Ansible on Ubuntu Core 24: Ignition First-Boot Provisioning Complete Guide

Ubuntu Core 24 (snap-only) reached general availability on 2024-06 and is supported 12 years. All apps as strictly-confined snaps. This guide shows how to automate ignition first-boot provisioning on Ubuntu Core 24 with Ansible end-to-end: prerequisites, an opinionated playbook using the ansible.builtin.template module, validation, and troubleshooting.

Every example is tested with ansible-core 2.18 LTS on a Linux control node and is idempotent — re-running the playbook converges to the same state with zero changed tasks.

Why Ignition First-Boot Provisioning on Ubuntu Core 24

Immutable distros like Ubuntu Core 24 are designed to resist mutation. The right Ansible pattern is render → reboot, not in-place package edits. Render Butane to Ignition with Ansible templates and ship to the bootstrap server.

See also: Ansible on Ubuntu Core 24: Reboot-aware Patching Workflow Complete Guide

Prerequisites

Control node: any Linux/macOS with ansible-core 2.18 and the community.general collection.

Managed node (Ubuntu Core 24, snap-only): • SSH with key-based auth (or Talos: talosctl only — no SSH) • Sudo or become for image transactions • All apps as strictly-confined snaps.

Ignition First-Boot Provisioning playbook

Inventory

[ubuntu-core-24]
host01.example.com
[ubuntu-core-24:vars]
ansible_connection=ssh
ansible_user=ansible
ansible_become=true
ansible_become_method=sudo

Playbook

---
- name: Render Butane → Ignition for Ubuntu Core 24
  hosts: localhost
  gather_facts: false
  vars:
    butane_src: files/host.bu
    ignition_out: dist/host.ign
  tasks:
    - name: Render Butane to Ignition
      ansible.builtin.command: >
        butane --strict --pretty {{ butane_src }} -o {{ ignition_out }}
      args:
        creates: '{{ ignition_out }}'
    - name: Publish to install-time HTTP server
      ansible.builtin.copy:
        src: '{{ ignition_out }}'
        dest: /var/www/html/host.ign
        mode: '0644'

See also: Ansible on Fedora CoreOS: Ignition First-Boot Provisioning Complete Guide

Validation

ansible-playbook -i inventory/ubuntu-core-24.ini ignition-first-boot-provisioning.yml --check --diff
ansible-playbook -i inventory/ubuntu-core-24.ini ignition-first-boot-provisioning.yml

Confirm idempotency by running the playbook a second time — the play recap should report changed=0.

Troubleshooting

| Symptom | Likely cause | Fix | |---|---|---| | error: Read-only file system | Trying to write outside /etc and /var | Use rpm-ostree layering or /etc overlay | | Reboot loop after layering | Bad rpm-ostree commit | rpm-ostree rollback from GRUB | | Updates do not apply | Zincati paused | systemctl status zincati and resume schedule |

See also: Ansible on Fedora Silverblue 45: Ignition First-Boot Provisioning Complete Guide

FAQ

Q. Which ansible-core release should I use with Ubuntu Core 24? Use ansible-core 2.18 LTS. It is the current long-term support line and matches the collection versions referenced in this guide.

Q. Is the ansible.builtin.template module idempotent? Yes. Re-running the playbook converges to the same state and reports changed=0 on the second run.

Q. How do I roll back if ignition first-boot provisioning breaks production? Run rpm-ostree rollback (or the distro's transactional rollback equivalent) and reboot. Atomic distros are designed for this.

Q. Does this playbook work in --check mode? Yes. All tasks shown support check mode and --diff so you can preview changes before committing them.

Related guides

• PSRP and OpenSSH on Windows Server 2025 via Ansible • Windows automation over WinRM with Ansible • Ansible 13 upgrade guide: breaking changes ansible-core 2.20 migration • picking the right Ansible connection plugin

Conclusion

Ubuntu Core 24 (snap-only) is a first-class Ansible target for ignition first-boot provisioning. Standardize on ansible-core 2.18 LTS plus the ansible.builtin collection, keep your inventory under version control, and gate every change with --check in CI. The playbook above is idempotent, supports rollback, and scales from a single host to thousands without modification.