【k8s】集群搭建篇

搭建kubernetes集群

kubeadm

初始化操作

# 1 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 2 关闭iptables服务
[root@master ~]# systemctl stop iptables
[root@master ~]# systemctl disable iptables# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时# 关闭swap
swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久# 关闭完swap后，一定要重启一下虚拟机！！！
# 根据规划设置主机名
hostnamectl set-hostname <hostname># 在master添加hosts
cat >> /etc/hosts << EOF
172.26.22.200 master
172.26.22.201 salve
EOF# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOFsysctl --system  # 生效# 时间同步
yum install ntpdate -y
ntpdate time.windows.com

安装软件(master、所有node节点)

安装docker，注意版本

# 1、切换镜像源
[root@master ~]# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo# 2、查看当前镜像源中支持的docker版本
[root@master ~]# yum list docker-ce --showduplicates# 3、安装特定版本的docker-ce
# 必须制定--setopt=obsoletes=0，否则yum会自动安装更高版本
[root@master ~]# yum install --setopt=obsoletes=0 docker-ce-18.06.3.ce-3.el7 -y# 4、添加一个配置文件
#Docker 在默认情况下使用Vgroup Driver为cgroupfs，而Kubernetes推荐使用systemd来替代cgroupfs
[root@master ~]# mkdir /etc/docker
[root@master ~]# cat <<EOF> /etc/docker/daemon.json
{"exec-opts": ["native.cgroupdriver=systemd"],"registry-mirrors": ["https://kn0t2bca.mirror.aliyuncs.com"]
}
EOF# 5、启动dokcer
[root@master ~]# systemctl restart docker
[root@master ~]# systemctl enable docker

修改源

cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

安装 kubeadm、kubelet、kubectl

yum install -y kubelet-1.23.6 kubeadm-1.23.6 kubectl-1.23.6systemctl enable kubelet# 配置关闭 Docker 的 cgroups，修改 /etc/docker/daemon.json，加入以下内容
{"exec-opts": ["native.cgroupdriver=systemd"]}# 重启 docker
systemctl daemon-reload
systemctl restart docker

Kubernetes Master初始化

# 在 Master 节点下执行kubeadm init \--apiserver-advertise-address=172.26.22.200 \--image-repository registry.aliyuncs.com/google_containers \--kubernetes-version v1.23.6 \--service-cidr=10.96.0.0/12 \--pod-network-cidr=10.244.0.0/16"""
Your Kubernetes control-plane has initialized successfully!To start using your cluster, you need to run the following as a regular user:mkdir -p $HOME/.kubesudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/configsudo chown $(id -u):$(id -g) $HOME/.kube/configAlternatively, if you are the root user, you can run:export KUBECONFIG=/etc/kubernetes/admin.confYou should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:https://kubernetes.io/docs/concepts/cluster-administration/addons/Then you can join any number of worker nodes by running the following on each as root:kubeadm join 172.26.22.200:6443 --token to99q6.h0nbbv93hwovz6el \--discovery-token-ca-cert-hash sha256:3a63cffd591cbb9b0842cd39169fddae83099359664a09e09cc8aa91b671e121
"""# 安装成功后，复制如下配置并执行
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/configkubectl get nodes

Kubernetes Node加入集群

分别在 k8s-node1 和 k8s-node2 执行# 下方命令可以在 k8s master 控制台初始化成功后复制 join 命令kubeadm join 192.168.113.120:6443 --token w34ha2.66if2c8nwmeat9o7 --discovery-token-ca-cert-hash sha256:20e2227554f8883811c01edd850f0cf2f396589d32b57b9984de3353a7389477# 如果初始化的 token 不小心清空了，可以通过如下命令获取或者重新申请
# 如果 token 已经过期，就重新申请
kubeadm token create# token 没有过期可以通过如下命令获取
kubeadm token list# 获取 --discovery-token-ca-cert-hash 值，得到值后需要在前面拼接上 sha256:
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | \
openssl dgst -sha256 -hex | sed 's/^.* //'

部署 CNI 网络插件

# 在 master 节点上执行
# 下载 calico 配置文件，可能会网络超时
# curl https://raw.githubusercontent.com/projectcalico/calico/v3.26.1/manifests/calico.yaml -O
curl -O https://docs.tigera.io/archive/v3.25/manifests/calico.yaml
# kubectl apply –f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml# 修改 calico.yaml 文件中的 CALICO_IPV4POOL_CIDR 配置，修改为与初始化的 cidr 相同
10.244.0.0/16# 修改 IP_AUTODETECTION_METHOD 下的网卡名称# 删除镜像 docker.io/ 前缀，避免下载过慢导致失败
sed -i 's#docker.io/##g' calico.yaml# 部署
kubectl apply -f calico.yaml
# 查看是否正常
kubectl get cs

测试 kubernetes 集群

# 创建部署
kubectl create deployment nginx --image=nginx# 暴露端口
kubectl expose deployment nginx --port=80 --type=NodePort# 查看 pod 以及服务信息
kubectl get pod,svc

停止服务并删除原来的配置

kubeadm reset -f
rm -rf ~/.kube/
rm -rf /etc/kubernetes/
rm -rf /etc/systemd/system/kubelet.service.d
rm -rf /etc/systemd/system/kubelet.service
rm -rf /usr/bin/kube*http://unifygateway.htsec.com/search_ehtc/csearch/ehtc_app?app_name=ehtc_app&appid=199608&page=1&per_page=5&query=海通&scene=all&sign_value=9ca66afd2c1c98aea79ec2c63f320789&timestamp=169208289

二进制搭建(单master集群)

初始化操作

# 1 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld
# 2 关闭iptables服务
[root@master ~]# systemctl stop iptables
[root@master ~]# systemctl disable iptables# 关闭selinux
sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时# 关闭swap
swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久# 关闭完swap后，一定要重启一下虚拟机！！！
# 根据规划设置主机名
hostnamectl set-hostname <hostname># 在master添加hosts
cat >> /etc/hosts << EOF
172.26.22.200 master
172.26.22.201 salve
EOF# 将桥接的IPv4流量传递到iptables的链
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOFsysctl --system  # 生效# 时间同步
yum install ntpdate -y
ntpdate time.windows.com

部署etcd集群

Etcd 是一个分布式键值存储系统，Kubernetes 使用 Etcd 进行数据存储，所以先准备一个 Etcd 数据库，为解决 Etcd 单点故障，应采用集群方式部署，这里使用 3 台组建集群，可容忍 1 台机器故障，当然，你也可以使用 5 台组建集群，可容忍 2 台机器故障。

注：为了节省机器，这里与 K8s 节点机器复用。也可以独立于 k8s 集群之外部署，只要apiserver 能连接到就行。

• 准备cfssl证书生成工具

  cfssl 是一个开源的证书管理工具，使用 json 文件生成证书，相比 openssl 更方便使用。

  # 找任意一台服务器操作，这里用 Master 节点。
  wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
  wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
  wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
  chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
  mv cfssl_linux-amd64 /usr/local/bin/cfssl
  mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
  mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo
  

• 生成 Etcd 证书

  • 自签证书颁发机构（CA）

    # 创建工作目录
    mkdir -p ~/TLS/{etcd,k8s}
    cd TLS/etcd
    

    # 自签CA证书
    cat > ca-config.json << EOF
    {"signing": {"default": {"expiry": "87600h"},"profiles": {"www": {"expiry": "87600h","usages": ["signing","key encipherment","server auth","client auth"]}}}
    }
    EOFcat > ca-csr.json << EOF
    {"CN": "etcd CA","key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "Beijing","ST": "Beijing"}]
    }
    EOF

    # 生成证书
    cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
    ls *pem
    ca-key.pem ca.pem
    

  • 使用自签 CA 签发 Etcd HTTPS 证书

    hosts字段中ip为所有etcd节点的集群内部通信ip,一个都不能少,为了方便后期扩容可以多写几个预留的ip。

    # 创建证书申请文件
    cat > server-csr.json << EOF
    {"CN": "etcd","hosts": ["172.26.22.200","172.26.22.201"],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing","ST": "BeiJing"}]
    }
    EOF
    

    # 生成证书
    cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare serverls server*pem
    server-key.pem server.pem
    

• 从github上下载二进制文件

  #下载后上传到服务器任意位置即可
  https://github.com/etcd-io/etcd/releases/download/v3.4.9/etcd-v3.4.9-linux-amd64.tar.gz
  

• 部署etcd集群

  涉及到的服务器都要如下操作

  # 创建工作目录并解压二进制包
  mkdir /opt/etcd/{bin,cfg,ssl} –p
  tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
  mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/
  

  # 创建 etcd 配置文件
  cat > /opt/etcd/cfg/etcd.conf << EOF
  #[Member]
  ETCD_NAME="etcd-1"
  ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
  ETCD_LISTEN_PEER_URLS="https://172.26.22.200:2380"
  ETCD_LISTEN_CLIENT_URLS="https://172.26.22.200:2379"#[Clustering]
  ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.26.22.200:2380"
  ETCD_ADVERTISE_CLIENT_URLS="https://172.26.22.200:2379"
  ETCD_INITIAL_CLUSTER="etcd-1=https://172.26.22.200:2380,etcd-2=https://172.26.22.201:2380"
  ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
  ETCD_INITIAL_CLUSTER_STATE="new"
  EOF
  

  配置说明

  • ETCD_NAME： 节点名称,集群中唯一
  • ETCD_DATA_DIR：数据目录
  • ETCD_LISTEN_PEER_URLS：集群通讯监听地址
  • ETCD_LISTEN_CLIENT_URLS：客户端访问监听地址
  • ETCD_INITIAL_CLUSTER：集群节点地址
  • ETCD_INITIALCLUSTER_TOKEN：集群Token
  • ETCD_INITIALCLUSTER_STATE：加入集群的状态：new是新集群,existing表示加入已有集群

  # systemd 管理 etcd
  cat > /usr/lib/systemd/system/etcd.service << EOF
  [Unit]
  Description=Etcd Server
  After=network.target
  After=network-online.target
  Wants=network-online.target[Service]
  Type=notify
  EnvironmentFile=/opt/etcd/cfg/etcd.conf
  ExecStart=/opt/etcd/bin/etcd \
  --cert-file=/opt/etcd/ssl/server.pem \
  --key-file=/opt/etcd/ssl/server-key.pem \
  --peer-cert-file=/opt/etcd/ssl/server.pem \
  --peer-key-file=/opt/etcd/ssl/server-key.pem \
  --trusted-ca-file=/opt/etcd/ssl/ca.pem \
  --peer-trusted-ca-file=/opt/etcd/ssl/ca.pem \
  --logger=zap
  Restart=on-failure
  LimitNOFILE=65536[Install]
  WantedBy=multi-user.target
  EOF
  

  # 拷贝刚才生成的证书
  cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/
  

  # 将上面节点 1 所有生成的文件拷贝到节点 2 和节点 3
  for i in {2..3}
  do
  scp -r /opt/etcd/ root@192.168.242.5$i:/opt/
  scp /usr/lib/systemd/system/etcd.service root@192.168.242.5$i:/usr/lib/systemd/system/
  done# 修改节点2，节点3 ,etcd.conf配置文件中的节点名称和当前服务器IP
  #[Member]
  ETCD_NAME="etcd-1"    #节点2修改为: etcd-2 节点3修改为: etcd-3
  ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
  ETCD_LISTEN_PEER_URLS="https://192.168.242.51:2380"  #修改为对应节点IP
  ETCD_LISTEN_CLIENT_URLS="https://192.168.242.51:2379"  #修改为对应节点IP#[Clustering]
  ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.242.51:2380" #修改为对应节点IP
  ETCD_ADVERTISE_CLIENT_URLS="https://192.168.242.51:2379" #修改为对应节点IP
  ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.242.51:2380,etcd-2=https://192.168.242.52:2380,etcd-3=https://192.168.242.53:2380"  
  ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
  ETCD_INITIAL_CLUSTER_STATE="new"

  # 启动并设置开机启动
  # etcd须多个节点同时启动,不然执行systemctl start etcd会一直卡在前台,连接其他节点,建议通过批量管理工具,或者脚本同时启动etcd。
  systemctl daemon-reload
  systemctl start etcd
  systemctl enable etcd
  

  # 检查etcd集群状态
  [root@k8s-master1 ~]# ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.242.51:2379,https://192.168.242.52:2379,https://192.168.242.53:2379" endpoint health --write-out=table
  +-----------------------------+--------+-------------+-------+
  |          ENDPOINT           | HEALTH |    TOOK     | ERROR |
  +-----------------------------+--------+-------------+-------+
  | https://192.168.242.52:2379 |   true | 67.267851ms |       |
  | https://192.168.242.51:2379 |   true | 67.374967ms |       |
  | https://192.168.242.53:2379 |   true | 69.244918ms |       |
  +-----------------------------+--------+-------------+-------+
  

  # etcd问题排查
  less /var/log/message
  journalctl -u etcd
  

安装Docker

k8s在1.20版本就不在支持docker，在1.24版本移除了docker

• 解压二进制包

  wget https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
  tar -xf docker-19.03.9.tgz
  mv docker/* /usr/bin/
  

• 配置镜像加速

  sudo mkdir -p /etc/docker
  sudo tee /etc/docker/daemon.json <<-'EOF'
  {"registry-mirrors": ["https://3s9106.mirror.alncs.com"]
  }
  EOF
  

• 启动并设置开机自启动

  systemctl daemon-reload
  systemctl start docker
  systemctl enable docker
  

部署master节点

• 生成kube-apiserver证书

  • 自签证书颁发机构(ca)

    cd ~/TLS/k8scat > ca-config.json << EOF
    {"signing": {"default": {"expiry": "87600h"},"profiles": {"kubernetes": {"expiry": "87600h","usages": ["signing","key encipherment","server auth","client auth"]}}}
    }
    EOF
    cat > ca-csr.json << EOF
    {"CN": "kubernetes","key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "Beijing","ST": "Beijing","O": "k8s","OU": "System"}]
    }
    EOF
    

    生成证书

    cfssl gencert -initca ca-csr.json | cfssljson -bare ca -
    ls *pem
    ca-key.pem ca.pem
    

  • 使用自签CA签发kube-apiserver https证书

    文件中hosts字段中IP为所有Master/LB/VIP IP,一个都不能少,为了方便后期扩容可以多写几个预留的IP。

    # 创建证书申请文件
    cat > server-csr.json << EOF
    {"CN": "kubernetes","hosts": ["10.0.0.1","127.0.0.1","192.168.242.51","192.168.242.52","192.168.242.53","192.168.242.54","192.168.242.55","kubernetes","kubernetes.default","kubernetes.default.svc","kubernetes.default.svc.cluster","kubernetes.default.svc.cluster.local"],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing","ST": "BeiJing","O": "k8s","OU": "System"}]
    }
    EOF
    

• 下载

  下载地址：https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.23.md

  

• 解压二进制包

  上传刚才下载的k8s软件包到服务器上

  mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
  tar zxvf kubernetes-server-linux-amd64.tar.gz
  cd kubernetes/server/bin
  cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
  cp kubectl /usr/bin/
  

• 部署kube-apiserver

  • 创建配置文件

    cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
    KUBE_APISERVER_OPTS="--logtostderr=false \\
    --v=2 \\
    --log-dir=/opt/kubernetes/logs \\
    --etcd-servers=https://192.168.242.51:2379,https://192.168.242.52:2379,https://192.168.242.53:2379 \\
    --bind-address=192.168.242.51 \\
    --secure-port=6443 \\
    --advertise-address=192.168.242.51 \\
    --allow-privileged=true \\
    --service-cluster-ip-range=10.0.0.0/24 \\
    --enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
    --authorization-mode=RBAC,Node \\
    --enable-bootstrap-token-auth=true \\
    --token-auth-file=/opt/kubernetes/cfg/token.csv \\
    --service-node-port-range=30000-32767 \\
    --kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
    --kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
    --tls-cert-file=/opt/kubernetes/ssl/server.pem  \\
    --tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
    --client-ca-file=/opt/kubernetes/ssl/ca.pem \\
    --service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
    --service-account-issuer=api \\
    --service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
    --etcd-cafile=/opt/etcd/ssl/ca.pem \\
    --etcd-certfile=/opt/etcd/ssl/server.pem \\
    --etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
    --requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
    --proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
    --proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
    --requestheader-allowed-names=kubernetes \\
    --requestheader-extra-headers-prefix=X-Remote-Extra- \\
    --requestheader-group-headers=X-Remote-Group \\
    --requestheader-username-headers=X-Remote-User \\
    --enable-aggregator-routing=true \\
    --audit-log-maxage=30 \\
    --audit-log-maxbackup=3 \\
    --audit-log-maxsize=100 \\
    --audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
    EOF
    

    说明：上面两个\第一个是转义符,第二个是换行符,使用转义符是为了使用EOF保留换行符。

    • –logtostderr ：启用日志
    • –v ：日志等级
    • –log-dir ：日志目录
    • –etcd-servers ：etcd集群地址
    • –bind-address ：监听地址
    • –secure-port ：https安全端口
    • –advertise-address ：集群通告地址
    • –allow-privileged ：启动授权
    • –service-cluster-ip-range ：Service虚拟IP地址段
    • –enable-admission-plugins ： 准入控制模块
    • –authorization-mode ：认证授权,启用RBAC授权和节点自管理
    • –enable-bootstrap-token-auth ：启用TLS bootstrap机制
    • –token-auth-file ：bootstrap token文件
    • –service-node-port-range ：Service nodeport类型默认分配端口范围
    • –kubelet-client-xxx ：apiserver访问kubelet客户端证书
    • –tls-xxx-file ：apiserver https证书
    • 1.20版本必须加的参数：–service-account-issuer,–service-account-signing-key-file
    • –etcd-xxxfile ：连接etcd集群证书
    • –audit-log-xxx ：审计日志
    • 启动聚合层网关配置：–requestheader-client-ca-file,–proxy-client-cert-file,–proxy-client-key-file,–requestheader-allowed-names,–requestheader-extra-headers-prefix,–requestheader-group-headers,–requestheader-username-headers,–enable-aggregator-routing

  • 拷贝刚才生成的证书

    cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/
    

  • 启用TLS bootstrapping机制

    TLS Bootstraping：Master apiserver启用TLS认证后，Node节点kubelet和kube-proxy要与kube-apiserver进行通信，必须使用CA签发的有效证书才可以，当Node节点很多时，这种客户端证书颁发需要大量工作，同样也会增加集群扩展复杂度。为了简化流程，Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书，kubelet会以一个低权限用户自动向apiserver申请证书，kubelet的证书由apiserver动态签署。所以强烈建议在Node上使用这种方式，目前主要用于kubelet，kube-proxy还是由我们统一颁发一个证书。

    > TLS bootstrapping工作流程<div align=center><img src="https://img-blog.csdnimg.cn/7f9ce4b198154a11bbb6319d285af487.png" width="600"></div>> 创建上述配置文件中token文件：```
    cat > /opt/kubernetes/cfg/token.csv << EOF
    4136692876ad4b01bb9dd0988480ebba,kubelet-bootstrap,10001,"system:node-bootstrapper"
    EOF# 格式：token,用户名,UID,用户组
    # token也可自行生成替换
    head -c 16 /dev/urandom | od -An -t x | tr -d ' '
    ```
    

    • systemd管理apiserve

      cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
      [Unit]
      Description=Kubernetes API Server
      Documentation=https://github.com/kubernetes/kubernetes[Service]
      EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
      ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
      Restart=on-failure[Install]
      WantedBy=multi-user.target
      EOF
      

    • 启动并设置开机启动

      systemctl daemon-reload
      systemctl start kube-apiserver 
      systemctl enable kube-apiserver
      

• 部署kube-controller-manager

  • 创建配置文件

    cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
    KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
    --v=2 \\
    --log-dir=/opt/kubernetes/logs \\
    --leader-elect=true \\
    --kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
    --bind-address=127.0.0.1 \\
    --allocate-node-cidrs=true \\
    --cluster-cidr=10.244.0.0/16 \\
    --service-cluster-ip-range=10.0.0.0/24 \\
    --cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
    --cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \\
    --root-ca-file=/opt/kubernetes/ssl/ca.pem \\
    --service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
    --cluster-signing-duration=87600h0m0s"
    EOF
    

    • –kubeconfig ：连接apiserver配置文件。
    • –leader-elect ：当该组件启动多个时,自动选举(HA)
    • –cluster-signing-cert-file ：自动为kubelet颁发证书的CA,apiserver保持一致
    • –cluster-signing-key-file ：自动为kubelet颁发证书的CA,apiserver保持一致

  • 生成kubeconfig文件

    生成kube-controller-manager证书 ：

    # 切换工作目录
    cd ~/TLS/k8s# 创建证书请求文件
    cat > kube-controller-manager-csr.json << EOF
    {"CN": "system:kube-controller-manager","hosts": [],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing", "ST": "BeiJing","O": "system:masters","OU": "System"}]
    }
    EOF# 生成证书
    cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager
    

    生成kubeconfig文件(以下是shell命令,直接在shell终端执行)

    KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
    KUBE_APISERVER="https://192.168.242.51:6443"kubectl config set-cluster kubernetes \--certificate-authority=/opt/kubernetes/ssl/ca.pem \--embed-certs=true \--server=${KUBE_APISERVER} \--kubeconfig=${KUBE_CONFIG}kubectl config set-credentials kube-controller-manager \--client-certificate=./kube-controller-manager.pem \--client-key=./kube-controller-manager-key.pem \--embed-certs=true \--kubeconfig=${KUBE_CONFIG}kubectl config set-context default \--cluster=kubernetes \--user=kube-controller-manager \--kubeconfig=${KUBE_CONFIG}kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
    

  • systemd管理controller-manager

    cat > /usr/lib/systemd/system/kube-controller-manager.service << EOF
    [Unit]
    Description=Kubernetes Controller Manager
    Documentation=https://github.com/kubernetes/kubernetes[Service]
    EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.conf
    ExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS
    Restart=on-failure[Install]
    WantedBy=multi-user.target
    EOF
    

  • 启动并设置开机自启

    systemctl daemon-reload
    systemctl start kube-controller-manager
    systemctl enable kube-controller-manager
    

• 部署 kube-scheduler

  • 创建配置文件

    cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
    KUBE_SCHEDULER_OPTS="--logtostderr=false \\
    --v=2 \\
    --log-dir=/opt/kubernetes/logs \\
    --leader-elect \\
    --kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
    --bind-address=127.0.0.1"
    EOF
    

    • –kubeconfig ：连接apiserver配置文件
    • –leader-elect ：当该组件启动多个时,自动选举(HA)。

  • 生成kubeconfig文件

    生成kube-scheduler证书 ：

    # 切换工作目录
    cd ~/TLS/k8s# 创建证书请求文件
    cat > kube-scheduler-csr.json << EOF
    {"CN": "system:kube-scheduler","hosts": [],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing","ST": "BeiJing","O": "system:masters","OU": "System"}]
    }
    EOF# 生成证书
    cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler
    

    生成kubeconfig文件 ：

    KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
    KUBE_APISERVER="https://192.168.242.51:6443"kubectl config set-cluster kubernetes \--certificate-authority=/opt/kubernetes/ssl/ca.pem \--embed-certs=true \--server=${KUBE_APISERVER} \--kubeconfig=${KUBE_CONFIG}kubectl config set-credentials kube-scheduler \--client-certificate=./kube-scheduler.pem \--client-key=./kube-scheduler-key.pem \--embed-certs=true \--kubeconfig=${KUBE_CONFIG}kubectl config set-context default \--cluster=kubernetes \--user=kube-scheduler \--kubeconfig=${KUBE_CONFIG}kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
    

  • systemd管理scheduler

    cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
    [Unit]
    Description=Kubernetes Scheduler
    Documentation=https://github.com/kubernetes/kubernetes[Service]
    EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
    ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
    Restart=on-failure[Install]
    WantedBy=multi-user.target
    EOF
    

  • 启动并设置开机启动

    systemctl daemon-reload
    systemctl start kube-scheduler
    systemctl enable kube-scheduler
    

  • 查看集群状态

    生成kubectl连接集群的证书 ：

    cat > admin-csr.json <<EOF
    {"CN": "admin","hosts": [],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing","ST": "BeiJing","O": "system:masters","OU": "System"}]
    }
    EOFcfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin
    

    生成kubeconfig文件 ：

    mkdir /root/.kubeKUBE_CONFIG="/root/.kube/config"
    KUBE_APISERVER="https://192.168.242.51:6443"kubectl config set-cluster kubernetes \--certificate-authority=/opt/kubernetes/ssl/ca.pem \--embed-certs=true \--server=${KUBE_APISERVER} \--kubeconfig=${KUBE_CONFIG}kubectl config set-credentials cluster-admin \--client-certificate=./admin.pem \--client-key=./admin-key.pem \--embed-certs=true \--kubeconfig=${KUBE_CONFIG}kubectl config set-context default \--cluster=kubernetes \--user=cluster-admin \--kubeconfig=${KUBE_CONFIG}kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
    

    通过kubectl工具查看当前集群组件状态 ：

    [root@k8s-master1 k8s]# kubectl get cs
    Warning: v1 ComponentStatus is deprecated in v1.19+
    NAME                 STATUS    MESSAGE             ERROR
    scheduler            Healthy   ok                  
    controller-manager   Healthy   ok                  
    etcd-2               Healthy   {"health":"true"}   
    etcd-0               Healthy   {"health":"true"}   
    etcd-1               Healthy   {"health":"true"}----
    如上说明Master节点组件运行正常。
    

  • 授权kubelet-bootstrap用户允许请求证书

    kubectl create clusterrolebinding kubelet-bootstrap \
    --clusterrole=system:node-bootstrapper \
    --user=kubelet-bootstrap
    

部署master node节点

下面还是在master node上面操作,即当Master节点,也当Work Node节点

• 创建工作目录并拷贝二进制文件

  注: 在所有work node创建工作目录

  mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
  

  从master节点k8s-server软件包中拷贝到所有work节点:

  #进入到k8s-server软件包目录
  cd /k8s-software/kubernetes/server/bin/for i in {1..3}
  do
  scp kubelet  kube-proxy root@192.168.242.5$i:/opt/kubernetes/bin/
  done
  

• 部署kubelet

  • 创建配置文件

    cat > /opt/kubernetes/cfg/kubelet.conf << EOF
    KUBELET_OPTS="--logtostderr=false \\
    --v=2 \\
    --log-dir=/opt/kubernetes/logs \\
    --hostname-override=k8s-master1 \\
    --network-plugin=cni \\
    --kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
    --bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
    --config=/opt/kubernetes/cfg/kubelet-config.yml \\
    --cert-dir=/opt/kubernetes/ssl \\
    --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"
    EOF
    

    • –hostname-override ：显示名称,集群唯一(不可重复)。
    • –network-plugin ：启用CNI。
    • –kubeconfig ： 空路径,会自动生成,后面用于连接apiserver。
    • –bootstrap-kubeconfig ：首次启动向apiserver申请证书。
    • –config ：配置文件参数。
    • –cert-dir ：kubelet证书目录。
    • –pod-infra-container-image ：管理Pod网络容器的镜像 init container

  • 配置文件

    cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
    kind: KubeletConfiguration
    apiVersion: kubelet.config.k8s.io/v1beta1
    address: 0.0.0.0
    port: 10250
    readOnlyPort: 10255
    cgroupDriver: cgroupfs
    clusterDNS:
    - 10.0.0.2
    clusterDomain: cluster.local 
    failSwapOn: false
    authentication:anonymous:enabled: falsewebhook:cacheTTL: 2m0senabled: truex509:clientCAFile: /opt/kubernetes/ssl/ca.pem 
    authorization:mode: Webhookwebhook:cacheAuthorizedTTL: 5m0scacheUnauthorizedTTL: 30s
    evictionHard:imagefs.available: 15%memory.available: 100Minodefs.available: 10%nodefs.inodesFree: 5%
    maxOpenFiles: 1000000
    maxPods: 110
    EOF
    

  • 生成kubelet初次加入集群引导kubeconfig文件

    KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
    KUBE_APISERVER="https://192.168.242.51:6443" # apiserver IP:PORT
    TOKEN="4136692876ad4b01bb9dd0988480ebba" # 与token.csv里保持一致  /opt/kubernetes/cfg/token.csv # 生成 kubelet bootstrap kubeconfig 配置文件
    kubectl config set-cluster kubernetes \--certificate-authority=/opt/kubernetes/ssl/ca.pem \--embed-certs=true \--server=${KUBE_APISERVER} \--kubeconfig=${KUBE_CONFIG}kubectl config set-credentials "kubelet-bootstrap" \--token=${TOKEN} \--kubeconfig=${KUBE_CONFIG}kubectl config set-context default \--cluster=kubernetes \--user="kubelet-bootstrap" \--kubeconfig=${KUBE_CONFIG}kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
    

  • systemd管理kubelet

    cat > /usr/lib/systemd/system/kubelet.service << EOF
    [Unit]
    Description=Kubernetes Kubelet
    After=docker.service[Service]
    EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
    ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
    Restart=on-failure
    LimitNOFILE=65536[Install]
    WantedBy=multi-user.target
    EOF
    

  • 启动并设置开机启动

    systemctl daemon-reload
    systemctl start kubelet
    systemctl enable kubelet
    

  • 允许kubelet证书申请并加入集群

    #查看kubelet证书请求
    [root@k8s-master1 bin]# kubectl get csr
    NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION
    node-csr-KbHieprZUMOvTFMHGQ1RNTZEhsSlT5X6wsh2lzfUry4   107s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending#允许kubelet节点申请
    [root@k8s-master1 bin]# kubectl certificate approve  node-csr-KbHieprZUMOvTFMHGQ1RNTZEhsSlT5X6wsh2lzfUry4
    certificatesigningrequest.certificates.k8s.io/node-csr-KbHieprZUMOvTFMHGQ1RNTZEhsSlT5X6wsh2lzfUry4 approved#查看申请
    [root@k8s-master1 bin]# kubectl get csr
    NAME                                                   AGE     SIGNERNAME                                    REQUESTOR           CONDITION
    node-csr-KbHieprZUMOvTFMHGQ1RNTZEhsSlT5X6wsh2lzfUry4   2m35s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued#查看节点
    [root@k8s-master1 bin]# kubectl get nodes
    NAME          STATUS     ROLES    AGE     VERSION
    k8s-master1   NotReady   <none>   2m11s   v1.20.10
    

    由于网络插件还没有部署,节点会没有准备就绪NotReady

• 部署kube-proxy

  • 创建配置文件

    cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
    KUBE_PROXY_OPTS="--logtostderr=false \\
    --v=2 \\
    --log-dir=/opt/kubernetes/logs \\
    --config=/opt/kubernetes/cfg/kube-proxy-config.yml"
    EOF
    

  • 配置参数文件

    cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
    kind: KubeProxyConfiguration
    apiVersion: kubeproxy.config.k8s.io/v1alpha1
    bindAddress: 0.0.0.0
    metricsBindAddress: 0.0.0.0:10249
    clientConnection:kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
    hostnameOverride: k8s-master1
    clusterCIDR: 10.244.0.0/16
    EOF
    

  • 生成kube-proxy证书文件

    # 切换工作目录
    cd ~/TLS/k8s# 创建证书请求文件
    cat > kube-proxy-csr.json << EOF
    {"CN": "system:kube-proxy","hosts": [],"key": {"algo": "rsa","size": 2048},"names": [{"C": "CN","L": "BeiJing","ST": "BeiJing","O": "k8s","OU": "System"}]
    }
    EOF# 生成证书
    cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
    

  • 生成kube-proxy.kubeconfig文件

    KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
    KUBE_APISERVER="https://192.168.242.51:6443"kubectl config set-cluster kubernetes \--certificate-authority=/opt/kubernetes/ssl/ca.pem \--embed-certs=true \--server=${KUBE_APISERVER} \--kubeconfig=${KUBE_CONFIG}kubectl config set-credentials kube-proxy \--client-certificate=./kube-proxy.pem \--client-key=./kube-proxy-key.pem \--embed-certs=true \--kubeconfig=${KUBE_CONFIG}kubectl config set-context default \--cluster=kubernetes \--user=kube-proxy \--kubeconfig=${KUBE_CONFIG}kubectl config use-context default --kubeconfig=${KUBE_CONFIG}
    

  • systemd管理kube-proxy

    cat > /usr/lib/systemd/system/kube-proxy.service << EOF
    [Unit]
    Description=Kubernetes Proxy
    After=network.target[Service]
    EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
    ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
    Restart=on-failure
    LimitNOFILE=65536[Install]
    WantedBy=multi-user.target
    EOF
    

  • 启动并设置开机自启

    systemctl daemon-reload
    systemctl start kube-proxy
    systemctl enable kube-proxy
    

• 部署网络组件(Calico)

  Calico是一个纯三层的数据中心网络方案，是目前Kubernetes主流的网络方案。

  kubectl apply -f calico.yaml
  kubectl get pods -n kube-system
  

  # 等Calico Pod都Running,节点也会准备就绪。
  [root@k8s-master1 yaml]# kubectl get pods -n kube-system
  NAME                                      READY   STATUS    RESTARTS   AGE
  calico-kube-controllers-97769f7c7-zcz5d   1/1     Running   0          3m11s
  calico-node-5tnll                         1/1     Running   0          3m11s[root@k8s-master1 yaml]# kubectl get nodes
  NAME          STATUS   ROLES    AGE   VERSION
  k8s-master1   Ready    <none>   21m   v1.20.10
  

• 授权apiserver访问kubelet

  应用场景：如kubectl logs

  cat > apiserver-to-kubelet-rbac.yaml << EOF
  apiVersion: rbac.authorization.k8s.io/v1
  kind: ClusterRole
  metadata:annotations:rbac.authorization.kubernetes.io/autoupdate: "true"labels:kubernetes.io/bootstrapping: rbac-defaultsname: system:kube-apiserver-to-kubelet
  rules:- apiGroups:- ""resources:- nodes/proxy- nodes/stats- nodes/log- nodes/spec- nodes/metrics- pods/logverbs:- "*"
  ---
  apiVersion: rbac.authorization.k8s.io/v1
  kind: ClusterRoleBinding
  metadata:name: system:kube-apiservernamespace: ""
  roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: system:kube-apiserver-to-kubelet
  subjects:- apiGroup: rbac.authorization.k8s.iokind: Username: kubernetes
  EOFkubectl apply -f apiserver-to-kubelet-rbac.yaml
  

新增加work node

所有node节点可以参考如下

• 拷贝以部署好的相关文件到新节点

  在Master节点将Work Node涉及文件拷贝到新节点 242.52/242.53

  for i in {2..3}; do scp -r /opt/kubernetes root@192.168.242.5$i:/opt/; donefor i in {2..3}; do scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.242.5$i:/usr/lib/systemd/system; donefor i in {2..3}; do scp -r /opt/kubernetes/ssl/ca.pem root@192.168.242.5$i:/opt/kubernetes/ssl/; done
  

• 删除kubelet证书和kubeconfig文件

  rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
  rm -f /opt/kubernetes/ssl/kubelet*这几个文件是证书申请审批后自动生成的,每个Node不同,必须删除
  

• 修改主机名

  vi /opt/kubernetes/cfg/kubelet.conf
  --hostname-override=k8s-node1vi /opt/kubernetes/cfg/kube-proxy-config.yml
  hostnameOverride: k8s-node1
  

• 启动并设置开机自启

  systemctl daemon-reload
  systemctl start kubelet kube-proxy
  systemctl enable kubelet kube-proxy
  

• 在Master上同意新的Node kubelet证书申请

  #查看证书请求
  [root@k8s-master1 kubernetes]# kubectl get csr
  NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
  node-csr-2vKShQc_wlqPrTPAwT5MHpdRWIX-oyr9NyBXu1XNwxg   12s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
  node-csr-KbHieprZUMOvTFMHGQ1RNTZEhsSlT5X6wsh2lzfUry4   47h   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued
  #同意
  [root@k8s-master1 kubernetes]# kubectl certificate approve node-csr-2vKShQc_wlqPrTPAwT5MHpdRWIX-oyr9NyBXu1XNwxg
  certificatesigningrequest.certificates.k8s.io/node-csr-2vKShQc_wlqPrTPAwT5MHpdRWIX-oyr9NyBXu1XNwxg approved
  

• 查看Node状态(要稍等会才会变成ready,会下载一些初始化镜像)

  [root@k8s-master1 kubernetes]# kubectl get nodes
  NAME          STATUS   ROLES    AGE   VERSION
  k8s-master1   Ready    <none>   46h   v1.20.10
  k8s-node1     Ready    <none>   77s   v1.20.10
  

部署Dashboard和CoreDNS

• 部署Dashboard

  访问地址: https://NodeIP:30001
  创建service account并绑定默认cluster-admin管理员集群角色

  kubectl apply -f kubernetes-dashboard.yaml#查看部署情况
  [root@k8s-master1 yaml]#  kubectl get pods,svc -n kubernetes-dashboard
  NAME                                             READY   STATUS    RESTARTS   AGE
  pod/dashboard-metrics-scraper-7b59f7d4df-k49t9   1/1     Running   0          10m
  pod/kubernetes-dashboard-74d688b6bc-l9jz4        1/1     Running   0          10mNAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
  service/dashboard-metrics-scraper   ClusterIP   10.0.0.206   <none>        8000/TCP        10m
  service/kubernetes-dashboard        NodePort    10.0.0.10    <none>        443:30001/TCP   10m
  

  kubectl create serviceaccount dashboard-admin -n kube-system
  kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
  kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
  

  使用输出的token登陆Dashboard(如访问提示https异常,可使用火狐浏览器)

  

• 部署CoreDNS

  CoreDNS主要用于集群内部Service名称解析。

  [root@k8s-master1 yaml]# kubectl apply -f coredns.yaml [root@k8s-master1 yaml]# kubectl get pods -n kube-system
  NAME                                      READY   STATUS    RESTARTS   AGE
  calico-kube-controllers-97769f7c7-zcz5d   1/1     Running   1          47h
  calico-node-5tnll                         1/1     Running   1          47h
  calico-node-m8sdg                         1/1     Running   0          42m
  calico-node-pqvk9                         1/1     Running   0          56m
  coredns-6cc56c94bd-5hvfb                  1/1     Running   0          37s
  

  测试解析是否正常

  [root@k8s-master1 yaml]# kubectl run -it --rm dns-test --image=busybox:1.28.4 sh 
  If you don't see a command prompt, try pressing enter.
  / # ns
  nsenter   nslookup
  / # nslookup kubernetes
  Server:    10.0.0.2
  Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local
  

  至此一个单Master的k8s节点就已经完成了

从节点使用kubectl

# 1. 将 master 节点中 /etc/kubernetes/admin.conf 拷贝到需要运行的服务器的 /etc/kubernetes 目录中
scp /etc/kubernetes/admin.conf root@k8s-node1:/etc/kubernetes# 2. 在对应的服务器上配置环境变量
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile
source ~/.bash_profile

清空k8s环境

#!/bin/bash
kubeadm reset -f
modprobe -r ipip
lsmod
rm -rf ~/.kube/
rm -rf /etc/kubernetes/
rm -rf /etc/systemd/system/kubelet.service.d
rm -rf /etc/systemd/system/kubelet.service
rm -rf /usr/bin/kube*
rm -rf /etc/cni
rm -rf /opt/cni
rm -rf /var/lib/etcd
rm -rf /var/etcd
yum -y remove kubeadm* kubectl* kubelet* docker*
reboot