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Classroom_Desktop/packaging/debian/postinst
T
ekklesiaandClaude Opus 5 55f4c183c7 feat: Presentations, for a teacher who downloaded tonight's session
PRESENTATIONS_ENABLED, off by default, independent of everything else. A
teacher downloads a session in ordinary Chrome and it is on the
Presentations screen a few seconds later, ready for the television. No
file manager, no import button, no Impress.

WHY NOTHING LAUNCHES A DOCUMENT APPLICATION. The brief was to use
existing presentation software, so the existing software was tried
first, on Debian 13, before any of this was designed. `soffice --show`
does start a real fullscreen slideshow — and needs XDG_SESSION_TYPE plus
a VCL plugin or it dies with "Failed to open display", shows a splash,
opened a "Tip of the Day: 1/225" dialog over the slides, and leaves the
Impress editor when the show ends. `okular --presentation` opens THREE
windows: the presentation, the ordinary document window behind it, and
an information dialog. zathura is not a presenter. pdfpc is the closest
and is another dependency with a presenter-console model. Every one of
them leaves an application on screen that can open any file on the
machine, and none of them knows there is a library to go back to.

So LibreOffice converts once, headless, at import, with no window on any
screen; poppler renders the pages; the classroom shows the pictures.
Measured: 0.34s for a ten-slide PPTX, 0.03s for its ten thumbnails,
0.10s for one slide at 1920px. That is not a new renderer — it is the
same engine Impress would have used live — and it means Escape is ours,
presenting is instant, and a PDF exported from Google Slides skips the
conversion entirely and keeps the appearance Google gave it.

THE THREE THINGS KEPT APART. The library thumbnail, the starting slide
and the retention clock are independent, because the first slide of a
Bible study session is a generic opening shared by every session and the
one that names it is usually the second. Quick Look chooses the picture;
it does not change where the slideshow starts and it does not count as
having presented anything. mark_presented() is called when a slide is
actually drawn, not when Present is pressed: an intention is not a
presentation, and a viewer that failed to start must not buy another
thirty days.

IMPORTING. The teacher's download is copied, never moved, renamed or
deleted. A file with a .crdownload beside it is still arriving. Wonder
Ink's own folder is not looked at. Two downloads of the same name are
two presentations, the second titled (2) — found in the lab, where a PDF
and a PPTX of one session both came out with the same name because the
import being named was excluded from the taken-titles set BY TITLE, and
a set holds one copy of a repeated string.

Metadata is written saying "importing" before any work, so a reboot
mid-conversion leaves a directory the next startup sweeps and imports
again. A file that cannot be converted gets a card saying so, offering
only Remove, with the teacher's download untouched.

Retention: 180 days never presented, 30 days from the last presentation,
every presentation starting the thirty over. The cleanup never touches a
presentation being shown, never leaves the library directory, and never
looks at Downloads.

The dock order is unchanged: Presentations is appended after the disc
player, so Wonder Ink, the browser and the player keep the places
teachers have been reaching for. There is a test for exactly that.

classroom-wonderink now asks feature() rather than carrying its own copy
of the default, so the panel and the command cannot disagree.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-22 20:21:19 -05:00

146 lines
6.6 KiB
Bash
Executable File

#!/bin/bash
set -e
if ! id classroom >/dev/null 2>&1; then
adduser \
--disabled-password \
--gecos "" \
classroom
fi
# Commands the room's own parts install. Listing them by name went wrong
# once already, when a command that had been removed was still chmod'ed
# here and the whole postinst failed; the package is the list.
for command in /usr/local/bin/classroom-*; do
[ -e "$command" ] || continue
chmod 0755 "$command"
done
# Reading the optical drive needs group cdrom. Takes effect at the next
# login, which the OTA reboot provides.
if getent group cdrom >/dev/null 2>&1; then
adduser classroom cdrom >/dev/null 2>&1 || true
fi
# Create device.conf on a new endpoint, or append only settings an older
# endpoint does not yet know. The helper preserves every existing byte apart
# from the append, so per-room choices always survive an upgrade.
PYTHONPATH=/usr/local/lib/ekklesia-classroom python3 - <<'PY'
from classroom_config import ensure_device_config
ensure_device_config()
PY
# The broker password lives here, so the file stops being world readable.
# Everything that reads it runs as root or as the classroom user.
chown root:classroom /etc/ekklesia-classroom/device.conf 2>/dev/null || true
chmod 0640 /etc/ekklesia-classroom/device.conf
# Converge a machine that was something else: the old bar and notification
# daemon stopped and deactivated, the login shell that used to start sway
# removed, and device.conf moved off settings this package cannot carry
# out. Runs on every install, does nothing on a machine that is already
# this classroom.
/usr/local/bin/classroom-migrate || true
systemctl daemon-reload || true
# The power button stops working immediately rather than at the next
# boot. Verified in the lab: logind re-reads its drop-ins on reload and
# reports ignore afterwards, and the running graphical session is not
# disturbed by it.
systemctl reload systemd-logind >/dev/null 2>&1 || true
# Autologin into the classroom, and back into it if the session ever ends.
systemctl enable sddm.service >/dev/null 2>&1 || true
# The room's own user services: the audio policy, and the drop-in that
# stops Plasma giving up on a repeatedly crashing panel. The display scale
# is applied by an XDG autostart entry instead, which is already how it
# reaches a session on the classroom machines.
systemctl --global enable ekklesia-classroom-audio.service >/dev/null 2>&1 || true
systemctl --global enable ekklesia-classroom-desktop.service >/dev/null 2>&1 || true
# The presentation watcher. Enabled on every machine and started by every
# session, because whether it does anything is device.conf's answer, not
# the installer's: with PRESENTATIONS_ENABLED=false — which is the
# default, and therefore every existing classroom — it exits immediately
# and the room never runs an importer it has no use for.
systemctl --global enable ekklesia-classroom-presentations.service >/dev/null 2>&1 || true
# The panel's disc player is decided before the display manager starts, not
# at the same time as it. Enabled rather than started: this install has
# just run the same command directly, below.
systemctl enable ekklesia-classroom-layout.service >/dev/null 2>&1 || true
# So a drive plugged in later is noticed without a reboot.
udevadm control --reload-rules >/dev/null 2>&1 || true
# Match the bar to this machine now, so the first login already has the
# right one rather than waiting for the next provisioning run.
/usr/local/bin/classroom-desktop-layout >/dev/null 2>&1 || true
# NetworkManager ships nmtui and deliberately leaves interfaces declared in
# /etc/network/interfaces under ifupdown's control (managed=false). This gives
# administrators saved, auto-reconnecting Wi-Fi without taking over an
# existing static Ethernet setup. No classroom service needs to hold boot for
# NetworkManager's online wait, so keep that waiter disabled.
systemctl enable NetworkManager.service || true
systemctl disable NetworkManager-wait-online.service || true
systemctl start NetworkManager.service || true
# CUPS is ready at boot, but no queue is created until an administrator runs
# classroom-printer-setup. cups-browsed is unnecessary here and would expose
# every advertised printer on the church network if installed independently.
systemctl enable cups.socket cups.service || true
systemctl disable --now cups-browsed.service || true
# Direct DNS-SD destinations still appear through Avahi even when
# cups-browsed is inactive. Nothing else in this appliance uses Avahi, so stop
# both activation paths and keep unrelated church printers out of print lists.
systemctl disable --now avahi-daemon.socket avahi-daemon.service || true
systemctl mask avahi-daemon.socket avahi-daemon.service || true
systemctl start cups.socket || true
systemctl enable ekklesia-classroom-update.timer || true
systemctl start ekklesia-classroom-update.timer || true
# Google Chrome, and the DVD codecs when the room has a drive, are
# fetched by the provisioning service at the next boot.
#
# Deliberately enabled but not started here. It cannot run during this
# script anyway, because dpkg holds the apt lock throughout. Starting it
# straight afterwards would race the reboot that an OTA update performs
# the moment this install finishes, and an apt run killed by that reboot
# leaves dpkg half-configured. Every OTA reboots, so waiting for the next
# boot costs nothing and cannot corrupt anything.
#
# Provisioning is still enabled at boot so machines that were offline or
# interrupted get another chance automatically.
systemctl enable ekklesia-classroom-provision.service || true
# Also schedule provisioning after this package installation completes.
# Do not start it synchronously from postinst: dpkg/apt still owns its locks.
# A short delayed systemd job lets the outer apt transaction finish first.
#
# If an OTA reboot happens before this fires, the normal enabled boot service
# handles provisioning on the next boot instead.
systemd-run \
--unit=ekklesia-classroom-provision-after-install \
--on-active=15s \
--property=Type=oneshot \
/bin/systemctl start ekklesia-classroom-provision.service \
>/dev/null 2>&1 || true
# Gives Chrome a chance to close properly on reboot, so its profile is
# not marked as crashed. Best effort: it must never hold a shutdown up.
systemctl enable ekklesia-classroom-shutdown.service || true
# The room's link to the church broker. Enabled always; it does nothing
# at all until a broker is configured in device.conf.
systemctl enable ekklesia-classroom-mqtt.service || true
systemctl restart ekklesia-classroom-mqtt.service || true
systemctl start ekklesia-classroom-shutdown.service || true
exit 0