WIP : Socket metrics

Dockerfile.socket

@@ -10,5 +10,6 @@ RUN npm install -g --unsafe-perm prisma
 RUN npx prisma generate
 
 EXPOSE 4000
+EXPOSE 4001
 
 CMD [ "npm", "run", "socket" ]

docker-compose.yml

@@ -73,6 +73,7 @@ services:
       SOCKET_PORT: '${SOCKET_PORT}'
     ports:
       - '127.0.0.1:${SOCKET_PORT}:4000'
+      - '127.0.0.1:${SOCKET_METRICS_PORT}:4001'
     networks:
      - back
 

package.json

@@ -44,6 +44,7 @@
     "node-fetch": "^2.6.7",
     "node-pushnotifications": "^2.0.3",
     "nodemailer": "^6.8.0",
+    "prom-client": "^14.1.0",
     "socket.io": "^4.5.1",
     "webhook-discord": "^3.7.8"
   },

src/services/socket/listeners/chat.socket.listeners.ts

@@ -4,9 +4,10 @@ import { AuthenticatedSocket } from '@interfaces/auth.interface';
 
 import { throwIfNotFunction, throwIfNotNumber, throwIfNotString } from '@utils/controller.utils';
 import { Logger } from '@utils/logs.utils';
-import { handleSocketRawError, getUsersSockets } from '@utils/socket.utils';
+import { handleSocketRawError } from '@utils/socket.utils';
 
 import * as chatSocket from '../emitters/chat.socket.emitters';
+import { totalUsersOnSocket } from '@services/socket/metrics/metrics.socket';
 
 export function startSocket() {
   chatNamespace.on('connection', async (socket: AuthenticatedSocket) => {
@@ -16,6 +17,7 @@ export function startSocket() {
       handleSocketRawError(null, error);
     }
     const logger = new Logger('Chat Socket', socket.user);
+    totalUsersOnSocket.inc();
     logger.log('Connected');
 
     socket.on('join_conversation', async (data, callback) => {
@@ -106,6 +108,7 @@ export function startSocket() {
     socket.on('disconnecting', async () => {
       try {
         await chatSocket.sendConnectionStatus(socket, false);
+        totalUsersOnSocket.dec();
         logger.log('Disconnected');
       } catch (error) {
         console.error('Disconnection handling error', error);

src/services/socket/listeners/dropy.socket.listeners.ts

@@ -14,7 +14,6 @@ export function startSocket() {
   dropyNamespace.on('connection', async (socket: AuthenticatedSocket) => {
     const logger = new Logger('Dropy Socket', socket.user);
     socket.user = await resetUserBadgeNotification(socket.user);
-
     logger.log('Connected');
 
     socket.on('zones_update', async (data: any, callback) => {

src/services/socket/metrics/metrics.socket.ts

@@ -0,0 +1,14 @@
+import Prometheus, { Counter, Gauge } from 'prom-client';
+import { Express } from 'express';
+
+export const totalUsersOnSocket = new Gauge({
+  name: 'total_users_on_socket',
+  help: 'Number of users connected to  the socket',
+});
+
+export const addMetricsRoute = (server: Express) => {
+  server.get('/metrics', async (req, res) => {
+    res.set('Content-Type', Prometheus.register.contentType);
+    res.end(await Prometheus.register.metrics());
+  });
+};

src/services/socket/socket.ts

@@ -1,5 +1,6 @@
 import { Server } from 'socket.io';
-import { NextFunction } from 'express';
+import express, { NextFunction } from 'express';
+import { addMetricsRoute } from './metrics/metrics.socket';
 
 import { logStartedService } from '@/utils/logs.utils';
 
@@ -11,6 +12,7 @@ import * as dropySocket from './listeners/dropy.socket.listeners';
 import * as chatSocket from './listeners/chat.socket.listeners';
 
 const socketPort = 4000;
+const metricsPort = 4001;
 
 const io = new Server(socketPort, {
   maxHttpBufferSize: 1e8,
@@ -38,4 +40,11 @@ chatSocket.startSocket();
 
 logStartedService('Dropy Socket', socketPort);
 
+const metrics_server = express();
+addMetricsRoute(metrics_server);
+
+metrics_server.listen(metricsPort, () => {
+  logStartedService('Socket Metrics', metricsPort);
+});
+
 export default io;