实验环境
系统: centos 6.9 mini
机器名 ip 虚拟ip
kn1 192.168.126.10
kn2 192.168.126.20 192.168.126.100
web1 192.168.126.30
web2 192.168.126.40
1、在kn1和kn2上分别安装keepalived
[root@kn1 ~]# yum install -y keepalived
[root@kn2 ~]# yum install -y keepalived
2、在web1和web2上分别部署web服务，并且启动服务
[root@web1 yum.repos.d]# yum install -y httpd
[root@web1 yum.repos.d]# echo "web1" >/var/www/html/index.html
[root@web1 yum.repos.d]# service httpd restart
停止 httpd： [确定]
正在启动 httpd：
[root@web2 ~]# yum install -y httpd
[root@web2 ~]# echo "web2">/var/www/html/index.html
[root@web2 ~]# service httpd restart
停止 httpd： [确定]
正在启动 httpd： [确定]
3、配置keepalived,编写nginx进程检测脚本nginx.sh
(keepalived是通过检测keepalived进程是否存在判断服务器是否宕机，如果keepalived进程在但是nginx进程不在了那么keepalived是不会做主备切换，所以我们需要写个脚本来监控nginx进程是否存在，如果nginx不存在，则试着启动它，如果启动不成功，就将keepalived进程杀掉。)
3.1 在kn1上
[root@kn1 keepalived]# cat nginx.sh
#!/bin/bash
N=`ps -C nginx --no-header |wc -l`
if [ $N -eq 0 ];then
/usr/local/nginx/sbin/nginx
sleep 10
if [ `ps -C nginx --no-header |wc -l` -eq 0 ]; then
killall keepalived
fi
fi
[root@kn1 keepalived]# chmod 755 /etc/keepalived/nginx.sh
[root@kn1 ~]# crontab -l
*/2 * * * * /etc/keepalived/nginx.sh
[root@kn1 ~]# vi /etc/keepalived/keepalived.conf
#全局配置
global_defs {
router_id kn1 #运行keepalived机器的一个标识，用hostname
}
vrrp_script nginx {
script "/etc/keepalived/nginx.sh" ##监控脚本
interval 10 ##时间间隔，10秒
weight 2 ##权重
}
vrrp_instance VI_1 {
state MASTER #标示状态为MASTER 备份机为BACKUP
interface eth0 #设置实例绑定的网卡
virtual_router_id 51 #同一实例下virtual_router_id必须相同
priority 100 #MASTER权重要高于BACKUP
advert_int 1 #MASTER与BACKUP负载均衡器之间同步检查的时间间隔，单位是秒
authentication {
auth_type PASS #设置认证
auth_pass 1111 #主从服务器验证方式
}
track_script {
nginx #监控脚本
}
virtual_ipaddress { #设置vip
192.168.126.100 #可以多个虚拟IP，换行即可
}
}
[root@kn1 ~]# /etc/init.d/keepalived restart
停止 keepalived： [失败]
正在启动 keepalived： [确定]
3.2 在kn2上
[root@kn1 keepalived]# cat nginx.sh
#!/bin/bash
N=`ps -C nginx --no-header |wc -l`
if [ $N -eq 0 ];then
/usr/local/nginx/sbin/nginx
sleep 10
if [ `ps -C nginx --no-header |wc -l` -eq 0 ]; then
killall keepalived
fi
fi
[root@kn1 keepalived]# chmod 755 /etc/keepalived/nginx.sh
[root@kn1 ~]# crontab -l
*/2 * * * * /etc/keepalived/nginx.sh
[root@kn2 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id kn2
}
vrrp_script nginx {
script "/etc/keepalived/nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
nginx
}
virtual_ipaddress {
192.168.126.100
}
}
[root@kn2 ~]# /etc/init.d/keepalived restart
停止 keepalived： [确定]
正在启动 keepalived： [确定]
4、安装并且配置nginx（kn1和kn2的操作是一样的）
4.1 安装依赖包
[root@kn1 ~]#yum -y install gcc pcre-devel zlib-devel openssl-devel wget
4.2 安装nginx
[root@kn1 ~]#cd /usr/local/src/
[root@kn1 src]#wget http://nginx.org/download/nginx-1.9.5.tar.gz
[root@kn1 src]#tar zxvf nginx-1.9.5.tar.gz
[root@kn1 src]#cd nginx-1.9.5
[root@kn1 src]#./configure --with-http_stub_status_module
[root@kn1 src]#make && make install
4.3 配置nginx(红色的部分就是添加的)
[root@kn1 ~]# cat /usr/local/nginx/conf/nginx.conf
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
upstream web_up {
server 192.168.126.30 max_fails=3 fail_timeout=60s weight=1;
server 192.168.126.40 max_fails=3 fail_timeout=60s weight=2;
}
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root html;
index index.html index.htm;
proxy_pass http://web_up;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwared-For $proxy_add_x_forwarded_for;
}
4.4 启动服务
[root@kn1 ~]#/usr/local/nginx/sbin/nginx
[root@kn1 ~]#/usr/local/nginx/sbin/nginx -s reload
[root@kn1 ~]#/etc/init,d/keepalive restart
5、测试
5.1 在kn1上查看虚拟ip
[root@kn1 ~]# ip addr list
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:d1:9e:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.126.20/24 brd 192.168.126.255 scope global eth0
inet 192.168.126.100/32 scope global eth0
inet6 fe80::20c:29ff:fed1:9e5c/64 scope link tentative dadfailed
valid_lft forever preferred_lft forever
5.2 通过虚拟ip（域名）访问nignx
[root@kn1 ~]# curl http://192.168.126.100
web2
[root@kn1 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.126.100 test.ku.com
[root@kn19 ~]# curl http://test.ku.com
web2
5.3 当kn1 的nginx 服务不能启动了，检查脚本nginx.sh就会执行，stop掉keepalived,此时，vip切换到kn2上
在kn1上的操作
[root@kn1 ~]# /usr/local/nginx/sbin/nginx -s stop
[root@kn1 ~]# /etc/init.d/keepalived status
keepalived 已死，但是 subsys 被锁
You have new mail in /var/spool/mail/root
[root@kn1 ~]# tail -10 /var/log/messages
Feb 5 13:56:01 kn1 Keepalived_healthcheckers[2590]: Netlink reflector reports IP 192.168.126.100 removed
在kn2上的操作
[root@kn2 ~]# ip addr list
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:35:6d:f2 brd ff:ff:ff:ff:ff:ff
inet 192.168.126.20/24 brd 192.168.126.255 scope global eth0
inet 192.168.126.100/32 scope global eth0
inet6 fe80::20c:29ff:fe35:6df2/64 scope link
valid_lft forever preferred_lft forever
5.4 在kn1和kn2 的keepalived.cof 中 配置多个虚拟ip，并且访问
[root@kn1 ~]# vi /etc/keepalived/keepalived.conf
virtual_ipaddress {
192.168.126.100
192.168.126.150
}
}
[root@kn2 ~]# vi /etc/keepalived/keepalived.conf
virtual_ipaddress {
192.168.126.100
192.168.126.150
}
}
[root@kn1 ~]# /etc/init.d/keepalived restart
[root@kn2 ~]# /etc/init.d/keepalived restart
[root@kn2 ~]# ip addr list
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:35:6d:f2 brd ff:ff:ff:ff:ff:ff
inet 192.168.126.20/24 brd 192.168.126.255 scope global eth0
inet 192.168.126.100/32 scope global eth0
inet 192.168.126.150/32 scope global eth0
[root@kn2 ~]# curl http://192.168.126.100
web2
[root@kn2 ~]# curl http://192.168.126.150
web2