kubernetes系列之十六：Kubernetes CRD sample-controller的编译和测试

「爱情、让人受尽委屈。」 2022-05-24 12:14 392阅读 0赞

**一、前言**

在文章[《kubernetes系列之十四：Kubernetes CRD(CustomResourceDefinition)概览》][kubernetes_Kubernetes CRD_CustomResourceDefinition]中，对于[Kubernetes官方提供的CRD例子][Kubernetes_CRD]进行了分析，包括CRD的定义以及后端controller的实现。同时如下两篇文章也对k8s的controller进行了更详尽的分析和示例：

*  [A Deep Dive Into Kubernetes Controllers][]
 *  [Kubewatch, An Example Of Kubernetes Custom Controller][Kubewatch_ An Example Of Kubernetes Custom Controller]

但是由于k8s官方提供的CRD以及controller的例子没有相关编译和运行的说明，本文将给出step-by-step设置编译环境和进行编译的例子，以及通过Dockerfile进行一键编译和运行的例子。

转载自https://blog.csdn.net/cloudvtech

**二、CRD example-controllerde编译**

2.1 编译环境

CentOS Linux release 7.4.1708 (Core)

yum install -y go git

2.2 下载代码和依赖

mkdir /root/gowork 
    export GOPATH=/root/gowork/ 
    cd /root/gowork/
    git clone https://github.com/kubernetes/sample-controller.git
    mv sample-controller src
    cd src
    mkdir -p k8s.io/sample-controller
    cp -a pkg k8s.io/sample-controller 
    go get k8s.io/apimachinery

其中安装apimachinery是根据[这篇文章的提示][Link 1]，否则会出现类似如下错误：

Error: Failed executing generator: some packages had errors:
    type "k8s.io/apimachinery/pkg/runtime.Object" in k8s:deepcopy-gen:interfaces tag of type k8s.io/apimachinery/pkg/runtime.Object is not an interface, but: ""
    goroutine 1 [running]:

2.3 运行codegen

./hack/update-codegen.sh 
    Generating deepcopy funcs
    Generating clientset for samplecontroller:v1alpha1 at k8s.io/sample-controller/pkg/client/clientset
    Generating listers for samplecontroller:v1alpha1 at k8s.io/sample-controller/pkg/client/listers
    Generating informers for samplecontroller:v1alpha1 at k8s.io/sample-controller/pkg/client/informers

2.4 编译sample-controller

\cp -af vendor/* ./
    rm -rf vendor/
    go build -v -o samplecontroller
    …
    k8s.io/sample-controller/pkg/apis/samplecontroller
    k8s.io/sample-controller/pkg/apis/samplecontroller/v1alpha1
    k8s.io/sample-controller/pkg/client/clientset/versioned/scheme
    k8s.io/sample-controller/pkg/client/clientset/versioned/typed/samplecontroller/v1alpha1
    k8s.io/sample-controller/pkg/client/clientset/versioned
    k8s.io/sample-controller/pkg/client/informers/externalversions/internalinterfaces
    k8s.io/sample-controller/pkg/client/listers/samplecontroller/v1alpha1
    k8s.io/sample-controller/pkg/client/informers/externalversions/samplecontroller/v1alpha1
    k8s.io/sample-controller/pkg/client/informers/externalversions/samplecontroller
    k8s.io/sample-controller/pkg/client/informers/externalversions
    k8s.io/sample-controller/pkg/signals

编译出来的binary名为samplecontroller，在src目录下面。

转载自https://blog.csdn.net/cloudvtech

**三、运行sample-controller并部署CRD**

3.1 example CRD的功能

这个CRD的功能就是在Foo类型CRD的实例example-foo被创建的时候，sample-controller根据example-foo里面指定的replica来部署一个具有相应数目replica的nginx的deployment。

3.2 运行sample-controller

sample-controller的参数如下：

./samplecontroller --help
    Usage of ./samplecontroller:
      -alsologtostderr
        	log to standard error as well as files
      -kubeconfig string
        	Path to a kubeconfig. Only required if out-of-cluster.
      -log_backtrace_at value
        	when logging hits line file:N, emit a stack trace
      -log_dir string
        	If non-empty, write log files in this directory
      -logtostderr
        	log to standard error instead of files
      -master string
        	The address of the Kubernetes API server. Overrides any value in kubeconfig. Only required if out-of-cluster.
      -stderrthreshold value
        	logs at or above this threshold go to stderr
      -v value
        	log level for V logs
      -vmodule value
        	comma-separated list of pattern=N settings for file-filtered logging

通过kubeconfig可以指定cluster的access，测试Kubernetes的cluster的kubeconfig在如下位置：

/etc/kubernetes/admin.conf

运行：

./samplecontroller -kubeconfig /etc/kubernetes/admin.conf

3.3 部署CRD

[root@k8s-master src]# kubectl apply -f artifacts/examples/crd.yaml 
    customresourcedefinition.apiextensions.k8s.io "foos.samplecontroller.k8s.io" created
    [root@k8s-master src]# kubectl apply -f artifacts/examples/example-foo.yaml 
    foo.samplecontroller.k8s.io "example-foo" created

3.4 查看状态

[root@k8s-master src]# kubectl get crd
    NAME                           AGE
    foos.samplecontroller.k8s.io   52s
    
    
    [root@k8s-master src]# kubectl get Foo
    NAME          AGE
    example-foo   44s
    
    
    [root@k8s-master src]# kubectl describe Foo example-foo
    Name:         example-foo
    Namespace:    default
    Labels:       <none>
    Annotations:  kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"samplecontroller.k8s.io/v1alpha1","kind":"Foo","metadata":{"annotations":{},"name":"example-foo","namespace":"default"},"spec":{"deploym...
    API Version:  samplecontroller.k8s.io/v1alpha1
    Kind:         Foo
    Metadata:
      Cluster Name:        
      Creation Timestamp:  2018-05-25T20:28:47Z
      Generation:          1
      Resource Version:    79222
      Self Link:           /apis/samplecontroller.k8s.io/v1alpha1/namespaces/default/foos/example-foo
      UID:                 3a4e7cd3-605a-11e8-9f24-000c29d3e746
    Spec:
      Deployment Name:  example-foo
      Replicas:         1
    Status:
      Available Replicas:  1
    Events:
      Type    Reason  Age               From               Message
      ----    ------  ----              ----               -------
      Normal  Synced  16s (x8 over 1m)  sample-controller  Foo synced successfully

查看deployment和POD

[root@k8s-master src]# kubectl get deployments
    NAME          DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
    example-foo   1         1         1            1           1m
    [root@k8s-master src]# kubectl get pods
    NAME                          READY     STATUS    RESTARTS   AGE
    example-foo-d74cd7fbc-nql68   1/1       Running   0          2m

转载自https://blog.csdn.net/cloudvtech

**四、Dockerfile方式编译和部署**

4.1 Dockerfile

FROM centos
    ENV PATH=$PATH:/user/bin/
    ENV GOPATH=/gowork
    
    WORKDIR /gowork
    RUN yum install -y go git
    RUN git clone https://github.com/kubernetes/sample-controller.git
    RUN mv sample-controller src
    
    WORKDIR /gowork/src
    RUN mkdir -p k8s.io/sample-controller
    RUN cp -a pkg k8s.io/sample-controller
    RUN echo || go get k8s.io/apimachinery
    RUN \cp -af vendor/* ./
    RUN rm -rf vendor/
    RUN go build -v -o samplecontroller

4.2 build

docker build -t samplecontrolle .

4.3 运行

[root@k8s-master sample-controller_docker]# docker run -it -v /etc/kubernetes:/k8s a9
    [root@9640be7aa387 src]# /gowork/src/samplecontroller -kubeconfig /k8s/admin.conf

转载自https://blog.csdn.net/cloudvtech

[kubernetes_Kubernetes CRD_CustomResourceDefinition]: https://blog.csdn.net/cloudvtech/article/details/80277960
[Kubernetes_CRD]: https://github.com/kubernetes/sample-controller
[A Deep Dive Into Kubernetes Controllers]: https://engineering.bitnami.com/articles/a-deep-dive-into-kubernetes-controllers.html
[Kubewatch_ An Example Of Kubernetes Custom Controller]: https://engineering.bitnami.com/articles/kubewatch-an-example-of-kubernetes-custom-controller.html
[Link 1]: https://github.com/kubernetes/code-generator/issues/21