桃之夭夭，灼灼其华

kubernetes 使用

docker kubernetes
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2020/07/28 Share
命令 类型 描述
get 查 列出某个类型的下属资源
describe 查 查看某个资源的详细信息
logs 查 查看某个 pod 的日志
create 增 新建资源
explain 查 查看某个资源的配置项
delete 删 删除某个资源
edit 改 修改某个资源的配置项
apply 改 应用某个资源的配置项

常用命令

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# 查看集群信息
kubectl cluster-info

# 获取k8s上的所有节点
kubectl get nodes
# 获取服务
kubectl get service
# 获取ReplicaSet
kubectl get rs
# 获取Deployment
kubectl get deployments

# 描述一个节点的信息
kubectl describe node
# 获取命名空间kube-system 下的所有pod。 -o 显示IP 和node 
kubectl get pod -n kube-system -o wide

单节点k8s服务

  • 准备docker镜像
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    FROM alpine:latest
    LABEL maintainer="liion"
    # 拷贝编译程序
    ADD main /
    WORKDIR /
    # 打开8080端口
    EXPOSE 8080
    # 运行!
    CMD ["./main"]
    准备GO web项目，编译go项目
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    CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o main
    生成docker镜像
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    docker build -t k8s-test:0.1 .
  • 创建pod，创建pod.yml
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    apiVersion: v1
    kind: Pod
    metadata:
      name: k8s-test
      labels:
        app: k8s-test #标签
    spec:
      containers:
        - name: k8s-test
          image: k8s-test:0.1 #对应的docker镜像
          ports:
            - containerPort: 8080 #监听端口
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    ➜ kubectl create -f pod.yml
    pod/k8s-test created
    ➜ kubectl get pods
    NAME       READY   STATUS    RESTARTS   AGE
    k8s-test   1/1     Running   0          13s
    ➜ kubectl describe pods | grep Labels
    Labels:       <none>
    ➜ kubectl apply -f pod.yml
    Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
    pod/k8s-test configured
    ➜ kubectl describe pods | grep Labels
    Labels:       app=k8s-test
  • 配置服务Service
    Service 的作用有点像建立了一个反向代理和负载均衡器，负责把请求分发给后面的 pod
  • 创建svc.yml
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    apiVersion: v1
    kind: Service
    metadata:
      name: k8s-test-svc
      labels:
        app: k8s-test
    spec:
      type: NodePort
      ports:
        - port: 8080
          nodePort: 30050 #暴露端口类似docker容器的端口映射，将本地的30050 -> 8080
      selector:
        app: k8s-test
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    ➜ kubectl create -f svc.yml
    service/k8s-test-svc created
    ➜ kubectl get service      
    NAME           TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
    k8s-test-svc   NodePort    10.107.103.59   <none>        8080:30050/TCP   5s
    kubernetes     ClusterIP   10.96.0.1       <none>        443/TCP          10d
  • curl http://127.0.0.1:30050
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    ➜ curl http://127.0.0.1:30050
    {"IP":"10.1.0.63","message":"Hello GO!","time":"2020-07-28 13:01:30"}
  • 删除pod
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    ➜ kubectl delete pod k8s-test
    pod "k8s-test" deleted

横向扩展、滚动更新、版本回滚

  • 创建deployment.yml
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    apiVersion: apps/v1 #kubernetes 1.18 版本 apiVersion 从extensions/v1beta1 调整为apps/v1
    kind: Deployment
    metadata:
      name: k8s-test-deployment
    spec:
      replicas: 10 #指deployment要有10个pod
      minReadySeconds: 10 #更新间隔，指在更新了一个pod后，需要在它进入正常状态后10秒再更新下一个pod
      strategy:
        type: RollingUpdate
        rollingUpdate:
          maxUnavailable: 1 #指同时处于不可用状态的pod不能超过一个
          maxSurge: 1 #指多余的 pod 不能超过一个
      selector:
        matchLabels:
          app: k8s-test
      template:
        metadata:
          labels:
            app: k8s-test
        spec:
          containers:
            - name: k8s-test-pod
            #   image: k8s-test:0.1
              image: k8s-test:0.2 #修改时升级版本为0.2
              ports:
                - containerPort: 8080 #监听端口
  • 横向扩展
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    ➜ kubectl create -f deployment.yml
    deployment.apps/k8s-test-deployment created
    ➜ kubectl get rs
    NAME                             DESIRED   CURRENT   READY   AGE
    k8s-test-deployment-75958fb65d   10        10        10      40s
    ➜ kubectl get deployments
    NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
    k8s-test-deployment   10/10   10           10          2m49s
  • 滚动更新
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    kubectl apply -f deployment.yml --record=true
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    ➜ CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o main
    ➜ docker build -t k8s-test:0.2 .
    Sending build context to Docker daemon  30.59MB
    Step 1/7 : FROM alpine:latest
     ---> a24bb4013296
    Step 2/7 : LABEL maintainer="liion"
     ---> Using cache
     ---> 076011b6935a
    Step 3/7 : ADD main /
     ---> 1d328bb849d4
    Step 4/7 : RUN chmod +x /main
     ---> Running in 66e8b70c65e8
    Removing intermediate container 66e8b70c65e8
     ---> 42fdf5cc92a8
    Step 5/7 : WORKDIR /
     ---> Running in 7c55500f2990
    Removing intermediate container 7c55500f2990
     ---> 85c301d1da3c
    Step 6/7 : EXPOSE 8080
     ---> Running in 505734fdd2fe
    Removing intermediate container 505734fdd2fe
     ---> d33ce9247036
    Step 7/7 : CMD ["./main"]
     ---> Running in f427fd82e054
    Removing intermediate container f427fd82e054
     ---> 24eb5672269b
    Successfully built 24eb5672269b
    Successfully tagged k8s-test:0.2
    ➜ kubectl apply -f deployment.yml --record=true
    Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
    deployment.apps/k8s-test-deployment configured
    ➜ kubectl get pods
    NAME                                   READY   STATUS    RESTARTS   AGE
    k8s-test-deployment-69ff46fd95-4tw7s   1/1     Running   0          4s
    k8s-test-deployment-69ff46fd95-5tqwz   1/1     Running   0          16s
    k8s-test-deployment-69ff46fd95-7zpdq   1/1     Running   0          4s
    k8s-test-deployment-69ff46fd95-85w7m   1/1     Running   0          16s
    k8s-test-deployment-75958fb65d-67bqq   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-fx4pl   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-l7vmm   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-lr2kj   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-ng7k8   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-ts79t   1/1     Running   0          31m
    k8s-test-deployment-75958fb65d-xvrps   1/1     Running   0          31m
    ➜ kubectl rollout status deployment k8s-test-deployment
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    deployment "k8s-test-deployment" successfully rolled out
  • 版本回滚
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    kubectl rollout undo deployment k8s-test-deployment --to-revision=1
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    ➜ kubectl rollout undo deployment k8s-test-deployment --to-revision=1
    deployment.apps/k8s-test-deployment rolled back
    ➜ kubectl rollout status deployment k8s-test-deployment              
    Waiting for deployment "k8s-test-deployment" rollout to finish: 2 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 8 out of 10 new replicas have been updated...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    Waiting for deployment "k8s-test-deployment" rollout to finish: 1 old replicas are pending termination...
    deployment "k8s-test-deployment" successfully rolled out
  • 删除
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    ➜ kubectl delete deployment k8s-test-deployment
    deployment.apps "k8s-test-deployment" deleted

参考文档

Author：liion

原文链接：https://liion.top/2020/07/28/document-0728/

发表日期：July 28th 2020, 8:58:12 pm

更新日期：July 29th 2020, 8:36:59 am

版权声明：本文采用知识共享署名-非商业性使用 4.0 国际许可协议进行许可

CATALOG
  1. 1. 常用命令
  2. 2. 单节点k8s服务
  3. 3. 横向扩展、滚动更新、版本回滚
  4. 4. 参考文档
Total : 18
2021
2020
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