cf-asg-lambda-sns.json

"MyLambdaLifecycleFunction": {
  "Type": "AWS::Lambda::Function",
  "Properties": {
    "Handler": "asg-graceful-lifecycle-termination.lambda_handler",
    "Role": { "Fn::GetAtt" : ["LambdaExecutionRole", "Arn"] },
    "Code": {
      "S3Bucket": "lambda-functions",
      "S3Key": "asg-graceful-lifecycle-termination.zip"
    },
    "Runtime": "python2.7",
    "Timeout": "300"
  }
}

"myLifecycleHookTopic" : {
   "Type" : "AWS::SNS::Topic",
   "Properties" : {
      "Subscription" : [
         { "Endpoint" : { "Fn::GetAtt" : [ "MyLambdaLifecycleFunction", "Arn" ] }, "Protocol" : "lambda" }
      ]
   }
}

"myLifecycleHook": {
  "Type": "AWS::AutoScaling::LifecycleHook",
  "Properties": {
    "AutoScalingGroupName": { "Ref": "myAutoScalingGroup" },
    "HeartbeatTimeout": 300,
    "LifecycleTransition": "autoscaling:EC2_INSTANCE_TERMINATING",
    "NotificationMetadata": { "Ref": "StackName" },
    "NotificationTargetARN": { "Ref": "myLifecycleHookTopic" },
    "RoleARN": { "Fn::GetAtt": [ "lifecycleHookRole", "Arn" ] }
  }
}