Add ntp time source and browser policy

CLAUDE.md

@@ -152,6 +152,13 @@ instead of working around it.
   build; the supplicant config carries both options.
 - erofs module availability on the target RHEL kernel (fallback:
   journal-less ext4 in `extract-artifacts.sh`).
+- NTP via DHCP option 42 → chrony (no public-pool egress): confirm on a booted
+  host `chronyc sources` lists the DHCP-handed lab server (not `*.pool.ntp.org`).
+  Assumes (a) NM exports the lease's NTP servers to the dispatcher as
+  `$DHCP4_NTP_SERVERS`, and (b) RHEL 9 `/etc/chrony.conf` honours
+  `sourcedir /run/chrony-dhcp` (the provisioner appends it if absent). If sources
+  are empty, the dispatcher didn't fire or the env var name differs — check
+  `journalctl -u NetworkManager` and `ls /run/chrony-dhcp/`.
 - `fleet` Plymouth theme: confirm (a) the script plugin package actually
   installed (`/usr/lib64/plymouth/script.so` — else the build fell back to
   `spinner`, logged as a WARNING), (b) the scripted theme + a font got bundled

diskless.pkr.hcl

@@ -262,6 +262,16 @@ build {
       # secure mode, reserving the physical NIC for wpa_supplicant.
       "chmod 0755 /usr/lib/dracut/modules.d/95dot1x-macsec/*.sh",
 
+      # ---- NTP from DHCP (option 42) -> chrony, no public-pool egress --------
+      # NM dispatcher writes DHCP-provided NTP servers into chrony's sourcedir
+      # (replaces the removed dhclient.d/chrony.sh bridge). Strip the baked public
+      # pool so the host syncs ONLY from the lab NTP server handed via DHCP — the
+      # workstation never reaches *.pool.ntp.org.
+      "install -D -m0755 /tmp/etc-stage/NetworkManager/dispatcher.d/10-chrony-dhcp-ntp /etc/NetworkManager/dispatcher.d/10-chrony-dhcp-ntp",
+      "restorecon /etc/NetworkManager/dispatcher.d/10-chrony-dhcp-ntp",
+      "sed -i -E 's/^[[:space:]]*(pool|server)[[:space:]]/#&/' /etc/chrony.conf",
+      "grep -q '^sourcedir /run/chrony-dhcp' /etc/chrony.conf || echo 'sourcedir /run/chrony-dhcp' >> /etc/chrony.conf",
+
       # Inject the fleet NIC drivers into the dracut config
       "sed -i 's/@NIC_DRIVERS@/${var.nic_drivers}/' /etc/dracut.conf.d/90-diskless.conf",
 
@@ -341,15 +351,18 @@ build {
       "install -D -m0644 /tmp/kiosk/weston.ini /etc/xdg/weston/weston.ini",
       # Chromium managed policy: stops the browser phoning home to Google
       # (sign-in, variations, optimization-guide, component/auto update, metrics,
-      # safe browsing). EPEL chromium reads /etc/chromium/policies/managed/*.json.
+      # safe browsing). The managed-policy dir differs across chromium builds
+      # (/etc/chromium vs /etc/chromium-browser), and a policy in the wrong dir is
+      # silently ignored — so install to BOTH. Verify at runtime via chrome://policy.
       # Pairs with the hardening flags in kiosk-session.
       "install -D -m0644 /tmp/kiosk/chromium-kiosk-policy.json /etc/chromium/policies/managed/10-kiosk-lockdown.json",
+      "install -D -m0644 /tmp/kiosk/chromium-kiosk-policy.json /etc/chromium-browser/policies/managed/10-kiosk-lockdown.json",
       # URL from the var (weston renderer is set via --use-pixman in the unit).
       "install -d -m0755 /etc/kiosk",
       "printf 'KIOSK_URL=%s\\n' \"$KIOSK_URL\" > /etc/kiosk/kiosk.env",
       "chmod 0644 /etc/kiosk/kiosk.env",
       # Label the new files so they survive into the enforcing erofs.
-      "restorecon -R /usr/local/bin/kiosk-session /etc/systemd/system/kiosk.service /etc/xdg/weston /etc/kiosk /etc/chromium",
+      "restorecon -R /usr/local/bin/kiosk-session /etc/systemd/system/kiosk.service /etc/xdg/weston /etc/kiosk /etc/chromium /etc/chromium-browser",
       # Boot graphical and start the kiosk (replaces the tty1 getty).
       "systemctl enable kiosk.service",
       "systemctl set-default graphical.target",

docs/TODO.md

@@ -155,15 +155,32 @@ Path to getting here (don't re-discover):
   avc`; the kiosk user is unconfined so likely none — but do NOT set permissive
   if they appear; add a policy module). Admin SSH (the key user) still works for
   debug even if the kiosk fails (it lands at graphical.target either way).
-- **Phone-home lockdown (done 2026-06-17):** Chromium was dialing Google
+- **Phone-home lockdown (done 2026-06-17/18):** Chromium was dialing Google
   (accounts/variations/optimization-guide/component+auto update/safe browsing —
-  seen in dnsmasq logs). Stopped via a managed policy
+  seen in dnsmasq logs). Two layers:
-  (`files/kiosk/chromium-kiosk-policy.json` → `/etc/chromium/policies/managed/`)
+  - **Flags** in `kiosk-session` (`--disable-background-networking`,
-  plus hardening flags in `kiosk-session` (`--disable-background-networking`,
+    `--disable-component-update`, `--disable-features=OptimizationHints,...`) —
-  `--disable-component-update`, `--disable-features=OptimizationHints,...`, etc.).
+    confirmed killing variations/optimization-guide/update queries.
-  Verify with the dnsmasq query log after a rebuild — only `boot.fleet.lab`
+  - **Managed policy** `files/kiosk/chromium-kiosk-policy.json` for the
-  (kiosk page) + chrony NTP should remain. NTP is the OS (chrony), not Chromium;
+    policy-governed bits (sign-in `accounts.google.com`, sync). FIX 2026-06-18:
-  optionally point it at the serving host to fully contain egress.
+    the managed-policy dir differs by build, so it's installed to BOTH
+    `/etc/chromium/policies/managed/` AND `/etc/chromium-browser/policies/managed/`
+    (a policy in the wrong dir is silently ignored — the reason
+    `accounts.google.com`/`android.clients.google.com` persisted). Verify via
+    `chrome://policy` (Status: OK per entry).
+  - **Serving-side sinkhole** (defense-in-depth, `serving/docker-compose.yml`
+    dnsmasq `--address=/google.com|googleapis.com|gstatic.com/0.0.0.0`): the
+    kiosk is local-only, so block egress at the resolver. Stops the *leak*; the
+    query still logs (answered 0.0.0.0, not forwarded) — eliminating the query
+    is the browser policy's job. Production: do this at the boot-LAN firewall.
+  - **NTP egress closed (done 2026-06-18):** the `*.pool.ntp.org` lookups were
+    the OS (chrony), not Chromium. Now: a `chrony` NTP server in the serving
+    stack (`serving/chrony/`), dnsmasq hands it via **DHCP option 42**, and the
+    image's NM dispatcher (`files/etc/NetworkManager/dispatcher.d/10-chrony-dhcp-ntp`)
+    feeds it into chrony's `sourcedir /run/chrony-dhcp`; the baked public pool is
+    stripped from `/etc/chrony.conf`. Result: the workstation syncs time only
+    from the lab server — no external NTP egress. BENCH-VERIFY: on a booted host
+    `chronyc sources` shows the lab server (the DHCP one), not a public pool.
 - **Image size:** Chromium+Mesa add hundreds of MB to the *uncompressed* erofs —
   feeds the "shrink the rootfs" concern (and #7); reconsider whether a lighter
   browser/render path is viable.

files/etc/NetworkManager/dispatcher.d/10-chrony-dhcp-ntp

@@ -0,0 +1,36 @@
+#!/bin/bash
+# NetworkManager dispatcher: feed DHCP option 42 (NTP servers) into chrony.
+#
+# Replaces the old dhclient.d/chrony.sh bridge — we use NetworkManager's internal
+# DHCP now (the network-manager dracut port), and NM exports the lease's NTP
+# servers to dispatcher scripts as $DHCP4_NTP_SERVERS. chrony.conf carries
+# `sourcedir /run/chrony-dhcp`, so writing <iface>.sources there and reloading
+# makes chronyd use the DHCP-provided server. The image's baked public pool is
+# stripped (see the provisioner), so the host syncs ONLY from the lab NTP server
+# — no time egress from the workstation.
+#
+# Installed 0755 root:root at /etc/NetworkManager/dispatcher.d/. Lenient on
+# purpose: a hiccup here must never break networking.
+
+interface="$1"
+action="$2"
+
+case "$action" in
+    up|dhcp4-change|reapply) ;;
+    *) exit 0 ;;
+esac
+
+dir=/run/chrony-dhcp
+file="$dir/${interface}.sources"
+mkdir -p "$dir"
+
+if [ -n "${DHCP4_NTP_SERVERS:-}" ]; then
+    : > "$file"
+    for s in $DHCP4_NTP_SERVERS; do
+        printf 'server %s iburst\n' "$s" >> "$file"
+    done
+    # Pick up the new sources without restarting chronyd.
+    chronyc reload sources >/dev/null 2>&1 || true
+fi
+
+exit 0

files/kiosk/chromium-kiosk-policy.json

@@ -6,6 +6,7 @@
   "DeviceMetricsReportingEnabled": false,
 
   "BrowserSignin": 0,
+  "SigninAllowed": false,
   "SyncDisabled": true,
 
   "SafeBrowsingProtectionLevel": 0,

scripts/preview-plymouth.sh

@@ -0,0 +1,79 @@
+#!/usr/bin/env bash
+# preview-plymouth.sh — fast local preview of the 'fleet' boot splash WITHOUT
+# building/booting the full diskless image. The splash is just plymouthd + the
+# theme + status tokens, so it runs on any Linux box with plymouth installed
+# (root), driven by the same `plymouth update --status=` tokens the dracut hooks
+# emit (dot1x-macsec-up.sh / nvmf-connect.sh).
+#
+#   sudo bash scripts/preview-plymouth.sh [secure|test]
+#
+# Seeing it:
+#   - Windowed: needs the X11 renderer (Debian/Ubuntu: `apt install plymouth-x11`,
+#     run inside an X session). Fedora/RHEL often don't package it.
+#   - No X11 renderer: switch to a spare VT (Ctrl+Alt+F3), run there, watch,
+#     Ctrl+Alt+F1 back — plymouthd grabs DRM on that VT.
+#   - Headless/CI screenshot: Xvfb + x11 renderer + a grab tool.
+#
+# Iterate: edit files/plymouth/themes/fleet/fleet.script, re-run this. Seconds,
+# not a 30-min image build. (On an already-booted diskless host the root overlay
+# is writable, so you can scp the theme to /usr/share/plymouth/themes/fleet and
+# run this there for a real distro/font/plugin stack.)
+set -euo pipefail
+
+[ "$(id -u)" -eq 0 ] || { echo "run as root (plymouthd needs it)" >&2; exit 1; }
+
+mode=${1:-secure}
+theme_src=${THEME_SRC:-files/plymouth/themes/fleet}
+dest=/usr/share/plymouth/themes/fleet
+
+command -v plymouthd >/dev/null 2>&1 || {
+    echo "ERROR: plymouthd not found — install plymouth, plymouth-scripts," >&2
+    echo "       plymouth-plugin-label, and the script plugin first." >&2
+    exit 1
+}
+[ -f "$theme_src/fleet.script" ] || {
+    echo "ERROR: $theme_src/fleet.script not found (run from the repo root, or set THEME_SRC)." >&2
+    exit 1
+}
+
+echo "==> installing theme: $theme_src -> $dest"
+mkdir -p "$dest"
+cp -a "$theme_src"/. "$dest"/
+plymouth-set-default-theme fleet 2>/dev/null || \
+    echo "WARNING: plymouth-set-default-theme failed (plymouth-scripts missing?) — continuing" >&2
+
+if [ ! -e /usr/lib64/plymouth/script.so ] && [ ! -e /usr/lib/plymouth/script.so ]; then
+    echo "WARNING: plymouth script plugin (script.so) not found — the theme will not render." >&2
+fi
+
+echo "==> starting plymouthd (debug log: /tmp/plymouth-preview.log)"
+plymouth quit 2>/dev/null || true
+plymouthd --no-daemon --debug --debug-file=/tmp/plymouth-preview.log &
+ply_pid=$!
+trap 'plymouth quit 2>/dev/null || true; kill "$ply_pid" 2>/dev/null || true' EXIT
+
+sleep 1
+plymouth show-splash
+sleep 1
+
+emit() {
+    echo "   --status=$1"
+    plymouth update --status="$1" || true
+    sleep "${2:-1.2}"
+}
+
+echo "==> driving the '$mode' handshake sequence"
+if [ "$mode" = test ]; then
+    emit mode-test 0.6
+    emit net-active;  emit net-done
+    emit nvme-active; emit nvme-done 1.5
+else
+    emit tpm-active;    emit tpm-done
+    emit dot1x-active 1.6;  emit dot1x-done
+    emit macsec-active; emit macsec-done
+    emit net-active 1.6;    emit net-done
+    emit nvme-active 1.6;   emit nvme-done 2
+fi
+
+echo "==> sequence complete; press Enter to quit the splash"
+read -r _ || true

serving/README.md

@@ -61,6 +61,9 @@ curl -sI http://${SERVER_IP}/fleet-${IMAGE_VERSION}.efi | head -1   # 200 OK
 # HTTP: kiosk test page is served (what the diskless kiosk loads by default)
 curl -sI http://${SERVER_IP}/kiosk/ | head -1                       # 200 OK
 
+# NTP: lab time server answers (diskless hosts get it via DHCP option 42)
+chronyc -h ${SERVER_IP} tracking 2>/dev/null || ntpdate -q ${SERVER_IP}
+
 # NVMe/TCP: target is listening + discoverable
 ss -lntp | grep 4420
 sudo nvme discover -t tcp -a ${SERVER_IP} -s 4420                   # lists the subsystem

serving/chrony/Dockerfile

@@ -0,0 +1,9 @@
+# Minimal chrony NTP server for the lab boot LAN. Diskless workstations get this
+# host as their time source via DHCP option 42 (dnsmasq), so they never reach the
+# public NTP pool (no workstation egress). Config is bind-mounted from
+# chrony.conf in docker-compose.yml. Build our own so the version is pinned.
+FROM alpine:3.20
+RUN apk add --no-cache chrony
+# -d: run in the foreground (don't daemonise) so the container stays up and logs
+# to stdout for `docker compose logs`.
+ENTRYPOINT ["chronyd", "-d", "-f", "/etc/chrony/chrony.conf"]

serving/chrony/chrony.conf

@@ -0,0 +1,20 @@
+# Lab NTP server (serving stack). Syncs from upstream and serves the boot LAN so
+# diskless workstations get time INTERNALLY (handed out as DHCP option 42 by
+# dnsmasq) instead of egressing to the public pool. Only this host reaches the
+# internet for time; the workstations never do.
+
+# Upstream time source (this serving host has internet; the workstations don't).
+pool pool.ntp.org iburst
+
+# Serve the boot LAN. This is an isolated lab/boot network, so allow all; scope
+# to your subnet (e.g. `allow 192.168.50.0/24`) for anything less trusted.
+allow all
+
+# Serve our own clock at a high stratum if upstream is unreachable, so a diskless
+# boot never blocks waiting for time.
+local stratum 10
+
+# Step the clock on large initial offsets (containers can start far off), then
+# slew. driftfile is best-effort (container fs is ephemeral).
+makestep 1.0 3
+driftfile /var/lib/chrony/drift

serving/docker-compose.yml

@@ -63,11 +63,24 @@ services:
       # resolve the per-environment DNS name to this serving host.
       - --address=/${NVME_HOST}/${SERVER_IP}
       - --address=/${BOOT_HOST}/${SERVER_IP}
+      # Kiosk is LOCAL-ONLY (loads boot.fleet.lab), so sinkhole Chromium's
+      # call-home to 0.0.0.0 — telemetry can't leave the lab even if the browser
+      # tries. Defense-in-depth behind the in-image Chromium policy/flags; in
+      # production this belongs in the boot-LAN firewall's egress rules. NOTE: the
+      # client still *emits* the query (you'll see it in this log answered locally,
+      # not "forwarded"); stopping the query itself is the browser policy's job.
+      - --address=/google.com/0.0.0.0
+      - --address=/googleapis.com/0.0.0.0
+      - --address=/gstatic.com/0.0.0.0
       # ---- DHCP ----
       - --dhcp-authoritative
       - --dhcp-range=${DHCP_RANGE_START},${DHCP_RANGE_END},${DHCP_LEASE}
       - --dhcp-option=option:router,${GATEWAY_IP}
       - --dhcp-option=option:dns-server,${SERVER_IP}
+      # NTP server (option 42): point diskless hosts at the lab 'ntp' service
+      # below so they sync time internally and never reach the public NTP pool.
+      # The image's NM dispatcher (10-chrony-dhcp-ntp) feeds this into chrony.
+      - --dhcp-option=option:ntp-server,${SERVER_IP}
       # ---- UEFI HTTP Boot ----
       # Firmware sends vendor-class "HTTPClient"; we must echo it back (opt 60)
       # and hand over the UKI URL (opt 67). IP in the URL avoids a DNS round-trip
@@ -96,6 +109,20 @@ services:
     # For HTTPS boot (production), terminate TLS here with the boot-infra CA's
     # cert and switch the dhcp-boot URL above to https://. Left HTTP for the lab.
 
+  # --- NTP server (serves time to the boot LAN; handed out via DHCP opt 42) ---
+  ntp:
+    build: ./chrony
+    network_mode: host        # serve NTP on udp/123 across the boot LAN
+    cap_add:
+      - SYS_TIME              # discipline the (host-shared) clock it serves
+    restart: unless-stopped
+    volumes:
+      - ./chrony/chrony.conf:/etc/chrony/chrony.conf:ro
+    # NOTE: with host networking + SYS_TIME this chronyd disciplines the Docker
+    # HOST clock (the clock isn't namespaced) — intended: the serving host is the
+    # lab time source. Drop SYS_TIME (and add `chronyd -x`) if the host already
+    # runs its own NTP and you only want this to relay.
+
   # --- NVMe/TCP target (serves rootfs.erofs, read-only) ----------------------
   nvmeof:
     # Prebuilt by CI (.gitea/workflows/spdk-image.yaml) and pulled here — no