watchcat: interface resolution races netifd at boot, leaving the daemon permanently misconfigured

Package Name

watchcat

Maintainer

@danielfdickinson, @dhrm1k

OpenWrt Version

OpenWrt 25.12.5 r33051-f5dae5ece4

OpenWrt Target/Subtarget

mediatek/filogic

Steps to Reproduce

1. Configure a restart_iface instance with interface='@wan' (DHCP WAN on eth0).
2. Reboot the device.
3. Check the log: logread | grep watchcat

Actual Behaviour

Device: OpenWrt One. Package version: watchcat-1-r25.

Observed:

daemon.warn watchcat[4026]: Could not resolve interface "@wan" for pinging.
daemon.warn watchcat[4026]: Could not resolve interface "@wan" for restart.

Restarting the service by hand once the system is up resolves cleanly and produces no warning. ubus call network.interface.wan status reports "l3_device": "eth0" at that point.

watchcat_resolve_ping_iface and watchcat_resolve_restart_iface are called once, at daemon startup. START=97 runs after /etc/init.d/network, but that script returns as soon as netifd is launched — not when interfaces are attached. With a DHCP WAN the lease arrives later, so network_get_device fails and the daemon keeps the failed result for its whole lifetime. restart_iface stays empty, so the watchdog can detect an outage but can no longer repair it.

With the historical interface='wan' form the same race is silent and far worse: the caller falls back to ping_iface="$iface", every ping runs as ping -I wan, busybox rejects it, and the daemon restarts the WAN every 15 minutes indefinitely. This ran for 8 days on our device — 735 interface restarts, each reloading both radios — before we traced it. No warning is logged in that path.

service_triggers() only declares procd_add_reload_trigger "watchcat", which fires on UCI config changes, never on network events. An interface trigger would make the daemon re-resolve when the monitored network comes up.

Confirmation Checklist

• The package is maintained in this repository.
• I understand that issues related to the base OpenWrt repository or LuCI repository will be closed.
• I am reporting an issue for OpenWrt, not an unsupported fork.

Start with watchcat_resolve_ping_iface, watchcat_resolve_restart_iface, and service_triggers(), then inspect how START=97 and network_get_device behave during DHCP startup. Ensure resolution is retried when the monitored network becomes available and that failed resolution does not leave an invalid fallback. Verify by rebooting with restart_iface set to @wan and checking logread plus subsequent ping and restart behavior.