centos7安装部署keepalived

安装环境说明

• 两台服务器，系统centos7
• 服务器1 IP 192.168.2.191
• 服务器2 IP 192.168.2.192
• 软件版本，keepalived-1.3.5.tar.gz
• keepalive安装包百度云连接 密码：hmd7
• 服务器1 VIP 192.168.2.95
• 服务器2 VIP 192.168.2.96
• 本次配置，服务器1和服务器2互为主备

编译安装

# tar zxvf keepalived-1.3.5.tar.gz     #解压
# cd keepalived-1.3.5/
# ./configure
# make && make install      #编译安装

配置文件

• 机器1配置

在/etc/keepalived/ 目录下建立keepalived.conf

# vim /etc/keepalived/keepalived.conf     #添加如下内容

! Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost
    }   
    notification_email_from www@example.com
    smtp_server mail.example.com
    smtp_connect_timeout 30
    router_id LVS_DEVEL
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_nginx.sh" 
    interval 2 
    weight -5  
    fall 3   
    rise 2 
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0          #网卡接口名称
    virtual_router_id 51
    priority 101 
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }   
    virtual_ipaddress {
        192.168.2.95       #虚拟地址1
    }   
    track_script {
       chk_nginx
    }
}
vrrp_instance VI_2 {
    state BACKUP
    interface eth0           #网卡接口名
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.96    #虚拟地址2
    }
    track_script {
       chk_nginx
    }
}

• 服务器2配置

在/etc/keepalived/ 目录下建立keepalived.conf

vim /etc/keepalived/keepalived.conf     #添加如下内容

Configuration File for keepalived
global_defs {
    notification_email {
        root@localhost
    }
    notification_email_from www@example.com
    smtp_server mail.example.com
    smtp_connect_timeout 30
    router_id LVS_DEVEL
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_nginx.sh"
    interval 2
    weight -5
    fall 3
    rise 2
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth0            #网卡名称
    virtual_router_id 51
    priority 100 
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }   
    virtual_ipaddress {
        192.168.2.95      #虚拟地址1
    }   
    track_script {
       chk_nginx
    }
}
vrrp_instance VI_2 {
    state MASTER
    interface eth0         #网卡名称
    virtual_router_id 52
    priority 101
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.2.96      #虚拟地址2
    }
    track_script {
       chk_nginx
    }
}

• nginx检查脚本

# vim /etc/keepalived/check_nginx.sh

#!/bin/bash
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
    /usr/local/nginx/sbin/nginx
    sleep 2
    counter=$(ps -C nginx --no-heading|wc -l)
    if [ "${counter}" = "0" ]; then
        service keepalived stop
    fi
fi

# chmod +x check_nginx.sh

系统服务配置

# vim /lib/systemd/system/keepalived.service

[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network.target

[Service]
Type=simple
PIDFile=/usr/local/var/run/keepalived.pid
KillMode=process
EnvironmentFile=-/usr/local/etc/sysconfig/keepalived
ExecStart=/usr/local/sbin/keepalived --dont-fork -D
ExecReload=/bin/kill -HUP $MAINPID

[Install]
WantedBy=multi-user.target

启动命令

# systemctl enable keepalived.service  # 设置开机自启动
# systemctl start keepalived.service
# systemctl stop keepalived.service

注意事项

防火墙启用状态下执行

# firewall-cmd --direct --permanent --add-rule ipv4 filter INPUT 0 \
  --in-interface enp0s8 --destination 224.0.0.18 --protocol vrrp -j ACCEPT

# firewall-cmd --direct --permanent --add-rule ipv4 filter OUTPUT 0 \
  --out-interface enp0s8 --destination 224.0.0.18 --protocol vrrp -j ACCEPT

# firewall-cmd --reload

修改为单播通讯

服务器网络环境中，路由交换层禁用了ARP的广播限制，形成了keepalived主备协议没法经过广播的方式进行通讯，形成主备两台服务器都强制占用HAVIP地址，出现同时两台服务器都有VIP地址的状况出现。必须经过配置来指定IP的两台服务器间进行通

须要修改配置文件

priority 100
    unicast_src_ip  192.168.2.192    #本机实际IP
    unicast_peer {
             192.168.2.191         #对端实际IP
    }

另外一台服务器配置类似，只是互换IP地址

验证

服务启动后，可查看VIP是否绑定

# ip addr

显示结果