Keepalived+Nginx高可用集群

安装环境：centos6.6 X64

nginx版本：1.9.3

keepalived版本：1.2.18

配置规划：

 IPVIP主节点192.168.11.21192.168.11.20备节点192.168.11.22192.168.11.20

一、安装Nginx

1、安装准备

1.1、安装openssl

# tar -zxvf openssl-1.0.0s.tar.gz

# ./configure

# make && make install

2、解压pcre

# tar -zxvf pcre-7.8.tar.gz

3、安装nginx

# tar -zxvf nginx-1.9.3.tar.gz

# cd nginx-1.9.3

# ./configure --prefix=/usr/local/nginx--with-pcre=/usr/local/src/pcre-7.8

# make && make install

 设置Nginx开机启动，编辑/etc/rc.local文件，在末尾添加如下内容：

/usr/loca/nginx/sbin/nginx

二、安装Keepalived

# tar -zxvf keepalived-1.2.18.tar.gz

# cd keepalived-1.2.18

# ./configure --prefix=/usr/local/keepalived

# make && make install

将keepalived安装成Linux系统服务：

# 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/

设置keepalived服务开机启动

# chkconfig keepalived on

修改Keepalived配置文件

(1) MASTER节点配置文件（192.168.11.21）

# vi/etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
    router_id 21
}

vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh"
    interval 2
    weight -20
}

vrrp_instance VI_1 {
    #state MASTER
    state BACKUP
    interface eth2
    virtual_router_id 51
    priority 100
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.11.20
    }
    track_script {
        chk_nginx
    }
}

(2)BACKUP节点配置文件（192.168.11.22）:

# vi/etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
    router_id 22
}

vrrp_script chk_nginx { 
    script "/etc/keepalived/nginx_check.sh"
    interval 2   
    weight -20 
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth3
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.11.20
    }
    track_script { 
    chk_nginx
    } 
}

编写Nginx状态检测脚本/etc/keepalived/nginx_check.sh

内容如下：

#!/bin/bash
A=`ps -C nginx --no-header |wc -l` 
if [ $A -eq 0 ];then
/usr/local/nginx/sbin/nginx
sleep 2
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
killall keepalived
service keepalived stop
fi
fi

保存后，给脚本赋执行权限：

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

关闭防火墙:

#service iptable stop

分别在两台主机上启动Nginx和Keepalived

# /usr/loca/nginx/sbin/nginx

 # service keepalived start

查看虚拟IP添加是否成功（红色部分为VIP）

# ip a

eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdiscpfifo_fast state UP qlen 1000

   link/ether 00:0c:29:2e:4c:00brd ff:ff:ff:ff:ff:ff

   inet 192.168.11.21/24 brd192.168.152.255 scope global eth1

   inet 192.168.11.20/32scope global eth1

   inet6fe80::20c:29ff:fe2e:4c00/64 scope link

      valid_lft foreverpreferred_lft forever