CloudFormation 未知标签 !<!Cidr>

Question

我正在尝试使用 Amazon CloudFormation 构建 VPC 和子网，但在尝试使用 !Cidr function to specify the CidrBlock of the subnets.

时我一直 运行 遇到问题

最小示例，我使用的 CF 模板直接来自 Amazon 文档中的 !Cidr 函数。我将它保存到一个文件中，创建一个新堆栈，选择加载到该文件中，然后在 Designer 中查看。我收到此错误：

Cannot render the template because of an error.: YAMLException: unknown tag !<!Cidr> at line 18, column 75: ... Att ExampleVpc.CidrBlock, 1, 8 ]] ^

这是我正在使用的模板：

AWSTemplateFormatVersion: "2010-09-09"
Description: "Try to create VPC and Subnet using Cidr function"
Resources:
  ExampleVpc:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"
  IPv6CidrBlock:
    Type: AWS::EC2::VPCCidrBlock
    Properties:
      AmazonProvidedIpv6CidrBlock: true
      VpcId: !Ref ExampleVpc
  ExampleSubnet:
    Type: AWS::EC2::Subnet
    DependsOn: IPv6CidrBlock
    Properties:
      AssignIpv6AddressOnCreation: true
      CidrBlock: !Select [ 0, !Cidr [ !GetAtt ExampleVpc.CidrBlock, 1, 8 ]]
      Ipv6CidrBlock: !Select [ 0, !Cidr [ !Select [ 0, !GetAtt ExampleVpc.Ipv6CidrBlocks], 1, 64 ]]
      VpcId: !Ref ExampleVpc

是我的模板有问题，还是 CloudFormation Template Designer 有问题？

Answer 1

您必须重新组织 模板。 Designer 语法分析器一定有一些错误。这应该有效：

AWSTemplateFormatVersion: "2010-09-09"
Description: "Try to create VPC and Subnet using Cidr function"
Resources:
  ExampleVpc:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"
  IPv6CidrBlock:
    Type: AWS::EC2::VPCCidrBlock
    Properties:
      AmazonProvidedIpv6CidrBlock: true
      VpcId: !Ref ExampleVpc
  ExampleSubnet:
    Type: AWS::EC2::Subnet
    DependsOn: IPv6CidrBlock
    Properties:
      AssignIpv6AddressOnCreation: true
      CidrBlock:
        !Select
            - 0
            - Fn::Cidr: [ !GetAtt ExampleVpc.CidrBlock, 1, 8 ]
      Ipv6CidrBlock:
        !Select
          - 0
          - Fn::Cidr: [ !Select [ 0, !GetAtt ExampleVpc.Ipv6CidrBlocks], 1, 64 ]
      VpcId: !Ref ExampleVpc