amazon-web-services - AWS 云信息 : How to split a string on 'NewLine' character

Question

我在 Cloudformation 中有一组字符串，这就是它们在命令行上的显示方式:

arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app0/yyy
arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app4/yyy
arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app1/yyy
arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app2/yyy
arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app3/yyy

我需要在“\n”(新行字符)上进行分割

字符串是由 CF 的 CommandRunner 生成的:

  GetElbv2Arns:
    Type: AWSUtility::CloudFormation::CommandRunner
    Properties: 
      Role: InfrastructureManagement
      LogGroup: !Ref LogGroup
      SubnetId: !Ref subnetId1
      Command: 
        !Sub 
          - | 
            aws elbv2 describe-load-balancers \
            --region ${AWS::Region} \
            --query "LoadBalancers[].[LoadBalancerArn]" \
            --output text  \
            > /command-output.txt
          - dummy: ""

Answer 1

事实证明，尽管该值以“\n”作为新行开始，但在 CF 获取该值时，它实际上只是“\n”作为文本。这是 CF 输出 Pane 中显示的内容:

arn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app0/yyy\narn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app4/yyy\narn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app1/yyy\narn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app2/yyy\narn:aws:elasticloadbalancing:us-east-1:xxx:loadbalancer/app/app3/yyy

解析值的方法是转义“\”:

Outputs:
  ARNs1:
    Description: "elbv2 Arns-0"
    Value: 
       !Select [0, !Split  [ "\\n", !GetAtt GetElbv2Arns.Output] ]