Step-by-Step Guide to Building a Keepalived + Nginx High‑Availability Setup

1. Server environment preparation

Define four machines: 192.168.210.85 as the primary Nginx/Keepalived server, 192.168.210.177 as the secondary Nginx/Keepalived server, and 192.168.210.176 and 192.168.210.195 as backend services.

2. Configure the primary server (192.168.210.85)

[root@k8s-master1~]# vim /etc/keepalived/keepalived.conf
[root@k8s-master1~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        [email protected]
    }
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 200
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.210.11
    }
}

vrrp_instance VI_2 {
    state BACKUP
    interface ens33
    virtual_router_id 52
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 2222
    }
    virtual_ipaddress {
        192.168.210.12
    }
}

Restart Keepalived and verify the virtual IP is active on the master node.

3. Configure the backup server (192.168.210.177)

[root@k8s-node1~]# vim /etc/keepalived/keepalived.conf
[root@k8s-node1~]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    notification_email {
        [email protected]
    }
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 150
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.210.11
    }
}

vrrp_instance VI_2 {
    state MASTER
    interface ens33
    virtual_router_id 52
    priority 200
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 2222
    }
    virtual_ipaddress {
        192.168.210.12
    }
}

Restart Keepalived on the backup node and confirm the virtual IPs are now managed by the backup when the master is down.

4. Testing failover

Stop Keepalived on the master:

[root@k8s-master1~]# systemctl stop keepalived

Observe that the VIPs (192.168.210.11 and 192.168.210.12) are automatically taken over by the backup server, and both can still be accessed via Nginx. Restart the service to restore the original state.

Throughout the process, screenshots illustrate the IP status before and after failover, confirming that the high‑availability configuration works as expected.