AWS CloudFormation - AWS::ElasticLoadBalancingV2::LoadBalancer - SecurityGroups

Question

CFN 模板中是否有可能根据参数向 ALB 添加一些特定的安全组？

我遇到两个安全组添加到 ALB 的情况：

ALB
  Type: AWS::ElasticLoadBalancingV2::LoadBalancer
  Properties:
    ...
    SecurityGroups:
      - !Ref 'SecurityGroup1'
      - !Ref 'SecurityGroup2'

现在有一个SecurityGroup3，只有在某些参数具有特定值时，我才会最终添加它。假设如果参数add_sg3 等于yes，则将第三个 SG 添加到 ALB。我总是在类似的情况下使用"!If，但有超过 2 个 SG。任何的建议都受欢迎。谢谢！

Answer 1

您可以使用Condition 和AWS::NoValue 伪参数来实现。下面是一个完整的例子：

Parameters:
    Environment:
        Type: String
        Default: dev
        AllowedValues: ["dev", "prod"]
    VpcId:
        Type: 'AWS::EC2::VPC::Id'
    Subnet1:
        Type: 'AWS::EC2::Subnet::Id'
    Subnet2:
        Type: 'AWS::EC2::Subnet::Id'

Conditions:
    MyTest: !Equals ["dev", !Ref Environment]

Resources:
    ALB:
        Type: 'AWS::ElasticLoadBalancingV2::LoadBalancer'
        Properties:
            SecurityGroups:
            - !Ref SecurityGroup1
            - !If [ MyTest, !Ref SecurityGroup2, !Ref 'AWS::NoValue' ]
            Subnets:
            - !Ref Subnet1
            - !Ref Subnet2

    SecurityGroup1:
        Type: 'AWS::EC2::SecurityGroup'
        Properties:
            GroupDescription: 'Group 1'
            VpcId: !Ref VpcId

    SecurityGroup2:
        Type: 'AWS::EC2::SecurityGroup'
        Properties:
            GroupDescription: 'Group 2'
            VpcId: !Ref VpcId