Add LLDP collect page with conservative fabric edge lifecycle.

Move scheduled discovery under Network → LLDP links, mark absent edges missing after one successful scan, purge only after four miss cycles, and expose unmatched/raw job detail.

Co-authored-by: Cursor <cursoragent@cursor.com>

netx_api/lldp_collect_scheduler.py

@@ -0,0 +1,96 @@
+"""Background scheduler for periodic fabric LLDP collect."""
+
+from __future__ import annotations
+
+import logging
+import threading
+import time
+from datetime import datetime
+
+from .config import settings
+from .db import SessionLocal
+from .lldp_collect_service import (
+    ensure_policy,
+    has_running_job,
+    next_due_at,
+    start_collect,
+)
+
+_log = logging.getLogger("netx.lldp_collect.scheduler")
+_stop = threading.Event()
+_thread: threading.Thread | None = None
+_BOOT_MONO = time.monotonic()
+
+
+def _utcnow() -> datetime:
+    return datetime.utcnow()
+
+
+def startup_grace_remaining_sec() -> float:
+    grace = max(0, int(getattr(settings, "lldp_collect_startup_grace_sec", 3600) or 0))
+    elapsed = time.monotonic() - _BOOT_MONO
+    return max(0.0, float(grace) - elapsed)
+
+
+def in_startup_grace() -> bool:
+    return startup_grace_remaining_sec() > 0
+
+
+def try_start_scheduled_collect() -> str | None:
+    if not bool(getattr(settings, "lldp_collect_scheduler_enabled", True)):
+        return None
+    if in_startup_grace():
+        return None
+    db = SessionLocal()
+    try:
+        policy = ensure_policy(db)
+        if not policy.enabled:
+            return None
+        if has_running_job(db) is not None:
+            return None
+        due = next_due_at(db, policy)
+        if due is not None and due > _utcnow():
+            return None
+        out = start_collect(db, trigger_mode="schedule")
+        job_id = str((out.get("job") or {}).get("id") or "")
+        _log.info("lldp_collect scheduled job started id=%s", job_id)
+        return job_id or None
+    except Exception as exc:  # noqa: BLE001
+        db.rollback()
+        detail = getattr(exc, "detail", None)
+        if detail in {"no_selected_targets", "lldp_collect_already_running"}:
+            _log.info("lldp_collect schedule skip: %s", detail)
+            return None
+        _log.exception("lldp_collect schedule start failed")
+        return None
+    finally:
+        db.close()
+
+
+def _loop() -> None:
+    tick = max(15, int(getattr(settings, "lldp_collect_scheduler_tick_sec", 60) or 60))
+    grace = max(0, int(getattr(settings, "lldp_collect_startup_grace_sec", 3600) or 0))
+    _log.info("lldp_collect scheduler started tick=%ss startup_grace=%ss", tick, grace)
+    while not _stop.is_set():
+        try:
+            try_start_scheduled_collect()
+        except Exception:
+            _log.exception("lldp_collect scheduler tick failed")
+        _stop.wait(tick)
+    _log.info("lldp_collect scheduler stopped")
+
+
+def start_lldp_collect_scheduler() -> None:
+    global _thread
+    if not bool(getattr(settings, "lldp_collect_scheduler_enabled", True)):
+        _log.info("lldp_collect scheduler disabled by settings")
+        return
+    if _thread is not None and _thread.is_alive():
+        return
+    _stop.clear()
+    _thread = threading.Thread(target=_loop, name="lldp-collect-scheduler", daemon=True)
+    _thread.start()
+
+
+def stop_lldp_collect_scheduler() -> None:
+    _stop.set()