ansible/roles/pi_kiosk/tasks/main.yml

---
- name: Packages
  ansible.builtin.apt:
    name:
      - xserver-xorg
      - xinit
      - x11-xserver-utils
      # Without a window manager, a browser's request to go full-screen (which is all
      # --kiosk does) has nobody to answer it, and it settles for its default window
      # size in the corner of the screen. Openbox answers it, and nothing else.
      - openbox
      - unclutter
      # The MusicMouse front-end's icons are emoji characters in the markup, not an icon
      # font. Lite images ship no emoji font at all, so without this every icon renders
      # as an empty box.
      - fonts-noto-color-emoji
    cache_valid_time: 7200
  notify: Reload systemd and restart getty

- name: Ensure the Xorg config directory exists
  ansible.builtin.file:
    path: /etc/X11/xorg.conf.d
    state: directory
    mode: "0755"

- name: Point X at the display controller
  # The Pi 4 and 5 have two DRM devices: v3d (the 3D GPU, no outputs) and vc4 (the
  # HDMI display controller). Left to itself Xorg cannot tell which to drive and dies
  # with "Cannot run in framebuffer mode. Please specify busIDs for all framebuffer
  # devices", so the kiosk loops on a blank screen. Display goes through vc4; rendering
  # still lands on v3d, because glamor's GL context is routed there by Mesa (kmsro).
  # Raspberry Pi's desktop image ships this same file; the Lite image does not.
  ansible.builtin.copy:
    dest: /etc/X11/xorg.conf.d/99-vc4.conf
    content: |
      Section "OutputClass"
        Identifier "vc4"
        MatchDriver "vc4"
        Driver "modesetting"
        Option "PrimaryGPU" "true"
      EndSection
    mode: "0644"
  notify: Reload systemd and restart getty

- name: Browser
  # Chromium comes from archive.raspberrypi.com, not Debian: that build carries the
  # "+rpt" suffix and Raspberry Pi's own patches for the V3D GPU on this board. Debian
  # also ships a much older `chromium`, so pinning the wrong archive here would quietly
  # undo the reason for choosing it.
  ansible.builtin.apt:
    name: "{{ 'chromium' if pi_kiosk_browser == 'chromium' else 'firefox-esr' }}"
    cache_valid_time: 7200
  notify: Reload systemd and restart getty

- name: Debugging tools for the attached screen
  # Only pulled in for pi_kiosk_mode=debug; apt does not take them away again when the
  # host goes back to kiosk mode, which is fine - they are inert and small.
  ansible.builtin.apt:
    name:
      - xterm       # a terminal that is ours, whatever x-terminal-emulator points at
      - x11-utils   # xwininfo, xprop: is the window actually the size of the screen?
      - mesa-utils  # glxinfo, glxgears: is anything accelerated, or is this llvmpipe?
      - xdotool     # drive the UI from ssh, so a measurement can be taken on a real
                    # screen rather than an idle one
      - scrot       # and see what that screen actually shows, over ssh
    cache_valid_time: 7200
  when: pi_kiosk_mode == 'debug'

- name: Create kiosk user
  ansible.builtin.user:
    name: "{{ pi_kiosk_user }}"
    groups: [video, input, tty]
    shell: /bin/bash
    create_home: true

- name: Own the directories X and Firefox write into
  # Xorg runs as root here (Debian's wrapper, allowed_users=console) with HOME set to
  # the kiosk user's, so it creates ~/.cache itself - root-owned and 0700 - the first
  # time it writes a mesa shader cache. Firefox then cannot create ~/.cache/mozilla and
  # gives up with "Your Firefox profile cannot be loaded. It may be missing or
  # inaccessible". Creating these up front, owned by the user, means root only ever
  # adds subdirectories to a directory the user already owns.
  ansible.builtin.file:
    path: "/home/{{ pi_kiosk_user }}/{{ item }}"
    state: directory
    owner: "{{ pi_kiosk_user }}"
    group: "{{ pi_kiosk_user }}"
    mode: "0700"
  loop:
    - .cache
    - .mozilla

- name: Autologin the kiosk user on tty1
  ansible.builtin.file:
    path: /etc/systemd/system/getty@tty1.service.d
    state: directory
    mode: "0755"

- name: Install getty autologin override
  ansible.builtin.template:
    src: autologin.conf.j2
    dest: /etc/systemd/system/getty@tty1.service.d/autologin.conf
    mode: "0644"
  notify: Reload systemd and restart getty

- name: Enable the autologin getty on tty1
  # Enabling it is the part that survives a reboot. These images do not enable
  # getty@tty1 themselves - getty.target pulls in getty-static.service and nothing
  # else - so without this the drop-in above is installed, the handler starts the unit
  # once, and the kiosk then silently stops coming up after the next reboot.
  ansible.builtin.systemd:
    name: "getty@tty1"
    enabled: true
    state: started
    daemon_reload: true

- name: Install .bash_profile (starts X on tty1 login)
  ansible.builtin.template:
    src: bash_profile.j2
    dest: "/home/{{ pi_kiosk_user }}/.bash_profile"
    owner: "{{ pi_kiosk_user }}"
    group: "{{ pi_kiosk_user }}"
    mode: "0644"
  notify: Reload systemd and restart getty

- name: Install .xinitrc (starts Openbox, then the browser)
  ansible.builtin.template:
    src: xinitrc.j2
    dest: "/home/{{ pi_kiosk_user }}/.xinitrc"
    owner: "{{ pi_kiosk_user }}"
    group: "{{ pi_kiosk_user }}"
    mode: "0755"
  notify: Reload systemd and restart getty

- name: Ensure the browser policy directory exists
  ansible.builtin.file:
    path: "{{ '/etc/chromium/policies/managed' if pi_kiosk_browser == 'chromium' else '/etc/firefox-esr' }}"
    state: directory
    mode: "0755"
  # The packages normally create these; a backstop in case a layout changes

- name: Install the browser's enterprise policy
  # Everything that is a setting rather than a startup flag: no sign-in, no sync, no
  # metrics, no password manager, no translate bar. The flags themselves are in
  # .xinitrc, where they have to be.
  ansible.builtin.copy:
    src: "{{ 'chromium-policies.json' if pi_kiosk_browser == 'chromium' else 'policies.json' }}"
    dest: >-
      {{ '/etc/chromium/policies/managed/kiosk.json'
         if pi_kiosk_browser == 'chromium' else '/etc/firefox-esr/policies.json' }}
    mode: "0644"
  notify: Reload systemd and restart getty

- name: Ensure the Openbox config directories exist
  # Both levels explicitly, and owned by the user: a file: task creates missing parents
  # as root, and a root-owned ~/.config is the same trap that broke the Firefox profile
  # above.
  ansible.builtin.file:
    path: "/home/{{ pi_kiosk_user }}/{{ item }}"
    state: directory
    owner: "{{ pi_kiosk_user }}"
    group: "{{ pi_kiosk_user }}"
    mode: "0755"
  loop:
    - .config
    - .config/openbox

- name: Install the Openbox root menu
  ansible.builtin.template:
    src: openbox-menu.xml.j2
    dest: "/home/{{ pi_kiosk_user }}/.config/openbox/menu.xml"
    owner: "{{ pi_kiosk_user }}"
    group: "{{ pi_kiosk_user }}"
    mode: "0644"
  notify: Reload systemd and restart getty