######################################
# 1️⃣ HAProxy + Keepalived 설치
######################################
sudo apt update
sudo apt install -y haproxy keepalived

######################################
# 2️⃣ HAProxy 설정 (공통)
######################################
cat <<EOF | sudo tee /etc/haproxy/haproxy.cfg
global
    log /dev/log    local0
    maxconn 2000
    user haproxy
    group haproxy

defaults
    log     global
    mode    tcp
    option  tcplog
    timeout connect 10s
    timeout client 1m
    timeout server 1m

frontend k8s_apiserver
    bind *:6443
    default_backend k8s_masters

backend k8s_masters
    balance     roundrobin
    option      tcp-check
    server      master1 10.10.10.21:6443 check
    server      master2 10.10.10.22:6443 check
    server      master3 10.10.10.23:6443 check
EOF

sudo systemctl restart haproxy
sudo systemctl enable haproxy

######################################
# 3️⃣ Keepalived 설정 - master1 전용
######################################
ip link show
# ❗ NIC_NAME 변수는 실제 인터페이스 이름으로 교체 필요 (예: eth0, ens33)
NIC_NAME="eth0"

cat <<EOF | sudo tee /etc/keepalived/keepalived.conf
vrrp_instance VI_1 {
    state MASTER
    interface ${NIC_NAME}
    virtual_router_id 51
    priority 120
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1234
    }
    virtual_ipaddress {
        10.10.10.100
    }
}
EOF

sudo systemctl restart keepalived
sudo systemctl enable keepalived

######################################
# 4️⃣ Keepalived 설정 - master2 전용
######################################
# ❗ NIC_NAME 변수는 실제 인터페이스 이름으로 교체 필요 (예: eth0, ens33)
NIC_NAME="enp2s0"

cat <<EOF | sudo tee /etc/keepalived/keepalived.conf
vrrp_instance VI_1 {
    state BACKUP
    interface ${NIC_NAME}
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1234
    }
    virtual_ipaddress {
        10.10.10.100
    }
}
EOF

sudo systemctl restart keepalived
sudo systemctl enable keepalived

######################################
# ✅ VIP / 포트 / 헬스체크 확인
######################################
# VIP 확인
ip addr | grep 10.10.10.100

# 6443 포트 리슨 중인지 확인
sudo ss -ntlp | grep 6443

# API 서버 응답 확인 (API가 열려 있다면)
curl -k <https://10.10.10.100:6443/livez>

######################################
# 🚀 Kubernetes 마스터 초기화 명령어
######################################
sudo kubeadm init \\\\
  --control-plane-endpoint="10.10.10.100:6443" \\\\
  --upload-certs \\\\
  --pod-network-cidr=10.244.0.0/16