nginx と keepalived を組み合わせて高可用性を実現する方法

yum install pcre-devel zlib zlib-devel openssl openssl-devel

tar zxvf nginx-1.12.2.tar.gz

mkdir -p /usr/local/nginx
./configure --prefix=/usr/local/nginx

make && make install

cd /usr/local/nginx/sbin/
./nginx
./nginx -s stop
./nginx -s start

yum install -y keepalived

vim /etc/keepalived/keepalived.conf

#新增的配置
vrrp_script chk_http_port {
 script "/shell/nginx_check.sh" #脚本地址
 interval 2 #检测脚本执行的间隔
 weight 2 #比重
}

vrrp_instance vi_1 {
 state master #主服务器为master,从服务器为backup
 interface eth0 #网卡
 virtual_router_id 51 #主、备机的virtual_router_id必须相同
 priority 100 #主、备机不同的优先级，主机优先级较大，备机值较小，默认是100
 advert_int 1
 authentication {
  auth_type pass
  auth_pass 1111
 }
 #虚拟ip地址
 virtual_ipaddress {
  192.168.126.88
 }
}

mkdir /shell/nginx_check.sh
vim /shell/nginx_check.sh

#!/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
  fi
fi

vrrp_instance vi_1 {
  state backup #主服务器为master,从服务器为backup
  interface eth0 #网卡
  virtual_router_id 51 #主、备机的virtual_router_id必须相同
  priority 50 #主、备机不同的优先级，主机优先级较大，备机值较小
  advert_int 1
  authentication {
    auth_type pass
    auth_pass 1111
  }
  #虚拟ip地址
  virtual_ipaddress {
    192.168.126.88
  }
}

service keepalived start

ip addr
1: lo: <loopback,up,lower_up> mtu 65536 qdisc noqueue state unknown 
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
  inet6 ::1/128 scope host 
    valid_lft forever preferred_lft forever
2: eth0: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state up qlen 1000
  link/ether 00:0c:29:4f:31:ce brd ff:ff:ff:ff:ff:ff
  inet 192.168.126.100/24 brd 192.168.126.255 scope global eth0
  inet 192.168.126.88/32 scope global eth0
  inet6 fe80::20c:29ff:fe4f:31ce/64 scope link 
    valid_lft forever preferred_lft forever

service iptables stop
#查看防火墙是否开机自启动
chkconfig --list | grep iptables
chkconfig iptables off

http://192.168.126.88/