CloudFormation-更好地发现RDS DBSubnetGroup列表的EC2子网/可用区？

Question

cfn-lint抱怨通过这种方式对可用区进行硬编码：

Resources:
  SubnetWest2a:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: us-west-2a
      CidrBlock: 10.0.0.0/24
      VpcId: !Ref GlobalVPC

  SubnetWest2b:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: us-west-2b
      CidrBlock: 10.0.1.0/24
      VpcId: !Ref GlobalVPC

  SubnetWest2c:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: us-west-2c
      CidrBlock: 10.0.2.0/24
      VpcId: !Ref GlobalVPC

所以我是这样做的：

Resources:
  #...
  SubnetWest1:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: 10.0.0.0/24
      VpcId: !Ref GlobalVPC
      AvailabilityZone: !Select
        - 0
        - Fn::GetAZs: !Ref 'AWS::Region'

  SubnetWest2:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: 10.0.1.0/24
      VpcId: !Ref GlobalVPC
      AvailabilityZone: !Select
        - 1
        - Fn::GetAZs: !Ref 'AWS::Region'

  SubnetWest3:
    Type: AWS::EC2::Subnet
    Properties:
      CidrBlock: 10.0.2.0/24
      VpcId: !Ref GlobalVPC
      AvailabilityZone: !Select
        - 2
        - Fn::GetAZs: !Ref 'AWS::Region'

但是警告来自Fn::GetAZs docs：

  

类似于来自describe-availability-zones AWS CLI命令的响应，不能保证Fn :: GetAZs函数的结果顺序，并且在添加新的可用区时可能会更改。

取决于这些子网和CIDR块的节是：

GlobalDBSubnetGroup:
  Type: AWS::RDS::DBSubnetGroup
  Properties:
    DBSubnetGroupDescription: Multi-AZ RDS subnet group
    SubnetIds:
      - !Ref SubnetWest1
      - !Ref SubnetWest2
      - !Ref SubnetWest3

鉴于这两个互斥的最佳实践提示，有没有更好的方法来发现（或更好的方法来为多可用区RDS创建此相互依赖的资源集合） ），并在每次运行此堆栈时获得确定性结果？