使用kubeadm快速部署一套K8S集群以及众多神坑记录

 

一、Kubernetes概述

1.1 Kubernetes是什么

• Kubernetes是Google在2014年开源的一个容器集群管理系统，Kubernetes简称K8S。

• K8S用于容器化应用程序的部署，扩展和管理。

• K8S提供了容器编排，资源调度，弹性伸缩，部署管理，服务发现等一系列功能。

• Kubernetes目标是让部署容器化应用简单高效。

1.2 Kubernetes特性

• 自我修复

• 在节点故障时重新启动失败的容器，替换和重新部署，保证预期的副本数量；杀死健康检查失败的容器，并且在未准备好之前不会处理客户端请求，确保线上服务不中断。

• 弹性伸缩

• 使用命令、UI或者基于CPU使用情况自动快速扩容和缩容应用程序实例，保证应用业务高峰并发时的高可用性；业务低峰时回收资源，以最小成本运行服务。

• 自动部署和回滚

• K8S采用滚动更新策略更新应用，一次更新一个Pod，而不是同时删除所有Pod，如果更新过程中出现问题，将回滚更改，确保升级不受影响业务。

• 服务发现和负载均衡

• K8S为多个容器提供一个统一访问入口（内部IP地址和一个DNS名称），并且负载均衡关联的所有容器，使得用户无需考虑容器IP问题。

• 机密和配置管理

• 管理机密数据和应用程序配置，而不需要把敏感数据暴露在镜像里，提高敏感数据安全性。并可以将一些常用的配置存储在K8S中，方便应用程序使用。

• 存储编排

• 挂载外部存储系统，无论是来自本地存储，公有云（如AWS），还是网络存储（如NFS、GlusterFS、Ceph）都作为集群资源的一部分使用，极大提高存储使用灵活性。

• 批处理

• 提供一次性任务，定时任务；满足批量数据处理和分析的场景。

1.3 Kubernetes集群架构与组件

 

 

1.4 Kubernetes集群组件介绍

1.4.1 Master组件

• kube-apiserver

• Kubernetes API，

  集群的统一入口

  ，各组件协调者，以RESTful API提供接口服务，所有对象资源的增删改查和监听操作都交给APIServer处理后再提交给Etcd存储。

• kube-controller-manager

• 处理集群中常规后台任务，一个资源对应一个控制器，而ControllerManager就是负责管理这些控制器的。

• kube-scheduler

• 根据调度算法为新创建的Pod选择一个Node节点，可以任意部署,可以部署在同一个节点上,也可以部署在不同的节点上。

• etcd

• 分布式键值存储系统。用于保存集群状态数据，比如Pod、Service等对象信息。

1.4.2 Node组件

• kubelet

• kubelet是Master在Node节点上的Agent，管理本机运行容器的生命周期，比如创建容器、Pod挂载数据卷、下载secret、获取容器和节点状态等工作。kubelet将每个Pod转换成一组容器。

• kube-proxy

• 在Node节点上实现Pod网络代理，维护网络规则和四层负载均衡工作。

• docker或rocket

• 容器引擎，运行容器。

1.5 Kubernetes 核心概念

• Pod

• 最小部署单元

• 一组容器的集合

• 一个Pod中的容器共享网络命名空间

• Pod是短暂的

• Controllers

• ReplicaSet ：确保预期的Pod副本数量

• Deployment ：无状态应用部署

• StatefulSet ：有状态应用部署

• DaemonSet ：确保所有Node运行同一个Pod

• Job ：一次性任务

• Cronjob ：定时任务

更高级层次对象，部署和管理Pod

• Service

• 防止Pod失联
• 定义一组Pod的访问策略

• Label ：标签，附加到某个资源上，用于关联对象、查询和筛选

• Namespaces：命名空间，将对象逻辑上隔离

• Annotations ：注释

二、kubeadm 快速部署K8S集群

2.1 kubernetes 官方提供的三种部署方式

• minikube

Minikube是一个工具，可以在本地快速运行一个单点的Kubernetes，仅用于尝试Kubernetes或日常开发的用户使用。部署地址：https://kubernetes.io/docs/setup/minikube/

• kubeadm

Kubeadm也是一个工具，提供kubeadm init和kubeadm join，用于快速部署Kubernetes集群。部署地址：https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm/

• 二进制包

推荐，从官方下载发行版的二进制包，手动部署每个组件，组成Kubernetes集群。下载地址：https://github.com/kubernetes/kubernetes/releases

2.2 安装kubeadm环境准备

 

2.2.1 环境需求

环境：centos 7.4 +(版本尽量在7.3-7.5之间，尽量不要用8或者以上版本)

硬件需求：CPU>=2c ,内存>=2G

2.2.2 环境角色

IP	角色	安装软件
192.168.73.138	k8s-Master	kube-apiserver  kube-schduler  kube-controller-manager  docker  flannel  kubelet
192.168.73.139	k8s-node01	kubelet  kube-proxy  docker  flannel
192.168.73.140	k8s-node01	kubelet  kube-proxy  docker  flannel

2.2.3 环境初始化

 

获得权限，输入密码，不然后面有很多东西报错，无法判断是否是由权限引起:

sudo su

 

PS : 以下所有操作，在三台节点全部执行

1、关闭防火墙及selinux

$ systemctl stop firewalld && systemctl disable firewalld​

$ sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config  && setenforce 0

2、关闭 swap 分区

$ swapoff -a # 临时

$ sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab #永久

3、分别在192.168.73.138、192.168.73.139、192.168.73.140上设置主机名及配置hosts

$ hostnamectl set-hostname k8s-master（192.168.73.138主机打命令）
$ hostnamectl set-hostname k8s-node01（192.168.73.139主机打命令）
$ hostnamectl set-hostname k8s-node02 (192.168.73.140主机打命令)

4、在所有主机上上添加如下命令

$ cat >> /etc/hosts << EOF 192.168.4.34 k8s-master 192.168.4.35 k8s-node01 192.168.4.36 k8s-node02 EOF

5、内核调整,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
EOF
sysctl --system  # 生效

6、设置系统时区并同步时间服务器

yum install ntpdate -y
ntpdate time.windows.com

噩梦的开始，第一个坑:如果centos版本是8的话，它是不支持安装ntpdate的，所以就要用另一个方法：

#安装软件 chrony
yum install -y chrony
#安装好工具，先启动
systemctl start chronyd
#设为系统自动启动
systemctl enable chronyd
#编辑配置文件
vim /etc/chrony.conf

/etc/chrony.conf配置文件内容：

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#pool 2.centos.pool.ntp.org iburst （这一行注释掉，增加以下两行）
server ntp.aliyun.com iburst
server cn.ntp.org.cn iburst

 重新加载配置：

[root@kiccleaf home]# systemctl restart chronyd.service
[root@kiccleaf home]# chronyc sources -v
210 Number of sources = 2
  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
 / .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample               
===============================================================================
^* 203.107.6.88                  2   6     7     2   -188us[+6871us] +/-   24ms
^- 61.177.189.190                3   6    17    19   +663us[ +663us] +/-   97ms

#再次查看时间
[root@kiccleaf home]# date
Sat Aug 29 16:26:08 CST 2020
 

 

2.2.4 docker 安装

$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
#安装指定版本的docker
$ yum -y install docker-ce-18.06.1.ce-3.el7
# docker生效并启动
$ systemctl enable docker && systemctl start docker
# 查看docker版本
$ docker --version
Docker version 18.06.1-ce, build e68fc7a 

 

2.2.5 添加kubernetes YUM软件源

[root@k8s-master]# cat > /etc/yum.repos.d/kubernetes.repo << EOF

输出如下:
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

 

2.2.6 安装kubeadm,kubelet和kubectl

 

所有主机都需要操作，由于版本更新频繁，这里指定版本号部署

 

#安装指定版本
[root@k8s-master]# yum install -y kubelet-1.15.0 kubeadm-1.15.0 kubectl-1.15.0
#生效
[root@k8s-master]# systemctl enable kubelet

 

2.3 部署Kubernetes Master

只需要在Master 节点执行，这里的apiserve需要修改成自己的master地址。

[root@k8s-master ]# kubeadm init \
--apiserver-advertise-address=192.168.73.138 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.15.0 \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16

 

service-cidr 的选取不能和PodCIDR及本机网络有重叠或者冲突。

一般可以选择一个本机网络和PodCIDR都没有用到的私网地址段，比如PODCIDR使用192.168.0.1/16, 那么service cidr可以选择172.16.0.1/20. 主机网段可以选10.1.0.1/8. 三者之间网络无重叠冲突即可。

也就是上面的复制就行了，除了第一个ip需要改成master的主ip地址，其它复制粘贴完事。

 

 由于默认拉取镜像地址k8s.gcr.io国内无法访问，这里指定阿里云镜像仓库地址。

输出结果:

[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Activating the kubelet service
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.1.0.1 192.168.4.34]
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.4.34 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.4.34 127.0.0.1 ::1]
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
......(省略)
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

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/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You 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 192.168.73.138:6443 --token 2nm5l9.jtp4zwnvce4yt4oj \
    --discovery-token-ca-cert-hash sha256:12f628a21e8d4a7262f57d4f21bc85f8802bb717d

 

红色区域是重点。 

 

根据第一个红色代码复制，依次进行操作：

[root@k8s-master ~]# mkdir -p $HOME/.kube
[root@k8s-master ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@k8s-master ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config

 

然后保存一下上面生成的红色token值和ca证书,一会会用到。这里说下，默认token的有效期为24小时，当过期之后，该token就不可用了，

如果后续有nodes节点加入，解决方法如下：

重新生成新的token:

kubeadm token create
[root@k8s-master ~]# kubeadm token create
0w3a92.ijgba9ia0e3scicg
[root@k8s-master ~]# kubeadm token list
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION                                                EXTRA GROUPS
0w3a92.ijgba9ia0e3scicg   23h       2019-09-08T22:02:40+08:00   authentication,signing   <none>                                                     system:bootstrappers:kubeadm:default-node-token
t0ehj8.k4ef3gq0icr3etl0   22h       2019-09-08T20:58:34+08:00   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token
[root@k8s-master ~]#

获取ca证书sha256编码hash值:

[root@k8s-master ~]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'
ce07a7f5b259961884c55e3ff8784b1eda6f8b5931e6fa2ab0b30b6a4234c09a

 

然后如果是后续加入新的节点，那么拿着新生成token和ca证书，直接命令就完事。

如果是原先已有的节点重新加入集群，跳转到本篇文章的结尾，依次操作，

然后再使用加入命令，就完事了。

 

2.4 加入Kubernetes Node

在两个 Node 节点执行

使用kubeadm join 注册Node节点到Matser

kubeadm join 的内容，在上面kubeadm init 已经生成好了

[root@k8s-node01 ~]# kubeadm join 192.168.4.34:6443 --token 2nm5l9.jtp4zwnvce4yt4oj \
    --discovery-token-ca-cert-hash sha256:12f628a21e8d4a7262f57d4f21bc85f8802bb717dd6f513bf9d33f254fea3e89 

输出内容如下:

[preflight] Running pre-flight checks
    [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...

This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.

Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

 

2.5 安装网络插件

 

只需要在Master 节点执行，下面是坑，不生效，后面会说另一个方法，先别学。修改

[root@k8s-master ~]# wget https://raw.githubusercontent.com/coreos/flannel/a70459be0084506e4ec919aa1c114638878db11b/Documentation/kube-flannel.yml

修改镜像地址：(有可能默认不能拉取，确保能够访问到quay.io这个registery,否则修改如下内容)

[root@k8s-master ~]# vim kube-flannel.yml

进入编辑，把106行，120行的内容，替换如下image，替换之后查看如下为正确

 

[root@k8s-master ~]# cat -n  kube-flannel.yml|grep lizhenliang/flannel:v0.11.0-amd64
   106            image: lizhenliang/flannel:v0.11.0-amd64
   120            image: lizhenliang/flannel:v0.11.0-amd64
[root@k8s-master ~]# kubectl apply -f kube-flannel.yml
[root@k8s-master ~]# ps -ef|grep flannel
root      2032  2013  0 21:00 ?        00:00:00 /opt/bin/flanneld --ip-masq --kube-subnet-mgr

上面的几点操作就是新的神坑出现，地址根本访问不到，也就拿不到kube-flannel.yml,玩你打野，采用硬核办法。

 

方法①:去https://github.com/flannel-io/flannel/releases手动下载flannel，选择12版本的，flanneld-v0.12.0-amd64.docker，

拉到linux中，执行命令 

docker load < flanneld-v0.12.0-amd64.docker

查看已安装的镜像，会发现已经有了 flanneld

docker images

 

再执行命令:

kubectl apply -f kube-flannel.yml

方法②：自行创建kube-flannel.yml文件

填写如下内容：

apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
    - configMap
    - secret
    - emptyDir
    - hostPath
  allowedHostPaths:
    - pathPrefix: "/etc/cni/net.d"
    - pathPrefix: "/etc/kube-flannel"
    - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  # Users and groups
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  # Privilege Escalation
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation: false
  # Capabilities
  allowedCapabilities: ['NET_ADMIN']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  # Host namespaces
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  # SELinux
  seLinux:
    # SELinux is unused in CaaSP
    rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
rules:
  - apiGroups: ['extensions']
    resources: ['podsecuritypolicies']
    verbs: ['use']
    resourceNames: ['psp.flannel.unprivileged']
  - apiGroups:
      - ""
    resources:
      - pods
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes/status
    verbs:
      - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "cniVersion": "0.3.1",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-amd64
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - amd64
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-amd64
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-arm64
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - arm64
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-arm64
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-arm64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-arm
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - arm
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-arm
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-arm
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-ppc64le
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - ppc64le
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-ppc64le
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-ppc64le
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-s390x
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
              - matchExpressions:
                  - key: beta.kubernetes.io/os
                    operator: In
                    values:
                      - linux
                  - key: beta.kubernetes.io/arch
                    operator: In
                    values:
                      - s390x
      hostNetwork: true
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.12.0-s390x
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.12.0-s390x
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg

 

然后执行命令：

kubectl apply -f kube-flannel.yml

我亲测是用第二种方法成功的，复制粘贴。干就完了。

查看集群的node状态，安装完网络工具之后，只有显示如下状态，所有节点全部都Ready好了之后才能继续后面的操作:

 

[root@k8s-master ~]# kubectl get nodes
NAME         STATUS   ROLES    AGE     VERSION
k8s-master   Ready    master   37m     v1.15.0
k8s-node01   Ready    <none>   5m22s   v1.15.0
k8s-node02   Ready    <none>   5m18s   v1.15.0
[root@k8s-master ~]# kubectl get pod -n kube-system
NAME                                 READY   STATUS    RESTARTS   AGE
coredns-bccdc95cf-h2ngj              1/1     Running   0          14m
coredns-bccdc95cf-m78lt              1/1     Running   0          14m
etcd-k8s-master                      1/1     Running   0          13m
kube-apiserver-k8s-master            1/1     Running   0          13m
kube-controller-manager-k8s-master   1/1     Running   0          13m
kube-flannel-ds-amd64-j774f          1/1     Running   0          9m48s
kube-flannel-ds-amd64-t8785          1/1     Running   0          9m48s
kube-flannel-ds-amd64-wgbtz          1/1     Running   0          9m48s
kube-proxy-ddzdx                     1/1     Running   0          14m
kube-proxy-nwhzt                     1/1     Running   0          14m
kube-proxy-p64rw                     1/1     Running   0          13m
kube-scheduler-k8s-master            1/1     Running   0          13m

只有全部都为1/1则可以成功执行后续步骤，如果flannel需检查网络情况，重新进行如下操作

kubectl delete -f kube-flannel.yml

然后重新wget，然后修改镜像地址，然后

kubectl apply -f kube-flannel.yml

神坑继续出现，如果上面flannel不搞定，那么的话，

kubectl get nodes

看到的节点全部都会是NotReady状态，而且

kubectl get pod -n kube-system
看到的pod节点有以下两个，

coredns-bccdc95cf-h2ngj            
coredns-bccdc95cf-m78lt 

一直处于 pending状态，所以必须先搞定flannel。

其实coredns处于不正常状态(比如pending，CrashLoopBackOff状态以及Error状态)的原因有很多：
1、k8s集群中的网络插件没有安装(比如刚初始化完k8s的集群就查看集群节点状态，则coredns相关的pod可能处于pending状态，即集群网络不可用，需要安装flannel或者calico网络插件)；
2、多网络插件冲突(比如同时使用calico与flannel网络插件，也会导致coredns处于pending状态)；
3、启动pod的相关配置文件没有配置成功(比如有的配置文件中要添加command: [ “/bin/bash”, “-ce”, “tail -f /dev/null” ],使得与该pod相关的进程能够在后台持续运行)。
除此之外，pod处于ImagePullBackOff状态的一般是因为镜像拉取不成功，注意使用kubectl describe查看pod的日志信息时，观察具体是k8s集群中哪个节点没有成功拉取镜像。

解决方案：

#清除所有的iptables规则
iptables --flush
#清除NAT这一内建表中的规则
iptables -tnat --flush

如果status是init或者imagePullBackoff,可以稍等一下，意思是在初始化，在拉镜像。直到全部running的时候，就可以起飞了。

2.7 测试Kubernetes集群

在Kubernetes集群中创建一个pod，然后暴露端口，验证是否正常访问：

 

#创建nginx容器
[root@k8s-master ~]# kubectl create deployment nginx --image=nginx
deployment.apps/nginx created
#暴露对外端口
[root@k8s-master ~]# kubectl expose deployment nginx --port=80 --type=NodePort
service/nginx exposed
#查看nginx是否运行成功
[root@k8s-master ~]# kubectl get pods,svc
NAME                         READY   STATUS    RESTARTS   AGE
pod/nginx-554b9c67f9-wf5lm   1/1     Running   0          24s

NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.1.0.1       <none>        443/TCP        39m
service/nginx        NodePort    10.1.224.251   <none>        80:31745/TCP   9

 在浏览器访问。三个结点都可访问，说明集群已经搭建完成， 

访问地址：http://NodeIP:Port ,此例就是：http://192.168.73.138:32039 

 

 

 

扩容nginx副本wei3个，成功

kubectl scale deployment nginx --replicas=3

 

 

 kubectl get pods

 

 

 

 

2.8 部署Dashboard Web页面，可视化查看Kubernetes资源

[root@k8s-master ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml

[root@k8s-master ~]# vim kubernetes-dashboard.yaml
修改内容：
109     spec:
110       containers:
111       - name: kubernetes-dashboard
112         image: lizhenliang/kubernetes-dashboard-amd64:v1.10.1   # 修改此行

......

157 spec:
158   type: NodePort     # 增加此行
159   ports:
160     - port: 443
161       targetPort: 8443
162       nodePort: 30001   # 增加此行
163   selector:
164     k8s-app: kubernetes-dashboard

 

esc退出vim编辑器，:wq保存

#先Docker拉去镜像
docker pull  lizhenliang/kubernetes-dashboard-amd64:v1.10.1

#执行kubernetes-dashboard.yaml 文件
kubectl apply -f kubernetes-dashboard.yaml

 

#查看暴露的端口
kubectl get pods,svc -n kube-system

 

 

 

 访问 Dashboard的web界面
访问地址：https://NodeIP:30001 【必须是https】

 

 

 

 

 

 

创建service account并绑定默认cluster-admin管理员集群角色：【依次执行】

 

 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}‘)

 

[root@k8s-master ~]# kubectl create serviceaccount dashboard-admin -n kube-system
serviceaccount/dashboard-admin created
[root@k8s-master ~]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin
--serviceaccount=kube-system:dashboard-admin
[root@k8s-master ~]# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
Name:         dashboard-admin-token-d9jh2
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: dashboard-admin
              kubernetes.io/service-account.uid: 4aa1906e-17aa-4880-b848-8b3959483323

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1025 bytes
namespace:  11 bytes
token:      eyJhbGciOiJ...(省略如下)...AJdQ

token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.OkF6h7tVQqmNJniCHJhY02G6u6dRg0V8PTiF8xvMuJJUphLyWlWctgmplM4kjKVZo0fZkAthL7WAV5p_AwAuj4LMfo1X5IpxUomp4YZyhqgsBM0A2ksWoKoLDjbizFwOty8TylWlsX1xcJXZjmP9OvNgjjSq5J90N5PnxYIIgwAMP3fawTP7kUXxz5WhJo-ogCijJCFyYBHoqHrgAbk9pusI8DpGTNIZxBMxkwPPwFwzNCOfKhD0c8HjhNeliKsOYLryZObRdmTQXmxsDfxynTKsRxv_EPQb99yW9GXJPQL0OwpYb4b164CFv857ENitvvKEOU6y55P9hFkuQuAJdQ

 

 

 

 

 

已经部署完成。

 

解决其他浏览器不能访问的问题

[root@k8s-master ~]# cd /etc/kubernetes/pki/
[root@k8s-master pki]# mkdir ui
[root@k8s-master pki]# cp apiserver.crt  ui/
[root@k8s-master pki]# cp apiserver.key  ui/
[root@k8s-master pki]# cd ui/
[root@k8s-master ui]# mv apiserver.crt dashboard.pem
[root@k8s-master ui]# mv  apiserver.key   dashboard-key.pem
[root@k8s-master ui]# kubectl delete secret kubernetes-dashboard-certs -n kube-system
[root@k8s-master ui]# kubectl create secret generic kubernetes-dashboard-certs --from-file=./ -n kube-system

[root@k8s-master]# vim kubernetes-dashboard.yaml #回到这个yaml的路径下修改
修改 dashboard-controller.yaml 文件，在args下面增加证书两行
          - --tls-key-file=dashboard-key.pem
          - --tls-cert-file=dashboard.pem
[root@k8s-master ~]kubectl apply -f kubernetes-dashboard.yaml
[root@k8s-master ~]# kubectl create serviceaccount dashboard-admin -n kube-system
serviceaccount/dashboard-admin created
[root@k8s-master ~]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin
--serviceaccount=kube-system:dashboard-admin
[root@k8s-master ~]# kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')
Name:         dashboard-admin-token-zbn9f
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: dashboard-admin
              kubernetes.io/service-account.uid: 40259d83-3b4f-4acc-a4fb-43018de7fc19

Type:  kubernetes.io/service-account-token

Data
====
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.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.E0hGAkeQxd6K-YpPgJmNTv7Sn_P_nzhgCnYXGc9AeXd9k9qAcO97vBeOV-pH518YbjrOAx_D6CKIyP07aCi_3NoPlbbyHtcpRKFl-lWDPdg8wpcIefcpbtS6uCOrpaJdCJjWFcAEHdvcfmiFpdVVT7tUZ2-eHpRTUQ5MDPF-c2IOa9_FC9V3bf6XW6MSCZ_7-fOF4MnfYRa8ucltEIhIhCAeDyxlopSaA5oEbopjaNiVeJUGrKBll8Edatc7-wauUIJXAN-dZRD0xTULPNJ1BsBthGQLyFe8OpL5n_oiHM40tISJYU_uQRlMP83SfkOpbiOpzuDT59BBJB57OQtl3w
ca.crt:     1025 bytes

 

 

坑1记录：

当K8S配置过程中出现出现以下错误：

使用以下命令，将这个文件删除

rm -rf /var/lib/etcd

 

坑2记录：使用kubectl 命令是报错

[root@k8s-master ~]# kubectl get pod
The connection to the server localhost:8080 was refused - did you specify the right host or port?

原因，根据反馈得知找不到/etc/kubernetes/admin.conf这个文件。虽然不知道为啥这个文件莫名其妙消失了，但是无妨，见招拆招吧直接。

具体根据情况，此处记录linux设置该环境变量
#方式一：编辑文件设置
vim /etc/profile
在底部增加新的环境变量 export KUBECONFIG=/etc/kubernetes/admin.conf
#方式二:直接追加文件内容
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> /etc/profile

#生效:

source /etc/profile

坑3记录:k8s + Dashboard 部署成功后一直访问不了

执行这个命令

 iptables -P FORWARD ACCEPT

 

 

第一次安装部署集群成功后，后面从xshell从linux断开后重新开启k8s步骤流程:

#获得权限
sudo su

主节点:

#主节点初始化k8s
kubeadm init \
--apiserver-advertise-address=172.16.8.96 \
--image-repository registry.aliyuncs.com/google_containers \
--kubernetes-version v1.18.0 \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16

 

会报错,执行以下命令：

rm -rf /var/lib/etcd

 

成功初始化后，执行以下程序脚本:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

 

enter回车键 确认覆盖。

执行:

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> /etc/profile

#生效:

source /etc/profile

 

🆗，这样就是重新初始化成功了，再把别的节点加入进来就ok了。

然后kubectl apply -f kube-flannel.yml

等一会，等待5分钟，flannel的两个pod状态也是running了，就完事了。

 

子节点重新加入流程:

#获得权限
sudo su 

 

1、删除node节点

执行kubectl delete node node01（应该是在主节点执行，没测node01应该是一开始set-hostname设置的名字）

2、这时如果直接执行加入，会报错。如下：

[root@k8s-node02 pki]# kubeadm join 192.168.140.128:6443 --token abcdef.0123456789abcdef   --discovery-token-ca-cert-hash sha256:a3d9827be411208258aea7f3ee9aa396956c0a77c8b570503dd677aa3b6eb6d8 
[preflight] Running pre-flight checks
 [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.12. Latest validated version: 18.09
error execution phase preflight: [preflight] Some fatal errors occurred:
 [ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists
 [ERROR FileAvailable--etc-kubernetes-bootstrap-kubelet.conf]: /etc/kubernetes/bootstrap-kubelet.conf already exists
 [ERROR Port-10250]: Port 10250 is in use
 [ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

 

解决方案：

根据报错可以看到端口被占用，配置文件可ca证书已经生成，所以需要删除这些配置文件和证书，并且kill掉占用的端口。建议删除之前先备份。

[root@k8s-node02 pki]# lsof -i:10250
COMMAND PID USER  FD  TYPE DEVICE SIZE/OFF NODE NAME
kubelet 694 root  30u IPv6 26021   0t0 TCP *:10250 (LISTEN)
[root@k8s-node02 pki]# kill -9 694
[root@k8s-node02 pki]# cd /etc/kubernetes/
[root@k8s-node02 kubernetes]# ls
bootstrap-kubelet.conf kubelet.conf manifests pki
[root@k8s-node02 kubernetes]# mv bootstrap-kubelet.conf bootstrap-kubelet.conf_bk
[root@k8s-node02 kubernetes]# mv kubelet.conf kubelet.conf_bk
[root@k8s-node02 kubernetes]# cd pki/
[root@k8s-node02 pki]# ls
ca.crt
[root@k8s-node02 pki]# rm -rf ca.crt 

3、再次执行加入，又出现报错。

[root@k8s-node02 ~]# kubeadm join 192.168.140.128:6443 --token abcdef.0123456789abcdef   --discovery-token-ca-cert-hash sha256:a3d9827be411208258aea7f3ee9aa396956c0a77c8b570503dd677aa3b6eb6d8 
[preflight] Running pre-flight checks
 [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.12. Latest validated version: 18.09
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
[kubelet-check] Initial timeout of 40s passed.
error execution phase kubelet-start: error uploading crisocket: timed out waiting for the condition

解决方案：

执行kubeadm reset子节点重置

[root@k8s-node02 ~]# kubeadm reset
[reset] WARNING: Changes made to this host by 'kubeadm init' or 'kubeadm join' will be reverted.
[reset] Are you sure you want to proceed? [y/N]: y
[preflight] Running pre-flight checks
W0710 10:22:57.487306  31093 removeetcdmember.go:79] [reset] No kubeadm config, using etcd pod spec to get data directory
[reset] No etcd config found. Assuming external etcd
[reset] Please, manually reset etcd to prevent further issues
[reset] Stopping the kubelet service
[reset] Unmounting mounted directories in "/var/lib/kubelet"
[reset] Deleting contents of config directories: [/etc/kubernetes/manifests /etc/kubernetes/pki]
[reset] Deleting files: [/etc/kubernetes/admin.conf /etc/kubernetes/kubelet.conf /etc/kubernetes/bootstrap-kubelet.conf /etc/kubernetes/controller-manager.conf /etc/kubernetes/scheduler.conf]
[reset] Deleting contents of stateful directories: [/var/lib/kubelet /etc/cni/net.d /var/lib/dockershim /var/run/kubernetes]
 
The reset process does not reset or clean up iptables rules or IPVS tables.
If you wish to reset iptables, you must do so manually.
For example:
iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X
 
If your cluster was setup to utilize IPVS, run ipvsadm --clear (or similar)
to reset your system's IPVS tables.
 
The reset process does not clean your kubeconfig files and you must remove them manually.
Please, check the contents of the $HOME/.kube/config file.

4、最后执行加入，问题解决。

[root@k8s-node02 ~]# kubeadm join 192.168.140.128:6443 --token abcdef.0123456789abcdef   --discovery-token-ca-cert-hash sha256:a3d9827be411208258aea7f3ee9aa396956c0a77c8b570503dd677aa3b6eb6d8 
[preflight] Running pre-flight checks
 [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.12. Latest validated version: 18.09
[preflight] Reading configuration from the cluster...
[preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.15" ConfigMap in the kube-system namespace
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Activating the kubelet service
[kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap...
 
This node has joined the cluster:
* Certificate signing request was sent to apiserver and a response was received.
* The Kubelet was informed of the new secure connection details.
 
Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

5、查看master节点，加入成功。

[root@k8s-master01 ~]# kubectl get nodes
NAME      STATUS  ROLES  AGE  VERSION
k8s-master01  Ready  master  120m  v1.15.1
k8s-node01   Ready  <none>  100m  v1.15.1
k8s-node02   Ready  <none>  83m  v1.15.1