From 2a90c9b8dd765da08eff9bba910bb87b1c224247 Mon Sep 17 00:00:00 2001
From: dv <dv@caps.caps>
Date: Fri, 10 Apr 2026 15:10:42 +0300
Subject: [PATCH] =?UTF-8?q?=D1=84=D0=B8=D0=BA=D1=81=20=D0=BA=D0=BE=D0=BB?=
 =?UTF-8?q?=D0=B8=D1=87=D0=B5=D1=81=D1=82=D0=B2=D0=B0=20ssh?=
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---
 backend/app/services/device_discovery.py | 70 ++++++++++++------------
 1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/backend/app/services/device_discovery.py b/backend/app/services/device_discovery.py
index b33db66..f4de001 100644
--- a/backend/app/services/device_discovery.py
+++ b/backend/app/services/device_discovery.py
@@ -527,24 +527,29 @@ async def _discover_mikrotik_multi(host: str, port: int, options: list) -> str |
     return None
 
 
-async def _check_if_slave_multi(
-    host: str, port: int, options: list, master_ip: str, config_path: str
-) -> tuple[bool, str, str]:
-    """Multi-auth version of _check_if_slave."""
+async def _fetch_slave_config(
+    host: str, port: int, options: list, config_path: str
+) -> str | None:
+    """Read config from a slave candidate via SSH (one connection). Returns None on failure."""
     try:
-        config_text = await _ssh_run_multi(host, port, options, f"cat {config_path}", timeout=15)
-        parser = RawConfigParser(strict=False)
-        parser.read_string(config_text)
-        linking_cls = parser.get("plugin:linking", "cls", fallback="")
-        linking_uri = parser.get("plugin:linking", "uri", fallback="")
-        identifier = parser.get("caps.rack", "identifier", fallback="").strip()
-        if "secondary" in linking_cls.lower() and master_ip in linking_uri:
-            return True, identifier or host, config_text
+        return await _ssh_run_multi(host, port, options, f"cat {config_path}", timeout=15)
     except Exception:
-        pass
+        return None
+
+
+def _parse_slave_config(config_text: str, master_ip: str, host: str) -> tuple[bool, str, str]:
+    """Check parsed config against one master_ip. No network I/O."""
+    parser = RawConfigParser(strict=False)
+    parser.read_string(config_text)
+    linking_cls = parser.get("plugin:linking", "cls", fallback="")
+    linking_uri = parser.get("plugin:linking", "uri", fallback="")
+    identifier  = parser.get("caps.rack", "identifier", fallback="").strip()
+    if "secondary" in linking_cls.lower() and master_ip in linking_uri:
+        return True, identifier or host, config_text
     return False, "", ""
 
 
+
 async def _open_tunnel(tunnel_host: str, tunnel_port: int, ssh_options: list, target_host: str, target_port: int):
     """Try each ssh_option in order; return open asyncssh connection on first success or raise."""
     last_exc: Exception = Exception("No SSH options provided")
@@ -1194,30 +1199,27 @@ async def discover_via_ssh(
     for candidate_ip in slave_candidates:
         logger.info(f"[ssh_discovery] Checking slave candidate {candidate_ip}...")
         await _emit("disc_action", {"message": f"Проверяем слейв-кандидата {candidate_ip}..."})
-        # Check each rack host that could be the master — slave's linking.uri must match
+
+        # Fetch config once — then check against all masters without extra SSH connections
+        slave_config_text = await _fetch_slave_config(candidate_ip, ssh_port, ssh_options, config_path)
         is_slave = False
         slave_identifier = ""
-        slave_config_text = ""
         master_ip_for_slave = ""
-        for _, master_host, _, _ in rack_hosts:
-            ok, identifier, slave_cfg = await _check_if_slave_multi(
-                host=candidate_ip,
-                port=ssh_port,
-                options=ssh_options,
-                master_ip=master_host,
-                config_path=config_path,
-            )
-            if ok:
-                is_slave = True
-                slave_config_text = slave_cfg
-                master_ip_for_slave = master_host
-                # Derive slave name from master's external_id: "lane-1-1" → "lane-1-1-slave"
-                master_ext_id = next(
-                    (ext_id for ext_id, host, _, _ in rack_hosts if host == master_host),
-                    master_host,
-                )
-                slave_identifier = f"{master_ext_id}-slave"
-                break
+
+        if slave_config_text is None:
+            logger.info(f"[ssh_discovery] {candidate_ip} — could not read config, skipping")
+        else:
+            for _, master_host, _, _ in rack_hosts:
+                ok, identifier, _ = _parse_slave_config(slave_config_text, master_host, candidate_ip)
+                if ok:
+                    is_slave = True
+                    master_ip_for_slave = master_host
+                    master_ext_id = next(
+                        (ext_id for ext_id, host, _, _ in rack_hosts if host == master_host),
+                        master_host,
+                    )
+                    slave_identifier = f"{master_ext_id}-slave"
+                    break
 
         if not is_slave:
             logger.info(f"[ssh_discovery] {candidate_ip} — not a slave rack (no secondary linking pointing to known master)")