amazon-web-services - AWS : how to use transform cloudformation function in YAML database name

Question

我在尝试组合两个似乎不起作用的代码函数时遇到了一点困难。aws cloudformation cli 工具似乎存在问题并引发错误:'list' 对象没有属性 'get'。

我正在尝试指定一个 lambda 函数(类型 AWS::Serverless::Function)，否则该函数可以工作，但我想将事件计划对象指定为小写(数据库需要)。

有问题的代码，最后 8 行是问题所在:

Resources:
  UpdatePartitionsLogTableFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: updatePartitionsTable.handler
      Runtime: nodejs12.x
      CodeUri: src
      Description: Updates partitions Athena tables
      MemorySize: 128
      Timeout: 60
      Policies:
        - Version: "2012-10-17"
          Statement:
            - Effect: Allow
              Action:
                - "athena:*"
              Resource:
                - "*"
            - Effect: Allow
              Action:
                - "glue:*"
              Resource:
                - "*"
            - Effect: Allow
              Action:
                - "s3:*"
              Resource:
                - "*"
      Events:
        Timer:
          Type: Schedule
          Properties:
            Schedule: cron(0 * * * ? *)
            Input:
              'Fn::Transform':
              - Name: 'String'
                Parameters:
                  InputString: !Sub |
                      {"database": "${AWS::StackName}_logs",
                        "tableNames": "${PartitionedTables}"}
                  Operation: Lower

我收到错误:

'list' object has no attribute 'get'

简化代码:

            Input: !Sub |
                {"database": "${AWS::StackName}_logs",
                  "tableNames": "${PartitionedTables}"}

如果我简化代码，我不会收到错误，但我的用例需要小写。有人可以帮忙吗？我有点卡住了。

Answer 1

感谢@Marcin 的帮助，我成功解决了这个问题不幸的是，我陷入了其他部署问题的困境，所以我想发布我的最终发现作为这个问题的答案。我希望这对其他人有帮助。

在我原来的问题中，确实有一个 - 导致了问题，需要删除它并解决第一个错误。

工作代码如下:(不要忘记在同一模板和其他模板中类似地转换对数据库的任何引用，可以使用相同的宏转换代码)

            Input:
              'Fn::Transform':
                Name: 'StringTransform'
                Parameters:
                  InputString: !Sub |
                      {"database": "${AWS::StackName}_logs",
                        "tableNames": "${PartitionedTables}"}
                  Operation: Lower

完成此工作所需的 CloudFormation 宏 Lambda 代码:

Resources:
  # Custom Transform Macro Function
  # Function is called to manipulate (transform) strings
  TransformFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        ZipFile: |
          import traceback


          def handler(event, context):
              response = {
                  "requestId": event["requestId"],
                  "status": "success"
              }
              try:
                  operation = event["params"]["Operation"]
                  input = event["params"]["InputString"]
                  no_param_string_funcs = ["Upper", "Lower", "Capitalize", "Title", "SwapCase"]
                  if operation in no_param_string_funcs:
                      response["fragment"] = getattr(input, operation.lower())()
                  elif operation == "Strip":
                      chars = None
                      if "Chars" in event["params"]:
                          chars = event["params"]["Chars"]
                      response["fragment"] = input.strip(chars)
                  elif operation == "Replace":
                      old = event["params"]["Old"]
                      new = event["params"]["New"]
                      response["fragment"] = input.replace(old, new)
                  elif operation == "MaxLength":
                      length = int(event["params"]["Length"])
                      if len(input) <= length:
                          response["fragment"] = input
                      elif "StripFrom" in event["params"]:
                          if event["params"]["StripFrom"] == "Left":
                              response["fragment"] = input[len(input)-length:]
                          elif event["params"]["StripFrom"] != "Right":
                              response["status"] = "failure"
                      else:
                          response["fragment"] = input[:length]
                  else:
                      response["status"] = "failure"
              except Exception as e:
                  traceback.print_exc()
                  response["status"] = "failure"
                  response["errorMessage"] = str(e)
              return response

      Handler: index.handler
      Runtime: python3.7
      Role: !GetAtt TransformExecutionRole.Arn
      FunctionName: !Sub ${AWS::StackName}-StringTransform

宏的其他附带资源:

  # Role for TransformFunction
  TransformExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service: [lambda.amazonaws.com]
            Action: ['sts:AssumeRole']
      Path: /
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action: ['logs:*']
                Resource: 'arn:aws:logs:*:*:*'
  # Permission for TransformFunction
  TransformFunctionPermissions:
    Type: AWS::Lambda::Permission
    Properties:
      Action: 'lambda:InvokeFunction'
      FunctionName: !GetAtt TransformFunction.Arn
      Principal: 'cloudformation.amazonaws.com'
  # Actual CloudFormationMacro entrypoint for TransformFunction
  Transform:
    Type: AWS::CloudFormation::Macro
    Properties:
      Name: 'StringTransform'
      Description: Provides various string processing functions
      FunctionName: !GetAtt TransformFunction.Arn

再次感谢@Marcin