nginx+keepalived高可用

规划

nginx+keepalived 主            192.168.57.3
nginx+keepalived备             192.168.57.4
VIP 192.168.57.100
nginx1 192.168.57.5
nginx2 192.168.57.6

所有机器上安装nginx服务

[root@master ~]# cat /etc/yum.repos.d/nginx.repo 
[nginx-stable] 
name=nginx stable repo 
baseurl=http://nginx.org/packages/centos/7/$basearch/ 
gpgcheck=0
enabled=1
gpgkey=http://nginx.org/keys/nginx_signing.key

主备机器上安装keepalived，需要先安装epel源

yum install -y  keepalived

配置keepalived

[root@master ~]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
notification_email {
root@local
xxx@xx.com
}
notification_email_from root@local
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id nginx_keepalived
}
vrrp_script chk_nginx {
script /etc/keepalived/nginx_check.sh
interval 2
weight -20

}
vrrp_instance VI_1 {
state MASTER         #从节点这里配置BACKUP
interface enp0s8
virtual_router_id 50
priority 100         #从节点这里配置90，这个代表优先级，越大优先级越高
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_nginx
}
virtual_ipaddress {
192.168.57.100/24 dev enp0s8

}
}

主备机器上配置nginx

[root@master ~]# cat /etc/nginx/conf.d/default.conf 
upstream backend {
server 192.168.57.5:80 weight=1 max_fails=3 fail_timeout=20s;
server 192.168.57.6:80 weight=1 max_fails=3 fail_timeout=20s;
}
server {
listen 80;
server_name l92.168.57.100;

location / {
proxy_pass http://backend;
proxy_set_header Host $host:$proxy_port;
proxy_set_header X-Forwarded-For $remote_addr;
}

配置检测脚本

[root@master ~]# cat /etc/keepalived/nginx_check.sh 
#!/bin/bash
while true
do
if [ $(netstat -tlnpgrep nginxwc -l) -ne 1 ]
then
systemctl stop keepalived 
fi
sleep 2
done

添加执行权限，并启动nginx和keepalived

chmod  +x /etc/keepalived/nginx_check.sh

systemctl start nginx

systemctl start keepalived

nginx1和nginx2上配置nginx

[root@realserver2 ~]# echo realserver2 >/usr/share/nginx/html/index.html 
[root@realserver2 ~]# systemctl start nginx
[root@realserver2 ~]# systemctl enable nginx
Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service.
[root@realserver2 ~]# 

[root@realserver1 ~]# echo realserver1 >/usr/share/nginx/html/index.html
[root@realserver1 ~]# systemctl start nginx
[root@realserver1 ~]# systemctl enable nginx
Created symlink from /etc/systemd/system/multi-user.target.wants/nginx.service to /usr/lib/systemd/system/nginx.service.
[root@realserver1 ~]# 

配置完毕，启动测试，curl http://192.168.57.100