feat: Implement the core InterNetX DDNS updater application with API, services, middleware, Docker support, and a detailed README.

src/routes/update.route.js

@@ -0,0 +1,98 @@
+const express = require('express');
+const router = express.Router();
+const ddnsService = require('../services/ddns.service');
+const authenticate = require('../middleware/auth.middleware');
+const { validate, updateSchema } = require('../middleware/validation.middleware');
+const { updateLimiter } = require('../middleware/rateLimiter.middleware');
+const { getClientIP } = require('../utils/ipHelper');
+const { logger } = require('../utils/logger');
+
+/**
+ * GET/POST /update
+ * Update DNS record for router DDNS
+ * 
+ * Query/Body Parameters:
+ * - hostname: Full hostname (e.g., "home.ddns.netstack.berlin")
+ * - myip: IPv4 address (optional)
+ * - myipv6: IPv6 address (optional)
+ * - token: Authentication token
+ */
+router.all('/update',
+    updateLimiter,
+    validate(updateSchema),
+    authenticate,
+    async (req, res) => {
+        try {
+            const { hostname, myip, myipv6 } = req.validatedData;
+            const clientIP = getClientIP(req);
+
+            // Use provided IPs or fallback to client IP
+            let ipv4 = myip;
+            let ipv6 = myipv6;
+
+            // If no IP provided, use client IP (auto-detect version)
+            if (!ipv4 && !ipv6) {
+                const { detectIPVersion } = require('../utils/ipHelper');
+                const version = detectIPVersion(clientIP);
+
+                if (version === 'ipv4') {
+                    ipv4 = clientIP;
+                } else if (version === 'ipv6') {
+                    ipv6 = clientIP;
+                }
+            }
+
+            logger.info('DDNS update request', {
+                hostname,
+                ipv4,
+                ipv6,
+                clientIP,
+                token: req.tokenPrefix,
+            });
+
+            // Update DNS record
+            const result = await ddnsService.updateDNSRecord(hostname, ipv4, ipv6);
+
+            if (!result.success) {
+                logger.error('DDNS update failed', {
+                    hostname,
+                    error: result.error,
+                });
+
+                return res.status(500).json({
+                    status: 'error',
+                    message: result.error || 'Failed to update DNS record',
+                });
+            }
+
+            // Success response
+            logger.info('DDNS update successful', {
+                hostname,
+                results: result.results,
+            });
+
+            res.json({
+                status: 'success',
+                message: 'DNS record updated successfully',
+                hostname,
+                updates: result.results.map(r => ({
+                    type: r.type,
+                    action: r.action,
+                    value: r.record?.value,
+                })),
+            });
+        } catch (error) {
+            logger.error('Unexpected error in update endpoint', {
+                error: error.message,
+                stack: error.stack,
+            });
+
+            res.status(500).json({
+                status: 'error',
+                message: 'An unexpected error occurred',
+            });
+        }
+    }
+);
+
+module.exports = router;