feat:metrics exposed

package.json

@@ -27,15 +27,17 @@
         "@types/mustache": "^0.8.32",
         "@types/node": "^12.0.2",
         "@types/request": "^2.48.1",
-        "body-parser": "^1.20.2",
         "axios": "1.6.8",
+        "body-parser": "^1.20.2",
         "express": "^4.19.2",
+        "express-promise-router": "^4.1.1",
         "js-yaml": "^3.13.1",
         "json-rules-engine": "^2.3.6",
         "moment-timezone": "^0.5.31",
         "mustache": "^3.0.1",
         "notifme-sdk": "^1.14.1",
         "pg": "^8.2.1",
+        "prom-client": "^15.1.2",
         "reflect-metadata": "^0.1.13",
         "typeorm": "0.3.17",
         "winston": "^3.2.1"

src/server.ts

@@ -29,6 +29,9 @@ import { WebhookService } from './destination/destinationHandlers/webhookHandler
 import { WebhookConfig } from './entities/webhookconfig';
 import * as process from "process";
 import bodyParser from 'body-parser';
+import {register,collectDefaultMetrics} from 'prom-client';
+import expressPromiseRouter from 'express-promise-router';
+
 const app = express();
 app.use(bodyParser.json({ limit: '10mb' }));
 
@@ -108,5 +111,18 @@ app.post('/notify', (req, res) => {
     notificationService.sendNotification(req.body)
     res.send('notifications sent')
 });
+const router = expressPromiseRouter();
+
+// Initialize Prometheus metrics
+collectDefaultMetrics();
+
+// Endpoint to expose metrics
+router.get('/metrics', async (req, res) => {
+    res.set('Content-Type', register.contentType);
+    res.end(await register.metrics());
+});
+
+// Mount the router to the app
+app.use(router);
 
 app.listen(3000, () => logger.info('Notifier app listening on port 3000!'))