aws-cloudformation - AWS CloudFormation Fn::ImportValue 不喜欢 !Join？

Question

我的 CloudFormation 模板中有以下资源正在尝试创建监听器规则。我的想法是，根据传入的 EnvironmentType 和 AWS 区域，我想从导出监听器 ARN 的相应 CloudFormation 堆栈中导入监听器 ARN。

Parameters:
  EnvironmentType:
    Type: String
    Default: "sandbox"
  ECSClusterStackNameParameter:
    Type: String
    Default: "ECS-US-Sandbox"

Mappings:
  production:
    us-east-1:
      stackWithAlbListenerInfo: "ECS-US-Prod"
    eu-north-1:
      stackWithAlbListenerInfo: "ECS-EU-Prod"
  staging:
    us-east-1:
      stackWithAlbListenerInfo: "ECS-US-Staging"
    eu-north-1:
      stackWithAlbListenerInfo: ""
  sandbox:
    us-east-1:
      stackWithAlbListenerInfo: "ECS-US-Sandbox"
    eu-north-1:
      stackWithAlbListenerInfo: ""

Conditions:
  StackExists:
    !Not [ !Equals [ !FindInMap [ !Ref EnvironmentType, !Ref "AWS::Region", stackWithAlbListenerInfo ], ""] ]

Resources:
  AlbListenerRule:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Condition: UseListenerRule
    Properties:
      ListenerArn:
        !If
          - StackExists
          -
            - Fn::ImportValue:
                !Join
                  - "-"
                  - - !FindInMap [ !Ref EnvironmentType, !Ref "AWS::Region", stackWithAlbListenerInfo ]
                    - "ListenerArn"
          - Fn::ImportValue:
              - !Sub "${ECSClusterStackNameParameter}-ListenerArn"

但是，由于此错误，它验证失败，并且似乎第一个 Fn::ImportValue: 不喜欢 !Join。但是 !Join 返回的连接字符串正确吗？我错过了什么？

ERROR: Service: marcom-stats-service, cfnUpdate error: com.amazonaws.services.cloudformation.model.AmazonCloudFormationException: Template error: the attribute in Fn::ImportValue must be a string or a function that returns a string (Service: AmazonCloudFormation; Status Code: 400; Error Code: ValidationError; Request ID: 2678552e-cf6c-46e1-b640-a7c07de385c2; Proxy: null)

更新:

虽然 Robert Kossenney 的回答纠正了我的错误，但我原来的模板是错误的。这确实是我想做的。我希望它对某人有帮助。

  AlbListenerRule:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Condition: UseListenerRule
    Properties:
      ListenerArn:
        Fn::ImportValue: !Sub
          - ${StackName}-ListenerArn
          - { StackName: !If [ StackExists, !FindInMap [ !Ref EnvironmentType, !Ref "AWS::Region", stackWithAlbListenerInfo ], !Ref ECSClusterStackNameParameter ] }

Answer 1

现在我想我明白了。在第二次导入时，您需要删除 !Sub 前面的破折号:

- Fn::ImportValue:
  !Sub "${ECSClusterStackNameParameter}-ListenerArn"