keepalive简介和安装

keepalived简介和安装

keepalived简介

• 官网：http://keepalived.org

1）vrrp协议的软件实现，原生设计目的为了高可用ipvs服务。

2）keepalived功能

• 基于vrrp协议完成地址流动
• 为vip地址所在的节点生成ipvs规则(在配置文件中预先定义)
• 为ipvs集群的各后端服务器做健康状态检测
• 基于脚本调用接口通过执行脚本完成脚本中定义的功能，进而影响集群事务，以此支持nginx、haproxy等服务

3）keepalived组件

• 用户空间核心组件：
  vrrp stack-VIP消息通告
  checkers-监测real server
  system call-标记real server权重
  SMTP-邮件组件
  ipvs wrapper-生成IPVS规则
  Netlink Reflector-网络接口
  WatchDog-监控进程

• 控制组件：配置文件解析器

• IO复用器

• 内存管理组件

• 图示：
  

• http://keepalived.org/documentation.html

4）keepalived相关术语

• vrrp协议：Virtual Router Redundancy Protocol 虚拟路由冗余协议

• 虚拟路由器：Virtual Router

• 虚拟路由器标识：VRID(0-255)，唯一标识虚拟路由器

• 物理路由器：
  master：主设备
  backup：备用设备
  priority：优先级

• VIP：Virtual IP

• VMAC：Virutal MAC (00-00-5e-00-01-VRID)

5）keepalived的工作模式：

• 主/备：单虚拟路由器
• 主/主：主/备（虚拟路由器1），备/主（虚拟路由器2）

6）keepalived的工作方式

• 抢占式
• 非抢占式

7）keepalived的安全工作

• 认证：
  无认证
  简单字符认证：预共享密钥

8）keepalived的通告：

• 心跳
• 优先级等
• 周期性

Keepalived环境准备

• 各节点时间必须同步
• 关闭selinux和防火墙

Keepalived安装

1）Keepalived安装

• #yum install keepalived (CentOS)
• #apt-get install keepalived (Ubuntu)

2）编译安装

①获取源码包并解压缩
~]# cd /usr/local/src/  （/usr/local/src/源码包存放路径）
src]# wget https://keepalived.org/software/keepalived-2.0.18.tar.gz
src]# tar xf keepalived-2.0.18/
src]# cd keepalived-2.0.18/


②提供编译环境
keepalived-2.0.18]# yum install -y gcc libnfnetlink-devel libnfnetlink ipvsadm libnl libnl-devel libnl3 libnl3-devel lm_sensors-libs net-snmp-agent-libs net-snmp-libs openssh-server openssh-clients openssl openssl-devel automake iproute 


③configure
keepalived-2.0.18]# ./configure --prefix=/usr/local/keepalived --disable-fwmark
    ==># echo $? ==>确认没报错


④make && make install
keepalived-2.0.18]# make && make install


⑤复制相关配置文件及启动脚本
keepalived-2.0.18]# cp /usr/local/src/keepalived-2.0.18/keepalived/etc/init.d/keepalived.rh.init  /etc/sysconfig/keepalived.sysconfig
keepalived-2.0.18]# cp /usr/local/src/keepalived-2.0.18/keepalived/keepalived.service  /usr/lib/systemd/system/
keepalived-2.0.18]# cp /usr/local/src/keepalived-2.0.18/bin/keepalived  /usr/local/bin/


⑥准备简单的配置测试keepalived能否使用
keepalived-2.0.18]# vim /etc/keepalived/keepalived.conf


global_defs {
        notification_email {
                root@localhost
        }
        notification_email_from root@localhost
        smtp_server 192.168.200.1
        smtp_connect_timeout 30
        router_id centos7-27
}

    vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 80
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.38.200 dev eth0 label eth0:0
    }
}


keepalived-2.0.18]# systemctl start keepalived

• #ifconfig （查看是否有VIP）
  

程序环境：

主配置文件：/etc/keepalived/keepalived.conf

主程序文件：/usr/sbin/keepalived

Service File：

• /usr/lib/systemd/system/keepalived.service (CentOS)
• /lib/systemd/system/keepalived.service (Ubuntu)
• Unit File的环境配置文件：/etc/sysconfig/keepalived