feat: Add watchdog and healthcheck (#22)

Author: tomquist

Dockerfile

@@ -43,7 +43,15 @@ RUN mkdir -p /app/config
 
 # Set environment variables
 ENV CONFIG_PATH=/app/config/config.json \
-    CERT_PATH=/app/certs
+    CERT_PATH=/app/certs \
+    NODE_ENV=production
+
+# Expose health check port
+EXPOSE 8080
+
+# Add health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/health || exit 1
 
 # Run the application
 CMD ["node", "dist/forwarder.js"]

hassio-addon/config.yaml

@@ -13,6 +13,7 @@ startup: application
 boot: auto
 services:
   - mqtt:need
+watchdog: "http://[HOST]:[PORT:8080]/health"
 options:
   inverse_forwarding: false
   devices:

src/forwarder.ts

@@ -4,8 +4,9 @@ import {readFileSync} from 'fs';
 import {join} from 'path';
 import {createHash} from 'crypto';
 import fetch from 'node-fetch';
+import { HealthServer } from './health';
 
-const deviceGenerations = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16] as const;
+const deviceGenerations = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 50] as const;
 type DeviceGen = typeof deviceGenerations[number];
 const deviceTypes = ["A", "B", "D", "E", "F", "G", "J", "K"] as const;
 type DeviceType = typeof deviceTypes[number];
@@ -149,6 +150,7 @@ function cleanAndValidate(config: Config): void {
 class MQTTForwarder {
   private configBroker!: mqtt.MqttClient;
   private hameBroker!: mqtt.MqttClient;
+  private healthServer!: HealthServer;
   private readonly MESSAGE_HISTORY_TIMEOUT = 1000; // 1 second timeout
   private readonly RATE_LIMIT_INTERVAL = 59900; // Rate limit interval in milliseconds
   private readonly MESSAGE_CACHE_TIMEOUT = 1000; // 1 second timeout for message loop prevention
@@ -161,6 +163,8 @@ class MQTTForwarder {
   constructor(private readonly config: Config) {
     // Initialize brokers
     this.initializeBrokers();
+    // Initialize health server
+    this.healthServer = new HealthServer(this.configBroker, this.hameBroker);
   }
 
   /**
@@ -429,6 +433,7 @@ class MQTTForwarder {
   public close(): void {
     this.configBroker.end();
     this.hameBroker.end();
+    this.healthServer.close();
   }
 
   // Clean up old message history entries periodically

src/health.ts

@@ -0,0 +1,39 @@
+import { createServer, IncomingMessage, ServerResponse } from 'http';
+import { MqttClient } from 'mqtt';
+
+export class HealthServer {
+  private server: ReturnType<typeof createServer>;
+  private configBroker: MqttClient;
+  private hameBroker: MqttClient;
+
+  constructor(configBroker: MqttClient, hameBroker: MqttClient, port: number = 8080) {
+    this.configBroker = configBroker;
+    this.hameBroker = hameBroker;
+    
+    this.server = createServer(this.handleRequest.bind(this));
+    this.server.listen(port, () => {
+      console.log(`Health server listening on port ${port}`);
+    });
+  }
+
+  private handleRequest(req: IncomingMessage, res: ServerResponse): void {
+    if (req.url === '/health' && req.method === 'GET') {
+      const status = {
+        status: 'ok',
+        configBroker: this.configBroker.connected,
+        hameBroker: this.hameBroker.connected,
+        timestamp: new Date().toISOString()
+      };
+
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify(status));
+    } else {
+      res.writeHead(404);
+      res.end();
+    }
+  }
+
+  public close(): void {
+    this.server.close();
+  }
+}