【运维学习】lvs + keepalived + 主从dns 项目搭建

需求

主机规划

环境搭建

配置主从dns

主dns

从dns

配置web服务

搭建lvs + keepalived

 配置master

 配置backup

更改dns配置

添加VIP

配置内核参数

更改web配置

添加VIP

配置内核参数

客户端测试

---

需求

主机规划

主机名	IP	角色
lvs-master	192.168.239.105	主lvs，同时做web和dns调度
lvs-backup	192.168.239.106	副lvs，同时做web和dns调度
dns-master	192.168.239.107	VIP：192.168.239.100 主从dns服务器
dns-slave	192.168.239.108
web1	192.168.239.201	VIP：192.168.239.200
web2	192.168.239.202
web3	192.168.239.203
client	192.168.239.10	客户端

环境搭建

为所有主机配置IP、主机名、关闭防火墙与selinux。此处省略配置命令

配置主从dns

主dns

安装bind软件

[root@dns-master ~]# dnf install -y bind

 配置主配置文件

[root@dns-master ~]# cat /etc/named.conf 
options {listen-on port 53 { 192.168.239.100;192.168.239.107; };directory 	"/var/named";
};
zone "yili.com" IN {type master;file "named.yili";allow-transfer { 192.168.239.108; };
};
zone "239.168.192.in-addr.arpa" IN {type master;file "named.yilifan";allow-transfer { 192.168.239.108; };
};

配置区域文件

正向解析

[root@dns-master ~]# cat /var/named/named.yili
$TTL 1D
@	IN	SOA	@	admin.yili.com. ( 0 1 1 1 1 )IN	NS	ns1.yili.com.IN	NS	ns2.yili.com.
ns1	IN	A	192.168.239.107
ns2	IN	A	192.168.239.108
www	IN	A	192.168.239.200
txt	IN	TXT	"AaBbCcDdEeFf"

反向解析

[root@dns-master ~]# cat /var/named/named.yilifan 
$TTL 1D
@	IN	SOA	@	admin.yili.com. ( 0 1 1 1 1 )IN	NS	ns1.yili.com.IN	NS	ns2.yili.com.
ns1	IN	A	192.168.239.107
ns2	IN	A	192.168.239.108
200	IN	PTR	www.yili.com.
txt	IN	TXT	"AaBbCcDdEeFf"

dig测试

[root@dns-master ~]# dig -t NS yili.com @192.168.239.107; <<>> DiG 9.16.23-RH <<>> -t NS yili.com @192.168.239.107
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31688
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 3;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: 63188e14befb57a0010000006800c0330548ef93da209357 (good)
;; QUESTION SECTION:
;yili.com.			IN	NS;; ANSWER SECTION:
yili.com.		86400	IN	NS	ns1.yili.com.
yili.com.		86400	IN	NS	ns2.yili.com.;; ADDITIONAL SECTION:
ns1.yili.com.		86400	IN	A	192.168.239.107
ns2.yili.com.		86400	IN	A	192.168.239.108;; Query time: 0 msec
;; SERVER: 192.168.239.107#53(192.168.239.107)
;; WHEN: Thu Apr 17 16:47:47 CST 2025
;; MSG SIZE  rcvd: 133

从dns

安装bind软件

[root@dns-slave ~]# dnf install -y bind

配置主配置文件

[root@dns-slave ~]# cat /etc/named.conf 
options {listen-on port 53 { 192.168.239.108;192.168.239.100; };directory 	"/var/named";
};
zone "yili.com" IN {type slave;masters { 192.168.239.107; };file "slaves/named.yili";
};
zone "239.168.192.in-addr.arpa" IN {type slave;masters { 192.168.239.107; };file "slaves/named.yilifan";
};

dig测试

[root@dns-slave ~]# dig -t NS yili.com @192.168.239.108; <<>> DiG 9.16.23-RH <<>> -t NS yili.com @192.168.239.108
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57027
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 3;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: a41f8061a58c1cc1010000006800c170045a7201efa1982f (good)
;; QUESTION SECTION:
;yili.com.			IN	NS;; ANSWER SECTION:
yili.com.		86400	IN	NS	ns1.yili.com.
yili.com.		86400	IN	NS	ns2.yili.com.;; ADDITIONAL SECTION:
ns1.yili.com.		86400	IN	A	192.168.239.107
ns2.yili.com.		86400	IN	A	192.168.239.108;; Query time: 1 msec
;; SERVER: 192.168.239.108#53(192.168.239.108)
;; WHEN: Thu Apr 17 16:53:04 CST 2025
;; MSG SIZE  rcvd: 133

配置web服务

web1

安装nginx软件

[root@web1 ~]# dnf install -y nginx

更改index.html页面内容

[root@web1 ~]# echo $(hostname;hostname -I) > /usr/share/nginx/html/index.html

启动服务并测试

[root@web1 ~]# systemctl start nginx
[root@web1 ~]# curl localhost
web1 192.168.239.201

 web2

安装nginx软件

[root@web2 ~]# dnf install -y nginx

更改index.html页面内容

[root@web2 ~]# echo $(hostname;hostname -I) > /usr/share/nginx/html/index.html

启动服务并测试

[root@web2 ~]# systemctl start nginx
[root@web2 ~]# curl localhost
web2 192.168.239.202

 web3

安装nginx软件

[root@web3 ~]# dnf install -y nginx

更改index.html页面内容

[root@web3 ~]# echo $(hostname;hostname -I) > /usr/share/nginx/html/index.html

启动服务并测试

[root@web3 ~]# systemctl start nginx
[root@web3 ~]# curl localhost
web3 192.168.239.203

搭建lvs + keepalived

本次项目lvs使用DR模式

 配置master

安装ipvsadm、keepalived

[root@lvs-master ~]# dnf install -y ipvsadm keepalived

更改keepalived配置文件

[root@lvs-master ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
vrrp_instance VI_web {state MASTERinterface ens160virtual_router_id 51priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.239.200}
}virtual_server 192.168.239.200 80 {delay_loop 6lb_algo wrrlb_kind DRprotocol TCPreal_server 192.168.239.201 80 {weight 1TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}real_server 192.168.239.202 80 {weight 2TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}real_server 192.168.239.203 80 {weight 3TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}
}
vrrp_instance VI_dns {state BACKUPinterface ens160virtual_router_id 52priority 90advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.239.100}
}
virtual_server 192.168.239.100 53 {delay_loop 6lb_algo rrlb_kind DRprotocol UDPreal_server 192.168.239.107 53 {wight 1MISC_CHECK {connect_timeout 3misc_path "/etc/keepalived/checkdns.sh -h 192.168.239.107 txt.yili.com"}}real_server 192.168.239.108 53 {wight 1MISC_CHECK {connect_timeout 3misc_path "/etc/keepalived/checkdns.sh -h 192.168.239.108 txt.yili.com"}}
}

启动并测试

[root@lvs-master ~]# ipvsadm-save > /etc/sysconfig/ipvsadm
[root@lvs-master ~]# systemctl start keepalived.service ipvsadm.service[root@lvs-master ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.239.200:80 wrr-> 192.168.239.201:80           Route   1      0          0         -> 192.168.239.202:80           Route   2      0          0         -> 192.168.239.203:80           Route   3      0          0         
UDP  192.168.239.100:53 rr-> 192.168.239.107:53           Route   1      0          0         -> 192.168.239.108:53           Route   1      0          0         

 配置backup

安装ipvsadm、keepalived

[root@lvs-backup ~]# dnf install -y ipvsadm keepalived

更改keepalived配置文件

[root@lvs-backup ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
vrrp_instance VI_web {state BACKUPinterface ens160virtual_router_id 51priority 90advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.239.200}
}
virtual_server 192.168.239.200 80 {delay_loop 6lb_algo wrrlb_kind DRprotocol TCPreal_server 192.168.239.201 80 {weight 3TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}real_server 192.168.239.202 80 {weight 2TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}real_server 192.168.239.203 80 {weight 1TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}
}
vrrp_instance VI_dns {state MASTERinterface ens160virtual_router_id 52priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.239.100}
}
virtual_server 192.168.239.200 80 {delay_loop 6lb_algo rrlb_kind DRprotocol TCPreal_server 192.168.239.201 80 {weight 1TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}real_server 192.168.239.202 80 {weight 2TCP_CHECK {connect_timeout 3retry 3delay_before_retry 3}}
}
virtual_server 192.168.239.100 53 {delay_loop 6lb_algo rrlb_kind DRprotocol UDPreal_server 192.168.239.107 53 {wight 1MISC_CHECK {connect_timeout 3misc_path "/etc/keepalived/checkdns.sh -h 192.168.239.107 txt.yili.com"}}real_server 192.168.239.108 53 {wight 1MISC_CHECK {connect_timeout 3misc_path "/etc/keepalived/checkdns.sh -h 192.168.239.108 txt.yili.com"}}
}

启动并测试

[root@lvs-backup ~]# ipvsadm-save > /etc/sysconfig/ipvsadm
[root@lvs-backup ~]# systemctl start keepalived.service ipvsadm.service[root@lvs-backup ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags-> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.239.200:80 wrr-> 192.168.239.201:80           Route   3      0          0         -> 192.168.239.202:80           Route   2      0          0         -> 192.168.239.203:80           Route   1      0          0         
UDP  192.168.239.100:53 rr-> 192.168.239.107:53           Route   1      0          0         -> 192.168.239.108:53           Route   1      0          1         

更改dns配置

添加VIP

[root@dns-master ~]# ip addr add 192.168.239.100 dev lo
[root@dns-master ~]# ip addr show lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet 192.168.239.100/32 scope global lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever

配置内核参数

[root@dns-master ~]# vim /etc/sysctl.conf 
[root@dns-master ~]# 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

 

更改web配置

添加VIP

[root@web1 ~]# ip addr add 192.168.239.200 dev lo
[root@web1 ~]# ip addr show lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet 192.168.239.200/32 scope global lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope host valid_lft forever preferred_lft forever

配置内核参数

[root@web1 ~]# vim /etc/sysctl.conf 
[root@web1 ~]# sysctl -p
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.ip_forward = 0

客户端测试

修改dns地址

[root@client ~]# nmcli connection modify ens160 ipv4.dns 192.168.239.100
[root@client ~]# nmcli connection up ens160 

 测试与dns服务器的连通性

[root@client ~]# ping 192.168.239.100
PING 192.168.239.100 (192.168.239.100) 56(84) bytes of data.
64 bytes from 192.168.239.100: icmp_seq=1 ttl=64 time=0.321 ms
64 bytes from 192.168.239.100: icmp_seq=2 ttl=64 time=0.362 ms
^C
--- 192.168.239.100 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1059ms
rtt min/avg/max/mdev = 0.321/0.341/0.362/0.020 ms

测试dns解析

[root@client ~]# ping ns1.yili.com
PING ns1.yili.com (192.168.239.107) 56(84) bytes of data.
64 bytes from 192.168.239.107 (192.168.239.107): icmp_seq=1 ttl=64 time=0.422 ms
64 bytes from 192.168.239.107 (192.168.239.107): icmp_seq=2 ttl=64 time=0.332 ms
^C
--- ns1.yili.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 0.332/0.377/0.422/0.045 ms

测试web lvs负载均衡 

测试keepalived高可用

 

在lvs-master上关闭keepalived服务后发现，200的VIP漂移到了backup上

重新启动后，200VIP重新漂移到master上