The backend's bridge network can't see the host's NICs, so HOST_IP from
install.sh went stale silently after a DHCP change. Now:
- services/netinfo_helper.py runs as a new `netinfo` service (same backend
image, network_mode: host): every 60s it picks the PHYSICAL LAN address
(main-table default-route NIC if real hardware, else first real NIC with
IPv4; never WireGuard/Tailscale/ZeroTier/bridges/veths, ignores 169.254)
and writes it to the shared `netinfo` volume. Stdlib only. On Docker
Desktop (linuxkit/WSL2 kernel) it reports "unsupported" instead of the
VM's meaningless address.
- services/lan_ip.py: one resolver used by /api/system/status (lan_ip +
lan_ip_info), the pairing QR and the cloud heartbeat's local_ip:
override (pos_settings network.lan_ip_override) → live detection (ignored
when older than 5 min) → HOST_IP. Flags `mismatch` when a pinned address
is no longer on any of the machine's NICs.
- PUT /api/system/lan-ip-override (manager): set a private IPv4 or null to
return to automatic; public/loopback/link-local/IPv6 rejected (422).
- cloud_sync._get_local_ip uses the resolver (no more socket trick that
returned the container IP).
Tested: helper selection on a fake sysfs/route table (8 cases incl. VPN
default routes) + real ioctl/route parsing on a Linux kernel; resolver
priority/staleness/mismatch/validation (18 cases); isolated full stack:
HOST_IP fallback on Docker Desktop, override save/validate/auth, simulated
Linux detection incl. DHCP change and dead helper, heartbeat IP.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
