kubernetes 单节点版安装部署使用_kubernetes 单节点部署

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Kubernetes 单节点版安装部署

一、前期准备

1.Kubernete介绍

Kubernetes 是一个可移植的，可扩展的开源平台，用于管理容器化的工作负载和服务，方便了声明式配置和自动化。它拥有一个庞大且快速增长的生态系统。Kubernetes 的服务，支持和工具广泛可用。其集群由代表控制平面的组件和一组称为节点的机器组成。Kubernetes 通过将容器放入在节点（Node）上运行的 Pod 中来执行你的工作负载。 节点可以是一个虚拟机或者物理机器，取决于所在的集群配置。 每个节点包含运行 Pods 所需的服务； 这些节点由 控制面 负责管理。
通常集群中会有若干个节点；而在一个学习用或者资源受限的环境中，你的集群中也可能 只有一个节点。
节点上的组件包括 kubelet、 容器运行时以及 kube-proxy。

2.准备

Kubernete支持在物理服务器和虚拟机上运行，本次我才用安装了centos系统的服务器端进行安装演示K8s单节点的使用。

二、安装过程

1.环境配置

1.关闭系统防火墙

systemctl disable firewalld  
systemctl stop firewalld     //关闭防火墙
systemctl status firewalld   //查看防火墙状态
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2.关闭swap交换区

swapoff -a
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2.安装docker/kubernets

我们使用yum安装docker和kubernets
1.重新编译安装docker

yum makecache fast   
yum -y install docker-ce
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坑1：建议重新安装docker 保证版本的一致性不然在安装kubernets时会遇见找不到不匹配的问题。

2 .通过docker 安装kubernets
配置yum源使用阿里云提供的镜像

使用yum安装kubelet kubeadm kubectl

yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
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kubelet:运行在cluster所有节点上,负责启动POD和容器
kubeadm:用于初始化cluster
kubectl:kubectl是kubenetes命令行工具，通过kubectl可以部署和管理应用，查看各种资源，创建，删除和更新组件


安装成功后我们使用–version命令检查是否安装成功

kubelet --version
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我们这里使用的版本为1.23.6

至此我们完成了k8s的基本安装。

3.启动服务

1 启动kubernete服务

systemctl start kubelet && systemctl enable kubelet
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2 配置master节点
考虑单节点部署，只需要在该主机上运行下面命令。

kubeadm init \
--kubernetes-version=1.23.6 \
--apiserver-advertise-address=172.21.113.92 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.1.0.0/16 \
--pod-network-cidr=10.244.0.0/16
--ignore-prefilght-errors=all
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• –pod-network-cidr: 定义pod网段为：10.244.0.0/16
• –apiserver-advertise-address：master主机内网IP地址
• –image-repository：指定阿里云镜像仓库地址。由于kubeadm 默认从官网http://k8s.grc.io下载所需镜像，国内无法访问，因此需要通过–image-repository指定阿里云镜像仓库地址。（国外主机可以不用设定）
• 虑到该服务器是单核的，若不加–ignore-preflight-errors会提示cpu资源不足。

初始化异常

• 坑1 The connection to the server xxx:10248 was refused - did you
  specify the right host or port? 需要对服务器开放相应端口，最好需要哪个开哪个。

• 坑2
  经查阅docker和k8s使用的cgroup不一致导致的，我们需要其cgroup 修改相关配置

• 坑3 需要关闭交换区swap 之前是因为配置swap没有在配置文件中配置，使用swap off命令进行配置，这种配置才重新启动服务器后就会失效，因此初恋初始化超时的问题。
  解决上述问题后，我们重新运行初始化节点命令，即可启动成功。
  

三、 使用服务

1.使用部署

1 查看节点状态
配置kubecetl工具环境变量 查看节点状态

mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
kubectel get node
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节点目前为单节点，状态为notready

2 部署网络

3 再次查看节点状态 为ready 表明已启动成功并且可连接

2.可视化安装Dashboard

1创建密钥证书

mkdir dashboard-certs
cd dashboard-certs/
#创建命名空间
kubectl create namespace kubernetes-dashboard
# 创建私钥key文件
openssl genrsa -out dashboard.key 2048
#证书请求
openssl req -days 36000 -new -out dashboard.csr -key dashboard.key -subj '/CN=dashboard-cert'
#自签证书
openssl x509 -req -in dashboard.csr -signkey dashboard.key -out dashboard.crt
#创建kubernetes-dashboard-certs对象
kubectl create secret generic kubernetes-dashboard-certs --from-file=dashboard.key --from-file=dashboard.crt -n kubernetes-dashboard
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2 创建管理员账号

kubectl apply -f https://kuboard.cn/install-script/k8s-dashboard/auth.yaml

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3下载recommended.yaml配置文件，并修改相应配置
该配置文件不推荐自己从零写起，只需要去官方上下载并修改相应配置即可
官方配置文件下载地址

---

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:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30008
  selector:
    k8s-app: kubernetes-dashboard

---

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:v2.0.0-beta5
          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:
        "beta.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:v1.0.1
          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:
        "beta.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: {}

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5 访问dashboard
访问前需要获取认证token（beantoken）

kubectl -n kubernetes-dashboard describe secret $(kubectl -n kubernetes-dashboard get secret | grep admin-user | awk '{print $1}')

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使用节点ip加端口30008访问即可，我们这里使用公网ip从外部网络访问，并输入其上步得到token

总结

本文初步演示了kubernetes的单节点部署安装流程，在初始化master节点成功后会提供kubeadm join 字符串可帮助我们在其他工作节点加入该集群管理，本次由于物理服务器资源有限，就演示了节点的单机安装部署，同时为读者提供了一些常见的坑和错误，给大家避雷。通过这次的学习，对云计算课程的认识更加明确，后续还将继续补充完善云计算相关知识。