#!/bin/bash
set -e

# 1. 關閉 swap
sudo swapoff -a
sudo sed -i '/ swap / s/^/#/' /etc/fstab

# 2. 啟用橋接網路所需 kernel module + ip forward
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
overlay
br_netfilter
EOF

sudo modprobe overlay
sudo modprobe br_netfilter

cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.ipv4.ip_forward = 1
EOF

sudo sysctl --system

# 3. 安裝 containerd
sudo apt-get update
sudo apt-get install -y containerd

sudo mkdir -p /etc/containerd
sudo containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
sudo systemctl restart containerd
sudo systemctl enable containerd

# 4. 安裝 kubeadm, kubelet, kubectl
sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gnupg
sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /' | \
  sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl
sudo systemctl enable kubelet

# 取得本機 IP (排除 localhost / lo / IPv6) - 你可能需要根據網卡名稱調整
MY_IP=$(ip addr show | grep -E 'inet [0-9]' | grep -v '127.0.0.1' | grep -v 'inet6' | awk '{print $2}' | cut -d/ -f1 | head -n1)
echo "Detected local IP: $MY_IP"

# 5. master 初始化 (只在 master node 執行)
sudo kubeadm init \
  --control-plane-endpoint "10.10.0.83:6444" \
  --apiserver-advertise-address=${MY_IP} \
  --upload-certs \
  --pod-network-cidr=10.244.0.0/16

# 6. 設定 kubeconfig（使 kubectl 可用）
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

# 7. 等待 kube-apiserver + core components 啟動 (簡單 polling)
echo "等待 kube-apiserver 啟動..."
until kubectl get componentstatuses > /dev/null 2>&1; do
  echo "  尚未 ready，等待 5 秒..."
  sleep 5
done

# 8. 安裝 Flannel CNI (Pod network)
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

echo "=== 安裝 containerd + kubeadm/kubelet/kubectl + 初始化 master + 安裝 Flannel 完成 ==="