nginx使用keepalived实现高可用

环境：

主：linux-node1 110.0.0.137

备：linux-node2 110.0.0.138

VIP: 110.0.0.120

NGINX安装：

# rpm -ivh http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm

# yum install nginx

1.安装keepalived

# yum -y install kernel-devel make gcc openssl-devel libnl* popt*

# yum install -y openssl openssl-devel

# wget http://www.keepalived.org/software/keepalived-1.2.2.tar.gz

# tar zxf keepalived-1.2.2.tar.gz

# cd keepalived-1.2.2

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

# make && make install

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

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

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

# chmod +x /etc/init.d/keepalived

# mkdir /etc/keepalived

# /bin/cp /usr/local/sbin/keepalived /usr/sbin/

# ll /usr/sbin/

</code></pre>

2.配置keepalived

2.1.配置主nginx（linux-node1）

[root@linux-node1 ~]# cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {

notification_email {

sysadmin@firewall.loc

}

notification_email_from Alexandre.Cassen@firewall.loc

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id LVS_DEVEL

}

vrrp_script chk_http_port {

script "/opt/nginx_pid.sh"

interval 2

weight 2

}

vrrp_instance VI_1 {

state MASTER

interface eth0

virtual_router_id 51

mcast_src_ip 110.0.0.137

priority 100

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

track_script {

chk_http_port

}

virtual_ipaddress {

110.0.0.120

}

2.2.配置从nginx（linux-node2）

[root@linux-node2 keepalived]# cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {

notification_email {

sysadmin@firewall.loc

}

notification_email_from Alexandre.Cassen@firewall.loc

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id LVS_DEVEL

}

vrrp_script chk_http_port {

script "/opt/nginx_pid.sh"

interval 2

weight 2

}

vrrp_instance VI_1 {

state BACKUP

interface eth0

virtual_router_id 51

mcast_src_ip 110.0.0.138

priority 99

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

track_script {

chk_http_port

}

virtual_ipaddress {

110.0.0.120

}

3.编写nginx检查脚本（主备都需要）：

#!/bin/bash

A=`ps -C nginx --no-header |wc -l`

if [ $A -eq 0 ];then

/etc/init.d/nginx start

sleep 3

if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then

/etc/init.d/keepalived stop

4.启动nginx和keepalived

/etc/init.d/nginx start

/etc/init.d/keepalived start

5.检查虚拟化IP 是否绑定成功

主节点：

可以看到vip 110.0.0.120 已经绑定到主的nginx服务器上了。

6.测试：

停止nginx

# /etc/init.d/nginx stop

发现主的nginx无法停止，因为/opt/nginx_pid.sh 会检查nginx状态，如果nginx停止了，那么这个脚本就会自动启动nginx。如果nginx启动失败，那么会立刻停止keepalived，把vip转移到backup nginx上面

我们把nginx的配置文件设置错误，然后停止nginx，这个主的nginx就无法启动了。

检查主nginx机器ip状态：

检查backup nginx主机状态：

看到VIP已经转移到backup主机上了。

来自为知笔记(Wiz)