sample user_data aka cloud-init

#cloud-config
manage-resolv-conf: true
resolv_conf:
  nameservers:
    - '8.8.8.8'
    - '8.8.4.4'

groups:
  - ubuntu: [root,sys]
  - docker

users:
  - default
  - name: ubuntu
    gecos: tom
    shell: /bin/bash
    primary_group: ubuntu
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: sudo, ubuntu, docker
    lock_passwd: false
    ssh-authorized-keys:
      - ssh-rsa AAAAB3NzaC1ycblablahblah
runcmd:
  - sudo apt-get update -y
  - sudo apt-get install -y software-properties-common gnupg-agent curl apt-transport-https
  - sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
  - sudo add-apt-repository "deb [arch=$(dpkg --print-architecture)] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
  - sudo apt-get install -y docker-ce docker-ce-cli containerd.io
  - sudo systemctl start docker
  - sudo systemctl enable docker
  - su ubuntu

final_message: "The system is finally up, after $UPTIME seconds"