Kubernetes-tutorials（五）

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}}{{" "}}{{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