Debian 12 bookworm upgrade

yawn.md

Debian 12

To start, read the official release notes.

If your install fits into "vanilla Debian plus maybe a handful of 3rd-party repos", then this guide for a simple upgrade to Debian 12 "bookworm" from Debian 11 "bullseye" can be helpful. 3rd-party repos are handled with a find command.

Note upgrade is only supported from Debian 11 to Debian 12. If you are on Debian 10, upgrade to Debian 11 first and make sure to change the security repo as per the release notes. Then once on Debian 11, you can upgrade to Debian 12.

• Check free disk space

df -h

5 GiB free is a conservative amount. sudo apt clean and sudo apt autoremove can be used to free some disk space.

On a server with only docker installed, even 1 GiB free was sufficient. Do err on the side of caution here, however.

• Identify any 3rd-party repos that may need to be updated. They'll be changed with a find command, below.

ls /etc/apt/sources.list.d

• Update current distribution

sudo apt-get update && sudo apt-get dist-upgrade --autoremove -y

If this brought in a new kernel, sudo reboot - otherwise continue

• Change repo to bookworm, from bullseye.

sudo sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list

• Add non-free-firmware if non-free is currently in use

sudo sed -i '/non-free/ s/$/ non-free-firmware/' /etc/apt/sources.list

• Change all 3rd-party repos

sudo find /etc/apt/sources.list.d -type f -exec sed -i 's/bullseye/bookworm/g' {} \;

• Update Debian

For the following, say Yes to restarting services, and keep existing config files when prompted. If using msmtp, acknowledge warnings. AppArmor for msmtp worked for me.

sudo apt-get update && sudo apt-get dist-upgrade --autoremove -y

And finally, reboot

sudo reboot

Automated by Ansible

Playbook bookworm.yml:

---
- name: Upgrade to Debian bookworm
  hosts: all
  serial: 1
  gather_facts: false
  roles:
    - base/upgrade_bookworm

Role base/upgrade_bookworm/tasks/main.yml:

---
- name: Get distribution version
  setup:
    filter: ansible_distribution*
- name: Skip if not Debian 11
  meta: end_host
  when: ansible_distribution != 'Debian' or ansible_distribution_major_version != '11'
- name: apt clean
  apt:
    clean: yes
  become: yes
- name: Get filesystem facts
  setup:
    filter: ansible_mounts
- name: Fail if free space on / is below 5 GiB
  ansible.builtin.assert:
    that:
      - item.size_available > (5 * 1024 * 1024 * 1024)
    fail_msg: "Free disk space on {{ item.mount }} is below 5 GiB"
  loop: "{{ ansible_mounts }}"
  when: item.mount == "/"
- name: All apt packages up to date
  apt:
    upgrade: dist
    update_cache: yes
  become: yes
- name: apt autoremove
  apt:
    autoremove: yes
  become: yes
- name: apt clean
  apt:
    clean: yes
  become: yes
- name: Check if reboot required
  ansible.builtin.stat:
    path: /run/reboot-required
    get_md5: no
  register: reboot_required_file
- name: Reboot if required
  ansible.builtin.reboot:
    msg: "Reboot initiated by Ansible"
    connect_timeout: 5
    reboot_timeout: 600
    pre_reboot_delay: 0
    post_reboot_delay: 60
    test_command: whoami
  when: reboot_required_file.stat.exists
  become: true
- name: Switch OS from bullseye to bookworm
  ansible.builtin.replace:
    path: /etc/apt/sources.list
    regexp: 'bullseye'
    replace: 'bookworm'
  become: yes
- name: Add non-free-firmware if non-free is in use
  ansible.builtin.replace:
    path: /etc/apt/sources.list
    regexp: '(.*non-free.*)'
    replace: '\1 non-free-firmware'
  become: yes 
- name: Find all 3rd-party repos
  ansible.builtin.find:
    paths: /etc/apt/sources.list.d
    patterns: '*'
    recurse: no
  register: third_party_repos
- name: Switch 3rd-party repos from bullseye to bookworm
  ansible.builtin.replace:
    path: "{{ item.path }}"
    regexp: 'bullseye'
    replace: 'bookworm'
  loop: "{{ third_party_repos.files }}"
  loop_control:
    label: "{{ item.path }}"
  become: yes 
- name: Use apt to move to bookworm
  apt:
    upgrade: dist
    update_cache: yes
  become: yes
- name: Get distribution version
  setup:
    filter: ansible_distribution*
- name: Fail if not Debian 12
  assert:
    that:
      - ansible_distribution_major_version == '12'
    fail_msg: "Upgrade to Debian 12 failed"
- name: apt autoremove
  apt:
    autoremove: yes
  become: yes
- name: apt clean
  apt:
    clean: yes
  become: yes
- name: Re-enable msmtp apparmor profile
    ansible.builtin.file:
      path: /etc/apparmor.d/disable/usr.bin.msmtp
      state: absent
    become: yes
- name: Restart apparmor service
    ansible.builtin.systemd:
      name: apparmor
      state: restarted
    become: yes
- name: Reboot on bookworm
  ansible.builtin.reboot:
    msg: "Reboot initiated by Ansible"
    connect_timeout: 5
    reboot_timeout: 600
    pre_reboot_delay: 0
    post_reboot_delay: 60
    test_command: whoami
  become: yes
- name: Pause for 5 minutes for staggered upgrades
  pause:
    minutes: 5