kubeadm非高可用集群部署文档¶

集群信息¶

节点规划 ¶

部署k8s集群的节点按照用途可以划分为如下2类角色：

master：集群的master节点，集群的初始化节点，基础配置不低于2C4G
slave：集群的slave节点，可以多台，基础配置不低于2C4G

本例为了演示slave节点的添加，会部署一台master+2台slave，节点规划如下：

主机名	节点ip	角色	部署组件
k8s-master	172.21.51.143	master	etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel
k8s-slave1	172.21.51.67	slave	kubectl, kubelet, kube-proxy, flannel
k8s-slave2	172.21.51.68	slave	kubectl, kubelet, kube-proxy, flannel

组件版本 ¶

组件	版本	说明
CentOS	7.8.2003
Kernel	Linux 3.10.0-1127.10.1.el7.x86_64
etcd	3.4.13-0	使用Pod方式部署，默认数据挂载到本地路径
coredns	1.7.0
kubeadm	v1.21.5
kubectl	v1.21.5
kubelet	v1.21.5
kube-proxy	v1.21.5
flannel	v0.11.0

安装前准备¶

设置hosts解析 ¶

操作节点：所有节点（k8s-master，k8s-slave）均需执行

修改hostname hostname必须只能包含小写字母、数字、","、"-"，且开头结尾必须是小写字母或数字

# 在master节点
$ hostnamectl set-hostname k8s-master #设置master节点的hostname

# 在slave-1节点
$ hostnamectl set-hostname k8s-slave1 #设置slave1节点的hostname

# 在slave-2节点
$ hostnamectl set-hostname k8s-slave2 #设置slave2节点的hostname

添加hosts解析

$ cat >>/etc/hosts<<EOF
10.211.55.25 k8s-master
10.211.55.26 k8s-slave1
10.211.55.27 k8s-slave2
EOF

调整系统配置 ¶

操作节点：所有的master和slave节点（k8s-master,k8s-slave）需要执行

本章下述操作均以k8s-master为例，其他节点均是相同的操作（ip和hostname的值换成对应机器的真实值）

设置安全组开放端口

如果节点间无安全组限制（内网机器间可以任意访问），可以忽略，否则，至少保证如下端口可通： k8s-master节点：TCP：6443，2379，2380，60080，60081 UDP协议端口全部打开 k8s-slave节点：UDP协议端口全部打开

设置iptables

iptables -P FORWARD ACCEPT

关闭swap

swapoff -a
# 防止开机自动挂载 swap 分区
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

关闭selinux和防火墙

sed -ri 's#(SELINUX=).*#\1disabled#' /etc/selinux/config
setenforce 0
systemctl disable firewalld && systemctl stop firewalld

修改内核参数

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
vm.max_map_count=262144
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

设置yum源

$ curl -o /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
$ curl -o /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
$ cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
$ yum clean all && yum makecache

安装docker ¶

操作节点：所有节点

 ## 查看所有的可用版本
$ yum list docker-ce --showduplicates | sort -r
##安装旧版本 yum install docker-ce-cli-18.09.9-3.el7  docker-ce-18.09.9-3.el7
## 安装源里最新版本
$ yum install docker-ce-20.10.12 -y

## 配置docker加速
$ mkdir -p /etc/docker
vi /etc/docker/daemon.json
{
  "insecure-registries": [    
    "172.21.51.143:5000" 
  ],                          
  "registry-mirrors" : [
    "https://8xpk5wnt.mirror.aliyuncs.com"
  ]
}
## 启动docker
$ systemctl enable docker && systemctl start docker

初始化集群¶

安装 kubeadm, kubelet 和 kubectl ¶

操作节点：所有的master和slave节点(k8s-master,k8s-slave) 需要执行

$ yum install -y kubelet-1.21.5 kubeadm-1.21.5 kubectl-1.21.5 --disableexcludes=kubernetes
## 查看kubeadm 版本
$ kubeadm version
## 设置kubelet开机启动
$ systemctl enable kubelet

初始化配置文件 ¶

操作节点：只在master节点（k8s-master）执行

$ kubeadm config print init-defaults > kubeadm.yaml
$ cat kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: abcdef.0123456789abcdef
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 172.21.51.143  # 修改修改成master节点地址 
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master      # 修改
  taints: null
---
apiServer:
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers   # 镜像仓库地址修改成国内阿里云地址 
kind: ClusterConfiguration
kubernetesVersion: 1.21.5    # 修改
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16  # 修改 
  serviceSubnet: 10.96.0.0/12
scheduler: {}

对于上面的资源清单的文档比较杂，要想完整了解上面的资源对象对应的属性，可以查看对应的 godoc 文档，地址: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2。

提前下载镜像 ¶

操作节点：只在master节点（k8s-master）执行

  # 查看需要使用的镜像列表,若无问题，将得到如下列表
$ kubeadm config images list --config kubeadm.yaml
registry.aliyuncs.com/google_containers/kube-apiserver:v1.16.0
registry.aliyuncs.com/google_containers/kube-controller-manager:v1.16.0
registry.aliyuncs.com/google_containers/kube-scheduler:v1.16.0
registry.aliyuncs.com/google_containers/kube-proxy:v1.16.0
registry.aliyuncs.com/google_containers/pause:3.1
registry.aliyuncs.com/google_containers/etcd:3.3.15-0
registry.aliyuncs.com/google_containers/coredns:1.21.5
  # 提前下载镜像到本地
$ kubeadm config images pull --config kubeadm.yaml
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-apiserver:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-controller-manager:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-scheduler:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/kube-proxy:v1.16.0
[config/images] Pulled registry.aliyuncs.com/google_containers/pause:3.1
[config/images] Pulled registry.aliyuncs.com/google_containers/etcd:3.3.15-0
[config/images] Pulled registry.aliyuncs.com/google_containers/coredns:1.21.5

初始化master节点 ¶

操作节点：只在master节点（k8s-master）执行

$ kubeadm init --config kubeadm.yaml

若初始化成功后，最后会提示如下信息：

...
Your Kubernetes master 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 172.21.51.143:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

接下来按照上述提示信息操作，配置kubectl客户端的认证

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

⚠️注意：此时使用 kubectl get nodes查看节点应该处于notReady状态，因为还未配置网络插件

若执行初始化过程中出错，根据错误信息调整后，执行kubeadm reset后再次执行init操作即可

添加slave节点到集群中 ¶

操作节点：所有的slave节点（k8s-slave）需要执行在每台slave节点，执行如下命令，该命令是在kubeadm init成功后提示信息中打印出来的，需要替换成实际init后打印出的命令。

kubeadm join 172.21.51.143:6443 --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:1c4305f032f4bf534f628c32f5039084f4b103c922ff71b12a5f0f98d1ca9a4f

如果忘记添加命令，可以通过如下命令生成：

$ kubeadm token create --print-join-command

网路插件¶

操作节点：只在master节点（k8s-master）执行，CNI

下载flannel的yaml文件

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
-------------------------------------
v0.19.2 版本在 158行
# 仓库的地址
https://github.com/flannel-io/flannel/blob/f30ebbb670dcbfa7ff5f0d1dd9cccacd2d660a41/Documentation/kube-flannel.yml

[root@k8s-master ~]# cat kube-flannel.yml
---
kind: Namespace
apiVersion: v1
metadata:
  name: kube-flannel
  labels:
    pod-security.kubernetes.io/enforce: privileged
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
rules:
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - nodes
  verbs:
  - list
  - watch
- apiGroups:
  - ""
  resources:
  - nodes/status
  verbs:
  - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-flannel
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-flannel
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-flannel
  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
  namespace: kube-flannel
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni-plugin
       #image: flannelcni/flannel-cni-plugin:v1.1.0 for ppc64le and mips64le (dockerhub limitations may apply)
        image: docker.io/rancher/mirrored-flannelcni-flannel-cni-plugin:v1.1.0
        command:
        - cp
        args:
        - -f
        - /flannel
        - /opt/cni/bin/flannel
        volumeMounts:
        - name: cni-plugin
          mountPath: /opt/cni/bin
      - name: install-cni
       #image: flannelcni/flannel:v0.19.2 for ppc64le and mips64le (dockerhub limitations may apply)
        image: docker.io/rancher/mirrored-flannelcni-flannel:v0.19.2
        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: flannelcni/flannel:v0.19.2 for ppc64le and mips64le (dockerhub limitations may apply)
        image: docker.io/rancher/mirrored-flannelcni-flannel:v0.19.2
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=eth0
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
            add: ["NET_ADMIN", "NET_RAW"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        - name: EVENT_QUEUE_DEPTH
          value: "5000"
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
        - name: xtables-lock
          mountPath: /run/xtables.lock
      volumes:
      - name: run
        hostPath:
          path: /run/flannel
      - name: cni-plugin
        hostPath:
          path: /opt/cni/bin
      - name: cni
        hostPath:
          path: /etc/cni/net.d
      - name: flannel-cfg
        configMap:
          name: kube-flannel-cfg
      - name: xtables-lock
        hostPath:
          path: /run/xtables.lock
          type: FileOrCreate

修改配置，指定网卡名称，大概在文件的190行，添加一行配置：

$ vi kube-flannel.yml
...      
      containers:
      - name: kube-flannel
        image: rancher/mirrored-flannelcni-flannel:v0.16.1
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=eth0  # 如果机器存在多网卡的话，指定内网网卡的名称，默认不指定的话会找第一块网卡
        resources:
          requests:
            cpu: "100m"
...

执行安装flannel网络插件

# 先拉取镜像,此过程国内速度比较慢
$ docker pull rancher/mirrored-flannelcni-flannel:v0.16.1
# 执行flannel安装
$ kubectl apply -f kube-flannel.yml

集群设置¶

设置master节点是否可调度（可选）¶

操作节点：k8s-master

默认部署成功后，master节点无法调度业务pod，如需设置master节点也可以参与pod的调度，需执行：

$ kubectl taint node k8s-master node-role.kubernetes.io/master:NoSchedule-

课程后期会部署系统组件到master节点，因此，此处建议设置k8s-master节点为可调度

设置kubectl自动补全 ¶

操作节点：k8s-master

$ yum install bash-completion -y
$ source /usr/share/bash-completion/bash_completion
$ source <(kubectl completion bash)
$ echo "source <(kubectl completion bash)" >> ~/.bashrc

调整证书过期¶

使用kubeadm安装的集群，证书默认有效期为1年，可以通过如下方式修改为10年。

$ cd /etc/kubernetes/pki

# 查看当前证书有效期
$ for i in $(ls *.crt); do echo "===== $i ====="; openssl x509 -in $i -text -noout | grep -A 3 'Validity' ; done

$ # mkdir backup_key; cp -rp ./* backup_key/
$ mkdir ../backup_key ; cp -rp * ../backup_key/ ; mv ../backup_key ./
$ git clone https://github.com/yuyicai/update-kube-cert.git
$ cd update-kube-cert/ 
$ bash update-kubeadm-cert.sh all

# 重建管理服务
$ kubectl -n kube-system delete po kube-apiserver-k8s-master kube-controller-manager-k8s-master kube-scheduler-k8s-master

验证集群¶

操作节点：在master节点（k8s-master）执行

$ kubectl get nodes  #观察集群节点是否全部Ready

创建测试nginx服务

$ kubectl run  test-nginx --image=nginx:alpine

查看pod是否创建成功，并访问pod ip测试是否可用

$ kubectl get po -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE         NOMINATED NODE   READINESS GATES
test-nginx-5bd8859b98-5nnnw   1/1     Running   0          9s    10.244.1.2   k8s-slave1   <none>           <none>
$ curl 10.244.1.2
...
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

部署dashboard ¶

部署服务

# 推荐使用下面这种方式
$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml
$ vi recommended.yaml
# 修改Service为NodePort类型，文件的45行上下
......
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard
  type: NodePort  # 加上type=NodePort变成NodePort类型的服务
......

查看访问地址，本例为30133端口

$ kubectl apply -f recommended.yaml
$ kubectl -n kubernetes-dashboard get svc
NAME                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   10.105.62.124   <none>        8000/TCP        31m
kubernetes-dashboard        NodePort    10.103.74.46    <none>        443:30133/TCP   31m

使用浏览器访问 https://172.21.51.143:30133，其中172.21.51.143为master节点的外网ip地址，chrome目前由于安全限制，测试访问不了，使用firefox可以进行访问。

问题处理：您的连接不是私密连接；因为此网站发送了 Google Chrome 无法处理的杂乱凭据。网络错误和攻击通常是暂时的，因此，此网页稍后可能会恢复正常。

当前页面点击任意空白处，直接键盘输入“thisisunsafe”即可解决。

创建ServiceAccount进行访问

# kubectl -n kubernetes-dashboard create serviceaccount admin  #也可以用这个命令创建serviceaccount账户
$ vi dashboard-admin.conf
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: admin
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: admin
  namespace: kubernetes-dashboard

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kubernetes-dashboard

$ kubectl apply -f dashboard-admin.conf  #授权
[root@k8s-master ~]# kubectl -n kubernetes-dashboard get sa  #serviceaccount sa
[root@k8s-master ~]# kubectl -n kubernetes-dashboard get secret
$ kubectl -n kubernetes-dashboard get secret |grep admin-token
admin-token-7clrz                  kubernetes.io/service-account-token   3      7m17s
[root@k8s-master ~]# kubectl -n kubernetes-dashboard describe secret admin-token-7clrz
Name:         admin-token-7clrz
Namespace:    kubernetes-dashboard
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: admin
              kubernetes.io/service-account.uid: 8c64d21f-bdc6-4610-9bb1-ddb22017fed0

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1066 bytes
namespace:  20 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6Ik9VMi1HX3FFMlBUT193OUo3ZWI4eDh3aE9pc0dTYXMyQWRMNnRHNHJtMWsifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi03Y2xyeiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjhjNjRkMjFmLWJkYzYtNDYxMC05YmIxLWRkYjIyMDE3ZmVkMCIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlcm5ldGVzLWRhc2hib2FyZDphZG1pbiJ9.a7UIMu1PfZ3e4j51R2qIiWZm0yZgdn5TNoUOwNLtMKdGX0LsUQP7NhUJQY_uX4ymtjqQj3aBXY7t3fWamGSBxqkf7nD5s34ibBES-ve6IXUNgQYQg3o1kJWwen20VzjCcQbNcq8Ba6W7Zz37kx6IQQNCAq41Tzq030APZ2JsGnzL8HIkHxQ5SAu8HzKsUTg1Zu7r6aDh97CwRych3Wcr09BzF6R0gB3Gb2KvqAbWItusysdt1YYw_Vmu7YbUdmi437Zcsw6JBLDLrdnSEs4AYyXdSG5_63OevHKaWpDjx4uTCawt7fhP-MpzktOctUK-RpCAAp9dbr4VINwbOj51Tg
# 使用该命令拿到token，然后粘贴到
$ kubectl -n kubernetes-dashboard get secret admin-token-7clrz -o jsonpath={.data.token}|base64 -d
eyJhbGciOiJSUzI1NiIsImtpZCI6Ik9VMi1HX3FFMlBUT193OUo3ZWI4eDh3aE9pc0dTYXMyQWRMNnRHNHJtMWsifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi03Y2xyeiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjhjNjRkMjFmLWJkYzYtNDYxMC05YmIxLWRkYjIyMDE3ZmVkMCIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlcm5ldGVzLWRhc2hib2FyZDphZG1pbiJ9.a7UIMu1PfZ3e4j51R2qIiWZm0yZgdn5TNoUOwNLtMKdGX0LsUQP7NhUJQY_uX4ymtjqQj3aBXY7t3fWamGSBxqkf7nD5s34ibBES-ve6IXUNgQYQg3o1kJWwen20VzjCcQbNcq8Ba6W7Zz37kx6IQQNCAq41Tzq030APZ2JsGnzL8HIkHxQ5SAu8HzKsUTg1Zu7r6aDh97CwRych3Wcr09BzF6R0gB3Gb2KvqAbWItusysdt1YYw_Vmu7YbUdmi437Zcsw6JBLDLrdnSEs4AYyXdSG5_63OevHKaWpDjx4uTCawt7fhP-MpzktOctUK-RpCAAp9dbr4VINwbOj51Tg

清理集群¶

如果你的集群安装过程中遇到了其他问题，我们可以使用下面的命令来进行重置：

# 在全部集群节点执行
kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /run/flannel/subnet.env
rm -rf /var/lib/cni/
mv /etc/kubernetes/ /tmp
mv /var/lib/etcd /tmp
mv ~/.kube /tmp
iptables -F
iptables -t nat -F
ipvsadm -C
ip link del kube-ipvs0
ip link del dummy0

[root@k8s-master ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml
[root@k8s-master ~]# cat recommended.yaml
# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

apiVersion: v1
kind: Namespace
metadata:
  name: kubernetes-dashboard

---

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kubernetes-dashboard
type: Opaque

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-csrf
  namespace: kubernetes-dashboard
type: Opaque
data:
  csrf: ""

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-key-holder
  namespace: kubernetes-dashboard
type: Opaque

---

kind: ConfigMap
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-settings
  namespace: kubernetes-dashboard

---

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
rules:
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
  - apiGroups: [""]
    resources: ["secrets"]
    resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs", "kubernetes-dashboard-csrf"]
    verbs: ["get", "update", "delete"]
    # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
  - apiGroups: [""]
    resources: ["configmaps"]
    resourceNames: ["kubernetes-dashboard-settings"]
    verbs: ["get", "update"]
    # Allow Dashboard to get metrics.
  - apiGroups: [""]
    resources: ["services"]
    resourceNames: ["heapster", "dashboard-metrics-scraper"]
    verbs: ["proxy"]
  - apiGroups: [""]
    resources: ["services/proxy"]
    resourceNames: ["heapster", "http:heapster:", "https:heapster:", "dashboard-metrics-scraper", "http:dashboard-metrics-scraper"]
    verbs: ["get"]

---

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
rules:
  # Allow Metrics Scraper to get metrics from the Metrics server
  - apiGroups: ["metrics.k8s.io"]
    resources: ["pods", "nodes"]
    verbs: ["get", "list", "watch"]

---

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
        - name: kubernetes-dashboard
          image: kubernetesui/dashboard:v2.2.0
          imagePullPolicy: Always
          ports:
            - containerPort: 8443
              protocol: TCP
          args:
            - --auto-generate-certificates
            - --namespace=kubernetes-dashboard
            # Uncomment the following line to manually specify Kubernetes API server Host
            # If not specified, Dashboard will attempt to auto discover the API server and connect
            # to it. Uncomment only if the default does not work.
            # - --apiserver-host=http://my-address:port
          volumeMounts:
            - name: kubernetes-dashboard-certs
              mountPath: /certs
              # Create on-disk volume to store exec logs
            - mountPath: /tmp
              name: tmp-volume
          livenessProbe:
            httpGet:
              scheme: HTTPS
              path: /
              port: 8443
            initialDelaySeconds: 30
            timeoutSeconds: 30
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      volumes:
        - name: kubernetes-dashboard-certs
          secret:
            secretName: kubernetes-dashboard-certs
        - name: tmp-volume
          emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 8000
      targetPort: 8000
  selector:
    k8s-app: dashboard-metrics-scraper

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: dashboard-metrics-scraper
  template:
    metadata:
      labels:
        k8s-app: dashboard-metrics-scraper
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
    spec:
      containers:
        - name: dashboard-metrics-scraper
          image: kubernetesui/metrics-scraper:v1.0.6
          ports:
            - containerPort: 8000
              protocol: TCP
          livenessProbe:
            httpGet:
              scheme: HTTP
              path: /
              port: 8000
            initialDelaySeconds: 30
            timeoutSeconds: 30
          volumeMounts:
          - mountPath: /tmp
            name: tmp-volume
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      volumes:
        - name: tmp-volume
          emptyDir: {}

kubeadm高可用集群部署文档¶

集群信息¶

1. 节点规划 ¶

部署k8s集群的节点按照用途可以划分为如下2类角色：

master：集群的master节点，集群的初始化节点，基础配置不低于2C4G
node：集群的node节点，可以多台，基础配置不低于2C4G

本例为了演示node节点的添加，会部署一台master+2台node，节点规划如下：

主机名	节点ip	角色	部署组件
k8s-master1	172.21.51.67	master	etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel
k8s-master2	172.21.51.68	master	etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel
k8s-master3	172.21.51.55	master	etcd, kube-apiserver, kube-controller-manager, kubectl, kubeadm, kubelet, kube-proxy, flannel
	172.21.51.120	VIP	作为3台master节点的LB使用
k8s-node1	172.21.51.143	node	kubectl, kubelet, kube-proxy, flannel
k8s-node2	172.21.52.84	node	kubectl, kubelet, kube-proxy, flannel

2. 组件版本 ¶

组件	版本	说明
CentOS	7.8.2003
Kernel	Linux 3.10.0-1127.10.1.el7.x86_64
etcd	3.4.13-0	使用Pod方式部署，默认数据挂载到本地路径
coredns	1.8.0
kubeadm	v1.21.5
kubectl	v1.21.5
kubelet	v1.21.5
kube-proxy	v1.21.5
flannel	v0.11.0

安装前准备¶

1. 设置hosts解析 ¶

操作节点：所有节点（k8s-master，k8s-node）均需执行

修改hostname hostname必须只能包含小写字母、数字、","、"-"，且开头结尾必须是小写字母或数字

# 以其中一台master和node为例：

# 在k8s-master1节点
$ hostnamectl set-hostname k8s-master1 #设置master节点的hostname

# 在node-1节点
$ hostnamectl set-hostname k8s-node1 #设置node1节点的hostname

添加hosts解析

$ cat >>/etc/hosts<<EOF
172.21.51.67 k8s-master1
172.21.51.68 k8s-master2
172.21.51.50 k8s-master3
172.21.51.143 k8s-node1
172.21.52.84 k8s-node1
EOF

2. 调整系统配置 ¶

操作节点：所有的master和node节点（k8s-master,k8s-node）需要执行

本章下述操作均以k8s-master为例，其他节点均是相同的操作（ip和hostname的值换成对应机器的真实值）

设置安全组开放端口

如果节点间无安全组限制（内网机器间可以任意访问），可以忽略，否则，至少保证如下端口可通： k8s-master节点：TCP：6443，2379，2380，60080，60081UDP协议端口全部打开 k8s-node节点：UDP协议端口全部打开

设置iptables

iptables -P FORWARD ACCEPT

关闭swap

swapoff -a && sysctl -w vm.swappiness=0
# 防止开机自动挂载 swap 分区
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab

关闭selinux和防火墙

sed -ri 's#(SELINUX=).*#\1disabled#' /etc/selinux/config
setenforce 0
systemctl disable firewalld && systemctl stop firewalld

修改内核参数

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
vm.max_map_count=262144
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-iptables = 1
net.bridge.bridge-nf-call-ip6tables = 1
fs.may_detach_mounts = 1
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
fs.file-max=52706963
fs.nr_open=52706963
net.netfilter.nf_conntrack_max=2310720
net.ipv4.tcp_keepalive_time = 600
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_intvl =15
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_orphans = 327680
net.ipv4.tcp_orphan_retries = 3
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.ip_conntrack_max = 65536
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_timestamps = 0
net.core.somaxconn = 16384
EOF
modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

设置yum源

$ curl -o /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
$ curl -o /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
$ cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
        http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF
$ yum clean all && yum makecache
$ yum install ipvsadm ipset sysstat conntrack libseccomp -y

3. 安装docker ¶

操作节点：所有节点

 ## 查看所有的可用版本
$ yum list docker-ce --showduplicates | sort -r
##安装旧版本 yum install docker-ce-cli-18.09.9-3.el7  docker-ce-18.09.9-3.el7
## 安装源里最新版本
$ yum install docker-ce-20.10.12 -y

## 配置docker加速
$ mkdir -p /etc/docker
vi /etc/docker/daemon.json
{
  "insecure-registries": [    
    "172.21.51.67:5000" 
  ],                          
  "registry-mirrors" : [
    "https://8xpk5wnt.mirror.aliyuncs.com"
  ],
  "exec-opts": ["native.cgroupdriver=systemd"]
}
## 启动docker
$ systemctl enable docker && systemctl start docker

初始化集群¶

1. 安装 kubeadm, kubelet 和 kubectl ¶

操作节点：所有的master和node节点(k8s-master,k8s-node) 需要执行

$ yum install -y kubelet-1.21.5 kubeadm-1.21.5 kubectl-1.21.5 --disableexcludes=kubernetes
## 查看kubeadm 版本
$ kubeadm version
## 设置kubelet开机启动
$ cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=systemd --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2"
EOF
$ systemctl enable kubelet

2. 安装配置haproxy、keepalived ¶

操作节点：所有的master

$ yum install keepalived haproxy -y

# 所有master节点执行,注意替换最后的master节点IP地址
$ vi /etc/haproxy/haproxy.cfg
global
  maxconn  2000
  ulimit-n  16384
  log  127.0.0.1 local0 err
  stats timeout 30s
defaults
  log global
  mode  http
  option  httplog
  timeout connect 5000
  timeout client  50000
  timeout server  50000
  timeout http-request 15s
timeout http-keep-alive 15s
frontend monitor-in
  bind *:33305
  mode http
  option httplog
  monitor-uri /monitor
frontend k8s-master
  bind 0.0.0.0:7443
  bind 127.0.0.1:7443
  mode tcp
  option tcplog
  tcp-request inspect-delay 5s
  default_backend k8s-master
backend k8s-master
  mode tcp
  option tcplog
  option tcp-check
  balance roundrobin
  default-server inter 10s downinter 5s rise 2 fall 2 slowstart 60s maxconn 250 maxqueue 256 weight 100
  server k8s-master1    172.21.51.67:6443  check
  server k8s-master2    172.21.51.68:6443   check
  server k8s-master3    172.21.51.55:6443   check 


# 在k8s-master1节点，注意mcast_src_ip换成实际的master1ip地址，virtual_ipaddress换成lb地址
$ vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5
    weight -5
    fall 2
    rise 1
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    mcast_src_ip 172.21.51.67
    virtual_router_id 60
    priority 101
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        172.21.51.120
    }
    track_script {
       chk_apiserver
    }
}
# 在k8s-master2和k8s-master3分别创建/etc/keepalived/keepalived.conf，注意修改mcast_src_ip和virtual_ipaddress和state 改为BACKUP
# 在k8s-master2节点
$ cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
    router_id LVS_DEVEL
script_user root
    enable_script_security
}
vrrp_script chk_apiserver {
    script "/etc/keepalived/check_apiserver.sh"
    interval 5
    weight -5
    fall 2
rise 1
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    mcast_src_ip 172.21.51.68
    virtual_router_id 60
    priority 101
    advert_int 2
    authentication {
        auth_type PASS
        auth_pass K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        172.21.51.120
    }
    track_script {
       chk_apiserver
    }
}



#所有master节点配置KeepAlived健康检查文件：
$ cat /etc/keepalived/check_apiserver.sh
#!/bin/bash
err=0
for k in $(seq 1 3)
do
    check_code=$(pgrep haproxy)
    if [[ $check_code == "" ]]; then
        err=$(expr $err + 1)
        sleep 1
        continue
    else
        err=0
        break
    fi
done
if [[ $err != "0" ]]; then
    echo "systemctl stop keepalived"
    /usr/bin/systemctl stop keepalived
    exit 1
else
    exit 0
fi

# 启动haproxy和keepalived---->所有master节点
$ chmod +x /etc/keepalived/check_apiserver.sh
$ systemctl daemon-reload
$ systemctl enable --now haproxy
$ systemctl enable --now keepalived 


# 测试lbip是否生效
$ telnet 172.21.51.120 7443

3. 初始化配置文件 ¶

操作节点：只在master节点（k8s-master）执行

$ cat kubeadm.yaml
apiVersion: kubeadm.k8s.io/v1beta2
bootstrapTokens:
- groups:
  - system:bootstrappers:kubeadm:default-node-token
  token: 7t2weq.bjbawausm0jaxury
  ttl: 24h0m0s
  usages:
  - signing
  - authentication
kind: InitConfiguration
localAPIEndpoint:
  advertiseAddress: 172.21.51.67
  bindPort: 6443
nodeRegistration:
  criSocket: /var/run/dockershim.sock
  name: k8s-master01
  taints:
  - effect: NoSchedule
    key: node-role.kubernetes.io/master
---
apiServer:
  certSANs:
  - 172.21.51.120
  timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controlPlaneEndpoint: 172.21.51.120:7443
controllerManager: {}
dns:
  type: CoreDNS
etcd:
  local:
    dataDir: /var/lib/etcd
imageRepository: registry.cn-hangzhou.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.21.5
networking:
  dnsDomain: cluster.local
  podSubnet: 10.244.0.0/16
  serviceSubnet: 10.96.0.0/12
scheduler: {}

对于上面的资源清单的文档比较杂，要想完整了解上面的资源对象对应的属性，可以查看对应的 godoc 文档，地址: https://godoc.org/k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm/v1beta2。

4. 提前下载镜像 ¶

操作节点：所有master节点执行

  # 查看需要使用的镜像列表,若无问题，将得到如下列表
$ kubeadm config images list --config kubeadm.yaml
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.21.5
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.21.5
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.21.5
registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.21.5
registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.4.1
registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.13-0
registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:v1.8.0
  # 提前下载镜像到本地
$ kubeadm config images pull --config kubeadm.yaml

5. 初始化master节点 ¶

操作节点：只在master节点（k8s-master）执行

$ kubeadm init --config kubeadm.yaml --upload-certs

若初始化成功后，最后会提示如下信息：

...
Your Kubernetes master 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 172.21.51.120:7443 --token 7t2weq.bjbawausm0jaxury         --discovery-token-ca-cert-hash sha256:b0d875f1dafe9f479b23603c3424cad5e0e3aa0a47a8274f9d24432e97e3dbde         --control-plane --certificate-key 0ea981458813160b6fbc572d415e14cbc28c4bf958a765a7bc989b7ecc5dcdd6

接下来按照上述提示信息操作，配置kubectl客户端的认证

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

若执行初始化过程中出错，根据错误信息调整后，执行 kubeadm reset -f ; ipvsadm --clear ; rm -rf ~/.kube

6. 添加其他master节点到集群中 ¶

$ kubeadm join 172.21.51.120:7443 --token 7t2weq.bjbawausm0jaxury         --discovery-token-ca-cert-hash sha256:b0d875f1dafe9f479b23603c3424cad5e0e3aa0a47a8274f9d24432e97e3dbde         --control-plane --certificate-key 0ea981458813160b6fbc572d415e14cbc28c4bf958a765a7bc989b7ecc5dcdd6

7. 添加node节点到集群中 ¶

操作节点：所有的node节点（k8s-node）需要执行在每台node节点，执行如下命令，该命令是在kubeadm init成功后提示信息中打印出来的，需要替换成实际init后打印出的命令。

kubeadm join 172.21.51.120:7443 --token 7t2weq.bjbawausm0jaxury         --discovery-token-ca-cert-hash sha256:b0d875f1dafe9f479b23603c3424cad5e0e3aa0a47a8274f9d24432e97e3dbde

如果忘记添加命令，可以通过如下命令生成：

$ kubeadm token create --print-join-command

网络插件¶

操作节点：只在master节点（k8s-master）执行，CNI

下载flannel的yaml文件

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

修改配置，指定网卡名称，大概在文件的190行，添加一行配置：

$ vi kube-flannel.yml
...      
      containers:
      - name: kube-flannel
        image: rancher/mirrored-flannelcni-flannel:v0.16.1
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        - --iface=eth0  # 如果机器存在多网卡的话，指定内网网卡的名称，默认不指定的话会找第一块网卡
        resources:
          requests:
            cpu: "100m"
...

执行安装flannel网络插件

# 先拉取镜像,此过程国内速度比较慢
$ docker pull rancher/mirrored-flannelcni-flannel:v0.16.1
# 执行flannel安装
$ kubectl apply -f kube-flannel.yml

集群设置¶

设置master节点是否可调度（可选）¶

操作节点：k8s-master

默认部署成功后，master节点无法调度业务pod，如需设置master节点也可以参与pod的调度，需执行：

$ kubectl taint node k8s-master node-role.kubernetes.io/master:NoSchedule-

课程后期会部署系统组件到master节点，因此，此处建议设置k8s-master节点为可调度

设置kubectl自动补全 ¶

操作节点：k8s-master

$ yum install bash-completion -y
$ source /usr/share/bash-completion/bash_completion
$ source <(kubectl completion bash)
$ echo "source <(kubectl completion bash)" >> ~/.bashrc

调整证书过期¶

使用kubeadm安装的集群，证书默认有效期为1年，可以通过如下方式修改为10年。

$ cd /etc/kubernetes/pki

# 查看当前证书有效期
$ for i in $(ls *.crt); do echo "===== $i ====="; openssl x509 -in $i -text -noout | grep -A 3 'Validity' ; done

$ mkdir backup_key; cp -rp ./* backup_key/
$ git clone https://github.com/yuyicai/update-kube-cert.git
$ cd update-kube-cert/ 
$ bash update-kubeadm-cert.sh all

# 重建管理服务
$ kubectl -n kube-system delete po kube-apiserver-k8s-master01 kube-apiserver-k8s-master02 kube-apiserver-k8s-master03 kube-controller-manager-k8s-master01 kube-controller-manager-k8s-master02 kube-controller-manager-k8s-master03 kube-scheduler-k8s-master01 kube-scheduler-k8s-master02 kube-scheduler-k8s-master03

验证集群¶

操作节点：在master节点（k8s-master）执行

$ kubectl get nodes  #观察集群节点是否全部Ready

创建测试nginx服务

$ kubectl run  test-nginx --image=nginx:alpine

查看pod是否创建成功，并访问pod ip测试是否可用

$ kubectl get po -o wide
NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE         NOMINATED NODE   READINESS GATES
test-nginx-5bd8859b98-5nnnw   1/1     Running   0          9s    10.244.1.2   k8s-slave1   <none>           <none>
$ curl 10.244.1.2
...
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

部署dashboard ¶

部署服务

# 推荐使用下面这种方式
$ wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml
$ vi recommended.yaml
# 修改Service为NodePort类型，文件的45行上下
......
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard
  type: NodePort  # 加上type=NodePort变成NodePort类型的服务
......

查看访问地址，本例为30133端口

$ kubectl apply -f recommended.yaml
$ kubectl -n kubernetes-dashboard get svc
NAME                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)         AGE
dashboard-metrics-scraper   ClusterIP   10.105.62.124   <none>        8000/TCP        31m
kubernetes-dashboard        NodePort    10.103.74.46    <none>        443:30133/TCP   31m

使用浏览器访问 https://172.21.51.67:30133，其中172.21.51.67为master节点的外网ip地址，chrome目前由于安全限制，测试访问不了，使用firefox可以进行访问。
创建ServiceAccount进行访问

$ vi dashboard-admin.conf
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: admin
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: admin
  namespace: kubernetes-dashboard

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin
  namespace: kubernetes-dashboard

$ kubectl apply -f dashboard-admin.conf
$ kubectl -n kubernetes-dashboard get secret |grep admin-token
admin-token-fqdpf                  kubernetes.io/service-account-token   3      7m17s
# 使用该命令拿到token，然后粘贴到
$ kubectl -n kubernetes-dashboard get secret admin-token-fqdpf -o jsonpath={.data.token}|base64 -d
eyJhbGciOiJSUzI1NiIsImtpZCI6Ik1rb2xHWHMwbWFPMjJaRzhleGRqaExnVi1BLVNRc2txaEhETmVpRzlDeDQifQ.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlcm5ldGVzLWRhc2hib2FyZCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi1mcWRwZiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjYyNWMxNjJlLTQ1ZG...

清理集群¶

如果你的集群安装过程中遇到了其他问题，我们可以使用下面的命令来进行重置：

# 在全部集群节点执行
kubeadm reset
ifconfig cni0 down && ip link delete cni0
ifconfig flannel.1 down && ip link delete flannel.1
rm -rf /run/flannel/subnet.env
rm -rf /var/lib/cni/
mv /etc/kubernetes/ /tmp
mv /var/lib/etcd /tmp
mv ~/.kube /tmp
iptables -F
iptables -t nat -F
ipvsadm -C
ip link del kube-ipvs0
ip link del dummy0