[messaging] CloudEvents

설명

• https://cloudevents.io/
• 일반적인 방식으로 이벤트 데이터를 설명하기 위한 사양
• CNCF graduated projects
• 다양한 언어의 SDK 제공
  • C#, Go, Java, Javascript/TypeScript, PHP, Python, Ruby, Rust
• 서비스, 플랫폼 및 시스템 간의 상호 운용성을 제공
• 일관성 있는 개발 환경 보장과 비즈니스 로직에 집중 가능
• Argo Events, Azure Event Grid, Google Cloud Eventarc, …에서 사용

코드

• send event

   package main
  	
   import (
       "context"
       "log"
  	
       cloudevents "github.com/cloudevents/sdk-go/v2"
   )
  	
   func main() {
       client, err := cloudevents.NewClientHTTP()
       if err != nil {
           log.Fatalln(err)
       }
  	
       event := cloudevents.NewEvent()
       event.SetID("id")
       event.SetSubject("subject")
       event.SetSource("uri")
       event.SetType("type")
       event.SetData(cloudevents.ApplicationJSON, map[string]string{"hello": "world"})
  	
       ctx := cloudevents.ContextWithTarget(context.Background(), "http://localhost:10000/")
  	
       result := client.Send(ctx, event)
       if cloudevents.IsACK(result) == false {
           log.Fatalf("send, fail %v", result)
       }
   }
  

• receive event

   package main
  	
   import (
       "context"
       "log"
  	
       cloudevents "github.com/cloudevents/sdk-go/v2"
   )
  	
   func receive(event cloudevents.Event) {
       log.Println(event.ID())
       log.Println(event.Subject())
       log.Println(event.Source())
       log.Println(event.SpecVersion())
       log.Println(event.Type())
       log.Println(event.Time())
       log.Println(event.DataContentType())
       log.Println(string(event.Data()))
  	
       eventByte, err := event.MarshalJSON()
       if err != nil {
           log.Fatalln(err)
       }
  	
       eventUnmarshal := cloudevents.NewEvent()
       err = eventUnmarshal.UnmarshalJSON(eventByte)
       if err != nil {
           log.Fatalln(err)
       }
       log.Println(eventUnmarshal)
   }
  	
   func main() {
       client, err := cloudevents.NewClientHTTP(cloudevents.WithPort(10000))
       if err != nil {
           log.Fatalln(err)
       }
       log.Fatalln(client.StartReceiver(context.Background(), receive))
   }