web03中

[root@web01 ~]# scp /etc/nginx/conf.d/haha.conf  root@192.168.111.202:/etc/nginx/conf.d/haha.conf
root@192.168.111.202's password: 
haha.conf                                                                                     100%  165   106.4KB/s   00:00    
[root@web01 ~]# scp /etc/nginx/conf.d/haha.conf  root@192.168.111.203:/etc/nginx/conf.d/haha.conf
root@192.168.111.203's password: 
haha.conf                                                                                     100%  165   101.4KB/s   00:00                              

6、修改web02和web03欢迎页面

[root@web02 ~]# echo "welcome web02" > /usr/share/nginx/html/index.html
[root@web03 ~]# echo "welcome web03" > /usr/share/nginx/html/index.html
 

7、修改web02和web03的DNS

8、启动服务并测试

[root@web02 ~]# curl 192.168.111.202
welcome web02
[root@web03 ~]# curl 192.168.111.203
welcome web03

三、搭建Keepalived+Lvs

1.安装keepalived和ipvsadm

2、配置keepalived

[root@LB-master ~]# cat /etc/keepalived/keepalived.conf 
global_defs {
   router_id LVS_MASTER
}

vrrp_instance VI_1 {
    state MASTER
    interface ens160
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.111.100
    }
}

vrrp_instance VI_2 {
    state MASTER
    interface ens160
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.111.200
    }
}
virtual_server 192.168.111.100 53 {
    delay_loop 6
    lb_algo rr
    lb_kind NAT
    persistence_timeout 10
    protocol UDP

    real_server 192.168.111.107 53 {
        weight 1
        MISC_CHECK {
            connect_timeout 3
          misc_path "/etc/keepalived/haha.sh -h 192.168.111.107 txt.haha.com"
        }
    }
    real_server 192.168.111.108 53 {
        weight 1
        MISC_CHECK {
            connect_timeout 3
          misc_path "/etc/keepalived/haha.sh -h 192.168.111.108 txt.haha.com"
        }
    }
}

virtual_server 192.168.111.200 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 10
    protocol TCP

    real_server 192.168.111.201 80 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.111.202 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.111.203 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
}
 

3、编写执行脚本

[root@LB-master ~]# cat /etc/keepalived/haha.sh 
#!/bin/bash
[ $# -le 2 ] && { echo "usage: $0 -h <ip>"; exit 2; }
domain=$3
while getopts "h:" OPT; do
case $OPT in
h)
host=$OPTARG
;;
*)
echo "usage: $0 -h <ip>" && exit 1
;;
esac
done
dig @${host} txt ${domain} +time=1 | grep "\<AaBbCcDdEeFf\>" >/dev/null
exit $?
[root@LB-

4、将配置文件复制到backup中并修改

[root@LB-backup ~]# cat /etc/keepalived/keepalived.conf 
global_defs {
   router_id LVS_MASTER
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens160
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.111.100
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface ens160
    virtual_router_id 50
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.111.200
    }
}
virtual_server 192.168.111.100 53 {
    delay_loop 6
    lb_algo rr
    lb_kind NAT
    persistence_timeout 10
    protocol UDP

    real_server 192.168.111.107 53 {
        weight 1
        MISC_CHECK {
            connect_timeout 3
          misc_path "/etc/keepalived/haha.sh -h 192.168.111.107 txt.haha.com"
        }
    }
    real_server 192.168.111.108 53 {
        weight 1
        MISC_CHECK {
            connect_timeout 3
          misc_path "/etc/keepalived/haha.sh -h 192.168.111.108 txt.haha.com"
        }
    }
}

virtual_server 192.168.111.200 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 10
    protocol TCP

    real_server 192.168.111.201 80 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.111.202 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.111.203 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
}
 

5、重启服务

[root@LB-master ~]# systemctl restart keepalived.service  ipvsadm.service

[root@LB-backup ~]# systemctl restart keepalived.service  ipvsadm.service 

6、查看LVS规则

[root@LB-master ~]# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.111.200:80 wrr persistent 10
  -> 192.168.111.201:80           Route   3      0          0         
  -> 192.168.111.202:80           Route   1      0          0         
  -> 192.168.111.203:80           Route   1      0          0         
UDP  192.168.111.100:53 rr persistent 10
  -> 192.168.111.107:53           Masq    1      0          0         
  -> 192.168.111.108:53           Masq    1      0          0  

四、修改DNS

主DNS

1、增加虚拟ip

[root@DNS-master ~]# ifconfig lo:1 192.168.111.100 netmask 255.255.255.255  up

2、配置内核参数
[root@DNS-master ~]# cat /etc/sysctl.conf
# sysctl settings are defined through files in
# /usr/lib/sysctl.d/, /run/sysctl.d/, and /etc/sysctl.d/.
#
# Vendors settings live in /usr/lib/sysctl.d/.
# To override a whole file, create a new file with the same in
# /etc/sysctl.d/ and put new settings there. To override
# only specific settings, add a file with a lexically later
# name in /etc/sysctl.d/ and put new settings there.
#
# For more information, see sysctl.conf(5) and sysctl.d(5).
net.ipv4.ip_forward= 1
[root@DNS-master ~]# sysctl -p
net.ipv4.ip_forward = 1

3、增加路由

[root@DNS-master ~]# route add -host 192.168.111.100  dev lo:1

从DNS

与主DNS配置一样

五、修改Web服务（三台web配置一样）

1、添加虚拟ip

[root@web01 ~]# ifconfig lo:1 192.168.111.200 netmask 255.255.255.255  up

2、配置内核参数

[root@web01 ~]# vim /etc/sysctl.conf
[root@web01 ~]# sysctl -p
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

3、增加路由

[root@web01 ~]# route add -host 192.168.111.200 dev lo:1

4.重启服务，测试功能

[root@web01 ~]# curl www.haha.com
welcome web01

六、测试V

IP地址可以轮询访问写的web界面，证明我们的服务已经写好了。

七、扩展

这个项目还可以融入tomcat、时间服务器以及NFS来搭建一个更加完整的架构！！