nginx+keepalived 主备实现高可用

nginx+keepalived 主，当一台主机挂掉，由备用主机顶上

主机：

192.168.59.102：master

192.168.59.103：backup

1、安装nginx（两台主机都安装）

https://www.cnblogs.com/leihongnu/p/16265539.html

将nginx首页编辑为：102和103方便区分

2、安装keepalived（两台主机都安装）

安装下载地址：https://github.com/acassen/keepalived/tags

挑一个版本下载，解压

#tar -zxvf keepalived-1.4.5.tar.gz

编译

#cd keepalived-1.4.5

#安装路径为/usr/local/keepalived

#./configure –prefix=/usr/local/keepalived –with-init=SYSV

# make && make install

拷贝配置文件到系统目录方便启动

# mkdir /etc/keepalived

# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/

# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

# ln -s /usr/local/sbin/keepalived /usr/sbin/

# ln -s /usr/local/keepalived/sbin/keepalived /sbin/

编辑脚本 /etc/keepalived/nginx_check.sh（两台服务器都要编辑）

【

#!/bin/bash
A=`netstat -tnlp | grep 80 | grep nginx | wc -l`

if [ $A -eq 0 ];then

#nginx关闭，/usr/local/nginx/sbin/nginx重启
/usr/local/nginx/sbin/nginx
sleep 2
if [ `netstat -tnlp | grep 80 | grep nginx | wc -l` -eq 0 ];then
# 重启不行nginx则关闭keepalived服务
systemctl stop keepalived
fi
fi

】

给脚本添加执行权限

#chmod +x /etc/keepalived/nginx_check.sh

编辑配置文件 192.168.59.102 master

vi /etc/keepalived/keepalived.conf 

【

! Configuration File for keepalived

global_defs {
notification_email {
[email protected]
[email protected]
[email protected]   #健康检查报告通知邮箱
}
notification_email_from [email protected]  #发送邮件的地址
smtp_server 127.0.0.1   #邮件服务器
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_skip_check_adv_addr
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script_chk_nginx {
script “/etc/keepalived/nginx_check.sh”   #检查本地nginx是否存活脚本
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER    #定义为从，可选项MASTER|BACKUP
interface enp0s3  #使用的网卡 可以用ip addr查看
virtual_router_id 51  #定义组ID，matser和backup必须一致
priority 100  #优先级 master必须比backup大（0-250）
advert_int 1  #多久在组里广播一下自己的心跳信息，默认单位为秒s
nopreempt
authentication {
auth_type PASS

auth_pass 1111  #主从两个服务器的字符串要设定为相同的
}
virtual_ipaddress {
192.168.59.211/24   #虚拟ip
}
track_script {
chk_nginx
}
}

】

编辑配置文件 192.168.59.103 backup

vi /etc/keepalived/keepalived.conf 

【

! Configuration File for keepalived

global_defs {
notification_email {
[email protected]
[email protected]
[email protected]   #健康检查报告通知邮箱
}
notification_email_from [email protected]  #发送邮件的地址
smtp_server 127.0.0.1   #邮件服务器
smtp_connect_timeout 30
router_id LVS_DEVEL
vrrp_skip_check_adv_addr
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script_chk_nginx {
script “/etc/keepalived/nginx_check.sh”   #检查本地nginx是否存活脚本
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP #定义为从，可选项MASTER|BACKUP
interface enp0s3  #使用的网卡 可以用ip addr查看
virtual_router_id 51  #定义组ID，matser和backup必须一致
priority 90 #优先级 master必须比backup大（0-250）
advert_int 1  #多久在组里广播一下自己的心跳信息，默认单位为秒s
nopreempt
authentication {
auth_type PASS

auth_pass 1111  #主从两个服务器的字符串要设定为相同的
}
virtual_ipaddress {
192.168.59.211/24   #虚拟ip
}
track_script {
chk_nginx
}
}

】

3、启动nginx和keepalived服务

 4、验证

关闭192.168.59.102的keepalived服务