Kubernetes-tutorials（五）

theoforce

• The tutorials use Katacoda to run a virtual terminal in your web browser that runs Minikube, a small-scale local deployment of Kubernetes that can run anywhere. There's no need to install any software or configure anything; each interactive tutorial runs directly out of your web browser itself.
  
• A Kubernetes cluster that handles production traffic should have a minimum of three nodes.
  
• The nodes communicate with the master using the Kubernetes API, which the master exposes. End users can also use the Kubernetes API directly to interact with the cluster.
  

Module1

• 查看minikube是否安装
  

　　$ minikube version
　　minikube version: v0.17.1-katacoda

• 启动集群
  

　　$ minikube start
　　Starting local Kubernetes cluster...

• 查看客户端及服务端版本信息
  

　　$kubectl version
　　Client Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.0", GitCommit:"6e937839ac04a38cac63e6a7a306c5d035fe7b0a", GitTreeState:"clean", BuildDate:"2017-09-28T22:57:57Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
　　Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"08e099554f3c31f6e6f07b448ab3ed78d0520507", GitTreeState:"clean", BuildDate:"1970-01-01T00:00:00Z", GoVersion:"go1.7.1", Compiler:"gc", Platform:"linux/amd64"}

• 查看集群信息
  

　　$ kubectl cluster-info
　　Kubernetes master is running at http://host01:8080
　　heapster is running at http://host01:8080/api/v1/namespaces/kube-system/services/heapster/proxy
　　kubernetes-dashboard is running at http://host01:8080/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy
　　monitoring-grafana is running at http://host01:8080/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
　　monitoring-influxdb is running at http://host01:8080/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy

• 列出应用可用的节点信息
  

　　$ kubectl get nodes
　　NAME      STATUS    ROLES     AGE       VERSION
　　host01    Ready     <none>    4m        v1.5.2
Module 2
　　If the Node hosting an instance goes down or is deleted, the Deployment controller replaces it. This provides a self-healing mechanism to address machine failure or maintenance.
　　Applications need to be packaged into one of the supported container formats in order to be deployed on Kubernetes

• 命令用法查询
  

　　kubectl
　　kubectl get nodes --help

• 查看kubectl是否和集群正常通信
  

　　$ kubectl version
　　Client Version: version.Info{Major:"1", Minor:"8", GitVersion:"v1.8.0", GitCommit:"6e937839ac04a38cac63e6a7a306c5d035fe7b0a", GitTreeState:"clean", BuildDate:"2017-09-28T22:57:57Z", GoVersion:"go1.8.3", Compiler:"gc", Platform:"linux/amd64"}
　　Server Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"08e099554f3c31f6e6f07b448ab3ed78d0520507", GitTreeState:"clean", BuildDate:"1970-01-01T00:00:00Z", GoVersion:"go1.7.1", Compiler:"gc", Platform:"linux/amd64"}

• 查看集群中的节点信息
  

　　$ kubectl get nodes
　　NAME      STATUS    ROLES     AGE       VERSION
　　host01    Ready     <none>    6m        v1.5.2

• 在kubernetes上运行第一个应用
  

　　$ kubectl run kubernetes-bootcamp --image=docker.io/jocatalin/kubernetes-bootcamp:v1 --port=8080
　　deployment "kubernetes-bootcamp" created

• 获取已经部署的应用
  

　　$ kubectl get deployments
　　NAME                  DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
　　kubernetes-bootcamp   1         1         1            1       2m

• 运行一个proxy使得应用在外部和私有网络之间的通信
  

　　$ kubectl proxy
　　Starting to serve on 127.0.0.1:8001

• 通过API获取相关信息
  

　　$ curl http://localhost:8001/version
　　{
　　"major": "1",
　　"minor": "5",
　　"gitVersion": "v1.5.2",
　　"gitCommit": "08e099554f3c31f6e6f07b448ab3ed78d0520507",
　　"gitTreeState": "clean",
　　"buildDate": "1970-01-01T00:00:00Z",
　　"goVersion": "go1.7.1",
　　"compiler": "gc",
　　"platform": "linux/amd64"

• 通过proxy实现容器信息的查询
  

　　$ export POD_NAME=$(kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}}{{"\n"}}{{end}}')
　　$ echo Name of the Pod: $POD_NAME
　　Name of the Pod: kubernetes-bootcamp-390780338-xgkq1
　　$ curl http://localhost:8001/api/v1/proxy/namespaces/default/pods/$POD_NAME/
　　Hello Kubernetes bootcamp! | Running on: kubernetes-bootcamp-390780338-xgkq1 | v=1