Lab-CentOS uses Keepalived to build highly available clusters
Configure keepalivedHa Cluster
1) Experimental environment:
Server system: CentOS7.3
Service: nginx,keepalived
Client system: Windows 10centOS7.3
2) initialization operation: Master/Backup, operation of Tong Yan
# install keepalived software
[root@shiyan7 ~] # yum install keepalived
# install Nginx (need to configure EPEL source)
[root@shiyan7 ~] # yum install Nginx
# turn off and clear the firewall
[root@shiyan7 ~] # systemctl disable firewall.d
[root@shiyan7 ~] # systemctl stop firewall.d
[root@shiyan7] # iptables-F
# add host resolution
[root@shiyan7 ~] # vim / etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
:: 1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.18.17.34 shiyan.fore
172.18.17.31 shiyan.one
# disable Selinux (restart after configuration)
[root@shiyan7 ~] # vim / etc/selinux/config
Selinux=disabled
III) Master configuration
Nginx configuration
[root@shiyan7 ~] # mkdir / app/nginx/html
[root@shiyan7 ~] # echo "Sorry Server-1" > / app/nginx/html/index.html
[root@shiyan7 ~] # cp / etc/nginx/nginx.conf {, .bak}
[root@shiyan7 ~] # vim / etc/nginx/nginx.conf
Server {
Listen 80 default_server
Listen [::]: 80 default_server
Server_name _
Root / app/nginx/html
# Loadconfiguration files for the default server block.
Include/etc/nginx/default.d/*.conf
Location / {
}
Error_page404 / 404.html
Location = / 40x.html {
}
Error_page500 502 503 504 / 50x.html
Location = / 50x.html {
}
}
[root@shiyan7 ~] # systemctl start nginx
Test Nginx using a browser
KeepAlived configuration
[root@shiyan7 ~] # cp / etc/keepalived/keepalived.conf {, .bak}
[root@shiyan7 ~] # vim / etc/keepalived/keepalived.conf
Global_defs {
Notification_email {
Acassen@firewall.loc
Failover@firewall.loc
Sysadmin@firewall.loc
}
Notification_email_from Alexandre.Cassen@firewall.loc
Smtp_server192.168.200.1
Smtp_connect_timeout 30
Router_id node1
}
Vrrp_instance Ha_1 {
State BACKUP
Interface ens33
Virtual_router_id 51
Priority 100
Advert_int 1
Authentication {
Auth_type PASS
Auth_pass 1111
}
Virtual_ipaddress {
172.18.17.30/16 dev ens33
}
}
IV) Backup configuration
Nginx configuration
[root@shiyan7 ~] # mkdir / app/nginx/html
[root@shiyan7 ~] # echo "Sorry Server-2" > / app/nginx/html/index.html
[root@shiyan7 ~] # cp / etc/nginx/nginx.conf {, .bak}
[root@shiyan7 ~] # vim / etc/nginx/nginx.conf
Server {
Listen 80 default_server
Listen [::]: 80 default_server
Server_name _
Root / app/nginx/html
# Loadconfiguration files for the default server block.
Include/etc/nginx/default.d/*.conf
Location / {
}
Error_page404 / 404.html
Location = / 40x.html {
}
Error_page500 502 503 504 / 50x.html
Location = / 50x.html {
}
}
[root@shiyan7 ~] # systemctl start nginx
Test Nginx using a browser
KeepAlived configuration
[root@shiyan7 ~] # cp / etc/keepalived/keepalived.conf {, .bak}
[root@shiyan7 ~] # vim / etc/keepalived/keepalived.conf
Global_defs {
Notification_email {
Acassen@firewall.loc
Failover@firewall.loc
Sysadmin@firewall.loc
}
Notification_email_from Alexandre.Cassen@firewall.loc
Smtp_server192.168.200.1
Smtp_connect_timeout 30
Router_id node2
}
Vrrp_instance Ha_1 {
State BACKUP
Interface ens33
Virtual_router_id 51
Priority 99
Advert_int 1
Authentication {
Auth_type PASS
Auth_pass 1111
}
Virtual_ipaddress {
172.18.17.30/16 dev ens33
}
}
V) testing:
1) start the keepalived service of the master server and view the VIP/IP
Master
[root@shiyan7 ~] # systemctl start keepalived
[root@shiyan7 ~] # ip a l
Backup
[root@shiyan7 ~] # systemctl start keepalived
[root@shiyan7 ~] # ip a l
Test Nginx on the Master environment
2) close Master to test Backup
Master
[root@shiyan7 ~] # systemctl stop keepalived
[root@shiyan7 ~] # ip a l
Backup
[root@shiyan7 ~] # ip a l
Test Nginx on the Backup environment
3) enable Master
Master
[root@shiyan7 ~] # systemctl start keepalived
Root@shiyan7 ~] # ip a l
Backup
[root@shiyan7 ~] # ip a l
Test Nginx on the Master environment
