部署K8S的一个简单Demo

部署K8S的一个简单Demo

1、准备镜像

• 创建目录 mkdir ./demo
• 创建简单的http server

  $ vi server.js 
  
  var http = require('http');
  var handleRequest = function(request, response) {
    console.log('Received request for URL: ' + request.url);
    response.writeHead(200);
    response.end('Hello World!');
  };
  var www = http.createServer(handleRequest);
  www.listen(8088);
  
  

• 创建Dockerfile

  $ vi Dockerfile 
  	
  FROM node:6.14.2
  EXPOSE 8088
  COPY server.js .
  CMD node server.js
  

• 通过Dockerfile创建镜像

  $ docker build -t node:demo .
  

2、创建Deployment

• 创建Deployment 方式一：

  $ kubectl create deployment kube-demo --image=node:demo
  

• 创建Deployment 方式二：

  $ kubectl apply -f ./deployment.yaml
  
  #deployment.yaml
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: kube-demo
    labels:
      app: demo
  spec:
    replicas: 2
    selector:
      matchLabels:
        app: demo
    template:
      metadata:
        labels:
          app: demo
      spec:
        containers:
        - name: demo
          image: kube:demo
          resources:
            limits:
              cpu: 500
              memory: 128Mi
            requests:
              cpu: 500m
              memory: 128Mi
          ports:
          - containerPort: 8088
  
  

• 查看kubectl日志

  journalctl -xefu kubelet
  

• 查看Deployment \ pods

  $ kubectl get deployments
  NAME        READY   UP-TO-DATE   AVAILABLE   AGE
  kube-demo   2/2     2            2           10h
  
  $ kubectl get pods
  NAME                         READY   STATUS    RESTARTS   AGE
  kube-demo-79b9647795-lx7f4   1/1     Running   0          10h
  kube-demo-79b9647795-x4swx   1/1     Running   0          10h
  

3、创建Service

• 创建方式一：命令行

  $ kubectl expose deployment kube-demo --type=LoadBalancer --port=8090
  

• 创建方式二：yaml文件

  kubectl create -f service.yaml
  
  #service.yaml 
  apiVersion: v1
  kind: Service
  metadata:
    name: kube-demo
    labels:
      name: kube-demo
  spec:
    type: NodePort    #或使用 LoadBalancer
    ports:
    - port: 8090  #这里的端口和clusterIP 对应，供内部访问。
      targetPort: 8088 #端口一定要和container暴露出来的端口对应
      protocol: TCP
      nodePort: 32143   # 所有的节点都会开放此端口，此端口供外部调用。
    selector:
      app: demo # 名称与deployment中定义的app名称保持一致
  

• 查看服务 NodePort

  $ kubectl get services
  NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
  kube-demo    NodePort    10.107.253.208   <none>        8090:32143/TCP   11s
  kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP          3d23h
  
  

• 查看pod及服务

  $ kubectl get pod,svc -n kube-system
  NAME                                         READY   STATUS    RESTARTS   AGE
  pod/coredns-5c98db65d4-6wtmm                 1/1     Running   2          3d23h
  pod/coredns-5c98db65d4-fhns5                 1/1     Running   2          3d23h
  pod/etcd-docker-desktop                      1/1     Running   0          3d23h
  pod/kube-apiserver-docker-desktop            1/1     Running   0          3d23h
  pod/kube-controller-manager-docker-desktop   1/1     Running   0          3d23h
  pod/kube-proxy-q5r4c                         1/1     Running   0          3d23h
  pod/kube-scheduler-docker-desktop            1/1     Running   0          3d23h
  
  NAME               TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
  service/kube-dns   ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   3d23h
  

4、验证访问

• 通过curl

  $ curl 127.0.0.1:32143
  Hello World!
  

5、清理

• 清理

  kubectl delete service hello-node
  kubectl delete deployment hello-node
  

---

参考资料: kubernetes.io
代码地址：https://github.com/WangShuai822/kube-demo