Question

我有以下Cloudformation模板：

AWSTemplateFormatVersion: '2010-09-09'

Parameters:
  serviceRoleArn:
    Type: String
    Description: The role that's used when the task is executed.
  AWSInstanceID:
    Type: String
  awsSSMMaintenanceWindowTargetId:
    Type: String
  awsSSMMaintenanceWindowId:
    Type: String
  automationSSMTaskRole:
    Type: String
  automationSSMTaskType:
    Type: String
  automationSSMTaskDescription:
    Type: String
  automationSSMTaskARN:
    Type: String

Resources:
  startInstanceTask:
    Type: 'AWS::SSM::MaintenanceWindowTask'
    Properties:
      MaxErrors: "2"
      Description: !Ref "automationSSMTaskDescription"
      ServiceRoleArn:
        Ref: serviceRoleArn
      Priority: 1
      MaxConcurrency: "1"
      Targets:
      - Values:
        - !Ref "awsSSMMaintenanceWindowTargetId"
        Key: WindowTargetIds
      Name: !Ref "automationSSMTaskType"
      TaskArn: !Ref "automationSSMTaskARN"
      WindowId: !Ref "awsSSMMaintenanceWindowId"
      TaskType: "AUTOMATION"
      TaskInvocationParameters:
        MaintenanceWindowAutomationParameters:
          DocumentVersion: "$DEFAULT"
          Parameters:
            InstanceId:
              - !Ref AWSInstanceID
            AutomationAssumeRole:
              - Ref: automationSSMTaskRole

但是，AWSInstanceID转换为：

"InstanceId": ["i-0375357htn1a8ad40,i-0d0f0f724tytf4d37,i-0e61cc61hthf8c2b2"]

但这不是我想要的格式。如何获得以下输出？

"InstanceId": [
    "i-0375357htn1a8ad40",
    "i-0d0f0f724tytf4d37",
    "i-0e61cc61hthf8c2b2"
]

我想从String转换为CommaDelimitedList。

Answer 1

CloudFormation具有一个称为Fn::Split的内部函数。从用户指南中复制：

下面的示例在每个竖线（|）处分割字符串。该函数返回[“ a”，“ b”，“ c”]。

storage_name

所以对于您而言，我想它可以翻译为

!Split [ "|" , "a|b|c" ]

或者，您也可以尝试将!Split [ ",", !Ref AWSInstanceID ]指定为CommaDelimitedList类型，例如

AWSInstanceID

Answer 2

来自Parameters - AWS CloudFormation：

List<AWS::EC2::Instance::Id>

一系列Amazon EC2实例ID，例如i-1e731a32，i-1e731a34。

因此，请尝试从以下位置更改参数：

Type: String

收件人：

Type: List<AWS::EC2::Instance::Id>

将字符串转换为CommaDelimitedList Cloudformation模板

2 个答案: