#!/bin/sh # check-kiosk.sh — read-only report on a mirror kiosk client. Run ON THE CLIENT. # # sudo sh check-kiosk.sh # # PASS/FAIL describe this machine; WARN means "configured fine, but the thing # you can see on the screen will still be wrong". Exits non-zero on FAIL. # # Nothing here needs the console: every check is readable over SSH, which is # the whole point of a kiosk you never plug a keyboard into. KIOSK_USER="${KIOSK_USER:-kiosk}" FAILS=0 ok() { printf 'PASS %s\n' "$*"; } bad() { printf 'FAIL %s\n' "$*"; FAILS=$((FAILS + 1)); } warn() { printf 'WARN %s\n' "$*"; } info() { printf 'info %s\n' "$*"; } SUDO="" [ "$(id -u)" -eq 0 ] || SUDO="sudo" printf '%s\n' '--- machine ---' if [ -f /etc/os-release ]; then info "$( . /etc/os-release && printf '%s %s' "$NAME" "$VERSION_ID" ) on $(uname -m)" fi if command -v rpm-ostree >/dev/null 2>&1; then info "booted deployment: $(rpm-ostree status 2>/dev/null | sed -n 's/^ *● *//p' | head -1)" info "layered: $(rpm-ostree status 2>/dev/null | sed -n 's/^ *LayeredPackages: //p' | head -1)" fi printf '\n%s\n' '--- packages ---' for p in gnome-kiosk gnome-kiosk-script-session firefox; do if rpm -q "$p" >/dev/null 2>&1; then ok "$p installed"; else bad "$p not installed (rpm-ostree install $p)"; fi done printf '\n%s\n' '--- user ---' if id -u "$KIOSK_USER" >/dev/null 2>&1; then HOME_DIR=$(getent passwd "$KIOSK_USER" | cut -d: -f6) ok "user $KIOSK_USER exists, home $HOME_DIR" else bad "user $KIOSK_USER does not exist" HOME_DIR="" fi printf '\n%s\n' '--- payload ---' check_file() { path=$1 needle=$2 label=$3 if [ -f "$path" ]; then if [ -n "$needle" ] && ! $SUDO grep -q "$needle" "$path" 2>/dev/null; then bad "$label: $path exists but has no '$needle'" else ok "$label: $path" fi else bad "$label: $path is missing" fi } URL="" if [ -n "$HOME_DIR" ]; then check_file "$HOME_DIR/.local/bin/gnome-kiosk-script" "firefox --kiosk" "kiosk script" if [ -f "$HOME_DIR/.config/mirror/kiosk.conf" ]; then URL=$($SUDO sed -n 's/^MIRROR_KIOSK_URL="\{0,1\}\([^"]*\)"\{0,1\}$/\1/p' \ "$HOME_DIR/.config/mirror/kiosk.conf" 2>/dev/null | head -1) ok "kiosk URL: ${URL:-}" case "$URL" in */watch) : ;; "") bad "kiosk URL is empty" ;; *) warn "kiosk URL is not the /watch wall: $URL" ;; esac else bad "kiosk config $HOME_DIR/.config/mirror/kiosk.conf is missing" fi check_file "$HOME_DIR/.config/gnome-initial-setup-done" "" "initial-setup guard" fi check_file /etc/firefox/policies/policies.json "DisableAppUpdate" "firefox policy" check_file /usr/local/share/gnome-kiosk/window-config.ini "org.mozilla" "kiosk window rules" # Without this key the shipped gnome-kiosk session never registers with GDM and # GDM autospawns a greeter over the wall ~8s after auto-login. The single most # confusing failure this setup has: the kiosk keeps running underneath, so the # mirror roster and loginctl both still look perfect while the screen shows a # login prompt. check_file /usr/local/share/wayland-sessions/gnome-kiosk-script-wayland.desktop \ "X-GDM-SessionRegisters=true" "GDM session override" printf '\n%s\n' '--- session wiring ---' ACCT="/var/lib/AccountsService/users/$KIOSK_USER" if [ -f "$ACCT" ] && $SUDO grep -q '^Session=gnome-kiosk-script-wayland' "$ACCT"; then ok "AccountsService default session is the kiosk" else bad "AccountsService session for $KIOSK_USER is not gnome-kiosk-script-wayland" [ -f "$ACCT" ] && info "$($SUDO cat "$ACCT" 2>/dev/null | tr '\n' ' ')" fi if [ -f /etc/gdm/custom.conf ] && $SUDO grep -qi "^AutomaticLogin=$KIOSK_USER\$" /etc/gdm/custom.conf && $SUDO grep -qi "^AutomaticLoginEnable=True" /etc/gdm/custom.conf; then ok "gdm auto-login targets $KIOSK_USER" else bad "gdm auto-login is not enabled for $KIOSK_USER" fi printf '\n%s\n' '--- running state ---' SEAT_USER=$(loginctl list-sessions --no-legend 2>/dev/null | awk '$4=="seat0"{print $3; exit}') if [ -z "$SEAT_USER" ]; then warn "nobody is logged in on seat0 (sudo systemctl restart gdm)" elif [ "$SEAT_USER" = "$KIOSK_USER" ]; then ok "seat0 is logged in as $KIOSK_USER" else bad "seat0 is logged in as '$SEAT_USER', not $KIOSK_USER (sudo systemctl restart gdm)" fi SEAT_SESSION=$(loginctl list-sessions --no-legend 2>/dev/null | awk '$4=="seat0"{print $1; exit}') if [ -n "$SEAT_SESSION" ]; then info "seat0 session $SEAT_SESSION: class=$(loginctl show-session "$SEAT_SESSION" -p Class --value 2>/dev/null) type=$(loginctl show-session "$SEAT_SESSION" -p Type --value 2>/dev/null)" fi # Does the kiosk actually hold the screen? A session can be Active while another # one owns the foreground VT, which is what a covered wall looks like from here. KIOSK_SESSION=$(loginctl list-sessions --no-legend 2>/dev/null | awk -v u="$KIOSK_USER" '$3==u && $4=="seat0"{print $1; exit}') if [ -n "$KIOSK_SESSION" ]; then K_ACTIVE=$(loginctl show-session "$KIOSK_SESSION" -p Active --value 2>/dev/null) K_TTY=$(loginctl show-session "$KIOSK_SESSION" -p TTY --value 2>/dev/null) K_FG=$(sudo cat /sys/class/tty/tty0/active 2>/dev/null) if [ "$K_ACTIVE" = "yes" ] && [ -n "$K_TTY" ] && [ "$K_FG" = "$K_TTY" ]; then ok "the kiosk holds the console (foreground VT $K_FG)" else bad "console is on ${K_FG:-?} but the kiosk is on ${K_TTY:-?} (Active=$K_ACTIVE) — the screen is showing something else" info "fix: sudo loginctl activate $KIOSK_SESSION, then check the session override above" fi fi # Count the greeter *sessions* GDM created this boot, not every mention: a # healthy kiosk creates none, and the autospawn bug creates exactly one soon # after auto-login. (journalctl has no --no-legend; using it here once made this # test read an empty stream and pass unconditionally — a silent false green.) GREETERS=$(sudo journalctl -b --no-pager 2>/dev/null | grep -c "New session .* of user 'gdm-greeter'") if [ "${GREETERS:-0}" -gt 0 ]; then warn "$GREETERS GDM greeter session(s) this boot: the wall may be covered by a login screen" info "check X-GDM-SessionRegisters=true in /usr/local/share/wayland-sessions/" fi if [ -n "$HOME_DIR" ]; then KUID=$(id -u "$KIOSK_USER") FF=$(pgrep -u "$KUID" -a firefox 2>/dev/null | head -1) if [ -z "$FF" ]; then warn "no firefox running as $KIOSK_USER yet" else case "$FF" in *--kiosk*) ok "$FF" ;; *) warn "firefox is running without --kiosk: $FF" ;; esac fi if [ -f "$HOME_DIR/.local/state/mirror-kiosk.log" ]; then info "last kiosk log lines:" $SUDO tail -5 "$HOME_DIR/.local/state/mirror-kiosk.log" 2>/dev/null | sed 's/^/ /' fi fi printf '\n%s\n' '--- hang recovery ---' # An unattended wall has to end a hang with a reboot, not with a frozen frame for # a week. Two independent layers; ../kiosk-silverblue.md ("When the wall hangs"). sc() { sysctl -n "$1" 2>/dev/null || echo missing; } for k in kernel.softlockup_panic kernel.hardlockup_panic kernel.panic_on_oops; do v=$(sc "$k") case "$v" in 1) ok "$k = 1" ;; missing) warn "$k does not exist in this kernel build" warn " (kernel.hung_task_panic is absent from Fedora's kernel; the watchdog covers it)" ;; *) bad "$k = $v, expected 1 — fix /etc/sysctl.d/90-mirror-wall-selfheal.conf, then sudo sysctl --system" ;; esac done P=$(sc kernel.panic) case "$P" in ''|0|missing) bad "kernel.panic = ${P:-unset}: after a panic the box sits there forever" ;; *) ok "kernel.panic = $P (reboots $P s after a panic)" ;; esac if [ -e /dev/watchdog ]; then WD=$(systemctl show -p RuntimeWatchdogUSec --value 2>/dev/null || echo 0) WID=$(cat /sys/class/watchdog/watchdog0/identity 2>/dev/null || echo '?') case "$WD" in 0|''|infinity) bad "PID 1 is not kicking the $WID watchdog (RuntimeWatchdogUSec=$WD) — a wedged kernel here never recovers" ;; *) ok "hardware watchdog armed: $WID at $WD (no kick from PID 1 for $WD = chipset reset)" ;; esac else info "no /dev/watchdog on this box — the lockup panics are the only recovery layer" fi printf '\n%s\n' '--- firewall ---' if command -v firewall-cmd >/dev/null 2>&1 && firewall-cmd --state >/dev/null 2>&1; then ZONE=$(firewall-cmd --get-default-zone) PORTS=$(firewall-cmd --zone="$ZONE" --list-ports | tr ' ' '\n') if printf '%s\n' "$PORTS" | grep -qx '1025-65535/tcp'; then bad "$ZONE opens 1025-65535/tcp — on a box whose only access control is its address, that is every high port" else ok "$ZONE: 1025-65535/tcp closed" fi if printf '%s\n' "$PORTS" | grep -qx '1025-65535/udp'; then ok "$ZONE: 1025-65535/udp open (WebRTC media needs it — do not close it)" else bad "$ZONE: 1025-65535/udp closed — peer-to-peer media cannot flow, every tile reads 'unreachable'" fi else info "firewalld is not running — nothing listening, nothing to tighten" fi printf '\n%s\n' '--- what the screen will show ---' if [ -n "$URL" ]; then BODY=$(curl -fsSL -m 8 "$URL" 2>/dev/null) if [ -z "$BODY" ]; then warn "$URL is not reachable from this machine right now" else CODE=$(curl -s -o /dev/null -w '%{http_code}' -m 8 "$URL" 2>/dev/null) if printf '%s' "$BODY" | grep -q "Watch · mirror"; then ok "$URL serves the mirror watch page (HTTP $CODE)" else warn "$URL answered HTTP $CODE but it is NOT the mirror watch page — the kiosk" warn "will happily display whatever this is. Check DNS and the nginx vhost." info "title: $(printf '%s' "$BODY" | sed -n 's/.*\(.*\)<\/title>.*/\1/p' | head -1)" fi fi else info "no URL configured, nothing to fetch" fi printf '\n' if [ "$FAILS" -gt 0 ]; then printf '%s check(s) FAILED.\n' "$FAILS" exit 1 fi printf 'All checks passed.\n'