Add API to get number of active sockets

src/api/admin.ts

@@ -16,9 +16,18 @@
  */
 
 import { Router } from 'express'
+import { WebsocketApi } from '../websocket'
 
-export const createAdminRouter = () => {
+export const createAdminRouter = ({ websocket }: {
+  websocket: WebsocketApi
+}) => {
   const router = Router()
 
+  router.get('/status', (_, res) => {
+    res.json({
+      websocketClients: websocket.countConnections()
+    })
+  })
+
   return router
 }

src/api/index.ts

@@ -62,7 +62,7 @@ export const createApi = ({ database, websocket, connectedDevicesManager }: {
         res.sendStatus(401)
       }
     },
-    createAdminRouter()
+    createAdminRouter({ websocket })
   )
 
   return app

src/websocket/index.ts

@@ -27,9 +27,13 @@ export const createWebsocketHandler = ({ connectedDevicesManager, database }: {
   websocketServer: io.Server
   websocketApi: WebsocketApi
 } => {
+  let socketCounter = 0
   const server = io()
 
   server.on('connection', (socket) => {
+    socketCounter++
+    socket.on('disconnect', () => socketCounter--)
+
     socket.on('devicelogin', (deviceAuthToken: any, ack: any) => {
       socket.leaveAll()
 
@@ -89,7 +93,8 @@ export const createWebsocketHandler = ({ connectedDevicesManager, database }: {
       server
         .to(deviceByAuthTokenRoom(deviceAuthToken))
         .emit('sign out')
-    }
+    },
+    countConnections: () => socketCounter
   }
 
   return {
@@ -101,4 +106,5 @@ export const createWebsocketHandler = ({ connectedDevicesManager, database }: {
 export interface WebsocketApi {
   triggerSyncByDeviceAuthToken: (params: {deviceAuthToken: string, isImportant: boolean}) => void
   triggerLogoutByDeviceAuthToken: (params: {deviceAuthToken: string}) => void
+  countConnections: () => number
 }