van-leds: drive the R5C power/LAN/WAN/WiFi LEDs (ENABLE_LEDS, LED_* vars, post-check probe)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KqhjP7nud5gdBg25zCiRk9

leds/config.json

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+{"led_power": "@LED_POWER@", "led_lan": "@LED_LAN@", "led_wan": "@LED_WAN@", "led_wlan": "@LED_WLAN@", "lan_iface": "@LAN_IFACE@", "wlan_iface": "@WIFI_5G_IFACE@", "uplink_iface": "@STARLINK_IFACE@", "poll_interval_s": 5}

leds/van-leds

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+#!/usr/bin/env python3
+"""van-leds — drive the NanoPi R5C's four front LEDs (power / LAN / WAN / WiFi).
+
+  power  default-on
+  LAN    netdev on the LAN port (link + tx + rx)
+  WiFi   netdev on the 5GHz AP radio (link + tx + rx)
+  WAN    follows van-failover (/run/van-failover/state.json), re-evaluated each poll:
+           active WAN healthy            -> netdev on that device
+           active WAN unhealthy, or no failover info / no active WAN but the wired
+           uplink has carrier            -> heartbeat (link, no healthy internet)
+           nothing                       -> trigger none, off
+         Missing/invalid state file: fall back to the wired uplink (netdev if carrier).
+
+An LED whose name is empty in the config, or absent under sysfs, is skipped (logged
+once at start). Settings are re-asserted every poll but only written when they differ
+from what sysfs reads back. SIGTERM/SIGINT exit cleanly and leave the LEDs as they are.
+Stdlib only; config is /etc/van-leds/config.json (argv[1] overrides). Test-only config
+keys: "sysfs_leds", "sysfs_net", "failover_state".
+"""
+
+import json
+import os
+import signal
+import sys
+import threading
+
+DEFAULTS = {
+    "led_power": "", "led_lan": "", "led_wan": "", "led_wlan": "",
+    "lan_iface": "", "wlan_iface": "", "uplink_iface": "",
+    "poll_interval_s": 5,
+    "sysfs_leds": "/sys/class/leds",
+    "sysfs_net": "/sys/class/net",
+    "failover_state": "/run/van-failover/state.json",
+}
+LED_KEYS = (("power", "led_power"), ("lan", "led_lan"), ("wan", "led_wan"), ("wlan", "led_wlan"))
+
+stop = threading.Event()
+
+
+def log(msg):
+    print(msg, flush=True)
+
+
+def load_config(path):
+    cfg = dict(DEFAULTS)
+    with open(path) as f:
+        cfg.update(json.load(f))
+    return cfg
+
+
+def read_attr(path):
+    """Stripped file content; for a sysfs trigger list ("none [netdev] ...") the bracketed item."""
+    try:
+        with open(path) as f:
+            s = f.read().strip()
+    except OSError:
+        return None
+    if "[" in s and "]" in s:
+        s = s[s.index("[") + 1:s.index("]")]
+    return s
+
+
+def write_attr(path, value):
+    with open(path, "w") as f:
+        f.write(str(value))
+
+
+def desired_wan(state, uplink_carrier, uplink=None):
+    """-> ("netdev", device) | ("heartbeat", None) | ("none", None)."""
+    valid = isinstance(state, dict) and isinstance(state.get("wans"), list) and "active_device" in state
+    if not valid:  # no failover info: judge by the wired uplink alone
+        if not uplink_carrier:
+            return ("none", None)
+        return ("netdev", uplink) if uplink else ("heartbeat", None)
+    active = state.get("active_device")
+    if active:
+        for w in state["wans"]:
+            if isinstance(w, dict) and w.get("device") == active and w.get("healthy") is True:
+                return ("netdev", active)
+        return ("heartbeat", None)
+    return ("heartbeat", None) if uplink_carrier else ("none", None)
+
+
+def apply_led(led_dir, trigger, device=None):
+    """Make the LED match; write only what differs. Returns the list of files written."""
+    writes = []
+
+    def want(name, value):
+        p = os.path.join(led_dir, name)
+        if read_attr(p) != str(value):
+            write_attr(p, value)
+            writes.append(p)
+
+    want("trigger", trigger)
+    if trigger == "netdev":
+        want("device_name", device)
+        for a in ("link", "tx", "rx"):
+            want(a, 1)
+    elif trigger == "none":
+        want("brightness", 0)
+    return writes
+
+
+def load_state(path):
+    try:
+        with open(path) as f:
+            return json.load(f)
+    except (OSError, ValueError):
+        return None
+
+
+def carrier(cfg, iface):
+    return bool(iface) and read_attr(os.path.join(cfg["sysfs_net"], iface, "carrier")) == "1"
+
+
+def wanted(cfg):
+    """{role: (trigger, device)} for every role (before skipping absent LEDs)."""
+    wan = desired_wan(load_state(cfg["failover_state"]), carrier(cfg, cfg["uplink_iface"]), cfg["uplink_iface"] or None)
+    return {
+        "power": ("default-on", None),
+        "lan": ("netdev", cfg["lan_iface"]),
+        "wlan": ("netdev", cfg["wlan_iface"]),
+        "wan": wan,
+    }
+
+
+def usable_leds(cfg, announce=False):
+    """{role: led_dir} for the configured LEDs present in sysfs; optionally logs the skipped ones."""
+    out = {}
+    for role, key in LED_KEYS:
+        name = cfg[key]
+        if not name:
+            if announce:
+                log(f"LED {role}: no name configured, skipped")
+            continue
+        d = os.path.join(cfg["sysfs_leds"], name)
+        if not os.path.isdir(d):
+            if announce:
+                log(f"LED {role}: {name} not present under {cfg['sysfs_leds']}, skipped")
+            continue
+        out[role] = d
+    return out
+
+
+def poll_once(cfg):
+    """One evaluation of every usable LED. Returns the files written."""
+    want = wanted(cfg)
+    writes = []
+    for role, d in usable_leds(cfg).items():
+        trig, dev = want[role]
+        try:
+            w = apply_led(d, trig, dev)
+        except OSError as e:
+            log(f"LED {role}: cannot set {trig}: {e}")
+            continue
+        if w:
+            log(f"LED {role}: {trig}" + (f" {dev}" if dev else ""))
+        writes += w
+    return writes
+
+
+def main(argv):
+    path = argv[1] if len(argv) > 1 else "/etc/van-leds/config.json"
+    cfg = load_config(path)
+    signal.signal(signal.SIGTERM, lambda *_: stop.set())
+    signal.signal(signal.SIGINT, lambda *_: stop.set())
+    usable_leds(cfg, announce=True)
+    log(f"van-leds started ({path})")
+    while not stop.is_set():
+        try:
+            poll_once(cfg)
+        except Exception as e:  # never die on a transient sysfs/state oddity
+            log(f"poll failed: {e}")
+        stop.wait(float(cfg["poll_interval_s"]))
+    log("van-leds stopping, LEDs left as they are")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv))

leds/van-leds.service

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+[Unit]
+Description=NanoPi R5C front-panel LEDs (power / LAN / WAN / WiFi)
+After=van-failover.service
+# Restart limit: max 5 restarts per 5 minutes, then stay failed (as the other van services)
+StartLimitIntervalSec=300
+StartLimitBurst=5
+
+[Service]
+Type=simple
+ExecStartPre=-/sbin/modprobe ledtrig-netdev
+ExecStart=/usr/local/sbin/van-leds
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target