Cloud Init config that setups user, temporary password, SSH server settings, Docker and Node Exporter

user-data.yml

#cloud-config

users:
  - name: alex
    groups: sudo, docker
    shell: /bin/bash
    lock_passwd: false
    ssh_authorized_keys:
      - ssh-ed25519 ???

chpasswd:
  # Force user to change password on first login.
  expire: true
  users:
    - name: alex
      password: ???
      type: text

write_files:
  - path: /etc/ssh/sshd_config.d/10-security.conf
    content: |
      PermitRootLogin no
      PasswordAuthentication no
      PermitEmptyPasswords no
      X11Forwarding no
  - path: /etc/systemd/system/node-exporter.service
    content: |
      [Unit]
      Description=Node Exporter
      After=network.target
      [Service]
      ExecStart=/usr/local/bin/node_exporter
      [Install]
      WantedBy=multi-user.target

package_update: true
package_upgrade: true
packages:
  - ca-certificates
  - curl
  - gnupg
  - lsb-release
  - git
  - wget
  - tree
  - jq

runcmd:
  # Install Docker Engine.
  - mkdir -p /etc/apt/keyrings
  - curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
  - echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg]
    https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" > /etc/apt/sources.list.d/docker.list
  - apt update
  - apt install -y docker-ce docker-ce-cli containerd.io docker-compose-plugin
  # Install Node Exporter.
  - wget -O node_exporter.tar.gz
    "https://github.com/prometheus/node_exporter/releases/download/v1.5.0/node_exporter-1.5.0.linux-amd64.tar.gz"
  - mkdir node_exporter
  - tar xvf node_exporter.tar.gz -C node_exporter --strip-components=1
  - cp node_exporter/node_exporter /usr/local/bin
  - rm -rf node_exporter node_exporter.tar.gz
  - systemctl enable node-exporter
  - systemctl start node-exporter
  # Create standard directory for deploys.
  - mkdir /deploy
  - chown -R alex:sudo /deploy
  - chmod -R 770 /deploy
  - chmod g+s /deploy

Cloud Init reference: https://cloudinit.readthedocs.io/en/latest/topics/modules.html

Can be tested by creating VMs based on Ubuntu Cloud Images locally.

Setup Libvirt, QEMU and KVM on Linux: https://www.n0derunner.com/create-a-linux-vm-with-kvm-in-6-easy-steps

Create VM with Cloud Init config injected. Requires user-data file and jammy-server-cloudimg-amd64.img downloaded Ubuntu image.

cloud-localds user-data.img user-data
qemu-img create -b jammy-server-cloudimg-amd64.img -F qcow2 -f qcow2 my-cloud-vm.qcow2 20G
virt-install \
  --name my-cloud-vm \
  --vcpus 2 --memory 4096 --graphics none --import \
  --disk path=my-cloud-vm.qcow2,device=disk \
  --disk path=user-data.img,format=raw \
  --os-variant ubuntu22.04

Obtain IP assigned to VM. Then you can SSH into it.

virsh net-dhcp-leases default

Remove VM:

virsh destroy my-cloud-vm
virsh undefine my-cloud-vm --remove-all-storage