k8s学习笔记(1)

使用mac docker自带的k8s入门kubernetes：

Deploy an App

kubectl run k8s-redis --image=redis

kubectl get deployments
kubectl get pods

kubectl port-forward pod-name 6379:6379

Explore your App

kubectl exec -it pod_name bash

kubectl logs pod_name

Expose your App Publicly

kubectl get services
kubectl expose deployment/k8s-redis --type="NodePort" --port 6379
kubectl get services
kubectl describe services/k8s-redis
//找到NodePort一项，得到ip
redis-cli -p ip_from_last_command //连接成功

kubectl describe deployment //可以查看到相应的label
kubectl get pods -l run=k8s-redis
kubectl get services -l run=k8s-redis
kubectl label pod k8s-redis-7f9776d9f4-jzm2m app=v1
kubectl describe pods k8s-redis
kubectl get pods -l app=v1

kubectl delete service -l run=k8s-redis //这里用app=v1不行，会提示No resources found
kubectl get services
//仅仅删除service，pod还在的
kubectl exec -it pod_name bash //里面的数据都还在

Scale Your App

kubectl get pods
kubectl scale deployments/kubernetes-bootcamp --replicas=4
kubectl get deployments
kubectl get pods //将会显示4个pod
kubectl describe deployments/kubernetes-bootcamp
kubectl describe services/kubernetes-bootcamp //找到NodePort
curl发现，这4个服务是负载均衡[轮询?]的
kubectl scale deployments/kubernetes-bootcamp --replicas=2

Update Your App

kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=jocatalin/kubernetes-bootcamp:v2
kubectl get pods
kubectl describe services/kubernetes-bootcamp //查看NodePort
curl $(minikube ip):$NODE_PORT //内容已升级到v2
输出类似：Hello Kubernetes bootcamp! | Running on: kubernetes-bootcamp-cfc74666-qnps5 | v=2
kubectl rollout status deployments/kubernetes-bootcamp
kubectl describe pods
kubectl set image deployments/kubernetes-bootcamp kubernetes-bootcamp=gcr.io/google-samples/kubernetes-bootcamp:v10
kubectl get deployments //没有对应个数的实例
kubectl describe pods //查看详情，发现是image未找到，现在回滚
kubectl rollout undo deployments/kubernetes-bootcamp
kubectl get pods //此时又看到之前的4个pods
kubectl describe pods //查看image是v2的，回滚成功

使用 https://github.com/gotok8s/k8s-docker-desktop-for-mac 安装K8S环境

部署 Kubernetes Dashboard

$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended.yaml

# 开启本机访问代理
$ kubectl proxy

创建Dashboard管理员用户并用token登陆

# 创建 ServiceAccount kubernetes-dashboard-admin 并绑定集群管理员权限
$ kubectl apply -f https://raw.githubusercontent.com/gotok8s/gotok8s/master/dashboard-admin.yaml

# 获取登陆 token
$ kubectl -n kubernetes-dashboard describe secret $(kubectl -n kubernetes-dashboard get secret | grep kubernetes-dashboard-admin | awk '{print $1}')

通过下面的连接访问 Dashboard: http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/

输入上一步获取的token, 验证并登陆。

实际遇到了 kubernetesui/metrics-scraper:v1.0.4 这个镜像下载不了的问题。使用阿里云镜像加速即可解决。