主備（keepalived+nginx）
實驗環境
系統: centos 6.9 mini
機器名 ip 虛擬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上分別安裝keepalived
[root@kn1 ~]# yum install -y keepalived
[root@kn2 ~]# yum install -y keepalived
2、在web1和web2上分別部署web服務，並且啟動服務
[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： [確定]
正在啟動 httpd：
[root@web2 ~]# yum install -y httpd
[root@web2 ~]# echo "web2">/var/www/html/index.html
[root@web2 ~]# service httpd restart
停止 httpd： [確定]
正在啟動 httpd： [確定]
3、配置keepalived,編寫nginx進程檢測腳本nginx.sh
(keepalived是通過檢測keepalived進程是否存在判斷服務器是否宕機，如果keepalived進程在但是nginx進程不在了那麽keepalived是不會做主備切換，所以我們需要寫個腳本來監控nginx進程是否存在，如果nginx不存在，則試著啟動它，如果啟動不成功，就將keepalived進程殺掉。)
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 #運行keepalived機器的一個標識，用hostname
}
vrrp_script nginx {
script "/etc/keepalived/nginx.sh" ##監控腳本
interval 10 ##時間間隔，10秒
weight 2 ##權重
}
vrrp_instance VI_1 {
state MASTER #標示狀態為MASTER 備份機為BACKUP
interface eth0 #設置實例綁定的網卡
virtual_router_id 51 #同一實例下virtual_router_id必須相同
priority 100 #MASTER權重要高於BACKUP
advert_int 1 #MASTER與BACKUP負載均衡器之間同步檢查的時間間隔，單位是秒
authentication {
auth_type PASS #設置認證
auth_pass 1111 #主從服務器驗證方式
}
track_script {
nginx #監控腳本
}
virtual_ipaddress { #設置vip
192.168.126.100 #可以多個虛擬IP，換行即可
}
}
[root@kn1 ~]# /etc/init.d/keepalived restart
停止 keepalived： [失敗]
正在啟動 keepalived： [確定]
3.2 在kn2上
[root@kn1 keepalived]# cat nginx.sh
#!/bin/bash
N=`ps -C nginx --no-header |wc -l`
if [ $N -eq 0 ];then
/usr/local/nginx/sbin/nginx
sleep 10
if [ `ps -C nginx --no-header |wc -l` -eq 0 ]; then
killall keepalived
fi
fi
[root@kn1 keepalived]# chmod 755 /etc/keepalived/nginx.sh
[root@kn1 ~]# crontab -l
*/2 * * * * /etc/keepalived/nginx.sh
[root@kn2 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id kn2
}
vrrp_script nginx {
script "/etc/keepalived/nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
nginx
}
virtual_ipaddress {
192.168.126.100
}
}
[root@kn2 ~]# /etc/init.d/keepalived restart
停止 keepalived： [確定]
正在啟動 keepalived： [確定]
4、安裝並且配置nginx（kn1和kn2的操作是一樣的）
4.1 安裝依賴包
[root@kn1 ~]#yum -y install gcc pcre-devel zlib-devel openssl-devel wget
4.2 安裝nginx
[root@kn1 ~]#cd /usr/local/src/
[root@kn1 src]#wget http://nginx.org/download/nginx-1.9.5.tar.gz
[root@kn1 src]#tar zxvf nginx-1.9.5.tar.gz
[root@kn1 src]#cd nginx-1.9.5
[root@kn1 src]#./configure --with-http_stub_status_module
[root@kn1 src]#make && make install
4.3 配置nginx(紅色的部分就是添加的)
[root@kn1 ~]# cat /usr/local/nginx/conf/nginx.conf
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
#log_format main ‘$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 啟動服務
[root@kn1 ~]#/usr/local/nginx/sbin/nginx
[root@kn1 ~]#/usr/local/nginx/sbin/nginx -s reload
[root@kn1 ~]#/etc/init,d/keepalive restart
5、測試
5.1 在kn1上查看虛擬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 通過虛擬ip（域名）訪問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 當kn1 的nginx 服務不能啟動了，檢查腳本nginx.sh就會執行，stop掉keepalived,此時，vip切換到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 被鎖
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 配置多個虛擬ip，並且訪問
[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
主備（keepalived+nginx）