This config is for Ubuntu with Cloud-init in Proxmox

01-user-data

#cloud-config
hostname: example
fqdn: example.contoso.com
manage_etc_hosts: true

# Users and Groups
users:
  - name: usuario
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: adm, sudo
    home: /home/usuario
    shell: /bin/bash
    lock_passwd: true
    uid: 1000
    ssh-authorized-keys:
      - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC0WGP1EZfreNQSJWjV/Fant...

# Package Management
package_reboot_if_required: true
package_update: true
package_upgrade: true
packages:
  - vim
  - net-tools
  - curl
  - wget
  - lolcat
  - figlet
  - git
  - jq
  - cron
  - qemu-guest-agent

# Custom Files
write_files:
# Banner for SSH Login Ubuntu
  - path: /etc/update-motd.d/01-custom-logo
    permissions: '0755'
    content: |
      #!/bin/bash
      # This script print a banner with logo and system information.
      # Need two packages: figlet and lolcat
      # Fix: for lolcat to work properly, you have to move the binary from /usr/games/lolcat to /usr/bin/lolcat

      # Colors
      GREEN='\033[0;32m'
      BLUE='\033[0;34m'
      YELLOW='\033[0;33m'
      NC='\033[0m'
      LOGO='Example'
      MESSAGE='Example Message'

      # Banner
      figlet -w 70 -f slant -c "${LOGO}" | lolcat -f
      printf "             Welcome to ${LOGO}'s %s Server" "$(hostname -s)" | lolcat -f
      echo
      echo

      # Sysrem Information
      printf "       ${YELLOW}System Information at:${NC}  ${GREEN}%s${NC}\n" "$(date)"
      echo
      printf "${YELLOW}System Load:\t${NC}${BLUE}%s${NC}\t\t${YELLOW}Processes:\t${BLUE}%s${NC}\n" "$(cat /proc/loadavg | awk '{print $1, $2, $3}')" "$(ps aux --no-headings | wc -l)"
      printf "${YELLOW}Memory Usage:\t${NC}${BLUE}%s${NC}\t${YELLOW}IP Address:\t${BLUE}%s${NC}\n" "$(free -m | awk 'NR==2{printf "%s/%sMB (%.2f%%)\n", $3,$2,$3*100/$2 }')" "$(hostname -I | awk '{print $1}')"
      printf "${YELLOW}Disk Usage:\t${NC}${BLUE}%s${NC}\t\t${YELLOW}System Uptime:\t${BLUE}%s${NC}\n" "$(df -h / | awk 'NR==2{printf "%s/%s (%s)\n", $3,$2,$5}')" "$(uptime -p)"

      # Banner 2
      echo
      echo "         ${LOGO} - ${MESSAGE}" | lolcat -f
      echo

# Run Commands
runcmd:
  - mv /usr/games/lolcat /usr/bin/lolcat
  - chmod -x /etc/update-motd.d/*
  - chmod +x /etc/update-motd.d/01-custom-logo
  - sed -i 's/#Banner none/Banner none/g' /etc/ssh/sshd_config
  - sed -i 's/#PrintLastLog yes/PrintLastLog no/g' /etc/ssh/sshd_config
  - sed -i 's/session    optional   pam_motd.so noupdate/# session    optional   pam_motd.so noupdate/g' /etc/pam.d/login
  - systemctl restart ssh
  - systemctl start qemu-guest-agent
  - apt-get install -y unattended-upgrades
  - dpkg-reconfigure -f noninteractive unattended-upgrades
  - timedatectl set-timezone Europe/Madrid

02-network-config

version: 2
ethernets:
  ens18:
    dhcp4: true
    dhcp6: false
    optional: true
# Configuración estática (comentada)
#   addresses:
#     - 192.168.1.100/24
#   gateway4: 192.168.1.1
#   nameservers:
#     search: [example.com]
#     addresses: [8.8.8.8, 8.8.4.4]
#   routes:
#    - to: 0.0.0.0/0
#      via: 10.23.2.1
#      metric: 3
# ens19:
#   dhcp4: false
#   dhcp6: false
#   optional: true
#   addresses:
#     - 10.0.0.10/24
# Ejemplo de configuración de bonding
# bonds:
#   bond0:
#     interfaces: [ens18, ens19]
#     addresses: [192.168.1.100/24]
#     gateway4: 192.168.1.1
#     nameservers:
#       addresses: [8.8.8.8, 8.8.4.4]
#     parameters:
#       mode: active-backup
#       primary: ens18
# Ejemplo de configuración de VLAN
# vlans:
#   vlan15:
#     id: 15
#     link: ens18
#     addresses: [10.0.15.10/24]