如何使用 KubeBuilder 开发一个 Operator

云计算 2023-01-04 大白菜程序猿 手机阅读

通过 Operator 的方案，可以对 Kubernetes 的功能进行友好地扩展。Operatpr = CRD + Controller。首先通过 yaml 定义，生成 CRD ，然后 Controller 不断地监听 etcd 中的数据，执行相应动作。开发 Operator 时，有很多繁琐且重复的事情。KubeBuilder 可以帮助我们快速生成骨架代码，开发一个 Kubernetes 的扩展功能， 更多介绍可以参考文档：Kubernetes 复杂有状态应用管理框架 – Operator 。本篇文档，主要是尝试使用 KubeBuilder 开发一个 Operator 。

1. 环境准备

  • Go 开发环境
  • 远程 Kubernetes 环境
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git diff Dockerfile 

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@@ -7,7 +7,7 @@ COPY go.mod go.mod
 COPY go.sum go.sum
 1. cache deps before building and copying source so that we don't need to re-download as much
 1. and so that source changes don't invalidate our downloaded layer
-RUN go mod download
+RUN GOPROXY=https://gocenter.io go mod download

 1. Copy the go source
 COPY main.go main.go
@@ -19,7 +19,7 @@ RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o manager

 1. Use distroless as minimal base image to package the manager binary
 1. Refer to https://github.com/GoogleContainerTools/distroless for more details
-FROM gcr.io/distroless/static:latest
+FROM gcr.azk8s.cn/distroless/static:latest
 WORKDIR /
 COPY --from=builder /workspace/manager .
 ENTRYPOINT ["/manager"]

2.5. 构建并推送镜像测试

  • 本地构建并推送镜像
    • 安装 kustomize
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    brew install kustomize
    • 部署 CRD
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    make install
    • 查看 CRD
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    kubectl get crd
NAME                                      CREATED AT
apiexampleas.groupa.k8s.chenshaowen.com   2019-09-24T07:24:45Z
    • 部署 Controller
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    make deploy
    • 查看 deployment
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    kubectl get deploy  -n kube-api-system
NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
kube-api-controller-manager   1/1     1            1           46s
    • 创建 CRD 对象
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    kubectl apply -f config/samples/groupa_v1beta1_apiexamplea.yaml
    • 查看 CRD 对象
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    kubectl get apiexampleas.groupa.k8s.chenshaowen.com

NAME                 AGE
apiexamplea-sample   61s

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    kubectl get apiexampleas.groupa.k8s.chenshaowen.com apiexamplea-sample  -o yaml

apiVersion: groupa.k8s.chenshaowen.com/v1beta1
kind: ApiExampleA
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"groupa.k8s.chenshaowen.com/v1beta1","kind":"ApiExampleA","metadata":{"annotations":{},"name":"apiexamplea-sample","namespace":"default"},"spec":{"foo":"bar"}}
  creationTimestamp: "2019-09-24T07:29:16Z"
  generation: 1
  name: apiexamplea-sample
  namespace: default
  resourceVersion: "635450"
  selfLink: /apis/groupa.k8s.chenshaowen.com/v1beta1/namespaces/default/apiexampleas/apiexamplea-sample
  uid: 05398ab4-7d4a-4f2e-af30-b59e61680c7e
spec:
  foo: bar

    3. 在 Project 中写入逻辑