如何使用CloudFormation或CDK将另一个AWS帐户的事件总线指定为EventBridge规则的目标？

Question

如何使用CloudFormation或CDK将另一个AWS帐户的事件总线指定为CloudWatch规则的目标？

下面是一个使用CDK的示例规则，我尝试将CodeDeploy事件发送到另一个帐户：

Rule codedeployCreateDeploymentEventRule = Rule.Builder.create(this, "CodedeployCreateDeploymentEventRule")
                                                   .description("CloudWatch event rule covering CodeDeploy CreateDeployment notifications.")
                                                   .ruleName("MyRule")
                                                   .enabled(true)
                                                   .targets(List.of(...something here...))
                                                   .eventPattern(EventPattern.builder()
                                                                             .source(List.of("aws.codedeploy"))
                                                                             .detail(Map.of("eventName", List.of("CreateDeployment")))
                                                                             .build())
                                                   .build();

如何将另一个帐户的EventBus指定为目标？语法是什么？是ARN还是什么？

Answer 1

要在云信息中将CW事件从Acc1中继到Acc2，需要三件事：

AWS::E::EventBusPolicy，允许Acc1提交事件。例如：

  MyEventBusPolicy:
    Type: AWS::Events::EventBusPolicy
    Properties: 
      Action: events:PutEvents
      EventBusName: default
      Principal: 2234322123 # Account1 Id
      StatementId: AcceptEventsFromAcc1

IAM角色，允许Acc1中的CW事件将事件发布到Acc 2。示例：

  MyCWEventsRole:
    Type: AWS::IAM::Role
    Properties: 
      AssumeRolePolicyDocument:                   
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service: [events.amazonaws.com]
            Action: ["sts:AssumeRole"]
      Description: Role for CW event to be able to publish events to acc2
      Policies: 
        - PolicyName: MyEventPolicy
          PolicyDocument: !Sub |
            {
                "Version": "2012-10-17",
                "Statement": [
                    {
                        "Effect": "Allow",
                        "Action": [
                            "events:PutEvents"
                        ],
                        "Resource": [
                            "arn:aws:events:${RegionId}:${AccountId}:event-bus/default"
                         ]
                    }
                ]
            }

其中，AccountId和RegionId是Acc2值，而不是Acc1。

它将从第2步开始使用IAM角色。例如，要依赖CodeCommit事件（我之前设置过，所以我知道它有效）：

  MyRule:
    Type: AWS::Events::Rule
    Properties: 
      Description: Monitor master branch of our repo and rely to Acc2
      EventPattern: !Sub |
            {
              "source": [
                "aws.codecommit"
              ],
              "detail-type": [
                "CodeCommit Repository State Change"
              ],
              "resources": [
                "${GitRepoArn}"
              ],
              "detail": {
                "event": [
                  "referenceCreated",
                  "referenceUpdated"
                ],
                "referenceType": [
                  "branch"
                ],
                "referenceName": [
                  "master"
                ]
               }
             }  
      State: ENABLED
      Targets: 
        - Arn: !Sub "arn:aws:events:${RegionId}:${AccountId}:event-bus/default"
          Id: MyEventToAcc2
          RoleArn: !GetAtt MyCWEventsRole.Arn

其中，AccountId和RegionId是Acc2值，而不是Acc1。