keepalived+nginx负载安装

环境：centos7.6

keepalived工具可以生成虚拟浮动ip，绑定到网卡上。

172.21.210.19  master

172.21.210.20  backup

172.21.210.30  vip(浮动ip)

1、两个节点安装keepalived

yum -y install keepalived

2、确定要绑定的网卡（这儿使用eth0）

[root@tool-19 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether fa:16:3e:c5:ac:f5 brd ff:ff:ff:ff:ff:ff
    inet 172.21.210.19/25 brd 172.21.210.127 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fec5:acf5/64 scope link 
       valid_lft forever preferred_lft forever

3、master配置

[root@tool-19 ~]# more /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
   router_id kp01
}

vrrp_instance VI_1 {
    state MASTER             #master
    interface eth0           #网卡名称
    virtual_router_id 51 # 虚拟路由标识，这个标识是一个数字，并且同一个vrrp实例使用唯一的标识，即同一个vrrp_instance下，MASTER和BACKUP必须是一致的
    priority 151 # 定义优先级，数字越大，优先级越高，在一个vrrp_instance下，MASTER的优先级必须大于BACKUP的优先级
    advert_int 1 # 设定MASTER与BACKUP负载均衡器之间同步检查的时间间隔，单位是秒
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.21.210.30/25      #浮动ip
    }
}

3、backup节点配置

[root@harbor-20 ~]# more /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
   router_id kp02
}

vrrp_instance VI_1 {
    state BACKUP            #backup
    interface eth0
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.21.210.30/25
    }
}

4、启动服务

systemctl enable keepalived && systemctl start keepalived && systemctl status keepalived

5、进行验证

[root@harbor-20 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether fa:16:3e:c0:74:1e brd ff:ff:ff:ff:ff:ff
    inet 172.21.210.20/25 brd 172.21.210.127 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet 172.21.210.30/25 scope global secondary eth0
       valid_lft forever preferred_lft forever
现在在20上，重启20的keeplived服务，可以看到IP自动跳转到19
systemctl restart keepalived

6、配置nginx，两边配置一样服务，每次vip跳转到该服务器都是用一样的nginx，nginx具体的安装可以参考：https://www.cnblogs.com/wukc/p/13236699.html