SSM automation document to set all EBS volumes attached to a given EC2 instance to delete on instance terminate

ssm-automation-doc.yml

description: Set all EBS volumes of an EC2 instance to delete on instance termination
schemaVersion: '0.3'
parameters:
  InstanceId:
    type: String
  AutomationAssumeRole:
    type: String
    default: 'arn:{{global:AWS_PARTITION}}:iam::{{global:ACCOUNT_ID}}:role/AWS-SystemsManager-AutomationExecutionRole'
    description: >-
      (Optional) The ARN of the role that allows Automation to perform the actions on your behalf. If no role is
      specified, Systems Manager Automation uses your IAM permissions to run this runbook.
assumeRole: "{{ AutomationAssumeRole }}"
mainSteps:
  - name: SetDeleteOnTermination
    action: 'aws:executeScript'
    inputs:
        Runtime: python3.11
        Handler: handler
        InputPayload:
          InstanceId: "{{ InstanceId }}"
        Script: |-
          import json
          import boto3
          ec2 = boto3.client('ec2')

          def handler(event,context):
            inst = ec2.describe_instances(InstanceIds=[event['InstanceId']])['Reservations'][0]['Instances'][0]
            print(json.dumps(inst['BlockDeviceMappings'], default=str))

            bdms = []
            for bdm in inst['BlockDeviceMappings']:
              if 'Ebs' not in bdm:
                continue
              bdms.append({
                'DeviceName': bdm['DeviceName'],
                'Ebs': {'DeleteOnTermination': True},
              })
            print(json.dumps(bdms, default=str))
            ec2.modify_instance_attribute(
              InstanceId=event['InstanceId'],
              BlockDeviceMappings=bdms,
            )

            inst = ec2.describe_instances(InstanceIds=[event['InstanceId']])['Reservations'][0]['Instances'][0]
            bdms_json = json.dumps(inst['BlockDeviceMappings'], default=str)
            print(bdms_json)
            # JSON string return object renders nicely in automation console
            return bdms_json
    outputs:
    - Name: Payload
      Selector: "$.Payload"
      Type: "String"
    - Name: ExecutionLog
      Selector: "$.ExecutionLog"
      Type: "String"