# keepalived配置LVS

## NAT模式

| 主机名 | ip（NAT） | ip（LAN区段） | 角色 |
| :---- | :---- | :---- | :---- |
| Centos8 | 192.168.159.105 | 192.168.160.105 | keepalived |
| Centos8-1 | 192.168.159.106（禁掉） | 192.168.160.106 | nginx1 |
| Centos8-2 | 192.168.159.107（禁掉） | 192.168.160.107 | nginx2 |
|  |  | 192.168.160.200 | vip |

### 准备工作
配置新网卡、关闭防火墙、两台机器都安装nginx、将02和03两个节点上的nginx都监听8080端口

### 安装配置keepalived（Centos8上）
yum安装keepalived
```
yum install -y keepalived
```

### 编辑配置文件
vi /etc/keepalived/keepalived.conf  ##写入如下配置
```
global_defs {
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface ens224
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass amingLi
    }
    virtual_ipaddress {
        192.168.160.200
    }
}

virtual_server 192.168.160.200 80 {
    delay_loop 6
    ## 算法为wrr
    lb_algo wrr
    ## LVS模式为NAT模式
    lb_kind NAT
    #persistence_timeout 50
    protocol TCP

    real_server 192.168.160.106 80 {
        weight 3
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.160.107 80 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
}
```
### 打开路由转发
```
echo  "net.ipv4.ip_forward=1"  >>  /etc/sysctl.conf
sysctl -p
```
### 启动keepalived
```
systemctl start keepalived
```
### 另外两个节点上配置默认路由
```
route add default gw  192.168.159.105
```
### 测试（01节点上）
```
curl 192.168.160.200
```

## DR模式

| 主机名 | ip（NAT）| 角色 |
| :---- | :---- | :---- |
| Centos8 | 192.168.159.105 | keepalived |
| Centos8-1 | 192.168.159.106 | nginx1 |
| Centos8-2 | 192.168.159.107 | nginx2 |
|  | 192.168.160.200 | vip |

### 准备工作
关闭防火墙、三台机器都安装nginx、将Centos8-1和Centos8-2的nginx都监听80端口
如果做过上面的NAT实验，还需要恢复01和02上的第一块网卡，删除掉刚才配置的默认路由，01节点上的ip转发要关掉

### 安装配置keepalived（Centos8上）
yum安装keepalived
```
yum install -y keepalived
```

### 编辑配置文件
vi /etc/keepalived/keepalived.conf  ##写入如下配置
```
global_defs {
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface ens160
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass amingLi
    }
    virtual_ipaddress {
        192.168.160.200
    }
}

virtual_server 192.168.160.200 80 {
    delay_loop 6
    ## 算法为wrr
    lb_algo wrr
    ## LVS模式为DR模式
    lb_kind DR
    #persistence_timeout 50
    protocol TCP

    real_server 192.168.159.106 80 {
        weight 3
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.159.107 80 {
        weight 1
        HTTP_GET {
            url {
              path /
            }
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
}
```

### 启动服务
```
systemctl start keepalived
```

### 另外两个节点上编辑脚本
```
vi /usr/local/sbin/lvs_rs.sh  ##内容如下
#/bin/bash
vip=192.168.222.200
#把vip绑定在lo上，是为了实现rs直接把结果返回给客户端
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip lo:0
#以下操作为更改arp内核参数，目的是为了让rs顺利发送mac地址给客户端
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
```

### 执行脚本
```
sh  /usr/local/sbin/lvs_rs.sh
```

### 测试
浏览器访问vip 或者 再开启一台虚拟机访问