部署kubernetes集群脚本，支持 containerd && docker

如果一件事情你需要做不止一遍，每一遍至少花费你十分钟以上，那么就值得你为它做一个自动化流程。

前面写了两个使用kubeadm搭建k8s集群的文章，一篇使用的是docker，一篇是用的containerd，弄一个自动化部署脚本比较合适

操作步骤：

1. vi /usr/bin/kubestart

将以下内容复制进去

#! /bin/bash
###############################################
##       Simple Install Your K8S
###############################################

kube_pod_subnet="10.244.0.0/16"
kube_version="1.21.3"
kube_image_server="registry.cn-hangzhou.aliyuncs.com/google_containers"
crictl_url="https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.21.0/"
crictl_name="crictl-v1.21.0-linux-amd64.tar.gz"

function init-env-disable-selinux()
{
  sudo setenforce 0
  sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
}

function init-env-disable-firewalld()
{
  sudo systemctl stop firewalld
  sudo systemctl disable --now firewalld
}

function init-env-repository()
{
  sudo echo -e "[kubernetes] \nname=Kubernetes \nbaseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/ \nenabled=1 \ngpgcheck=1 \nrepo_gpgcheck=1 \ngpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg" > /etc/yum.repos.d/kubernetes.repo
  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
  yum install centos-release-openstack-rocky -y
}

function init-install-kube()
{
  sudo yum install -y kubeadm-${kube_version} kubectl-${kube_version} kubelet-${kube_version} --disableexcludes=kubernetes
}

function init-docker()
{
  yum install -y wget docker-ce openvswitch* certbot
  systemctl start docker
  systemctl enable docker
  systemctl enable kubelet
}

function init-containerd()
{
  sudo yum install -y wget containerd.io openvswitch* certbot
  mkdir -p /etc/containerd

  cd /home
  wget $crictl_url$crictl_name
  tar zxf $crictl_name
  mv crictl /usr/local/bin/

  rm -rf $crictl_name

  echo "overlay" > /etc/modules-load.d/containerd.conf  
  echo "br_netfilter" >> /etc/modules-load.d/containerd.conf  

  sudo modprobe overlay
  sudo modprobe br_netfilter

  echo "net.bridge.bridge-nf-call-iptables  = 1" > /etc/sysctl.d/99-kubernetes-cri.conf 
  echo "net.ipv4.ip_forward                 = 1" >> /etc/sysctl.d/99-kubernetes-cri.conf 
  echo "net.bridge.bridge-nf-call-ip6tables = 1" >> /etc/sysctl.d/99-kubernetes-cri.conf 
 
  sudo sysctl --system

  sudo containerd config default > /etc/containerd/config.toml

  sed -i 's/k8s.gcr.io\/pause:3.1/registry.cn-hangzhou.aliyuncs.com\/google_containers\/pause:3.2/g' /etc/containerd/config.toml

  sudo systemctl restart containerd
  sudo systemctl enable containerd
 
  echo "KUBELET_EXTRA_ARGS=--cgroup-driver=systemd" > /etc/sysconfig/kubelet 

  echo "runtime-endpoint: unix:///run/containerd/containerd.sock" > /etc/crictl.yaml
  echo "image-endpoint: unix:///run/containerd/containerd.sock" >> /etc/crictl.yaml
  echo "timeout: 10" >> /etc/crictl.yaml
  echo "debug: false" >> /etc/crictl.yaml

  sudo systemctl restart kubelet
  sudo systemctl enable kubelet
}

function init-env-kubeconfig()
{
  mkdir /etc/kubernetes

  echo -e "apiVersion: kubeadm.k8s.io/v1beta2" > /etc/kubernetes/kubeadm.yaml
  echo -e "kind: InitConfiguration" >> /etc/kubernetes/kubeadm.yaml
  echo -e "bootstrapTokens:" >> /etc/kubernetes/kubeadm.yaml
  echo -e "  - ttl: \"0\"" >> /etc/kubernetes/kubeadm.yaml
  echo -e "---" >> /etc/kubernetes/kubeadm.yaml
  echo -e "apiVersion: kubeadm.k8s.io/v1beta2" >> /etc/kubernetes/kubeadm.yaml
  echo -e "kind: ClusterConfiguration" >> /etc/kubernetes/kubeadm.yaml
  echo -e "networking:" >> /etc/kubernetes/kubeadm.yaml
  echo -e "  podSubnet: \"${kube_pod_subnet}\"" >> /etc/kubernetes/kubeadm.yaml
  echo -e "kubernetesVersion: \"v${kube_version}\"" >> /etc/kubernetes/kubeadm.yaml
  echo -e "imageRepository: \"${kube_image_server}\"" >> /etc/kubernetes/kubeadm.yaml
}

function init-env-kubecomp()
{
  # default calico cni
  echo -e "https://docs.projectcalico.org/archive/v3.17/manifests/calico.yaml" > /etc/kubernetes/kubeenv.list
  # flannel: cni config url
  # echo -e "https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml" > /etc/kubernetes/kubeenv.list
}

function init-env()
{
  init-env-disable-selinux
  init-env-disable-firewalld
  init-env-repository
  init-install-kube
  if [[ -z $2 ]]
  then
    init-containerd
  elif [[ $2 == "docker" ]]
  then
    init-docker
  elif [[ $2 == "containerd" ]]
  then
    init-containerd
  else
    echo "only support docker or containerd"
    exit 1
  fi
  init-env-kubeconfig
  init-env-kubecomp
}

function run-kube()
{
  sudo swapoff -a && sysctl -w vm.swappiness=0
  sudo sed -ri '/^[^#]*swap/s@^@#@' /etc/fstab

  systemctl restart kubelet

  echo "1" > /proc/sys/net/bridge/bridge-nf-call-iptables
  echo "1" > /proc/sys/net/ipv4/ip_forward 
 
  kubeadm init --config /etc/kubernetes/kubeadm.yaml  

  rm -rf $HOME/.kube
  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config
  iptables -P FORWARD ACCEPT
  
  while read line
  do
    kubectl apply -f $line
  done  < /etc/kubernetes/kubeenv.list

}

function help()
{
  echo -e "Commands:"
  echo -e "  init-env      :\t(Init): Initialize the environment configuration, simplify configuring node, such as disable selinux, install docker or containerd..."
  echo -e "  run-kube      :\t(Init): deploy Kubernetes as your want by editing /etc/kubernetes/kubeenv.list. Now it includes calico, flannel"
}

case $1 in
  "init-env")
    init-env $*
    ;;
  "run-kube")
    run-kube $*
    ;;
  "--help")
    help
    ;;
  *)
  help
  ;;
esac

2. sudo chmod 777 /usr/bin/kubestart

3.然后你就可以使用以下两条命令去创建你的k8s集群了

# 初始化各种环境配置
kubestart init-env
# 启动集群，应用cni
kubestart run-kube
# 帮助命令
kubestart help

脚本说明：

脚本开头的几个参数，是关于你想使用的 k8s 版本以及 crictl 安装包，想要使用其他版本的可以在开头改一下。想要更换版本可以使用

yum list --showduplicates kubeadm --disableexcludes=kubernetes

命令查看一下自己的yum源支持哪些版本。

kubestart init-env 命令后面还可以添加其他参数，选择容器运行时，可以使用 docker 或者 containerd，默认是 containerd。

执行 kubeadm init 命令使用的是 /etc/kubernetes/kubeadm.yaml 配置文件启动的，如果有特殊需要，在执行完 init-env 命令后去修改这个文件内容就可以，其实启动集群的方式就是这条命令：

kubeadm init --config /etc/kubernetes/kubeadm.yaml

默认使用的是 calico 作为 cni 应用，你如果想使用其他的，去修改一下脚本里面的 init-env-kubecomp 函数即可。