1) HAProxy Installation

HAProxy is an open-source proxy and load balancing solution used to provide high availability. Below is the installation guide for Ubuntu operating systems.


sudo apt update
sudo apt install haproxy
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The configuration file is edited.

sudo vi /etc/haproxy/haproxy.cfg
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frontend kubernetes-frontend
  bind *:6443
  mode tcp
  option tcplog
  default_backend kubernetes-backend
 
backend kubernetes-backend
  option httpchk GET /healthz
  http-check expect status 200
  mode tcp
  option ssl-hello-chk
  balance roundrobin
    server master1hostname <MASTER_1_IP>:6443 check fall 3 rise 2
    server master2hostname <MASTER_2_IP>:6443 check fall 3 rise 2
    server master3hostname <MASTER_3_IP>:6443 check fall 3 rise 2
POWERSHELL 
systemctl enable haproxy && systemctl restart haproxy
systemctl status haproxy
POWERSHELL

1)Keepalived Installation

Keepalived typically provides a Virtual IP address among several control nodes (master and backup masters) and is used to ensure the continuous operation of other services.

sudo vim /etc/keepalived/check_apiserver.sh
POWERSHELL 
#!/bin/sh
 
errorExit() {
  echo "*** $@" 1>&2
  exit 1
}
 
curl --silent --max-time 2 --insecure https://localhost:6443/ -o /dev/null || errorExit "Error GET https://localhost:6443/"
if ip addr | grep -q <VIRTUAL_IP>; then
  curl --silent --max-time 2 --insecure https://<VIRTUAL_IP>:6443/ -o /dev/null || errorExit "Error GET https://<VIRTUAL_IP>:6443/"
fi
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chmod +x /etc/keepalived/check_apiserver.sh
POWERSHELL


Note: Add the appropriate network interface in the 'Interface' field.



sudo vim /etc/keepalived/keepalived.conf
POWERSHELL 
vrrp_script check_apiserver {
  script "/etc/keepalived/check_apiserver.sh"
  interval 3
  timeout 10
  fall 5
  rise 2
  weight -2
}
 
vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 1
    priority 100
    advert_int 5
    authentication {
        auth_type PASS
        auth_pass mysecret
    }
    virtual_ipaddress {  
     <VIRTUAL_IP>    
 }
    track_script {
        check_apiserver
    }
}
POWERSHELL 



systemctl enable --now keepalived
POWERSHELL

Initializing Kubernetes Cluster


You can perform the Kubernetes installation using the document  Installation of Apinizer on Ubuntu OS 


Important: During the init process, you should enter your own virtual IP address as the endpoint.

kubeadm init --control-plane-endpoint="<VIRTUAL_IP>:6443" --upload-certs --pod-network-cidr=10.244.0.0/16
POWERSHELL