AWS Lambda的动态环境变量,使用cloudformation模板

Question

我必须在我的应用程序的各种堆栈中使用AWS lambda,因此我创建了一个通用的云形成模板来创建lambda函数.此模板可以包含在另一个云形成模板中,以进一步用作嵌套堆栈.

    # Basics
AWSTemplateFormatVersion: '2010-09-09'
Description: AWS CloudFormation Template to create a lambda function for java 8 or nodejs

# Parameters
Parameters:
  FunctionName:
    Type: String
    Description: Funciton Name
  HandlerName:
    Type: String
    Description: Handler Name
  FunctionCodeS3Bucket:
    Type: String
    Description: Name of s3 bucket where the function code is present
    Default: my-deployment-bucket
  FunctionCodeS3Key:
    Type: String
    Description: Function code present in s3 bucket
  MemorySize:
    Type: Number
    Description: Memory size between 128 MB - 1536 MB and multiple of 64
    MinValue: '128'
    MaxValue: '1536'
    Default: '128'
  RoleARN:
    Type: String
    Description: Role ARN for this function
  Runtime:
    Type: String
    Description: Runtime Environment name e.g nodejs, java8
    AllowedPattern: ^(nodejs6.10|nodejs4.3|java8)$
    ConstraintDescription: must be a valid environment (nodejs6.10|nodejs4.3|java8) name.
  Timeout:
    Type: Number
    Description: Timeout in seconds
    Default: '3'
  Env1:
    Type: String
    Description: Environment Variable with format Key|value
    Default: ''
  Env2:
    Type: String
    Description: Environment Variable with format Key|value
    Default: ''
  Env3:
    Type: String
    Description: Environment Variable with format Key|value
    Default: ''
  Env4:
    Type: String
    Description: Environment Variable with format Key|value
    Default: ''

# Conditions
Conditions:
  Env1Exist: !Not [ !Equals [!Ref Env1, '']]
  Env2Exist: !Not [ !Equals [!Ref Env2, '']]
  Env3Exist: !Not [ !Equals [!Ref Env3, '']]
  Env4Exist: !Not [ !Equals [!Ref Env4, '']]

# Resources
Resources:
  LambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        S3Bucket: !Ref 'FunctionCodeS3Bucket'
        S3Key: !Ref 'FunctionCodeS3Key'
      Description: !Sub 'Lambda function for: ${FunctionName}'
      Environment:
        Variables:
          'Fn::If':
            - Env1Exist
            -
              - !Select [0, !Split ["|", !Ref Env1]]: !Select [1, !Split ["|", !Ref Env1]]
              - 'Fn::If':
                - Env2Exist
                - !Select [0, !Split ["|", !Ref Env2]]: !Select [1, !Split ["|", !Ref Env2]]
                - !Ref "AWS::NoValue"
              - 'Fn::If':
                - Env3Exist
                - !Select [0, !Split ["|", !Ref Env3]]: !Select [1, !Split ["|", !Ref Env3]]
                - !Ref "AWS::NoValue"
              - 'Fn::If':
                - Env4Exist
                - !Select [0, !Split ["|", !Ref Env4]]: !Select [1, !Split ["|", !Ref Env4]]
                - !Ref "AWS::NoValue"
            - !Ref "AWS::NoValue"
      FunctionName: !Ref 'FunctionName'
      Handler: !Ref 'HandlerName'
      MemorySize: !Ref 'MemorySize'
      Role: !Ref 'RoleARN'
      Runtime: !Ref 'Runtime'
      Timeout: !Ref 'Timeout'
Outputs:
  LambdaFunctionARN:
    Value: !GetAtt 'LambdaFunction.Arn'

我想将环境变量注入到函数中,并将从父堆栈传递,如下所示:

# Resouces
Resources:
  # Lambda for search Function
  ChildStackLambdaFunction:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: <<REF_TO_ABOVE_LAMBDA_STACK.yml>>
      Parameters:
        FunctionName: test
        HandlerName: 'index.handler'
        FunctionCodeS3Bucket: <<BUCKET_NAME>>
        FunctionCodeS3Key: <<FUNCTION_DEPLOYMENT_NAME>>
        MemorySize: '256'
        RoleARN: <<ROLE_ARN>>
        Runtime: nodejs6.10
        Timeout: '60'
        Env1: !Sub 'AWS_REGION|${AWS::Region}'

当我部署这个堆栈时,我遇到了错误.任何人都可以帮我解决这个问题吗？

模板格式错误:[/ Resources/LambdaFunction/Type/Environment/Variables/Fn :: If/1/0]映射键必须是字符串; 收到地图而不是

传递键值参数在这里引用

Answer 1

所以,我尝试了很多方法来实现这一点,但我们无法将动态键值对从父堆栈传递给嵌套的lambda堆栈.我从AWS支持部门得到了一个确认,认为这是不可能的.

他们提出了另一种我喜欢和实施的方式,如下所述:

将key:value对作为JSON字符串传递,并在lambda函数中适当地解析它.

Environment:
  Variables:
    Env1: '{"REGION": "REGION_VALUE", "ENDPOINT": "http://SOME_ENDPOINT"}'  

这个建议在解析JSON字符串的编程上有一点开销,但是此时我会推荐这个作为上述问题的解决方案.