[SOLVED] How to set 'EC2 StopInstances' API call as EventBridge target using Cloudformation

Issue

I am trying to write a Cloudformation template which creates an EventBridge rule.

The EventBridge rule is supposed to stop an instance based on a schedule.

EventBridge target is expected as arn parameter in Cloudformation template. I couldn't figure out the arn value of the rule.

This is the template snippet I use:

 {
    "AWSTemplateFormatVersion": "2010-09-09"
    "Resources": {
        ...
        "Ec2StartStopRule": {
            "Type": "AWS::Events::Rule",
            "Properties": {
                "Name": "ec2-stop-start-rule",
                "RoleArn": {
                    "Fn::GetAtt": [
                        "Ec2StopStartRoleForEventBridge",
                        "Arn"
                    ]
                },
                "ScheduleExpression": "cron(0 12 * * ? *)",
                "Targets": [
                    {
                        "Arn": "ec2:StopInstances",
                        "Id": "Id1234",
                        "RunCommandParameters": {
                            "RunCommandTargets": [
                                {
                                    "Key": "InstanceIds",
                                    "Values": [
                                        "mydata"
                                    ]
                                }
                            ]
                        },
                        "RetryPolicy": {
                            "MaximumRetryAttempts": 2,
                            "MaximumEventAgeInSeconds": 3600
                        }
                    }
                ]
            }
        }
    }
}

I receive following error:

Parameter ec2:StopInstances is not valid. Reason: Provided Arn is not in correct format.

I am sure EventBridge supports EC2 StopInstances API call as target: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-events-rule.html

But I cannot configure it using Cloudformation.

How to set 'EC2 StopInstances' API call as EventBridge target using Cloudformation?

Solution

This is not possible. Please see this link:

AWS docs on target support

I would recommend to run a lambda as target and run the api call through it.

Answered By - Erik Asplund

Answer Checked By - Marilyn (WPSolving Volunteer)