Trigger script automatically on EC2 creation (no user data)-CodePudding

Everytime an EC2 instance gets created, I want to run a script on that instance. I understand this could be done using the user_data parameter but some of these instances get created manually so people may forget to fill in that parameter sometimes. I want to rely on something automatic instead.

I figured to do it with EventBrdige, catch an event that would indicate me that an instance has been created then trigger a lambda that would run the script. But when looking in the documentation I couldn't find any event that would relate to "EC2 created", see https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/monitoring-instance-state-changes.html.

Any idea how to get this done?

CodePudding user response：

Create an EventBridge rule with the following pattern to catch the event:

{
  "source": ["aws.ec2"],
  "detail-type": ["AWS API Call via CloudTrail"],
  "detail": {
    "eventSource": ["ec2.amazonaws.com"],
    "eventName": ["RunInstances"]
  }
}

and configure the target of the rule to be an AWS lambda function. Configure the lambda to parse the event and invoke an SSM run command against the instance.