HAProxy 로드밸런서 설정

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

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# 2️⃣ HAProxy 설정 (공통)
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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

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# 3️⃣ Keepalived 설정 - master1 전용
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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

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# 4️⃣ Keepalived 설정 - master2 전용
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# ❗ 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

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# ✅ VIP / 포트 / 헬스체크 확인
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# 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>

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