[Install] Kubernetes v1.28 - CRI-O (CentOS7)

• 아래 내용대로 진행 시, K8S 정상 설치 가능

---

• docker 완전 삭제 및 containerd 설치 및 설정 / k8s 1.28 설치

echo "[1] Docker 중지 및 제거"
sudo systemctl stop docker || true
sudo systemctl disable docker || true
sudo yum remove -y docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine || true

echo "[2] 남아있는 Docker 관련 데이터 정리"
sudo rm -rf /var/lib/docker
sudo rm -rf /etc/docker
sudo rm -rf /run/docker.sock

echo "[3] containerd 설치용 도커 리포 추가"
sudo yum install -y yum-utils device-mapper-persistent-data lvm2
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

echo "[4] containerd 설치"
sudo yum install -y containerd.io

echo "[5] containerd 설정 초기화 및 systemd cgroup 적용"
sudo mkdir -p /etc/containerd
containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml

echo "[6] containerd 재시작 및 부팅 시 자동 시작"
sudo systemctl restart containerd
sudo systemctl enable containerd

echo "[7] Kubernetes CRI 설정 (/etc/crictl.yaml)"
cat <<EOF | sudo tee /etc/crictl.yaml
runtime-endpoint: unix:///run/containerd/containerd.sock
image-endpoint: unix:///run/containerd/containerd.sock
timeout: 10
debug: false
EOF

echo "[8] kubelet, kubeadm, kubectl 설치 (Kubernetes v1.28)"
cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-\$basearch
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

sudo setenforce 0
sudo sed -i 's/^SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config

KUBE_VERSION=1.28.0
sudo yum install -y kubelet-${KUBE_VERSION} kubeadm-${KUBE_VERSION} kubectl-${KUBE_VERSION}

echo "[9] kubelet 및 swap 설정"
sudo systemctl enable --now kubelet
sudo swapoff -a
sudo sed -i '/ swap / s/^/#/' /etc/fstab

echo "✅ 전환 완료: Docker → containerd + Kubernetes 환경 준비됨!"
echo "🔧 다음 단계: kubeadm init 또는 kubeadm join 실행하세요."