在 CloudFormation 堆栈删除上执行 Lambda 函数

Question

有没有办法触发 Lambda 函数 在给定 stack[=19= 时用于创建堆栈的同一个 CFN 模板中声明的] 正在 删除?
最好我想实现与 片段相反的东西（即：一个相对简单的解决方案，省略了创建 SNS 主题等的需要）。
^{提前感谢任何建议。最好的祝福！ //M}

Answer 1

您可以通过创建 CustomResource 并将其与您的 lambda 函数挂钩来实现所需的行为。 来自 documentation page:

With AWS Lambda functions and custom resources, you can run custom code in response to stack events (create, update, and delete)

lambda 函数需要对 Delete event 做出反应，因此必须编写它以允许这样做。

---

示例 lambda 函数源代码

这是 AWS lambda 函数配置的示例，它需要对删除事件做出反应：

import cfnresponse
            
def lambda_handler(event, context):
    response = {}
        if event['RequestType'] == 'Delete':
            ... # do stuff
            response['output'] = ' Delete event.'
    cfnresponse.send(event, context, cfnresponse.SUCCESS, response)

lambda 函数示例

这是 lambda 函数的 CloudFormation 片段：

"MyDeletionLambda": {
  "Type": "AWS::Lambda::Function",
  "Properties": {
    "Code": {
      "ZipFile": {
        "Fn::Join": [
          "\n",
          [
            "import cfnresponse",
            "",
            "def lambda_handler(event, context):",
            "    response = {}",
            "    if event['RequestType'] == 'Delete':",
            "        response['output'] = 'Delete event.'",
            "    cfnresponse.send(event, context, cfnresponse.SUCCESS, response)"
          ]
        ]
      }
    },
    "Handler": "index.lambda_handler",
    "Runtime": "python3.8"
    }
  }
}

示例自定义资源

这是自定义资源的 CloudFormation 片段：

"OnStackDeletion": {
  "Type": "Custom::LambdaDependency",
  "Properties": {
    "ServiceToken": {
      "Fn::GetAtt": [
        "MyDeletionLambda",
        "Arn"
      ]
    }
  }
}