k8s-初探

一、第一步
1、建议
先利用示例网站体验一下k8s，再回来看文档。
例如：

1）minikube 创建集群 https://kubernetes.io/docs/tutorials/kubernetes-basics/ 
Kubernetes Bootcamp Terminal
>

> minikube version
minikube version: v0.15.0-katacoda

> minikube start
Starting local Kubernetes cluster...

> kubectl version
Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.2", GitCommit:"08e099554f3c31f6e6f07b448ab3ed78d0520507", GitTreeState:"clean", BuildDate:"2017-01-12T04:57:25Z", GoVersion:"go1.7.4", 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"}

> kubectl cluster-info
Kubernetes master is running at http://host01:8080 heapster is running at http://host01:8080/api/v1/proxy/namespaces/kube-system/services/heapster kubernetes-dashboard is running at http://host01:8080/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard monitoring-grafana is running at http://host01:8080/api/v1/proxy/namespaces/kube-system/services/monitoring-grafana monitoring-influxdb is running at http://host01:8080/api/v1/proxy/namespaces/kube-system/services/monitoring-influxdb 
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

> kubectl get nodes
NAME      STATUS    AGE
host01    Ready     30s

>

2）cubeadm 创建集群 http://play-with-k8s.com/ 
WARNING!!!!

This is a sandbox environment. Using personal credentials is HIGHLY! discouraged. Any consequences of doing so, are completely the user's responsibilites.

You can bootstrap a cluster as follows:

1. Initializes cluster master node:

kubeadm init --apiserver-advertise-address $(hostname -i)

2. Initialize cluster networking:

kubectl apply -n kube-system -f \
"https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

3. (Optional) Initialize kube-dashboard:

curl -L -s https://git.io/kube-dashboard  | sed 's/targetPort: 9090/targetPort: 9090\n  type: LoadBalancer/' | \
kubectl apply -f -

The PWK team.

[node1 /]$

2、实例
1）集群管理指令
kubectl version
kubectl cluster-info
kubectl get nodes
kubectl run kubernetes-bootcamp --image=docker.io/jocatalin/kubernetes-bootcamp:v1 --port=8080
kubectl get deployments

export POD_NAME=$(kubectl get pods -o go-template --template '{{range .items}}``.`metadata`.`name`{{"\n"}}`end`')
echo Name of the Pod: $POD_NAME

kubectl proxy
curl http://localhost:8001/api/v1/proxy/namespaces/default/pods/$POD_NAME/ 
kubectl describe pods
kubectl logs $POD_NAME
kubectl exec $POD_NAME env
kubectl exec -ti $POD_NAME bash

kubectl get pods
kubectl get services
kubectl expose deployment/kubernetes-bootcamp --type="NodePort" --port 8080
kubectl describe services/kubernetes-bootcamp
export NODE_PORT=$(kubectl get services/kubernetes-bootcamp -o go-template='{{(index .spec.ports 0).nodePort}}')
echo NODE_PORT=$NODE_PORT
curl host01:$NODE_PORT

kubectl describe deployment
kubectl get pods -l run=kubernetes-bootcamp
kubectl get services -l run=kubernetes-bootcamp
export POD_NAME=$(kubectl get pods -o go-template --template '{{range .items}}``.`metadata`.`name`{{"\n"}}`end`')
echo Name of the Pod: $POD_NAME
kubectl label pod $POD_NAME app=v1
kubectl describe pods $POD_NAME
kubectl get pods -l app=v1

kubectl delete service -l run=kubernetes-bootcamp
kubectl get services
curl host01:$NODE_PORT
kubectl exec -ti $POD_NAME curl localhost:8080

kubectl get deployments
kubectl scale deployments/kubernetes-bootcamp --replicas=4
kubectl get deployments
kubectl get pods -o wide
kubectl describe deployments/kubernetes-bootcamp
kubectl describe services/kubernetes-bootcamp
export NODE_PORT=$(kubectl get services/kubernetes-bootcamp -o go-template='{{(index .spec.ports 0).nodePort}}')
echo NODE_PORT=$NODE_PORT
curl host01:$NODE_PORT
kubectl scale deployments/kubernetes-bootcamp --replicas=2
kubectl get deployments
kubectl get pods -o wide

kubectl get deployments
kubectl get pods
kubectl describe pods
kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=jocatalin/kubernetes-bootcamp:v2
kubectl get pods
kubectl describe services/kubernetes-bootcamp
export NODE_PORT=$(kubectl get services/kubernetes-bootcamp -o go-template='{{(index .spec.ports 0).nodePort}}')
echo NODE_PORT=$NODE_PORT
curl host01:$NODE_PORT
kubectl rollout status deployments/kubernetes-bootcamp
kubectl describe pods

kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=jocatalin/kubernetes-bootcamp:v10
kubectl get deployments
kubectl get pods
kubectl describe pods
kubectl rollout undo deployments/kubernetes-bootcamp
kubectl get pods
kubectl describe pods

ZYXW、参考
1、doc https://kubernetes.io/docs/home/ https://kubernetes.feisky.xyz

2、版本
changelog: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md 
3、roadmap https://github.com/kubernetes/kubernetes/milestones/[/code]