---
url: https://chenlj.top/md/install/nginx/keepalived.md
---
# keepalived 安装

## 1、安装

### 安装依赖库

```shell
# 安装libnl环境
yum install -y libnl libnl-devel
```

### 下载

```shell
wget ...
```

### 移动

```shell
mv keepalived-2.0.18.tar.gz /usr/local
cd /usr/local
```

### 解压

```shell
tar -xvf keepalived-2.0.18.tar.gz
```

### 进行 configure 配置

```shell
#进入源码目录
cd /usr/local/keepalived-2.0.18
# 
./configure --prefix=/usr/local/keepalived --sysconf=/etc
```

> 说明
>
> 执行 configure 时，可使用的命令
>
> | 命令                            | 解释                                   |
> | ------------------------------- | -------------------------------------- |
> | `–prefix`                       | 指定 keepalived安装目录                |
> | `--sysconf`                     | 指定 keepalived配置目录                      |

### 编译

```shell
# 编译及安装
make && make install
```

### 启动命令

```shell
/usr/local/keepalived/sbin/keepalived //启动

/usr/local/nginx/sbin/nginx -s stop //关闭

/usr/local/nginx/sbin/nginx -s reload //重启

```

## 2、配置文件

主节点配置文件

```
! Configuration File for keepalived

global_defs {
    # 路由id：当前安装keepalived的节点主机标识符，保证全局唯一
    router_id keep_171
}
vrrp_instance VI_1 {
    # 表示状态是MASTER主机还是备用机BACKUP
    state MASTER
    # 该实例绑定的网卡
    interface ens33
    # 保证主备节点一致即可
    virtual_router_id 51
    # 权重，master权重一般高于backup，如果有多个，那就是选举，谁的权重高，谁就当选
    priority 100
    # 主备之间同步检查时间间隔，单位秒，默认1s
    advert_int 2
    # 认证权限密码，防止非法节点进入
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    # 虚拟出来的ip，可以有多个（vip）
    virtual_ipaddress {
        192.168.1.161
    }
}
```

从节点配置文件

```
! Configuration File for keepalived

global_defs {
    # 路由id：当前安装keepalived的节点主机标识符，保证全局唯一
    router_id keep_172
}
vrrp_instance VI_1 {
    # 表示状态是MASTER主机还是备用机BACKUP
    state BACKUP
    # 该实例绑定的网卡
    interface ens33
    # 保证主备节点一致即可
    virtual_router_id 51
    # 权重低于MASTER
    priority 80
    # 主备之间同步检查时间间隔，单位秒，默认1s
    advert_int 2
    # 认证权限密码，防止非法节点进入
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    # 虚拟出来的ip，可以有多个（vip）
    virtual_ipaddress {
        #注意：主备两台的vip都是一样的，绑定到同一个vip
        192.168.1.161
    }
}
```

## 3、设置开机自启

复制文件

```shell
cp /usr/local/keepalived-2.0.18/keepalived/etc/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived-2.0.18/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
systemctl daemon-reload
```

```shell
#开机自启
systemctl enable keepalived.service
#启动
systemctl start keepalived.service
#关闭
systemctl stop keepalived.service
#重启
systemctl restart keepalived.service
```

## 4、Keepalived配置Nginx自动重启

### （1）增加Nginx重启检测脚本

```shell
vim /etc/keepalived/check_nginx_alive_or_not.sh
```

填入内容

```shell
#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
# 判断nginx是否宕机，如果宕机了，尝试重启
if [ $A -eq 0 ];then
    /usr/local/nginx/sbin/nginx
    # 等待一小会再次检查nginx，如果没有启动成功，则停止keepalived，使其启动备用机
    sleep 3
    if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
        killall keepalived
    fi
fi
```

增加运行权限

```shell
chmod +x /etc/keepalived/check_nginx_alive_or_not.sh
```

### （2）配置keepalived监听nginx脚本

```
vrrp_script check_nginx_alive {
    script "/etc/keepalived/check_nginx_alive_or_not.sh"
    interval 2 # 每隔两秒运行上一行脚本
    weight 10 # 如果脚本运行失败，则升级权重+10
}
```

### （3）在 vrrp\_instance 中新增监控的脚本

```
track_script {
    check_nginx_alive # 追踪 nginx 脚本
}
```

### （4）重启Keepalived使得配置文件生效

```shell
systemctl restart keepalived
```