code update recorded at: 08/01/25 09:02:19

handler.js

@@ -0,0 +1,205 @@
+import { MongoClient } from 'mongodb';
+import { createTunnel } from 'tunnel-ssh';
+
+// Maximum allowed connections in the connection pool
+const MAX_CONNECTIONS = parseInt(process.env.MAX_CONNECTIONS || '10');
+// Connection pool to manage database connections
+const connectionPool = new Map();
+// Timeout for MongoDB connections, configurable via environment variables
+const CONNECTION_TIMEOUT = parseInt(process.env.CONNECTION_TIMEOUT || '10000');
+
+/**
+ * Validates the request body for required fields and structure.
+ * Ensures all necessary fields for MongoDB and SSH configurations are provided.
+ * @param {Object} body - Request body containing query and secretData.
+ * @throws {Error} If validation fails.
+ */
+const validateRequestBody = ({ query, secretData }) => {
+  const errors = [];
+
+  // Ensure the query string is provided
+  if (!query) {
+    errors.push('Query is required.');
+  }
+
+  // Validate database configuration
+  const { db_config, ssh_config, use_ssh } = secretData || {};
+  if (!db_config) {
+    errors.push('secretData.db_config is required.');
+  }
+
+  const { hosts, auth_db, database, username, password } = db_config || {};
+  if (!hosts || hosts.length === 0) errors.push('db_config.hosts is required.');
+  if (!auth_db) errors.push('db_config.auth_db is required.');
+  if (!database) errors.push('db_config.database is required.');
+  if (!username) errors.push('db_config.username is required.');
+  if (!password) errors.push('db_config.password is required.');
+
+  // Validate SSH configuration if required
+  if (use_ssh) {
+    if (!ssh_config) {
+      errors.push('secretData.ssh_config is required when use_ssh is true.');
+    } else {
+      const { host, port, username, private_key_file, auth_method } = ssh_config || {};
+      if (!host) errors.push('ssh_config.host is required.');
+      if (!port) errors.push('ssh_config.port is required.');
+      if (!username) errors.push('ssh_config.username is required.');
+      if (auth_method === 'private_key' && !private_key_file) {
+        errors.push('ssh_config.private_key_file is required for private_key auth.');
+      }
+    }
+  }
+
+  // Throw error if any validation fails
+  if (errors.length) {
+    throw new Error(`Validation errors: ${errors.join(' ')}`);
+  }
+};
+
+/**
+ * Creates a MongoDB connection with a timeout for connection attempts.
+ * Handles connection strings for both direct and SRV-based connections.
+ * @param {Object} config - Configuration for MongoDB.
+ * @param {number} [localPort=null] - Local port for SSH tunneling.
+ * @returns {Promise<Object>} The MongoDB database instance.
+ */
+const createMongoConnection = async (config, localPort = null) => {
+  const { use_ssh } = config.secretData;
+  const { username, password, auth_db, database, hosts, read_preference, is_srv } = config.secretData.db_config;
+
+  const host = use_ssh ? '127.0.0.1' : hosts[0]?.host;
+  const port = use_ssh ? localPort : hosts[0]?.port || 27017;
+  const connectionString = is_srv
+    ? `mongodb+srv://${username}:${encodeURIComponent(password)}@${host}/${auth_db}?directConnection=true&readPreference=${read_preference}`
+    : `mongodb://${username}:${encodeURIComponent(password)}@${host}:${port}/${auth_db}?directConnection=true&readPreference=${read_preference}`;
+
+  console.log(`Connecting to MongoDB URI: ${connectionString.replace(username, "<REDACTED>").replace(encodeURIComponent(password), "<REDACTED>")}`);
+
+  // MongoDB client instance
+  const client = new MongoClient(connectionString, { serverSelectionTimeoutMS: CONNECTION_TIMEOUT });
+
+  try {
+    // Attempt to connect to MongoDB within the defined timeout
+    await client.connect();
+    console.log('MongoDB connection successful.');
+    return client.db(database);
+  } catch (error) {
+    console.error(`MongoDB connection failed: ${error.message}`);
+    throw error;
+  }
+};
+
+/**
+ * Establishes an SSH tunnel for secure database connections.
+ * Provides port forwarding from a local port to the remote database server.
+ * @param {Object} sshConfig - SSH configuration.
+ * @param {string} dbHost - Database host.
+ * @param {number} dbPort - Database port.
+ * @returns {Promise<Object>} The SSH tunnel and local port.
+ */
+const createSSHTunnel = async (sshConfig, dbHost, dbPort) => {
+  try {
+    const { host, port, username, private_key_file, auth_method } = sshConfig;
+    const tunnelOptions = { autoClose: true };
+    const forwardOptions = { dstAddr: dbHost, dstPort: dbPort };
+    const sshOptions = {
+      host,
+      port,
+      username,
+      privateKey: auth_method === 'private_key' ? Buffer.from(private_key_file, 'utf-8') : undefined,
+    };
+
+    const [server, conn] = await createTunnel(tunnelOptions, null, sshOptions, forwardOptions);
+    const localPort = server.address().port;
+    console.log(`SSH tunnel established. Local port: ${localPort}`);
+
+    // Attach error listeners to the SSH server and connection
+    server.on('error', (err) => {
+      throw new Error(`SSH Tunnel Server Error: ${err.message}`);
+    });
+    conn.on('error', (err) => {
+      throw new Error(`SSH Tunnel Connection Error: ${err.message}`);
+    });
+
+    return { tunnel: server, localPort };
+  } catch (err) {
+    console.error(`Failed to establish SSH tunnel: ${err.message}`);
+    throw err;
+  }
+};
+
+/**
+ * Retrieves an existing connection or creates a new one if not available.
+ * Ensures that the number of active connections does not exceed the allowed limit.
+ * @param {Object} config - Configuration for the connection.
+ * @param {string} query - MongoDB query to execute.
+ * @returns {Promise<Object>} The MongoDB database instance.
+ */
+const getOrCreateConnection = async (config, query) => {
+  const configKey = JSON.stringify(config);
+
+  // Return existing connection if available
+  if (connectionPool.has(configKey)) {
+    return connectionPool.get(configKey);
+  }
+
+  // Check if connection pool has reached its limit
+  if (connectionPool.size >= MAX_CONNECTIONS) {
+    throw new Error('Connection limit reached.');
+  }
+
+  const { use_ssh, db_config, ssh_config } = config.secretData;
+
+  try {
+    // Create a new connection, either with or without SSH
+    const connection = use_ssh
+      ? await (async () => {
+        const { host: dbHost, port: dbPort } = db_config.hosts[0];
+        const { tunnel, localPort } = await createSSHTunnel(ssh_config, dbHost, dbPort);
+        const mongoConnection = await createMongoConnection(config, localPort);
+        mongoConnection._tunnel = tunnel; // Store tunnel instance for cleanup
+        return mongoConnection;
+      })()
+      : await createMongoConnection(config);
+
+    // Cache the newly created connection
+    connectionPool.set(configKey, connection);
+    return connection;
+  } catch (error) {
+    console.error('Error creating connection:', error.message);
+    throw error;
+  }
+};
+
+/**
+ * Express.js handler for incoming requests.
+ * Processes MongoDB queries based on provided configurations and query string.
+ * @param {Object} req - Express request object.
+ * @param {Object} res - Express response object.
+ */
+export const handler = async (req, res) => {
+  try {
+    // Ensure the request method is POST
+    if (req.method !== 'POST') {
+      return res.status(400).json({ error: 'Invalid method, only POST allowed.' });
+    }
+
+    // Extract and validate request body
+    const body = req.body;
+    validateRequestBody(body);
+
+    const { query, secretData } = body;
+    const db = await getOrCreateConnection({ secretData }, query);
+
+    // Execute the provided query in the MongoDB instance
+    const executeCommand = new Function('db', `return ${query}`);
+    const result = await executeCommand(db);
+
+    console.log('Query executed successfully:', JSON.stringify(result));
+    res.setHeader('Content-Type', 'application/json');
+    res.status(200).json(result);
+  } catch (error) {
+    console.error('Error handling request:', error.message);
+    res.status(500).json({ error: error.message });
+  }
+};

package.json

@@ -0,0 +1,19 @@
+{
+    "name": "boltic-mongodb-connector",
+    "version": "1.0.0",
+    "description": "The MongoDB connector enables seamless integration with any MongoDB database, allowing you to perform various operations efficiently.",
+    "main": "handler.js",
+    "scripts": {
+        "start": "node handler.js"
+    },
+    "dependencies": {
+        "mongodb": "^5.0.0",
+        "tunnel-ssh": "^5.1.2"
+    },
+    "engines": {
+        "node": ">=16.0.0"
+    },
+    "author": "Your Name",
+    "license": "MIT",
+    "type": "module"
+}