A custom “user-data” file is required for an unattended installation of Ubuntu. We will create this template file for use in our Ansible playbook to Generate Custom Unattended Ubuntu Install ISO.

Save the file and customize it as you need.

user-data.j2

#cloud-config
autoinstall:
  version: 1
  ssh:
    install-server: true
    # option "allow-pw" defaults to `true` if authorized_keys is empty, `false` otherwise.
    allow-pw: false
  storage:
    layout:
      name: lvm
      match:
        size: largest
  user-data:
    disable_root: true
    timezone: America/New_York
    package_upgrade: true
    packages:
    - network-manager
    - lldpd
    - git
    - python3-pip
    - ansible
    - arp-scan
    users:
      - name: {{ Global.username }}
        primary_group: users
        groups: sudo
        lock_passwd: true
        shell: /bin/bash
        ssh_authorized_keys:
          - "{{ Global.ssh_key }}"
        sudo: ALL=(ALL) NOPASSWD:ALL
  ansible:
    install_method: pip
    package_name: ansible
    #run_user: ansible
    galaxy:
      actions:
        - ["ansible-galaxy", "collection", "install", "community.general"]
  late-commands:
    # randomly generate the hostname & show the IP at boot
    - echo "{{ Global.system_name_prefix }}-$(openssl rand -hex 3)" > /target/etc/hostname
    # dump the IP out at login screen
    - echo "Ubuntu 22.04 LTS \nIP - $(hostname -I)\n" > /target/etc/issue

Create a new variables.yml file in the home directory (you are the user ansible now, so it's in /home/ansible).

Modify the file as follows:

• Replace the ssh key with the one you saved earlier
• Replace the bridge_interface_name value with the interface of your host machine
  • Ex., runip a and you will find the list of interfaces and IP addresses

variables.yml

---
Global:
  bridge_interface_name: "enp8s0"
  username: ansible
  ssh_key: "ssh-rsa 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 autobox@autobox"
  workingdir: "{{ lookup('env','HOME') }}/ubuntu-autoinstall"
  inventory_file: "{{ lookup('env','HOME') }}/inventory"
  vboxmanage_path: /usr/bin/vboxmanage
  ubuntu_iso: https://cdimage.ubuntu.com/ubuntu-server/jammy/daily-live/current/jammy-live-server-amd64.iso
  ubuntu_iso_filename: jammy-live-server-amd64.iso
  new_iso_filename: ubuntu-22.04-autoinstall.iso

For this level of automation, we need to know the IP addresses of the servers. Therefore instead of relying on DHCP, we will build the servers with static IP addresses.

These static IP addresses:

• are on the same subnet as your host machine
• need to be unique (no conflicts); assign IP addresses that are not in your router's DHCP scope/range
  • This is Linux, so static IP addresses are NOT in the DHCP scope; Windows fixed IP addresses are in the scope range
• are expressed in CIDR notation for the sake of the autoinstaller
  • Ex. 192.168.1.25 with the subnet 255.255.255.0 = 192.168.1.25
  • Ref. https://www.freecodecamp.org/news/subnet-cheat-sheet-24-subnet-mask-30-26-27-29-and-other-ip-address-cidr-network-references/

Since we are doing static IP addresses you will also need to provide:

• IPv4Gateway: the IP address of your router
  • on your host computer run route -n from Terminal/command line to set the gateway IP
• IPv4DNS: a DNS server
  • on your host computer run nmcli device show
  • shows the IP4.DNS[1] address and the IP4.GATEWAY address
  • you can always configure the Google DNS IP 8.8.8.8 here

The Search domain should match the domain you configured on your router, if any. Or use lablocal for a safe value.

You will also specify VM resources for each server:

• DiskSize in MB (10240 = 102240 MB = 10GB)
• MemorySize in MB (1024 = 1GB)
• CPUs in number of virtual cores

You will also enter the Name (VM name), Hostname (VM's OS hostname), local sudoer username and password.

In the following example the Lab router (192.168.99.254) provides a DNS resolver to clients.

Lab server list

• 1x Controller
  • 2 CPU cores
  • 2 GB RAM
  • 60 GB storage
• 1x SQL server node
  • 2 CPU cores
  • 2 GB RAM
  • 250 GB storage
• 2x app nodes
  • 1 CPU core
  • 2 GB RAM
  • 60 GB storage

This consumes 6 of the 8 cores in the NUC host, 8GB of RAM and <500GB storage.

If you have more cores give 2 cores to each App node and add another App node for 3 total (10 cores + 2 overhead = 12 cores at least).

server.yml

---
Server_List:
  - Name: controller
    Deploy: true
    Configuration:
      Storage:
        DiskSize: 61440
      Compute:
        MemorySize: 2048
        CPUs: 2
      OS:
        User: ubuntu
        Password: "virtualbox1!"
        Hostname: controller
        IPv4Address: 192.168.99.201/24
        IPv4Gateway: 192.168.99.254
        IPv4DNS: 192.168.99.254
        SearchDomain: lablocal
  - Name: node1
    Deploy: true
    Configuration:
      Storage:
        DiskSize: 256000
      Compute:
        MemorySize: 2048
        CPUs: 2
      OS:
        User: ubuntu
        Password: "virtualbox1!"
        Hostname: node1
        IPv4Address: 192.168.99.202/24
        IPv4Gateway: 192.168.99.254
        IPv4DNS: 192.168.99.254
        SearchDomain: lablocal
  - Name: node2
    Deploy: true
    Configuration:
      Storage:
        DiskSize: 61440
      Compute:
        MemorySize: 2048
        CPUs: 1
      OS:
        User: ubuntu
        Password: "virtualbox1!"
        Hostname: node2
        IPv4Address: 192.168.99.203/24
        IPv4Gateway: 192.168.99.254
        IPv4DNS: 192.168.99.254
        SearchDomain: lablocal
  - Name: node3
    Deploy: true
    Configuration:
      Storage:
        DiskSize: 61440
      Compute:
        MemorySize: 2048
        CPUs: 1
      OS:
        User: ubuntu
        Password: "virtualbox1!"
        Hostname: node3
        IPv4Address: 192.168.99.204/24
        IPv4Gateway: 192.168.99.254
        IPv4DNS: 192.168.99.254
        SearchDomain: lablocal

Next create the jinja (j2) template used to create the user-data file for each server's automatic installer ISO image. You can customize this (e.g., the timezone).

fleet-user-data.j2

#cloud-config
autoinstall:
  version: 1
  ssh:
    install-server: true
    allow-pw: false
  storage:
    layout:
      name: lvm
      match:
        size: largest
  network:
    network:
      version: 2
      ethernets:
        zz-all-en:
          match:
            name: "en*"
          dhcp4: no
          addresses: [{{ item.Configuration.OS.IPv4Address }}]
          gateway4: {{ item.Configuration.OS.IPv4Gateway }}
          nameservers:
              addresses: [{{ item.Configuration.OS.IPv4DNS }}]
  user-data:
    disable_root: true
    timezone: America/New_York
    package_upgrade: true
    packages:
    - network-manager
    - lldpd
    - git
    - python3-pip
    - ansible
    - arp-scan
    users:
      - name: {{ Global.username }}
        primary_group: users
        groups: sudo
        lock_passwd: true
        shell: /bin/bash
        ssh_authorized_keys:
          - "{{ Global.ssh_key }}"
        sudo: ALL=(ALL) NOPASSWD:ALL
  ansible:
    install_method: pip
    package_name: ansible
    galaxy:
      actions:
        - ["ansible-galaxy", "collection", "install", "community.general"]
  late-commands:
    - echo "{{ item.Configuration.OS.Hostname }}" > /target/etc/hostname
    - echo "Ubuntu 22.04 LTS \nIP - $(hostname -I)\n" > /target/etc/issue

The next playbook is the one that will do all the work.

Overview:

• set up working directory
• download the Ubuntu 20.20 server ISO (this may take some time depending on the Internet connection)
• create a customer bootable ISO for each server
• create a VM for each server with the required resources
• power on the new VMs in headless more
• add the static IP addresses assigned to the VMs to the inventory file inventory
• wait for the servers to boot and be configured, and finally come online
• add the ssh keys to the known_hosts file to enable seamless control using Ansible

build_fleet.yml

---
- hosts: localhost  # Run actions on the local machine
  name: build_fleet.yml
  connection: local
  gather_facts: false
  vars_files:
    - variables.yml
    - servers.yml
  tasks:
    - name: Create working directory
      file:
        path: "{{ Global.workingdir }}"
        state: directory
        mode: "755"
    - name: Download the latest ISO
      get_url:
        url: "{{ Global.ubuntu_iso }}"
        dest: "{{ Global.workingdir }}/jammy-live-server-amd64.iso"
        force: false
    - name: Create source files directory
      file:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files"
        state: directory
        mode: "755"
      loop: "{{ Server_List }}"
      when: item.Deploy
    - name: Extract ISO
      command: "7z -y x {{ Global.workingdir }}/{{ Global.ubuntu_iso_filename }} -o{{ Global.workingdir }}/{{ item.Name }}/source-files"
      changed_when: false
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Add write permissions to extracted files
      command: "chmod -R +w {{ Global.workingdir }}/{{ item.Name }}/source-files"    # Using chmod as Ansible (Python) can't handle the recursion depth on the Ubuntu ISO
      changed_when: false
      when: item.Deploy
      loop: "{{ Server_List }}"
    ## Start workaround issue with Ubuntu autoinstall
    ## Details of the issue and the workaround: https://askubuntu.com/questions/1394441/ubuntu-20-04-3-autoinstall-with-embedded-user-data-crashing-i-got-workaround
    - name: Extract the Packages.gz file on Ubuntu ISO
      command: "gunzip -f {{ Global.workingdir }}/{{ item.Name }}/source-files/dists/jammy/main/binary-amd64/Packages.gz --keep"
      changed_when: false
    ## End workaround issue with Ubuntu autoinstall
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Rename [BOOT] directory
      command:  "mv {{ Global.workingdir }}/{{ item.Name }}/source-files/'[BOOT]' {{ Global.workingdir }}/{{ item.Name}}/BOOT"
      changed_when: false
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Edit grub.cfg to modify menu
      blockinfile:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files/boot/grub/grub.cfg"
        create: true
        block: |
          menuentry "Autoinstall Ubuntu Server" {
             set gfxpayload=keep
             linux   /casper/vmlinuz quiet autoinstall ds=nocloud\;s=/cdrom/server/  ---
             initrd  /casper/initrd
          }
        insertbefore: 'menuentry "Try or Install Ubuntu Server" {'
        state: present
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Edit grub.cfg to set timeout to 1 second
      replace:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files/boot/grub/grub.cfg"
        regexp: '^(set timeout=30)$'
        replace: 'set timeout=5'
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Create directory to store user-data and meta-data
      file:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files/server"
        state: directory
        mode: "755"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Create empty meta-data file in directory
      file:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files/server/meta-data"
        state: touch
        mode: "755"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Copy user-data file to directory using template
      template:
        src: ./fleet-user-data.j2
        dest: "{{ Global.workingdir }}/{{ item.Name }}/source-files/server/user-data"
        mode: "755"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Create custom ISO
      command: "xorriso -as mkisofs -r \
               -V 'Ubuntu 22.04 LTS AUTO (EFIBIOS)' \
               -o {{ Global.workingdir }}/{{ item.Name }}/{{ Global.new_iso_filename }} \
               --grub2-mbr ../BOOT/1-Boot-NoEmul.img \
               -partition_offset 16 \
               --mbr-force-bootable \
               -append_partition 2 28732ac11ff8d211ba4b00a0c93ec93b ../BOOT/2-Boot-NoEmul.img \
               -appended_part_as_gpt \
               -iso_mbr_part_type a2a0d0ebe5b9334487c068b6b72699c7 \
               -c '/boot.catalog' \
               -b '/boot/grub/i386-pc/eltorito.img' \
               -no-emul-boot -boot-load-size 4 -boot-info-table --grub2-boot-info \
               -eltorito-alt-boot \
               -e '--interval:appended_partition_2:::' \
               -no-emul-boot \
               ."
      args:
        chdir: "{{ Global.workingdir }}/{{ item.Name }}/source-files/"
      changed_when: false
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Remove BOOT directory
      file:
        path: "{{ Global.workingdir }}/{{ item.Name }}/BOOT"
        state: absent
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Delete source files
      file:
        path: "{{ Global.workingdir }}/{{ item.Name }}/source-files"
        state: absent
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Create VM
      command: "{{ Global.vboxmanage_path }} createvm --name {{ item.Name }} --ostype Ubuntu_64 --register"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Create VM storage
      command: "{{ Global.vboxmanage_path }} createmedium disk --filename {{ item.Name }}.vdi --size {{ item.Configuration.Storage.DiskSize }} --format=VDI"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Add IDE controller
      command: "{{ Global.vboxmanage_path }} storagectl {{ item.Name }} --name IDE --add IDE --controller PIIX4"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Attach DVD drive
      command: "{{ Global.vboxmanage_path }} storageattach {{ item.Name }} --storagectl IDE --port 0 --device 0 --type dvddrive --medium {{ Global.workingdir }}/{{ item.Name }}/{{ Global.new_iso_filename }}"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Add SATA controller
      command: "{{ Global.vboxmanage_path }} storagectl {{ item.Name }} --name SATA --add SAS --controller LsiLogicSas"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Attach drive
      command: "{{ Global.vboxmanage_path }} storageattach {{ item.Name }} --storagectl SATA --port 0 --device 0 --type hdd --medium {{ item.Name }}.vdi"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Boot order
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name }} --boot1 disk --boot2 DVD --boot3 none --boot4 none"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Set VM CPU, RAM, video RAM
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name }} --cpus {{ item.Configuration.Compute.CPUs }} --memory {{ item.Configuration.Compute.MemorySize }} --vram 16"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Settings 1
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name}} --graphicscontroller vmsvga --hwvirtex on --nested-hw-virt on"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Settings 2
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name}} --ioapic on --pae off --acpi on --paravirtprovider default"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Settings 3
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name}} --nestedpaging on --keyboard ps2 --uart1 0x03F8 4"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Settings 4
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name}} --uartmode1 disconnected --uarttype1 16550A --macaddress1 auto --cableconnected1 on"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Network adapter
      command: "{{ Global.vboxmanage_path }} modifyvm {{ item.Name }} --nic1 bridged --bridgeadapter1 {{ Global.bridge_interface_name }}"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Start the virtual machine
      command: "{{ Global.vboxmanage_path }} startvm {{ item.Name }} --type headless"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Add to inventory file
      lineinfile:
        path: "{{ Global.inventory_file }}"
        line: "{{ item.Configuration.OS.IPv4Address.split('/')[0] }}"
        create: true
        regexp: "^{{ item.Configuration.OS.IPv4Address.split('/')[0] }}$"
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Wait for server availability on port 22
      wait_for:
        port: 22
        host: "{{ item.Configuration.OS.IPv4Address.split('/')[0] }}"
        state: started
        delay: 180
        timeout: 600
      when: item.Deploy
      loop: "{{ Server_List }}"
    - name: Make sure known_hosts exists
      file:
        path: "{{ lookup('env','HOME') }}/.ssh/known_hosts"
        state: touch
    - name: Add VM to known_hosts
      shell: ssh-keyscan -H {{ item.Configuration.OS.IPv4Address.split('/')[0] }} >> {{ lookup('env','HOME') }}/.ssh/known_hosts
      when: item.Deploy
      loop: "{{ Server_List }}"

Run the script: ansible-playbook build_fleet.yml

Do a quick ansible ping:

• ansible -i inventory all -m ping

Now that the servers are built and online, we will configure the local user listed in servers.yml and update all packages. A common issue with Ubuntu 20.04 regarding DNS failed lookups will be fixed.

Overview

• Extend the disk partition(s) to use all of the available disk space
• Enable username & password login and add the local user specified in the servers.yml file
• Update and upgrade all packages (rebooting as needed)
• Disable the DNS stub listener to prevent later issues with failed DNS lookups

configure_servers.yml

---
- hosts: all
  name: configure_fleet.yml
  become: true
  vars_files:
    - variables.yml
    - servers.yml
  tasks:
    - name: Look up information by IP
      when: item.Configuration.OS.IPv4Address.split('/')[0] == inventory_hostname
      set_fact:
        matching_system: "{{ item }}"
      loop: "{{ Server_List }}"
    - name: Wait for server to be up
      wait_for:
        host: "{{ inventory_hostname }}"
        state: started
        port: 22
        delay: 0
        timeout: 60
    - name: Extend logical volume
      command: lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
      when: matching_system.Configuration.Storage.DiskSize > 20470
    - name: Resize filesystem
      command: resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
      when: matching_system.Configuration.Storage.DiskSize > 20470
    - name: Add user
      user:
        name: "{{ matching_system.Configuration.OS.User }}"
        shell: /bin/bash
        home: "/home/{{ matching_system.Configuration.OS.User }}"
        password: "{{ matching_system.Configuration.OS.Password | password_hash('sha512') }}"
        groups: sudo
        append: true
    - name: Enable ssh password authentication step 1
      lineinfile:
        path: /etc/ssh/sshd_config
        line: "PasswordAuthentication yes"
        state: present
        create: true
    - name: Enable ssh password authentication step 2
      replace:
        path: /etc/ssh/sshd_config
        regexp: '^\s*#+PasswordAuthentication.*$'
        replace: "PasswordAuthentication yes"
    - name: Enable ssh password authentication step 3
      replace:
        path: /etc/ssh/sshd_config
        regexp: '^\s*#*KbdInteractiveAuthentication.*$'
        replace: "KbdInteractiveAuthentication yes"
    - name: restart ssh
      service:
        name: ssh
        state: restarted
    - name: Update and upgrade all apt packages
      apt: update_cache=true force_apt_get=true state=latest
    - name: Check if reboot is required
      register: file
      stat: path=/var/run/reboot-required get_md5=no
    - name: Reboot the server if required
      reboot:
        reboot_timeout: 180
      when: file.stat.exists == true
    - name: Disable DNS stub listener
      ini_file: dest=/etc/systemd/resolved.conf section=Resolve option=DNSStubListener value=no backup=yes
      tags: configuration
    - name: Restart NetworkManager
      systemd:
        name: NetworkManager
        state: restarted
    - name: Restart systemd-resolved
      systemd:
        name: systemd-resolved
        state: restarted
    - name: daemon-reload
      systemd:
        daemon_reload: true

Run the script: ansible-playbook -i inventory configure_fleet.yml

Do a quick ansible ping:

• ansible -i inventory all -m ping

Log in to servers and confirm everything is working with the correct user account & password, CPUs, storage, RAM

• ssh to the IP address of the server (password-less login as ansible using key)
• ssh to the IP address of the server as the user you specified in servers.yml
  • Ex. ssh myuser@192.168.99.201
  • You should be prompted for the password
• Test sudo access for each user
• Check the amount of disk space: df -h
• Check the amount of RAM: free -h
• Check the number of CPUs: grep processor /proc/cpuinfo | wc -l

Can you write a playbook to display this information?

Proceed to Step 3 - Set up Kubernetes

Or back to Step 1 - Set up the Host or Start.