#!/bin/bash
# @FileName  :k8s-node-init.sh
# @Time      :2024/9/14
# @Author    :Rohing

# 修改主机名，使用具体的 node 名称
hostnamectl set-hostname node1

# 配置 Rocky Linux 软件源
configure_repo() {
  cat > /etc/yum.repos.d/rocky.repo <<EOF
[baseos]
name=Rocky Linux \$releasever - BaseOS
baseurl=http://mirrors.sjtug.sjtu.edu.cn/rocky/\$releasever/BaseOS/\$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rockyofficial

[appstream]
name=Rocky Linux \$releasever - AppStream
baseurl=http://mirrors.sjtug.sjtu.edu.cn/rocky/\$releasever/AppStream/\$basearch/os/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rockyofficial
EOF
  yum clean all
  yum makecache
}

# 安装基本工具
install_basic_tools() {
  yum install -y epel-release vim wget curl net-tools git iproute-tc bash-completion chrony
}

# 禁用防火墙和 SELinux
disable_security() {
  systemctl stop firewalld
  systemctl disable firewalld
  setenforce 0
  sed -i 's/^SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
}

# 配置 Chrony 时间同步
configure_chrony() {
  systemctl enable chronyd
  systemctl start chronyd
  chronyc sources
}

# 配置系统限制
configure_limits() {
  cat > /etc/sysctl.d/k8s.conf <<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
vm.swappiness = 0
EOF
  sysctl --system
}

# 安装 ELRepo 并升级内核
install_elrepo() {
  yum install -y https://www.elrepo.org/elrepo-release-9.el9.elrepo.noarch.rpm
  yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
  yum --enablerepo=elrepo-kernel install -y kernel-ml
  grub2-set-default 0
  grub2-mkconfig -o /boot/grub2/grub.cfg
}

# 配置 Kernel 模块和网络
configure_kernel_network() {
  cat > /etc/modules-load.d/k8s.conf <<EOF
br_netfilter
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack
EOF

  modprobe br_netfilter
  modprobe ip_vs
}

# 安装 containerd 并配置
install_containerd() {
  yum install -y containerd
  systemctl enable containerd
  systemctl start containerd
  mkdir -p /etc/containerd
  containerd config default > /etc/containerd/config.toml
  sed -i 's#SystemdCgroup = false#SystemdCgroup = true#' /etc/containerd/config.toml
  systemctl restart containerd
}

# 配置 containerd 镜像加速器
configure_registry_mirrors() {
  sed -i 's#registry.k8s.io#registry.aliyuncs.com/google_containers#' /etc/containerd/config.toml
  systemctl restart containerd
}

# 安装 crictl 工具
install_crictl() {
  VERSION="v1.28.0"  # 和 Kubernetes 版本一致
  wget https://github.com/kubernetes-sigs/cri-tools/releases/download/$VERSION/crictl-$VERSION-linux-amd64.tar.gz
  tar zxvf crictl-$VERSION-linux-amd64.tar.gz -C /usr/local/bin
  chmod +x /usr/local/bin/crictl
  rm -f crictl-$VERSION-linux-amd64.tar.gz
}

# 安装 Kubernetes 组件
install_k8s_components() {
  cat <<EOF | tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes-new/core/stable/v1.28/rpm/
enabled=1
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes-new/core/stable/v1.28/rpm/repodata/repomd.xml.key
EOF

  yum install -y kubelet kubeadm kubectl
  systemctl enable kubelet
  systemctl start kubelet
}

# 节点加入 Kubernetes 集群
join_cluster() {
  # 替换为主节点执行 kubeadm init 后输出的 join 命令
  kubeadm join <Master-Node-IP>:6443 --token <Your-Token> \
    --discovery-token-ca-cert-hash sha256:<Discovery-Hash>
}

# 运行所有功能
main() {
  configure_repo
  install_basic_tools
  disable_security
  configure_chrony
  configure_limits
  install_elrepo
  configure_kernel_network
  install_containerd
  configure_registry_mirrors
  install_crictl
  install_k8s_components
  join_cluster
}

main