无法在serverless.yml中引用cloudformation资源。变量UserPoolId的变量引用语法无效

Question

我正在使用无服务器框架将无服务器应用程序部署到AWS。但是，cloudformation部分无法正常工作。我在网上查了一下，找不到我的Yaml有什么问题。

我正在使用Cloudformation创建UserPool，然后创建UserPoolClient。我有以下yaml用于resources:

resources:
  Resources:
    HttpBucket:
      Type: "AWS::S3::Bucket"
      Properties:
        BucketName: ${self:service}-${UserPoolId}
        AccessControl: PublicRead
        WebsiteConfiguration:
          IndexDocument: index.html
    UserPool:
      Type: "AWS::Cognito::UserPool"
      Properties:
        UserPoolName: ${self:service}-user-pool
        MfaConfiguration: "OFF"
        EmailVerificationSubject: "Your verification code"
        EmailVerificationMessage: "Your verification code is {####}. "  
        Schema:
          - Name: name
            AttributeDataType: String
            Mutable: true
            Required: true
          - Name: email
            AttributeDataType: String
            Mutable: false
            Required: true
          - Name: teamName
            AttributeDataType: String
            Mutable: true
            Required: false
          - Name: custom:supportedTeam
            AttributeDataType: String
            Mutable: true
            Required: false
          - Name: custom:payment
            AttributeDataType: String
            Mutable: true
            Required: false
            DeveloperOnlyAttribute: true
        UsernameAttributes:
          - email
        AutoVerifiedAttributes:
          - email
        AdminCreateUserConfig:
          InviteMessageTemplate:
            EmailMessage: 'Your username is {username} and temporary password is {####}. '
            EmailSubject: Your temporary password
            SMSMessage: 'Your username is {username} and temporary password is {####}. '
          UnusedAccountValidityDays: 7
          AllowAdminCreateUserOnly: false
        Policies:
          PasswordPolicy:
            RequireLowercase: true
            RequireSymbols: false
            RequireNumbers: true
            MinimumLength: 6
            RequireUppercase: true
    UserPoolClient:
      Type: "AWS::Cognito::UserPoolClient"
      Properties:
        ClientName: ${self:service}-client
        GenerateSecret: false
        UserPoolId: 
          Ref: UserPool
  Outputs:
    UserPoolId:
      Value: 
        Ref: UserPool
      Export:
        Name: "UserPool::Id"
    UserPoolClientId:
      Value: 
        Ref: UserPoolClient
      Export:
        Name: "UserPoolClient::Id"

UserPool指定时，我无法引用UserPoolClient（用作UserPoolId。以下内容：

UserPoolId: 
  Ref: UserPool

产生错误：

变量UserPoolId的变量引用语法无效。您只能引用环境变量，选项和文件。您可以查看我们的文档以获取更多信息。

我不确定的另一件事是，我看到人们共享包含以下语法的yaml：

UserPoolId: !Ref UserPool

但它也会失败，并会出现有关无效语法的错误（由于！Ref）。有人可以清除我的声音吗？

Answer 1

我发现在编写模板时有时会进行不正确的语法突出显示，我必须编写它以便它无法检查。

参考：用户池

Fn::Sub: '${UserPool}'

通过将其与 Substitute 交换，它无法检查字符串的内容是否有效，然后它将构造一个包含对 UserPool 的 Ref 或用户池 id 的字符串

Fn::子文档