Cloud Config i.e. Userdata that runs every single boot

cloud-cfg.yml

#cloud-config-archive
# vim:syntax=yaml
- type: "text/cloud-config"
  content: |
    cloud_final_modules:
      - [scripts-user, always]
- type: "text/x-shellscript"
  content: |
    #!/bin/bash
    exec > >(tee /var/log/user-data.log | logger -t user-data -s 2>/dev/console) 2>&1
    echo "$(date): Start UserData Script."
    touch /root/boot.txt
    echo "$(date): Executing UserData Script.." >> /root/boot.txt
    echo "$(date): Enable and start the Amazon SSM Agent service."
    systemctl daemon-reload
    systemctl enable --now --no-block amazon-ssm-agent.service
    echo "$(date): Done."