CloudFormation cfn-init表示用户数据脚本成功/失败

Question

I wrote a powershell EC2 userdata script. I would like to know how to use cfn-init.exe to signal success/failure back to CloudFormation? Please provide example and syntax as I am new to CloudFormation.

Answer 1

You need to use cfn-signal command for passing the signal to cloudformation. Please check the documentation at http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-signal.html

I have added cloudformation snippet which uses cfn-signal for passing the signal.

The scripting ensures, that cloudformation waits a maximum of 300 seconds on the instance to get created, before signaling a failure back to cloudformation.

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "EC2Instance": {
      "Type": "AWS::EC2::Instance",
      "Properties": {
        "ImageId": "<AMI>",
        "InstanceType": "<Instance Type>",
        "KeyName": "<Key_pair>",
        "Monitoring": "false",
        "UserData": {
          "Fn::Base64": {
            "Fn::Join": [
              "",
              [
                "#!/bin/bash -e\n",
                "yum update -y aws-cfn-bootstrap\n",
                "/opt/aws/bin/cfn-signal -e 0 -r \"Failed to create Instance\" ",
                {
                  "Ref": "WaitHandle"
                },
                "'\n"
              ]
            ]
          }
        }
      }
    },
    "WaitHandle": {
      "Type": "AWS::CloudFormation::WaitConditionHandle"
    },
    "WaitCondition": {
      "Type": "AWS::CloudFormation::WaitCondition",
      "DependsOn": "EC2Instance",
      "Properties": {
        "Handle": {
          "Ref": "WaitHandle"
        },
        "Timeout": "300"
      }
    }
  }
}