feat(MikrotikConnection): add MikroTik connection testing functionality in ServerModal; update API routes and README for new encryption key and connection endpoint

backend/routes/mikrotikConfigRoutes.js

@@ -13,6 +13,7 @@ const {
   buildMikrotikConfig,
 } = require('../utils/mikrotikInterfaceGenerator');
 const { readS3TextObject } = require('../services/s3Service');
+const { RouterOSAPI } = require('node-routeros');
 
 async function fetchJsonFromS3(key, defaultValue = null) {
   try {
@@ -162,8 +163,73 @@ async function generateRecursiveRoutes(req, res) {
   }
 }
 
+/**
+ * POST /api/mikrotik/test-connection
+ * Body: { serverId?: string, host?, port?, user?, password? }
+ * Если host/port/user/password переданы — тестирует с ними (без сохранения).
+ * Иначе берёт credentials из сервера по serverId.
+ */
+async function testMikrotikConnection(req, res) {
+  try {
+    const { serverId, host: bodyHost, port: bodyPort, user: bodyUser, password: bodyPassword } = req.body || {};
+
+    let host, port, user, password;
+
+    if (bodyHost && bodyPassword) {
+      host = bodyHost;
+      port = parseInt(bodyPort || '8728', 10) || 8728;
+      user = bodyUser || 'admin';
+      password = bodyPassword;
+    } else if (serverId) {
+      const servers = await fetchJsonFromS3('servers.json', []);
+      const server = servers.find(s => s.id === serverId || s.dns === serverId || s.ip === serverId);
+      if (!server) {
+        return sendError(res, 404, 'Server not found', 'E_NOT_FOUND');
+      }
+      if (server.type !== 'jumphost') {
+        return sendError(res, 400, 'Only jumphost servers have MikroTik credentials', 'E_BAD_REQUEST');
+      }
+      if (!server.encryptedMikrotikPassword) {
+        return sendError(res, 400, 'MikroTik password not configured for this server', 'E_BAD_REQUEST');
+      }
+      try {
+        password = decrypt(server.encryptedMikrotikPassword);
+      } catch (decErr) {
+        return sendError(res, 500, 'Failed to decrypt MikroTik password', 'E_DECRYPT');
+      }
+      host = server.mikrotikHost || server.ip || server.dns;
+      port = parseInt(server.mikrotikPort || '8728', 10) || 8728;
+      user = server.mikrotikUser || 'admin';
+    } else {
+      return sendError(res, 400, 'Provide serverId or (host + password)', 'E_BAD_REQUEST');
+    }
+
+    const conn = new RouterOSAPI({
+      host: String(host),
+      user: String(user),
+      password: String(password),
+      port: Number(port) || 8728,
+    });
+
+    await conn.connect();
+    await conn.write('/system/resource/print', []);
+    conn.close();
+
+    res.json({ ok: true, message: 'Соединение успешно' });
+  } catch (error) {
+    const msg = error.message || String(error);
+    res.status(400).json({
+      ok: false,
+      message: msg.includes('ECONNREFUSED') ? 'Соединение отклонено. Проверьте хост и порт.' :
+        msg.includes('Authentication') || msg.includes('login') ? 'Неверный логин или пароль' :
+          msg,
+    });
+  }
+}
+
 module.exports = {
   generateMikrotikConfig,
   generateInterfaces,
   generateRecursiveRoutes,
+  testMikrotikConnection,
 };