centos7使用kubeadm安装单Master多Node的kubernetes集群

1. 安装前提

在开始之前，使用kubeadm部署Kubernetes集群需要满足以下几个条件：

• 一台或多台机器，操作系统 CentOS7.x-86_x64
• 硬件配置：4GB或更多RAM，2个CPU或更多CPU，硬盘30GB或更多
• 集群中所有机器之间网络互通
• 可以访问外网，需要拉取镜像
• 禁止swap分区

2. 安装步骤

1. 在所有节点上安装Docker和kubeadm
2. 部署Kubernetes Master
3. 部署容器网络插件
4. 部署 Kubernetes Node，将节点加入Kubernetes集群中
5. 部署Dashboard Web页面，可视化查看Kubernetes资源

3. 准备环境

三台主机
IP:  192.168.202.128     主机名：k8s-master    系统： centos 7.9     配置： 2C 8G
IP:  192.168.202.129     主机名：k8s-node1     系统： centos 7.9      配置： 2C 8G
IP:  192.168.202.130     主机名：k8s-node2     系统： centos 7.9      配置： 2C 8G

三台主机全部关闭防火墙:
# systemctl stop firewalld
# systemctl disable firewalld

三台主机全部关闭selinux：
# sed -i 's/enforcing/disabled/' /etc/selinux/config 
# setenforce 0

三台主机全部关闭swap：
# swapoff -a  # 临时关闭
# vim /etc/fstab 注释到swap那一行 # 永久关闭

添加主机名与IP对应关系(三台主机都执行)：
# cat >> /etc/hosts << EOF
192.168.202.128 k8s-master
192.168.202.129 k8s-node1
192.168.202.130 k8s-node2
EOF

设置192.168.202.128主机主机名
# hostnamectl set-hostname  k8s-master

设置192.168.202.129主机主机名
# hostnamectl set-hostname  k8s-node1

设置192.168.202.130主机主机名
# hostnamectl set-hostname  k8s-node2

将桥接的IPv4流量传递到iptables的链(三台主机都执行)：
# cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
# sysctl --system

4. 所有节点安装Docker/kubeadm/kubelet

Kubernetes默认CRI（容器运行时）为Docker，因此先安装Docker。

4.1 安装Docker

每台机器上都安装Docker。

下载阿里云的docker yum源,并安装
# wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
# yum -y install docker-ce

启动docker,并设置docker开机自启
# systemctl start docker
# systemctl enable docker

设置阿里云镜像下载加速

进入到阿里云后台控制界面，点击产品与服务,选择容器镜像服务，左下角有个镜像加速器

选择自己的加速器地址，并且设置cgroup驱动，推荐systemd：

# cat > /etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["https://6ze43vnb.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

重启docker

systemctl daemon-reload
systemctl restart docker

4.2 添加阿里云YUM软件源

# 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=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

4.3 安装kubeadm，kubelet和kubectl

# yum install -y kubelet kubeadm kubectl
# systemctl enable kubelet

5. 部署Kubernetes Master

在192.168.202.128（Master）执行。

# kubeadm init \
  --apiserver-advertise-address=192.168.202.128 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.23.4 \
  --service-cidr=10.1.0.0/16 \
  --pod-network-cidr=10.244.0.0/16

​​注：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​​

初始化完成后，根据日志提示，在master节点上执行如下操作：

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

6. 将Node节点加入到Kubernetes集群中

在192.168.202.129/130（Node）分别执行。

向集群添加新节点，执行在kubeadm init输出的kubeadm join命令：

kubeadm join一行是master端 kubeadm init 生成的,实际你的会变化
# kubeadm join 192.168.202.128:6443 --token 6qf11n.pdyzp2zki1ydb2fc \
    --discovery-token-ca-cert-hash sha256:e9055d8b3cfcf40330124f5da18e820ebcb6eb9ff28eb64c0f593e0fb154b755

7. 安装Pod网络插件Flannel（CNI）

​到使用 kubectl apply -f ​https:​/​/raw.githubusercontent.com/coreos/flannel/master/Documentation/kube​-flannel.yml 安装flannel网络组件，如果访问不了，可以把如下内容保存为kube-flannel.yml，然后使用  kubectl apply -f kube-flannel.yml进行安装，kube-flannel.yml内容如下：​

---
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', 'NET_RAW']
  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/v1
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/v1
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
  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: 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:v1.0.1 for ppc64le and mips64le (dockerhub limitations may apply)
        image: rancher/mirrored-flannelcni-flannel-cni-plugin:v1.0.1
        command:
        - cp
        args:
        - -f
        - /flannel
        - /opt/cni/bin/flannel
        volumeMounts:
        - name: cni-plugin
          mountPath: /opt/cni/bin
      - name: install-cni
       #image: flannelcni/flannel:v0.16.3 for ppc64le and mips64le (dockerhub limitations may apply)
        image: rancher/mirrored-flannelcni-flannel:v0.16.3
        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:v0.16.3 for ppc64le and mips64le (dockerhub limitations may apply)
        image: rancher/mirrored-flannelcni-flannel:v0.16.3
        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", "NET_RAW"]
        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/
        - 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

查看Flannel安装结果：

#kubectl get pod -A
NAMESPACE     NAME                                 READY   STATUS    RESTARTS   AGE
kube-system   coredns-9d85f5447-htzgm              1/1     Running   0          27m
kube-system   coredns-9d85f5447-sz9kg              1/1     Running   0          27m
kube-system   etcd-k8s-master                      1/1     Running   0          27m
kube-system   kube-apiserver-k8s-master            1/1     Running   0          27m
kube-system   kube-controller-manager-k8s-master   1/1     Running   0          27m
kube-system   kube-flannel-ds-amd64-5r2qv          1/1     Running   0          4m13s
kube-system   kube-proxy-npgrm                     1/1     Running   0          27m
kube-system   kube-scheduler-k8s-master            1/1     Running   0          27m

8. 测试kubernetes集群

在Kubernetes集群中创建一个pod，验证是否正常运行：

# kubectl create deployment nginx --image=nginx
# kubectl expose deployment nginx --port=80 --type=NodePort
# kubectl get pod,svc

访问地址：http://NodeIP:Port

9. 安装 Kuboard

kubectl apply -f https://kuboard.cn/install-script/kuboard.yaml
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

查看 Kuboard 运行状态：

kubectl get pods -l k8s.kuboard.cn/name=kuboard -n kube-system

输出结果如下所示：

NAME                       READY   STATUS        RESTARTS   AGE
kuboard-54c9c4f6cb-6lf88   1/1     Running       0          45s

获取Token

执行命令

# 如果您参考 www.kuboard.cn 提供的文档安装 Kuberenetes，可在第一个 Master 节点上执行此命令
echo $(kubectl -n kube-system get secret $(kubectl -n kube-system get secret | grep kuboard-user | awk '{print $1}') -o go-template='{{.data.token}}' | base64 -d)

输出取输出信息中 token 字段

eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi11c2VyLXRva2VuLWc4aHhiIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFkbWluLXVzZXIiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiI5NDhiYjVlNi04Y2RjLTExZTktYjY3ZS1mYTE2M2U1ZjdhMGYiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWRtaW4tdXNlciJ9.DZ6dMTr8GExo5IH_vCWdB_MDfQaNognjfZKl0E5VW8vUFMVvALwo0BS-6Qsqpfxrlz87oE9yGVCpBYV0D00811bLhHIg-IR_MiBneadcqdQ_TGm_a0Pz0RbIzqJlRPiyMSxk1eXhmayfPn01upPdVCQj6D3vAY77dpcGplu3p5wE6vsNWAvrQ2d_V1KhR03IB1jJZkYwrI8FHCq_5YuzkPfHsgZ9MBQgH-jqqNXs6r8aoUZIbLsYcMHkin2vzRsMy_tjMCI9yXGiOqI-E5efTb-_KbDVwV5cbdqEIegdtYZ2J3mlrFQlmPGYTwFI8Ba9LleSYbCi4o0k74568KcN_w

访问Kuboard

​​http://任意一个Worker节点的IP地址:32567/​​