Offline addons, LAN-aware emergency hotspot, LAN time server

Offline bundle now carries every addon that works on a network without
internet: LMS (Lyrion's own .deb, from the addon's LMS_DEB_URL) +
Squeezelite, Asterisk Intercom (baresip), VNC, WireGuard and the
Emergency Hotspot packages - each list in a variable next to the code
that installs it (SQUEEZELITE_APT_PACKAGES, ASTERISK_INTERCOM_APT_PACKAGES,
VNC_APT_PACKAGES, WIREGUARD_APT_PACKAGES, EMERGENCY_HOTSPOT_APT_PACKAGES),
read by build-bundle.sh. Each install goes through
run_with_offline_fallback like CUPS, so they install offline from the
normal menus / Web UI. LMS installs as a bundle package when offline
(lms_offline_install_wanted); its online repo/direct-download paths are
unchanged. Tailscale/Netbird deliberately not bundled (vendor scripts,
vendor servers). Bundle: 524 MB (+87 MB).

Emergency hotspot: the boot check pinged only 8.8.8.8, so on a LAN with
no internet the hotspot started on every boot. Now chosen at setup:
"network" (default - router or internet must answer; a router that
ignores ping still counts if it answered ARP), "internet" (old check),
or "host" (a specific address). Three tries 10s apart. Existing scripts
keep the old check until Reconfigure.

New Core Settings -> Time Server (NTP) (menus/time_sync.sh): point
systemd-timesyncd at LAN time server(s) via a timesyncd.conf.d drop-in,
back to Ubuntu's defaults, or set the clock by hand (and the RTC) for a
network with no time server. Complete Uninstall resets it.

Also: lms_service_name used `systemctl list-unit-files | grep -q`, the
same pipefail/SIGPIPE pattern as the earlier cups_is_installed bug; now
`systemctl cat`.

Tested in a network-less chroot of the 26.04.1 server filesystem: kiosk
base, then action_wireguard_install and action_install_lms (real
functions) and the Squeezelite/Intercom/VNC/hotspot package sets all
installed from the bundle, apt left on normal sources after each.
Hotspot script generated for all three modes (plus an invalid address,
which falls back to "network") and its check run against simulated
networks: LAN-only with router answering ping or only ARP -> no hotspot
in "network" mode; nothing reachable -> hotspot. Time Server actions
driven with timedatectl stubbed: drop-in contents, input validation,
manual set-time sequence, reset removes the drop-in.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Cjz8a58eB5P9sUweqd3NHm

.github/workflows/build-iso.yml

@@ -41,9 +41,10 @@ on:
         default: ""
       offline:
         description: >-
-          Bundle everything install.sh downloads (~420 MB: all packages incl.
-          CUPS printing, Node.js, Electron) so the kiosk installs with no
-          internet on first boot.
+          Bundle everything install.sh downloads (~520 MB: all packages incl.
+          the CUPS, LMS/Squeezelite, Intercom, VNC, WireGuard and hotspot
+          addons, Node.js, Electron) so the kiosk and those addons install
+          with no internet.
         type: boolean
         default: true
       retention_days:

Readme.md

@@ -107,19 +107,21 @@ iso/build-iso.sh --offline   # also offers to install apt-utils, python3, gnupg,
 # -> iso/build/ubuntu-26.04.x-kiosk-offline-amd64.iso (~3.2 GB)
 ```
 
-This adds a ~420 MB bundle to the ISO:
-- Every Ubuntu package the kiosk install and the **CUPS printing addon**
-  need (all printer drivers included), with their dependencies, as a local
-  package repository.
+This adds a ~520 MB bundle to the ISO (~3.3 GB total):
+- Every Ubuntu package the kiosk install needs, plus the addons that make
+  sense on a network without internet: **CUPS printing** (all printer
+  drivers), **LMS (Lyrion) music server** and **Squeezelite** player,
+  **Asterisk Intercom**, **VNC**, **WireGuard** and the **Emergency
+  Hotspot** - with their dependencies, as a local package repository.
 - Node.js 22 (NodeSource).
 - Prebuilt Electron and Web UI modules.
 
 On first boot it still installs online when there's internet. With none,
 it waits 90 seconds and then installs entirely from the bundle. The bundle
-stays on the kiosk at `/opt/kiosk-offline`, so **Addons → CUPS Printing**
-(in `./install.sh` or the Web UI) works with no internet too: when it can't
-reach the Ubuntu archive, it installs from the bundle by itself and then
-switches apt back to normal.
+stays on the kiosk at `/opt/kiosk-offline`, so those addons install from
+the normal menus (`./install.sh` or the Web UI) with no internet too: when
+an install can't reach the Ubuntu archive, it uses the bundle by itself and
+then switches apt back to normal.
 
 Notes:
 - Build it on an **amd64** Ubuntu/Debian machine, or let the GitHub
@@ -128,8 +130,12 @@ Notes:
 - Bundled versions are whatever was current when the ISO was built.
   Once the kiosk is online, normal updates and Advanced → Upgrade bring it
   current.
-- Addons that download their own software (LMS/Squeezelite, Tailscale,
-  Netbird, Asterisk Intercom, VNC) still need internet.
+- Tailscale and Netbird aren't bundled: they install from their vendors'
+  scripts and only work with their vendors' servers on the internet.
+- On a network with no internet, set **Core Settings → Time Server (NTP)**
+  to a time server on your network (most routers can serve time), or set
+  the clock by hand there - otherwise the clock slowly drifts, and lockout
+  times, quiet hours and power schedules drift with it.
 - `sudo rm -rf /opt/kiosk-offline` frees the space if you don't need it.
 
 **No Linux machine handy?** Build it on GitHub instead: **Actions → Build
@@ -1105,6 +1111,12 @@ Automatically creates a WiFi access point when internet connectivity is lost.
 - Optional configuration with custom SSID and password
 - Can be deferred and configured later
 
+**What counts as "cut off"** (chosen when you set it up; `./install.sh`
+version): by default, *the local network itself* is unreachable - neither
+the router nor the internet answers - so a kiosk on a network without
+internet doesn't start the hotspot on every boot. "No internet" (the old
+check) and "a specific address doesn't answer" are options too.
+
 **How It Works:**
 1. Service monitors internet connectivity every 30 seconds
 2. When internet is lost, automatically:
@@ -1477,6 +1489,9 @@ full migration pass.
 - **All-in-one install ISO** (`iso/build-iso.sh`, or Actions → Build kiosk ISO): Ubuntu Server 26.04 plus the kiosk in one USB stick — the Ubuntu install, then `install.sh` automatically on first boot. Interactive, unattended, or fully automatic. See "All-in-One Install ISO" above.
 - **Offline installs** (`--offline`): the ISO carries every package (including CUPS printing and all printer drivers), Node.js 22, and prebuilt Electron/Web UI modules, so a kiosk installs with no internet. With internet it still installs current versions online. Addons → CUPS Printing (menu or Web UI) installs from the bundle by itself when offline.
 - **Local files as sites:** an absolute path (`/home/kiosk/docs/menu.pdf`) shows a local page, PDF or image; a folder (`/home/kiosk/photos/`) plays as a full-screen **image slideshow** that picks up added/removed images within a minute. Works in both the Sites menu and the Web UI.
+- **Offline addons:** the `--offline` bundle now also carries LMS (Lyrion) + Squeezelite, Asterisk Intercom, VNC, WireGuard and the Emergency Hotspot; their normal installs use it automatically when there's no internet.
+- **Emergency Hotspot fix:** by default it now starts only when the local network is unreachable (router *and* internet), not merely when there's no internet - on a LAN without internet it used to start on every boot. Existing setups keep the old check until Advanced → Emergency Hotspot → Reconfigure.
+- **New: Core Settings → Time Server (NTP)** - use a time server on your network, go back to Ubuntu's, or set the clock by hand; for networks without internet.
 - **Word documents as sites:** a `.docx` path renders in the kiosk via docx-preview (~1 MB of JavaScript, bundled offline), updating when the file changes. Slideshow folders can mix `.docx` documents and PDFs (rendered with pdf.js) in with images.
 - **Electron upgrade:** v42.x → v44.x (42 leaves Electron's support window when 45 ships). Existing kiosks move to it via Advanced → Upgrade.
 - **Fix:** the CUPS menu could report an installed CUPS as "not installed" (`dpkg -l | grep -q` failing under `set -o pipefail`).

install.sh

@@ -24,7 +24,8 @@
 #
 # Migrated so far, grouped the same way the legacy menu groups them:
 #   Core Settings: Sites & Page Timing, Display & Interaction, Timezone,
-#     Hidden Site PIN, Password Protection & Lockout, WiFi,
+#     Time Server (NTP - menus/time_sync.sh, a LAN time server or manual
+#     clock for networks without internet), Hidden Site PIN, Password Protection & Lockout, WiFi,
 #     Power/Display/Quiet Hours, Complete Uninstall
 #     (menus/complete_uninstall.sh - composed from every addon's own
 #     uninstall helper rather than re-implementing removal a second time).
@@ -72,6 +73,8 @@ source "$SCRIPT_DIR/menus/sites.sh"
 source "$SCRIPT_DIR/menus/display.sh"
 # shellcheck source=menus/timezone.sh
 source "$SCRIPT_DIR/menus/timezone.sh"
+# shellcheck source=menus/time_sync.sh
+source "$SCRIPT_DIR/menus/time_sync.sh"
 # shellcheck source=menus/hidden_pin.sh
 source "$SCRIPT_DIR/menus/hidden_pin.sh"
 # shellcheck source=menus/lockout.sh
@@ -151,6 +154,7 @@ core_settings_menu_builder() {
         "Sites & Page Timing"
         "Display & Interaction"
         "Timezone"
+        "Time Server (NTP)"
         "Hidden Site PIN"
         "Password Protection & Lockout"
         "WiFi"
@@ -161,6 +165,7 @@ core_settings_menu_builder() {
         sites_menu
         display_menu
         timezone_menu
+        time_sync_menu
         hidden_pin_menu
         lockout_menu
         wifi_menu

iso/build-iso.sh

@@ -70,8 +70,9 @@
 #   --repo-url URL        git remote recorded in the copied repo, used by
 #                         Advanced -> Upgrade (default: this checkout's
 #                         origin, else the upstream GitHub repo).
-#   --offline             Also bundle everything install.sh downloads (~420 MB:
-#                         every apt package incl. the CUPS printing addon,
+#   --offline             Also bundle everything install.sh downloads (~520 MB:
+#                         every apt package incl. the CUPS, LMS/Squeezelite,
+#                         Asterisk Intercom, VNC, WireGuard and hotspot addons,
 #                         Node.js, prebuilt Electron/Web UI node_modules), so
 #                         first boot can install the kiosk with NO internet.
 #                         With internet it still installs online as usual;

iso/offline/build-bundle.sh

@@ -8,17 +8,20 @@
 #
 # OUT_DIR ends up as /opt/kiosk-offline on the installed system:
 #   apt/              Local apt repository (flat, [trusted=yes]) with every
-#                     package install.sh's provisioning and the CUPS addon
-#                     install ask for, NodeSource's nodejs, and all their
+#                     package install.sh's provisioning and the addons ask
+#                     for (CUPS, LMS + Squeezelite, Asterisk Intercom, VNC,
+#                     WireGuard, Emergency Hotspot - not Tailscale/Netbird,
+#                     which need their vendors' servers anyway), Lyrion's
+#                     own .deb, NodeSource's nodejs, and all their
 #                     dependencies that a fresh Ubuntu Server install from
 #                     SOURCE_ISO doesn't already have.
 #   npm/kiosk-app-node_modules.tar.gz   Prebuilt node_modules (Electron
 #   npm/webui-node_modules.tar.gz       included) in place of `npm install`.
 #   bundle-info.txt   What was bundled, from where, when.
 #
-# Package lists are read from REPO_DIR's own lib/provision.sh and
-# menus/addon_cups.sh (PROVISION_APT_PACKAGES, PROVISION_INTEL_APT_PACKAGES,
-# CUPS_APT_PACKAGES), so the bundle always matches what install.sh asks for.
+# Package lists are read from REPO_DIR's own lib/provision.sh and menus/
+# (PROVISION_APT_PACKAGES, CUPS_APT_PACKAGES, SQUEEZELITE_APT_PACKAGES,
+# LMS_DEB_URL, ...), so the bundle always matches what install.sh asks for.
 #
 # Dependencies are resolved against SOURCE_ISO's own package manifest - a
 # fake dpkg status built from it (fake-dpkg-status.py) - so apt only
@@ -127,21 +130,45 @@ python3 "$HERE/fake-dpkg-status.py" "$manifest" "$R/var/lib/apt/lists" > "$R/var
 ################################################################################
 
 # shellcheck disable=SC1091,SC2034
+# Each list lives next to the code that installs it; lib/config.sh first
+# for the path defaults those files use at the top level.
 mapfile -t packages < <(
     SCRIPT_DIR="$REPO_DIR"
+    source "$REPO_DIR/lib/config.sh"
     source "$REPO_DIR/lib/provision.sh"
     source "$REPO_DIR/menus/addon_cups.sh"
+    source "$REPO_DIR/menus/addon_lms_squeezelite.sh"
+    source "$REPO_DIR/menus/addon_asterisk_intercom.sh"
+    source "$REPO_DIR/menus/addon_remote_access.sh"
+    source "$REPO_DIR/menus/advanced_emergency_hotspot.sh"
     printf '%s\n' "${PROVISION_APT_PACKAGES[@]}" "${PROVISION_INTEL_APT_PACKAGES[@]}" \
-        "${CUPS_APT_PACKAGES[@]}" "${EXTRA_APT_PACKAGES[@]}"
+        "${CUPS_APT_PACKAGES[@]}" "${SQUEEZELITE_APT_PACKAGES[@]}" \
+        "${ASTERISK_INTERCOM_APT_PACKAGES[@]}" "${VNC_APT_PACKAGES[@]}" \
+        "${WIREGUARD_APT_PACKAGES[@]}" "${EMERGENCY_HOTSPOT_APT_PACKAGES[@]}" \
+        "${EXTRA_APT_PACKAGES[@]}"
 )
 (( ${#packages[@]} > 20 )) || die "couldn't read the package lists from $REPO_DIR"
 
+# Lyrion Music Server isn't in Ubuntu's archive: bundle the exact .deb the
+# LMS addon downloads online, and let apt resolve its dependencies from it
+# (a local .deb path in the install list).
+# shellcheck disable=SC1091,SC2034
+lms_url="$(SCRIPT_DIR="$REPO_DIR"; source "$REPO_DIR/lib/config.sh"; source "$REPO_DIR/menus/addon_lms_squeezelite.sh"; echo "$LMS_DEB_URL")"
+lms_deb="$CACHE_DIR/$(basename "$lms_url")"
+if [[ ! -s "$lms_deb" ]]; then
+    info "Downloading $(basename "$lms_url")..."
+    curl -fL --retry 3 -o "$lms_deb.part" "$lms_url" || die "couldn't download $lms_url"
+    mv "$lms_deb.part" "$lms_deb"
+fi
+dpkg-deb -I "$lms_deb" >/dev/null 2>&1 || { rm -f "$lms_deb"; die "$lms_deb isn't a valid .deb - deleted, re-run to retry"; }
+packages+=("$lms_deb")
+
 info "Resolving ${#packages[@]} packages (with recommends, as install.sh installs them)..."
 # --print-uris against an empty archive dir: it leaves out anything already
 # in the cache, which on a rebuild would be everything.
 rm -rf "$R/empty-archives"; mkdir -p "$R/empty-archives/partial"
 mapfile -t debs < <("${APT[@]}" -qq -o "Dir::Cache::archives=$R/empty-archives" \
-    install --print-uris -y "${packages[@]}" | awk '{print $2}')
+    install --print-uris -y "${packages[@]}" | awk '$1 !~ /^.file:/ {print $2}')  # the local LMS .deb is copied below
 (( ${#debs[@]} )) || die "apt resolved nothing to download - check the output above"
 
 info "Downloading ${#debs[@]} .debs (cached between builds)..."
@@ -150,6 +177,7 @@ info "Downloading ${#debs[@]} .debs (cached between builds)..."
 for f in "${debs[@]}"; do
     cp "$R/var/cache/apt/archives/$f" "$OUT_DIR/apt/"
 done
+cp "$lms_deb" "$OUT_DIR/apt/"
 (
     cd "$OUT_DIR/apt"
     apt-ftparchive packages . > Packages 2>/dev/null

lib/config.sh

@@ -29,6 +29,7 @@
 : "${CRON_D_DIR:=/etc/cron.d}"
 : "${BIN_DIR:=/usr/local/bin}"
 : "${NETPLAN_DIR:=/etc/netplan}"
+: "${TIMESYNCD_CONF_DIR:=/etc/systemd/timesyncd.conf.d}"
 : "${POLKIT_DIR:=/etc/polkit-1/localauthority/50-local.d}"
 : "${WIREGUARD_DIR:=/etc/wireguard}"
 : "${WEBUI_DIR:=/opt/kiosk-webui}"

menus/addon_asterisk_intercom.sh

@@ -36,6 +36,9 @@
 ################################################################################
 
 BARESIP_CONFIG_DIR="${KIOSK_HOME}/.baresip"
+# Also read by iso/offline/build-bundle.sh to bundle them for offline installs.
+# pulseaudio-utils/pipewire-pulse: pactl, for audio routing.
+ASTERISK_INTERCOM_APT_PACKAGES=(baresip pulseaudio-utils pipewire-pulse)
 BARESIP_USER_SERVICE_DIR="${KIOSK_HOME}/.config/systemd/user"
 
 # Runs `systemctl --user ...` as $KIOSK_USER with the runtime dir/D-Bus
@@ -169,14 +172,13 @@ action_configure_asterisk_intercom() {
 
     echo
     echo "Installing Baresip..."
-    if ! command -v baresip &>/dev/null; then
-        if ! sudo apt install -y baresip; then
+    if ! command -v baresip &>/dev/null || ! command -v pactl &>/dev/null; then
+        if ! run_with_offline_fallback sudo apt install -y "${ASTERISK_INTERCOM_APT_PACKAGES[@]}"; then
             log_error "Failed to install baresip package"
             pause
             return 1
         fi
     fi
-    sudo apt install -y pulseaudio-utils pipewire-pulse 2>/dev/null || true
 
     sudo mkdir -p "$BARESIP_CONFIG_DIR"
 

menus/addon_lms_squeezelite.sh

@@ -22,10 +22,23 @@
 # Depends on: lib/menu.sh, lib/config.sh being sourced first.
 ################################################################################
 
+# Also read by iso/offline/build-bundle.sh, to bundle the same versions
+# for offline installs (the .deb itself plus its apt dependencies).
+LMS_DEB_URL="https://downloads.lms-community.org/LyrionMusicServer_v9.0.3/lyrionmusicserver_9.0.3_amd64.deb"
+SQUEEZELITE_APT_PACKAGES=(squeezelite)
+
+# True on a kiosk installed from an --offline ISO that can't reach the
+# internet right now - the one case where LMS comes from the bundle.
+lms_offline_install_wanted() {
+    grep -q '^Package: lyrionmusicserver$' "$KIOSK_OFFLINE_DIR/apt/Packages" 2>/dev/null && ! have_internet
+}
+
 lms_service_name() {
-    if systemctl list-unit-files 2>/dev/null | grep -q "lyrionmusicserver.service"; then
+    # `systemctl cat`, not `list-unit-files | grep -q`: grep -q exiting
+    # early can SIGPIPE systemctl, failing the pipeline under pipefail.
+    if systemctl cat lyrionmusicserver.service &>/dev/null; then
         echo "lyrionmusicserver"
-    elif systemctl list-unit-files 2>/dev/null | grep -q "logitechmediaserver.service"; then
+    elif systemctl cat logitechmediaserver.service &>/dev/null; then
         echo "logitechmediaserver"
     fi
 }
@@ -114,6 +127,16 @@ action_install_lms() {
 
     echo "Installing Lyrion Music Server..."
 
+    if lms_offline_install_wanted; then
+        # Kiosk installed from an --offline ISO with no internet right now:
+        # the bundle carries the same LMS_DEB_URL .deb as a package.
+        if ! run_with_offline_fallback sudo apt install -y lyrionmusicserver; then
+            log_error "Failed to install LMS from the offline bundle"
+            pause
+            return 1
+        fi
+        log_success "LMS installed from the offline bundle"
+    else
         # Try the repository method first.
         if wget -qO - https://debian.slimdevices.com/debian/squeezebox-keyring.gpg | sudo gpg --dearmor -o /usr/share/keyrings/lms-keyring.gpg 2>/dev/null; then
             echo "deb [signed-by=/usr/share/keyrings/lms-keyring.gpg] http://debian.slimdevices.com/debian stable main" | sudo tee /etc/apt/sources.list.d/lms.list
@@ -134,8 +157,8 @@ action_install_lms() {
         # either possible package.
         if ! command -v logitechmediaserver &>/dev/null && ! command -v lyrionmusicserver &>/dev/null; then
             local lms_deb="/tmp/lms.deb"
-        echo "Downloading LMS v9.0.3..."
-        if wget -q https://downloads.lms-community.org/LyrionMusicServer_v9.0.3/lyrionmusicserver_9.0.3_amd64.deb -O "$lms_deb"; then
+            echo "Downloading LMS ($(basename "$LMS_DEB_URL"))..."
+            if wget -q "$LMS_DEB_URL" -O "$lms_deb"; then
                 echo "Installing LMS package..."
                 if sudo apt install -y "$lms_deb"; then
                     log_success "LMS installed via direct download"
@@ -152,6 +175,7 @@ action_install_lms() {
                 return 1
             fi
         fi
+    fi
 
     local service_name
     service_name=$(lms_service_name)
@@ -250,7 +274,7 @@ action_install_squeezelite() {
     fi
 
     if ! command -v squeezelite &>/dev/null; then
-        if ! sudo apt install -y squeezelite; then
+        if ! run_with_offline_fallback sudo apt install -y "${SQUEEZELITE_APT_PACKAGES[@]}"; then
             log_error "squeezelite package installation failed"
             pause
             return 1

menus/addon_remote_access.sh

@@ -24,6 +24,12 @@
 # Depends on: lib/menu.sh, lib/config.sh being sourced first.
 ################################################################################
 
+# Also read by iso/offline/build-bundle.sh to bundle them for offline
+# installs. (Tailscale/Netbird aren't bundled: they install from their
+# vendors' scripts and need their vendors' servers to work anyway.)
+VNC_APT_PACKAGES=(x11vnc)
+WIREGUARD_APT_PACKAGES=(wireguard wireguard-tools)
+
 remote_access_status() {
     echo "VNC:       $(is_service_active x11vnc && echo "running" || echo "not installed")"
     echo "WireGuard: $(wireguard_connected && echo "connected" || (command -v wg &>/dev/null && echo "installed, not connected" || echo "not installed"))"
@@ -70,7 +76,7 @@ action_vnc_install() {
     echo
     ask_yes_no "Install x11vnc?" "n" || { echo "Cancelled"; return; }
 
-    if ! sudo apt install -y x11vnc; then
+    if ! run_with_offline_fallback sudo apt install -y "${VNC_APT_PACKAGES[@]}"; then
         log_error "x11vnc installation failed"
         return 1
     fi
@@ -182,7 +188,7 @@ action_wireguard_install() {
     echo
     ask_yes_no "Install WireGuard?" "n" || { echo "Cancelled"; return; }
 
-    if ! sudo apt install -y wireguard wireguard-tools; then
+    if ! run_with_offline_fallback sudo apt install -y "${WIREGUARD_APT_PACKAGES[@]}"; then
         log_error "WireGuard installation failed"
         return 1
     fi

menus/addon_webui.sh

@@ -163,6 +163,7 @@ source "$SCRIPT_DIR/lib/electron.sh"
 source "$SCRIPT_DIR/menus/sites.sh"
 source "$SCRIPT_DIR/menus/display.sh"
 source "$SCRIPT_DIR/menus/timezone.sh"
+source "$SCRIPT_DIR/menus/time_sync.sh"
 source "$SCRIPT_DIR/menus/hidden_pin.sh"
 source "$SCRIPT_DIR/menus/lockout.sh"
 source "$SCRIPT_DIR/menus/wifi.sh"

menus/advanced_emergency_hotspot.sh

@@ -1,8 +1,15 @@
 #!/bin/bash
 ################################################################################
 # menus/advanced_emergency_hotspot.sh - "Emergency Hotspot" (Advanced):
-# auto-starts a WiFi hotspot if no internet is detected 60 seconds after
-# boot, so the kiosk can be reached and reconfigured remotely.
+# auto-starts a WiFi hotspot if the kiosk finds itself cut off 60 seconds
+# after boot, so it can be reached and reconfigured remotely.
+# "Cut off" is chosen at setup (EMERGENCY_HOTSPOT_CHECK_MODE in the
+# generated script): by default the local network itself is unreachable -
+# neither the router nor the internet answers - so a kiosk on a LAN with
+# no internet (an offline install) doesn't start the hotspot on every
+# boot. The old internet-only check (ping 8.8.8.8) is still an option, as
+# is checking one specific address. Scripts generated before this choice
+# existed keep the internet-only check until Reconfigure is run.
 #
 # Writes a standalone runtime script ($BIN_DIR/kiosk-emergency-hotspot)
 # plus a oneshot systemd unit ($SYSTEMD_DIR) that runs it at boot - both
@@ -21,6 +28,8 @@
 ################################################################################
 
 EMERGENCY_HOTSPOT_SCRIPT="$BIN_DIR/kiosk-emergency-hotspot"
+# Also read by iso/offline/build-bundle.sh to bundle them for offline installs.
+EMERGENCY_HOTSPOT_APT_PACKAGES=(hostapd dnsmasq iptables)
 
 emergency_hotspot_is_configured() {
     [[ -f "$EMERGENCY_HOTSPOT_SCRIPT" ]]
@@ -38,8 +47,8 @@ advanced_emergency_hotspot_status() {
     else
         echo "Emergency Hotspot: Not configured"
     fi
-    echo "ℹ Auto-starts a WiFi hotspot if no internet is detected 60"
-    echo "  seconds after boot, so you can connect and reconfigure remotely."
+    echo "ℹ Auto-starts a WiFi hotspot if the kiosk can't reach its network"
+    echo "  60 seconds after boot, so you can connect and reconfigure remotely."
 }
 
 advanced_emergency_hotspot_menu_builder() {
@@ -62,7 +71,7 @@ advanced_emergency_hotspot_menu() {
 
 action_configure_emergency_hotspot() {
     echo
-    if ! sudo apt install -y hostapd dnsmasq iptables; then
+    if ! run_with_offline_fallback sudo apt install -y "${EMERGENCY_HOTSPOT_APT_PACKAGES[@]}"; then
         log_error "Failed to install hostapd/dnsmasq/iptables"
         pause
         return 1
@@ -91,6 +100,29 @@ action_configure_emergency_hotspot() {
         [[ ${#hotspot_pass} -lt 8 ]] && log_error "Password must be at least 8 characters"
     done
 
+    echo
+    echo "When should the hotspot start? (checked 60 seconds after boot)"
+    echo "  1) The local network is unreachable - neither the router nor the"
+    echo "     internet answers. Recommended; right for networks without"
+    echo "     internet too."
+    echo "  2) There's no internet. On a network without internet this starts"
+    echo "     the hotspot on every boot."
+    echo "  3) A specific address on your network doesn't answer (e.g. a server)."
+    local check_mode="network" check_host="" check_choice
+    check_choice=$(ask_integer "Choice" 1 1 3)
+    case "$check_choice" in
+        2) check_mode="internet" ;;
+        3)
+            check_host=$(ask_text "Address to check (IP or hostname)" "")
+            if [[ "$check_host" =~ ^[A-Za-z0-9.:-]+$ ]]; then
+                check_mode="host"
+            else
+                log_warning "Not a valid address - using option 1 instead"
+                check_host=""
+            fi
+            ;;
+    esac
+
     local hotspot_ip="192.168.50.1"
 
     sudo mkdir -p "$BIN_DIR"
@@ -98,9 +130,14 @@ action_configure_emergency_hotspot() {
 #!/bin/bash
 ################################################################################
 ### KIOSK EMERGENCY HOTSPOT
-### Auto-starts if no internet connection 60 seconds after boot
+### Auto-starts if the network check fails 60 seconds after boot
 ################################################################################
 
+# network  = neither the default gateway (router) nor the internet answers
+# internet = no internet (pings 8.8.8.8 / 1.1.1.1)
+# host     = CHECK_HOST doesn't answer
+CHECK_MODE="$check_mode"
+CHECK_HOST="$check_host"
 WIFI_IFACE="$wifi_iface"
 HOTSPOT_SSID="$hotspot_ssid"
 HOTSPOT_PASS="$hotspot_pass"
@@ -110,13 +147,36 @@ KIOSK_USER="$KIOSK_USER"
 # Wait 60 seconds after boot
 sleep 60
 
-# Check for internet connectivity
-if ping -c 3 -W 5 8.8.8.8 >/dev/null 2>&1; then
-    logger "KIOSK: Internet connected - emergency hotspot not needed"
-    exit 0
-fi
+ping_ok() { ping -c 2 -W 3 "\$1" >/dev/null 2>&1; }
+internet_ok() { ping_ok 8.8.8.8 || ping_ok 1.1.1.1; }
+# The router counts as there if it answers ping - or, for routers set to
+# ignore ping, if it answered the ARP lookup that ping just triggered.
+gateway_ok() {
+    local gw
+    gw=\$(ip -4 route show default 2>/dev/null | awk '{print \$3; exit}')
+    [[ -n "\$gw" ]] || return 1
+    ping_ok "\$gw" && return 0
+    ip neigh show "\$gw" 2>/dev/null | grep -qE 'REACHABLE|STALE|DELAY|PROBE'
+}
+connected() {
+    case "\$CHECK_MODE" in
+        internet) internet_ok ;;
+        host) ping_ok "\$CHECK_HOST" ;;
+        *) gateway_ok || internet_ok ;;
+    esac
+}
 
-logger "KIOSK: No internet detected - starting emergency hotspot"
+# Three tries, 10 seconds apart, so a slow DHCP lease or WiFi association
+# isn't mistaken for being cut off.
+for attempt in 1 2 3; do
+    if connected; then
+        logger "KIOSK: Network check (\$CHECK_MODE) passed - emergency hotspot not needed"
+        exit 0
+    fi
+    [[ \$attempt -lt 3 ]] && sleep 10
+done
+
+logger "KIOSK: Network check (\$CHECK_MODE) failed - starting emergency hotspot"
 
 # Stop any conflicting services
 systemctl stop wpa_supplicant 2>/dev/null || true

menus/complete_uninstall.sh

@@ -8,7 +8,7 @@
 # tailscale_do_uninstall, netbird_do_uninstall, lms_do_uninstall,
 # squeezelite_do_uninstall, asterisk_intercom_do_uninstall,
 # webui_do_uninstall, power_schedule_do_remove_all,
-# emergency_hotspot_do_disable) instead of
+# emergency_hotspot_do_disable, time_sync_do_reset) instead of
 # re-implementing removal logic for each addon a second time here - if an
 # addon's uninstall logic changes, this picks it up automatically. Only
 # the pieces no single addon owns - the kiosk user/files, Node.js/
@@ -62,6 +62,7 @@ action_complete_uninstall() {
     echo "  • LightDM and Openbox"
     echo "  • All kiosk schedules and services"
     echo "  • Emergency hotspot configuration"
+    echo "  • LAN time server setting (back to Ubuntu's defaults)"
     echo
     echo "⚠️  This CANNOT be undone!"
     echo
@@ -90,9 +91,10 @@ action_complete_uninstall() {
     asterisk_intercom_do_uninstall purge
     webui_do_uninstall
 
-    echo "[3/12] Removing schedules and emergency hotspot..."
+    echo "[3/12] Removing schedules, emergency hotspot and time server setting..."
     power_schedule_do_remove_all
     emergency_hotspot_do_disable
+    time_sync_do_reset
 
     # Must come after every addon teardown above - Asterisk Intercom's
     # helper still needs this user to resolve its systemd --user session.

menus/time_sync.sh

@@ -0,0 +1,167 @@
+#!/bin/bash
+################################################################################
+# menus/time_sync.sh - "Time Server (NTP)" (Core Settings).
+#
+# The kiosk keeps its clock right with systemd-timesyncd, which by default
+# asks Ubuntu's time servers on the internet. On a network with no
+# internet that never works and the clock slowly drifts - which matters
+# here, because lockout times, quiet hours and power schedules all go by
+# it. This menu points timesyncd at a time server on the local network
+# instead (most routers, Windows domain controllers and NAS boxes can
+# serve NTP), or, with no time server at all, sets the clock by hand.
+#
+# Writes one drop-in, $TIMESYNCD_CONF_DIR/50-kiosk-ntp.conf - removing it
+# (the "internet time servers" option, or Complete Uninstall via
+# time_sync_do_reset) puts Ubuntu's defaults back untouched.
+#
+# Depends on: lib/menu.sh, lib/config.sh being sourced first.
+################################################################################
+
+TIMESYNC_DROPIN="$TIMESYNCD_CONF_DIR/50-kiosk-ntp.conf"
+
+# The time server(s) this menu configured, or empty for Ubuntu's defaults.
+time_sync_servers() {
+    sed -n 's/^NTP=//p' "$TIMESYNC_DROPIN" 2>/dev/null | head -1
+}
+
+time_sync_status() {
+    local servers synced
+    servers=$(time_sync_servers)
+    synced=$(timedatectl show -p NTPSynchronized --value 2>/dev/null || echo "unknown")
+    echo "Current time:  $(date '+%Y-%m-%d %H:%M:%S %Z')"
+    echo "Time servers:  ${servers:-Ubuntu defaults (internet)}"
+    echo "Synchronized:  $([[ "$synced" == "yes" ]] && echo "yes" || echo "no")"
+}
+
+time_sync_menu_builder() {
+    MENU_LABELS=(
+        "Use a time server on my network"
+        "Use the internet time servers (Ubuntu default)"
+        "Set the date and time manually"
+        "Show sync details"
+    )
+    MENU_HANDLERS=(
+        action_time_sync_lan
+        action_time_sync_default
+        action_time_sync_manual
+        action_time_sync_details
+    )
+}
+
+time_sync_menu() {
+    run_menu "TIME SERVER (NTP)" time_sync_menu_builder time_sync_status
+}
+
+# Validate a space-separated list of hostnames / IPv4 / IPv6 addresses.
+time_sync_valid_servers() {
+    local s
+    [[ -n "$1" ]] || return 1
+    for s in $1; do
+        [[ "$s" =~ ^[A-Za-z0-9.:-]+$ ]] || return 1
+    done
+}
+
+time_sync_apply() {
+    sudo systemctl enable systemd-timesyncd 2>/dev/null || true
+    sudo timedatectl set-ntp true 2>/dev/null || true
+    sudo systemctl restart systemd-timesyncd 2>/dev/null || true
+}
+
+# Remove this menu's drop-in, back to Ubuntu's default time servers.
+# Also used by Complete Uninstall.
+time_sync_do_reset() {
+    sudo rm -f "$TIMESYNC_DROPIN"
+    time_sync_apply
+}
+
+################################################################################
+# Actions
+################################################################################
+
+action_time_sync_lan() {
+    echo
+    echo "Enter the address of a time (NTP) server on your network - often"
+    echo "the router (e.g. 192.168.1.1), a Windows domain controller, or a"
+    echo "NAS. Several can be given, separated by spaces."
+    local current servers
+    current=$(time_sync_servers)
+    servers=$(ask_text "Time server(s)" "${current:-$(ip -4 route show default 2>/dev/null | awk '{print $3; exit}')}")
+    if ! time_sync_valid_servers "$servers"; then
+        log_error "Not a valid address list: '$servers'"
+        pause
+        return 1
+    fi
+
+    sudo mkdir -p "$TIMESYNCD_CONF_DIR"
+    sudo tee "$TIMESYNC_DROPIN" > /dev/null <<EOF
+# Written by ubuntu-based-kiosk (Core Settings -> Time Server).
+# Delete this file to go back to Ubuntu's default time servers.
+[Time]
+NTP=$servers
+EOF
+    time_sync_apply
+
+    echo "Checking the time server (up to 15 seconds)..."
+    local i
+    for i in {1..15}; do
+        if [[ "$(timedatectl show -p NTPSynchronized --value 2>/dev/null)" == "yes" ]]; then
+            log_success "Clock synchronized with $servers"
+            pause
+            return
+        fi
+        sleep 1
+    done
+    log_warning "Saved, but no sync yet. timesyncd keeps retrying in the background."
+    echo "If it never syncs, check the address and that the server answers"
+    echo "NTP (UDP port 123): Core Settings -> Time Server -> Show sync details."
+    pause
+}
+
+action_time_sync_default() {
+    echo
+    if [[ ! -f "$TIMESYNC_DROPIN" ]]; then
+        echo "Already using Ubuntu's default (internet) time servers."
+        pause
+        return
+    fi
+    time_sync_do_reset
+    log_success "Back on Ubuntu's default (internet) time servers"
+    pause
+}
+
+# For a network with no time server at all: set the clock by hand.
+# Automatic sync stays on afterwards - it just has nothing to sync with
+# until a server becomes reachable, and then takes over again.
+action_time_sync_manual() {
+    echo
+    echo "Current time: $(date '+%Y-%m-%d %H:%M:%S %Z')"
+    echo "Enter the correct local date and time (timezone: $(timedatectl show -p Timezone --value 2>/dev/null))."
+    local when
+    when=$(ask_text "Date and time (YYYY-MM-DD HH:MM)" "$(date '+%Y-%m-%d %H:%M')")
+    if [[ ! "$when" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}\ [0-9]{2}:[0-9]{2}(:[0-9]{2})?$ ]] || ! date -d "$when" &>/dev/null; then
+        log_error "Not a valid date/time: '$when' (expected e.g. 2026-10-03 14:30)"
+        pause
+        return 1
+    fi
+    [[ "$when" =~ :[0-9]{2}:[0-9]{2}$ ]] || when="$when:00"
+
+    # timedatectl refuses set-time while automatic sync is on.
+    sudo timedatectl set-ntp false 2>/dev/null || true
+    if sudo timedatectl set-time "$when"; then
+        # Keep the hardware clock in step so the time survives a reboot.
+        sudo hwclock --systohc 2>/dev/null || true
+        log_success "Clock set to $(date '+%Y-%m-%d %H:%M:%S %Z')"
+    else
+        log_error "Couldn't set the clock"
+    fi
+    sudo timedatectl set-ntp true 2>/dev/null || true
+    pause
+}
+
+action_time_sync_details() {
+    echo
+    timedatectl status 2>/dev/null || true
+    echo
+    timedatectl timesync-status 2>/dev/null || echo "(timesync-status not available)"
+    pause
+}