首页 > 解决方案 > AWS EventBridge 作为 Lambda 目标

问题描述

我有两个 Lambda 函数,一个 EventProducer 和一个 EventConsumer。所需的场景如下:EventProducer 在自定义 AWS EventBridge 总线中添加一个事件,而 EventConsumer 读取该事件。

我想使用 Lambda 目标来实现这一点,但 EventBridge 似乎没有工作。我已经设法通过显式调用“AmazonEventBridge::putEvent”来推送我的事件来使消费者可以使用事件,但我没有通过返回输出和发送输出来做到这一点。

如果我使用 Lambda 或 SQS 作为目标,而不是 EventBridge,则该代码有效。当我使用 AWS CLI 发送消息时,消费者也会读取它们。

有没有人有一个使用 Lambda 目标从 Lambda 函数推送 EventBridge 中的事件的工作示例?

我的代码如下:

Handler code:

@Override
public void handleRequest(InputStream input, OutputStream output, Context context) throws IOException {
        DataciteDoiRequest sentDirectly = newDataciteDoiRequest();
        logger.info(lOG_HANDLER_HAS_RUN);
        putEventDirectlyToEventBridge(sentDirectly); 

        DataciteDoiRequest sentThroughLambdaDestination =
            sentDirectly.copy().withPublicationId(URI.create("https://localhost/fromOutputStream")).build();
        writeOutput(sentThroughLambdaDestination, output);
    }

    private <I> void writeOutput(I event, OutputStream outputStream)
        throws IOException {
        try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream))) {
            String responseJson = Optional.ofNullable(objectMapper.writeValueAsString(event))
                .map(StringUtils::replaceWhiteSpacesWithSpace)
                .map(StringUtils::removeMultipleWhiteSpaces)
                .orElseThrow();
            logger.info(responseJson);
            writer.write(responseJson);
        }
    }

    private void putEventDirectlyToEventBridge(DataciteDoiRequest dataciteDoiRequest) {
        PutEventsRequestEntry putEventsRequestEntry = new PutEventsRequestEntry()
            .withDetail(dataciteDoiRequest.toString())
            .withEventBusName(environment.readEnv(EVENT_BUS_ENV_VAR))
            .withSource(SOURCE)
            .withDetailType(dataciteDoiRequest.getType());

        PutEventsRequest putEventsRequest = new PutEventsRequest().withEntries(putEventsRequestEntry);
        eventBridgeClient.putEvents(putEventsRequest);
    }


CloudFormation template:

 EventConsumer:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: dynamo-event-to-datacite-request
      Handler: handlers.EventConsumer::handleRequest
      Runtime: java11
      MemorySize: 1400
      Role: !GetAtt LambdaRole.Arn
      Environment:
        Variables:
          EVENT_BUS: !GetAtt EventBus.Name
          AWC_ACCOUNT_ID: !Ref AWS::AccountId
      Events:
        EventBridgeEvent:
          Type: EventBridgeRule
          Properties:
            EventBusName: !GetAtt EventBus.Name
            Pattern: { "detail": { "type": [ "MyType" ] } }
  EventProducer:
    DependsOn:
      - EventBus
      - FailQueue
      - EventConsumer
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: dynamo-event-to-datacite-request
      Handler: handlers.EventProducer::handleRequest
      Runtime: java11
      MemorySize: 1400
      Role: !GetAtt LambdaRole.Arn
      EventInvokeConfig:
        DestinationConfig:
          OnSuccess:
            Type: EventBridge
            Destination: !GetAtt EventBus.Arn
          OnFailure:
            Type: SQS
            Destination: !GetAtt FailQueue.Arn

      Environment:
        Variables:
          EVENT_BUS: !GetAtt EventBus.Name
  EventBus:
    Type: AWS::Events::EventBus
    Properties:
      Name: orestis-event-bus
  FailQueue:
    Type: AWS::SQS::Queue
    Properties:
      MaximumMessageSize: 262144
      QueueName: orestis-failure-queue


标签: amazon-web-servicesaws-lambdaaws-event-bridge

解决方案


您的 EventConsumer Events -config 对我来说看起来不正确 EventBridgeRule。Pattern缺少source属性。这应该与您的发件人正在使用的 SOURCE 的名称相匹配。如果您使用它来区分不同的事件类型,“详细”属性也应该是“详细类型” : https ://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-events-rule.html

如果您像这样(全部在 Yaml 中)编写 Events -config 会怎样?

Events:
  EventBridgeEvent:
    Type: EventBridgeRule
    Properties:
      EventBusName: !GetAtt EventBus.Name
      Pattern:
       source:
         - "name.of.the.sender"
       detail-type:
         - "MyType"

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