使用 Knative 示例存储库

Knative 项目提供了一个 示例存储库，其中包含一个基本事件源控制器和接收器适配器的模板。

先决条件

• 您熟悉 Kubernetes 和 Go 开发。
• 您已安装 Git。
• 您已安装 Go。
• 您已克隆 sample-source 存储库。

可选

• 安装 ko CLI 工具。
• 安装 kubectl CLI 工具。
• 设置 minikube 或 kind。

示例文件概述

接收器适配器文件

• cmd/receive_adapter/main.go - 将资源变量转换为底层适配器结构，以便可以将其传递到 Knative 系统中。

• pkg/adapter/adapter.go - 支持将事件转换为 CloudEvents 的接收器适配器转换的函数。

控制器文件

• cmd/controller/main.go - 将事件源的 NewController 实现传递给共享的 main 方法。

• pkg/reconciler/sample/controller.go - 传递给共享的 main 方法的 NewController 实现。

CRD 文件

• pkg/apis/samples/VERSION/samplesource_types.go - 底层 API 类型的架构，它提供在资源 YAML 文件中定义以供使用的变量。

协调器文件

• pkg/reconciler/sample/samplesource.go - 接收器适配器的协调函数。

• pkg/apis/samples/VERSION/samplesource_lifecycle.go - 包含事件源协调详细信息的*状态*信息

  • 源就绪
  • 提供接收器地址
  • 已部署
  • 提供事件类型
  • Kubernetes 资源正确

步骤

1. 在 pkg/apis/samples/v1alpha1/samplesource_types.go 中定义资源架构所需的类型。

   这包括资源 YAML 中需要的字段，以及控制器使用源的 clientset 和 API 引用到的字段

   // +genclient
   // +genreconciler
   // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
   // +k8s:openapi-gen=true
   type SampleSource struct {
       metav1.TypeMeta `json:",inline"`
       // +optional
       metav1.ObjectMeta `json:"metadata,omitempty"`
   
       // Spec holds the desired state of the SampleSource (from the client).
       Spec SampleSourceSpec `json:"spec"`
   
       // Status communicates the observed state of the SampleSource (from the controller).
       // +optional
       Status SampleSourceStatus `json:"status,omitempty"`
   }
   
   // SampleSourceSpec holds the desired state of the SampleSource (from the client).
   type SampleSourceSpec struct {
       // inherits duck/v1 SourceSpec, which currently provides:
       // * Sink - a reference to an object that will resolve to a domain name or
       //   a URI directly to use as the sink.
       // * CloudEventOverrides - defines overrides to control the output format
       //   and modifications of the event sent to the sink.
       duckv1.SourceSpec `json:",inline"`
   
       // ServiceAccountName holds the name of the Kubernetes service account
       // as which the underlying K8s resources should be run. If unspecified
       // this will default to the "default" service account for the namespace
       // in which the SampleSource exists.
       // +optional
       ServiceAccountName string `json:"serviceAccountName,omitempty"`
   
       // Interval is the time interval between events.
       //
       // The string format is a sequence of decimal numbers, each with optional
       // fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m". Valid time
       // units are "ns", "us" (or "µs"), "ms", "s", "m", "h". If unspecified
       // this will default to "10s".
       Interval string `json:"interval"`
   }
   
   // SampleSourceStatus communicates the observed state of the SampleSource (from the controller).
   type SampleSourceStatus struct {
       duckv1.Status `json:",inline"`
   
       // SinkURI is the current active sink URI that has been configured
       // for the SampleSource.
       // +optional
       SinkURI *apis.URL `json:"sinkUri,omitempty"`
   }
   

2. 定义要反映在 status 和 SinkURI 字段中的生命周期

   const (
       // SampleConditionReady has status True when the SampleSource is ready to send events.
       SampleConditionReady = apis.ConditionReady
       // ...
   )
   

3. 通过定义要从协调函数调用的函数来设置生命周期条件。这通常在 pkg/apis/samples/VERSION/samplesource_lifecycle.go 中完成

   // InitializeConditions sets relevant unset conditions to Unknown state.
   func (s *SampleSourceStatus) InitializeConditions() {
       SampleCondSet.Manage(s).InitializeConditions()
   }
   
   ...
   
   // MarkSink sets the condition that the source has a sink configured.
   func (s *SampleSourceStatus) MarkSink(uri *apis.URL) {
       s.SinkURI = uri
       if len(uri.String()) > 0 {
           SampleCondSet.Manage(s).MarkTrue(SampleConditionSinkProvided)
       } else {
           SampleCondSet.Manage(s).MarkUnknown(SampleConditionSinkProvided, "SinkEmpty", "Sink has resolved to empty.%s", "")
       }
   }
   
   // MarkNoSink sets the condition that the source does not have a sink configured.
   func (s *SampleSourceStatus) MarkNoSink(reason, messageFormat string, messageA ...interface{}) {
       SampleCondSet.Manage(s).MarkFalse(SampleConditionSinkProvided, reason, messageFormat, messageA...)
   }