Windows环境下使用Minikube快速部署一个Node应用

叁歲伎倆 2021-10-14 00:42 414阅读 0赞

### 文章目录 ###

*   *   *  Node 应用Demo代码
         *  创建 Dockerfile
         *  启动 Minikube Docker 守护进程
         *  构建 Docker 镜像
         *  创建一个管理 Pod 的 Deployment
         *  查看 Deployment
         *  查看 Pod
         *  查看Pod描述信息
         *  查看 log
         *  创建 Service
         *  查看 Service
         *  查看 Service的描述信息
         *  访问 Service
         *  更新应用程序
         *  应用实例伸缩
         *  清理删除
         *  停止
         *  参考

### Node 应用Demo代码 ###

var http = require('http');
    
    var handleRequest = function(request, response) {
      console.log('Received request for URL: ' + request.url);
      response.writeHead(200);
      response.end('Hello World!');
    };
    var www = http.createServer(handleRequest);
    console.log("listen on port:8080");
    www.listen(8080);

### 创建 Dockerfile ###

创建一个文件 Dockerfile。Dockerfile 描述要生成的镜像。您可以通过扩展现有镜像来构建 Docker 容器镜像。本教程中的镜像扩展了现有的 Node.js 镜像。

FROM node:6.9.2
    EXPOSE 8080
    COPY server.js .
    CMD node server.js

构建的过程是从 Docker 仓库中找到的官方 Node.js LTS 镜像开始，然后暴露端口 8080，接着将您的 server.js 文件复制到镜像中，并启动 Node.js 服务器。

### 启动 Minikube Docker 守护进程 ###

本教程使用 Minikube，而不是将 Docker 镜像推送到仓库，可以使用与Minikube VM相同的Docker主机构建镜像，以使镜像自动存在。为此，请确保使用Minikube Docker守护进程：

eval $(minikube docker-env)

windows下使用PowerShell执行

minikube docker-env

他会告诉你执行如下命令

# Run this command to configure your shell:
    # & minikube docker-env | Invoke-Expression

然后在PowerShell中执行

& minikube docker-env | Invoke-Expression

执行完之后，我们再执行`docker images`

PS C:\Users\c\Desktop\hellonode> docker images
    REPOSITORY                                                                        TAG                 IMAGE ID            CREATED             SIZE
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy                    v1.14.3             004666307c5b        2 months ago        82.1MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver                v1.14.3             9946f563237c        2 months ago        210MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager       v1.14.3             ac2ce44462bc        2 months ago        158MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler                v1.14.3             953364a3ae7a        2 months ago        81.6MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-addon-manager            v9.0                119701e77cbc        7 months ago        83.1MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/coredns                       1.3.1               eb516548c180        7 months ago        40.3MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64    v1.10.1             f9aed6605b81        8 months ago        122MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/etcd                          3.3.10              2c4adeb21b4f        8 months ago        258MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-sidecar-amd64         1.14.13             4b2e93f0133d        10 months ago       42.9MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-kube-dns-amd64        1.14.13             55a3c5209c5e        10 months ago       51.2MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-dnsmasq-nanny-amd64   1.14.13             6dc8ef8287d3        10 months ago       41.4MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/pause                         3.1                 da86e6ba6ca1        20 months ago       742kB
    registry.cn-hangzhou.aliyuncs.com/google_containers/storage-provisioner           v1.8.1              4689081edb10        21 months ago       80.8MB

可以看到我们看到的是Minikube VM中docker的镜像，如果执行`eval $(minikube docker-env)`或者`& minikube docker-env | Invoke-Expression`命令。我们看到的如下的镜像

$ docker images
    REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
    hello-node          v1                  218dd3dba0d8        23 hours ago        655MB
    node                6.9.2               faaadb4aaf9b        2 years ago         655MB

而且如果不执行`eval $(minikube docker-env)`或者`& minikube docker-env | Invoke-Expression`命令,在创建好demo镜像后，`kubectl get pods` 执行遇到问题如下

Failed to pull image "hello-node:v1": rpc error: code = Unknown desc = Error response from daemon: pull access denied for car/configuration, repository does not exist or may require 'docker login'

而且我一开始也研究了半天`eval $(minikube docker-env)`为啥没用，提示找不到命令，原来是windows下面需要执行`& minikube docker-env | Invoke-Expression`，果然还是要认真看命令行提示。而且还是linux搭建开发环境比较人性化，windows太难了。。

### 构建 Docker 镜像 ###

执行完上面的命令之后我们就可以开始构建docker镜像了

docker build -t hello-node:v1 .

现在 Minikube VM 可以运行您构建的镜像了。

PS C:\Users\c\Desktop\hellonode> docker images
    REPOSITORY                                                                        TAG                 IMAGE ID            CREATED             SIZE
    hello-node                                                                        v1                  7792b6eadc5a        15 minutes ago      655MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy                    v1.14.3             004666307c5b        2 months ago        82.1MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager       v1.14.3             ac2ce44462bc        2 months ago        158MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver                v1.14.3             9946f563237c        2 months ago        210MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler                v1.14.3             953364a3ae7a        2 months ago        81.6MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kube-addon-manager            v9.0                119701e77cbc        7 months ago        83.1MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/coredns                       1.3.1               eb516548c180        7 months ago        40.3MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/kubernetes-dashboard-amd64    v1.10.1             f9aed6605b81        8 months ago        122MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/etcd                          3.3.10              2c4adeb21b4f        8 months ago        258MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-sidecar-amd64         1.14.13             4b2e93f0133d        10 months ago       42.9MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-kube-dns-amd64        1.14.13             55a3c5209c5e        10 months ago       51.2MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/k8s-dns-dnsmasq-nanny-amd64   1.14.13             6dc8ef8287d3        10 months ago       41.4MB
    registry.cn-hangzhou.aliyuncs.com/google_containers/pause                         3.1                 da86e6ba6ca1        20 months ago       742kB
    registry.cn-hangzhou.aliyuncs.com/google_containers/storage-provisioner           v1.8.1              4689081edb10        21 months ago       80.8MB
    node

可以看到我们的hello-node镜像已经构建好了。

### 创建一个管理 Pod 的 Deployment ###

使用 `kubectl run` 命令创建一个管理 Pod 的 Deployment。该 Pod 基于镜像 `hello-node:v1` 运行了一个容器：

PS C:\Users\c\Desktop\hellonode> kubectl run hello-node --image=hello-node:v1 --port=8080
    deployment "hello-node" created

### 查看 Deployment ###

PS C:\Users\c\Desktop\hellonode> kubectl get deployments
    NAME         DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    hello-node   1         1         1            1           23m
    PS C:\Users\c\Desktop\hellonode>

### 查看 Pod ###

PS C:\Users\c\Desktop\hellonode> kubectl get pods
    NAME                          READY     STATUS    RESTARTS   AGE
    hello-node-67f857c88c-fm678   1/1       Running   0          23m

### 查看Pod描述信息 ###

PS C:\Users\c\Desktop\hellonode> kubectl describe pods hello-node
    Name:           hello-node-67f857c88c-fm678
    Namespace:      default
    Node:           minikube/10.0.2.15
    Start Time:     Fri, 16 Aug 2019 23:50:19 +0800
    Labels:         pod-template-hash=67f857c88c
                    run=hello-node
    Annotations:    <none>
    Status:         Running
    IP:             172.17.0.5
    Controlled By:  ReplicaSet/hello-node-67f857c88c
    Containers:
      hello-node:
        Container ID:   docker://941055dffcaeeac8a34424153270fe07cfb08bc6905ab8fef1b2832abdacc8a7
        Image:          hello-node:v1
        Image ID:       docker://sha256:7792b6eadc5ab90437f2489de0ccc0279a23de27abff8c2db134ce20dc979606
        Port:           8080/TCP
        State:          Running
          Started:      Fri, 16 Aug 2019 23:50:20 +0800
        Ready:          True
        Restart Count:  0
        Environment:    <none>
        Mounts:
          /var/run/secrets/kubernetes.io/serviceaccount from default-token-gk66v (ro)
    Conditions:
      Type              Status
      Initialized       True
      Ready             True
      ContainersReady   True
      PodScheduled      True
    Volumes:
      default-token-gk66v:
        Type:        Secret (a volume populated by a Secret)
        SecretName:  default-token-gk66v
        Optional:    false
    QoS Class:       BestEffort
    Node-Selectors:  <none>
    Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                     node.kubernetes.io/unreachable:NoExecute for 300s
    Events:
      Type    Reason     Age   From               Message
      ----    ------     ----  ----               -------
      Normal  Scheduled  24m   default-scheduler  Successfully assigned default/hello-node-67f857c88c-fm678 to minikube
      Normal  Pulled     24m   kubelet, minikube  Container image "hello-node:v1" already present on machine
      Normal  Created    24m   kubelet, minikube  Created container hello-node
      Normal  Started    24m   kubelet, minikube  Started container hello-node
    
    PS C:\Users\c\Desktop\hellonode>

### 查看 log ###

PS C:\Users\c\Desktop\hellonode> kubectl logs hello-node-67f857c88c-fm678
    listen on port:8080

### 创建 Service ###

默认情况下，Pod 只能通过 Kubernetes 集群中的内部 IP 地址访问。要使得 hello-node 容器可以从 Kubernetes 虚拟网络的外部访问，必须将 Pod 暴露为 Kubernetes Service。

可以使用 kubectl expose 命令将 Pod 暴露给公网：

PS C:\Users\c\Desktop\hellonode> kubectl expose deployment hello-node --type=LoadBalancer
    service "hello-node" exposed

### 查看 Service ###

PS C:\Users\c\Desktop\hellonode> kubectl get services
    NAME         TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
    hello-node   LoadBalancer   10.99.150.179   <pending>     8080:30552/TCP   1m
    kubernetes   ClusterIP      10.96.0.1       <none>        443/TCP          1d

### 查看 Service的描述信息 ###

PS C:\Users\c\Desktop\hellonode> kubectl describe service hello-node
    Name:                     hello-node
    Namespace:                default
    Labels:                   run=hello-node
    Annotations:              <none>
    Selector:                 run=hello-node
    Type:                     LoadBalancer
    IP:                       10.99.150.179
    Port:                     <unset>  8080/TCP
    TargetPort:               8080/TCP
    NodePort:                 <unset>  30552/TCP
    Endpoints:                172.17.0.5:8080
    Session Affinity:         None
    External Traffic Policy:  Cluster
    Events:                   <none>

### 访问 Service ###

`--type=LoadBalancer`表示要在集群之外公开服务，向外部暴露服务。外部的负载均衡器可以路由到 NodePort 服务和 ClusterIP服务。(一般常用此类型向外暴露端口，并做负载均衡)。LoadBalancer模式将提供一个外部 IP（external IP） 来访问该服务。在 Minikube 上，LoadBalancer 使得服务可以通过命令 minikube service 访问。

PS C:\Users\c\Desktop\hellonode> minikube service hello-node
    * Opening kubernetes service default/hello-node in default browser...

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70][]

### 更新应用程序 ###

编辑server.js文件以返回新消息

response.end('Hello World Again!!');

docker build新版本镜像：

docker build -t hello-node:v2 .

Deployment更新镜像：

PS C:\Users\c\Desktop\hellonode> kubectl set image deployment/hello-node hello-node=hello-node:v2
    deployment "hello-node" image updated

再次在浏览器查看消息：

$ minikube service hello-nodePS C:\Users\c\Desktop\hellonode> minikube service hello-node
    * Opening kubernetes service default/hello-node in default browser...

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 1]

### 应用实例伸缩 ###

根据线上需求，扩容和缩容是常会遇到的问题。Scaling 是通过更改 Deployment 中的副本数量实现的。一旦有多个实例，就可以滚动更新，而不会停止服务。通过kubectl scale指令来扩容和缩容。

PS C:\Users\c\Desktop\hellonode> kubectl scale deployments/hello-node --replicas=4
    deployment "hello-node" scaled

PS C:\Users\c\Desktop\hellonode> kubectl get pods
    NAME                          READY     STATUS    RESTARTS   AGE
    hello-node-7f8df9f98d-8l72m   1/1       Running   0          21s
    hello-node-7f8df9f98d-gnrld   1/1       Running   0          21s
    hello-node-7f8df9f98d-lphps   1/1       Running   0          2m
    hello-node-7f8df9f98d-srvj2   1/1       Running   0          21s

从dashboard中也可以看到这4个实例

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 2]

总共有4个实例，那么就可通过Service 的 --type=LoadBalancer 进行负载均衡。

### 清理删除 ###

删除在群集中创建的资源：

kubectl delete service hello-node

kubectl delete deployment hello-node

### 停止 ###

minikube stop

### 参考 ###

感谢下面的博文，在我学习的过程中提供了很多帮助。  
[https://k8smeetup.github.io/docs/tutorials/stateless-application/hello-minikube/][https_k8smeetup.github.io_docs_tutorials_stateless-application_hello-minikube]  
[https://segmentfault.com/a/1190000014116698][https_segmentfault.com_a_1190000014116698]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70]: /images/20211013/40a032ed4c66468d85dd4144d132809d.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 1]: /images/20211013/179fe9b2c60b493aa005fe3fbef1a741.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70 2]: /images/20211013/3e163e23f88a4e96b0c00256b2a52555.png
[https_k8smeetup.github.io_docs_tutorials_stateless-application_hello-minikube]: https://k8smeetup.github.io/docs/tutorials/stateless-application/hello-minikube/
[https_segmentfault.com_a_1190000014116698]: https://segmentfault.com/a/1190000014116698