Release 1.2.4: export lease table for sibling tools; auto-select single NIC

- Write a lease-table snapshot to %PROGRAMDATA%\vegman\leases.json (contract consumed by vrcx for BMC/SDS discovery)
- Auto-select the network adapter when only one is found (configurable via auto_select_single; asked on first run)

src/dhcpsrv/__init__.py

@@ -5,5 +5,5 @@ The single source of truth for the project version. Bump this before tagging
 a release; CI reads the tag, the code reads this constant.
 """
 
-__version__ = "1.2.3"
+__version__ = "1.2.4"
 REPO = "engel/dhcpsrv"  # self-hosted Gitea (git.engelgardt23.ru)

src/dhcpsrv/app.py

@@ -21,7 +21,7 @@ from .config        import load_config
 from .i18n          import set_language, t
 
 
-def _select_nic(console: Console) -> dict | None:
+def _select_nic(console: Console, auto_single: bool = True) -> dict | None:
     console.rule(f"[bold cyan]{t('available_adapters')}")
     adapters = list_adapters()
     if not adapters:
@@ -30,6 +30,10 @@ def _select_nic(console: Console) -> dict | None:
     for i, a in enumerate(adapters, 1):
         ip = a.get("IPv4") or "—"
         console.print(f"  {i}) [{a['Status']}] {a['Name']}  ({a['Description']})  {ip}")
+    if auto_single and len(adapters) == 1:
+        only = adapters[0]
+        console.print(f"[green]{t('only_adapter', name=only['Name'])}[/]")
+        return only
     while True:
         s = Prompt.ask(t("select_adapter")).strip()
         if s.isdigit() and 1 <= int(s) <= len(adapters):
@@ -64,7 +68,7 @@ def main() -> None:
         console.print(title)
     console.print()
 
-    nic = _select_nic(console)
+    nic = _select_nic(console, cfg_data.get("auto_select_single", True))
     if not nic:
         input(t("press_enter")); return
 

src/dhcpsrv/config.py

@@ -20,16 +20,25 @@ CONFIG_HEADER = """\
 # ---------------------------------------------------------------------------
 # dhcpsrv configuration
 #
-# To change the interface language, edit the 'language' value below.
-# Valid values: en, ru
+# language            : interface language. Valid: en, ru
+# auto_select_single  : auto-pick the network adapter when only one is found,
+#                       without asking (yes/no).
 #
-# Чтобы сменить язык интерфейса, измените значение 'language' ниже.
-# Допустимые значения: en, ru
+# language            : язык интерфейса. Допустимо: en, ru
+# auto_select_single  : автоматически выбирать сетевой адаптер, если он
+#                       единственный, не спрашивая (yes/no).
 # ---------------------------------------------------------------------------
 
 """
 
 
+def _to_bool(s: str, default: bool) -> bool:
+    s = (s or "").strip().lower()
+    if s in ("yes", "true", "y", "1", "on"):  return True
+    if s in ("no",  "false", "n", "0", "off"): return False
+    return default
+
+
 def app_dir() -> Path:
     """Directory holding the running executable (or source folder when run via python)."""
     if getattr(sys, "frozen", False):
@@ -60,10 +69,26 @@ def _ask_language() -> str:
         print("Please enter 1 or 2 / Введите 1 или 2")
 
 
-def _write_config(lang: str) -> None:
+def _ask_auto_select() -> bool:
+    """First-run prompt — auto-select a lone adapter? Bilingual stdin."""
+    print()
+    print("Auto-select the network adapter when only one is found? (y/n)")
+    print("Автовыбор сетевого адаптера, если он единственный? (y/n)")
+    while True:
+        try:
+            c = input("> ").strip().lower()
+        except (EOFError, KeyboardInterrupt):
+            return True
+        if c in ("y", "yes", "д", "да", "1"):  return True
+        if c in ("n", "no",  "н", "нет", "0"): return False
+        print("y / n")
+
+
+def _write_config(lang: str, auto_select: bool) -> None:
     path = config_path()
     cp = configparser.ConfigParser()
-    cp["General"] = {"language": lang}
+    cp["General"] = {"language": lang,
+                     "auto_select_single": "yes" if auto_select else "no"}
     with path.open("w", encoding="utf-8") as f:
         f.write(CONFIG_HEADER)
         cp.write(f)
@@ -75,20 +100,22 @@ def load_config() -> dict:
     path = config_path()
     if not path.exists():
         lang = _ask_language()
+        auto = _ask_auto_select()
         try:
-            _write_config(lang)
+            _write_config(lang, auto)
         except OSError:
             # read-only location — fall back to in-memory default
             pass
-        return {"language": lang}
+        return {"language": lang, "auto_select_single": auto}
 
     cp = configparser.ConfigParser()
     try:
         cp.read(path, encoding="utf-8")
     except (configparser.Error, OSError):
-        return {"language": DEFAULT_LANG}
+        return {"language": DEFAULT_LANG, "auto_select_single": True}
 
     lang = (cp.get("General", "language", fallback=DEFAULT_LANG) or DEFAULT_LANG).strip().lower()
     if lang not in SUPPORTED_LANGS:
         lang = DEFAULT_LANG
-    return {"language": lang}
+    auto = _to_bool(cp.get("General", "auto_select_single", fallback="yes"), True)
+    return {"language": lang, "auto_select_single": auto}

src/dhcpsrv/dhcp.py

@@ -16,6 +16,7 @@ from typing      import Callable, Optional
 
 from .network import ping_one
 from .i18n    import t as _t
+from .leases  import write_leases
 
 
 # ---------- helpers ----------
@@ -147,6 +148,23 @@ class DhcpServer:
         o += bytes([255])
         return bytes(pkt) + bytes(o)
 
+    # --- lease-table export (contract for sibling tools, e.g. vrcx) ---
+    def export_leases(self) -> None:
+        """Snapshot the lease table to the shared JSON file. Best-effort."""
+        with self.lock:
+            leases = [
+                {
+                    "ip":      int2ip(c["ip_int"]),
+                    "mac":     mac,
+                    "host":    c.get("host", ""),
+                    "ping_ok": bool(c.get("ping_ok")),
+                    "last":    c.get("last", ""),
+                }
+                for mac, c in self.clients.items()
+                if c.get("ip_int")
+            ]
+        write_leases(self.cfg.server_ip, leases, now_s())
+
     # --- ping loop, runs in its own thread ---
     def ping_loop(self, stop: threading.Event) -> None:
         from concurrent.futures import ThreadPoolExecutor
@@ -166,6 +184,8 @@ class DhcpServer:
                         changed = True
             if changed:
                 self.on_change()
+            # Refresh the export every tick so its mtime reflects liveness.
+            self.export_leases()
 
     # --- main server loop ---
     def run(self, stop: threading.Event) -> None:

src/dhcpsrv/i18n.py

@@ -23,6 +23,7 @@ STRINGS: dict[str, dict[str, str]] = {
         "update_available":     "Update available ({tag})",
         "available_adapters":   "Available adapters",
         "no_adapters":          "No suitable wired adapters found.",
+        "only_adapter":         "Only one adapter, auto-selected: {name}",
         "select_adapter":       "Select adapter number",
         "invalid_selection":    "Invalid selection.",
         "press_enter":          "Press Enter to exit",
@@ -60,6 +61,7 @@ STRINGS: dict[str, dict[str, str]] = {
         "update_available":     "Доступно обновление ({tag})",
         "available_adapters":   "Доступные адаптеры",
         "no_adapters":          "Подходящие проводные адаптеры не найдены.",
+        "only_adapter":         "Адаптер один, выбран автоматически: {name}",
         "select_adapter":       "Введите номер адаптера",
         "invalid_selection":    "Неверный выбор.",
         "press_enter":          "Нажмите Enter для выхода",

src/dhcpsrv/leases.py

@@ -0,0 +1,51 @@
+"""
+Lease-table export — the shared contract with sibling tools (e.g. vrcx).
+
+dhcpsrv owns the DHCP state; other tools must NOT reach into it. Instead we
+periodically dump a small, self-describing JSON snapshot to a fixed,
+tool-neutral location. Consumers read that file (and judge its freshness by
+the file mtime). No shared code, no network call between the tools.
+
+Default location: %PROGRAMDATA%\\vegman\\leases.json  (override via the
+VEGMAN_LEASES env var). The directory is created on first write.
+"""
+
+from __future__ import annotations
+import json
+import os
+import tempfile
+from pathlib import Path
+
+SCHEMA = 1
+
+
+def leases_path() -> Path:
+    override = os.environ.get("VEGMAN_LEASES")
+    if override:
+        return Path(override)
+    base = os.environ.get("PROGRAMDATA") or os.environ.get("LOCALAPPDATA") or "."
+    return Path(base) / "vegman" / "leases.json"
+
+
+def write_leases(server_ip: str, leases: list[dict], updated: str) -> None:
+    """Atomically write the snapshot. Best-effort: swallow I/O errors so a
+    read-only/locked target can never disturb the DHCP service."""
+    path = leases_path()
+    payload = {
+        "schema":    SCHEMA,
+        "server_ip": server_ip,
+        "updated":   updated,
+        "leases":    leases,
+    }
+    try:
+        path.parent.mkdir(parents=True, exist_ok=True)
+        fd, tmp = tempfile.mkstemp(dir=str(path.parent), prefix=".leases-", suffix=".tmp")
+        try:
+            with os.fdopen(fd, "w", encoding="utf-8") as f:
+                json.dump(payload, f, ensure_ascii=False)
+            os.replace(tmp, path)
+        finally:
+            if os.path.exists(tmp):
+                os.remove(tmp)
+    except OSError:
+        pass