add ping pong to make sure websocket connection doesn't go stale

meshchat.py

@@ -2081,8 +2081,14 @@ class ReticulumMeshChat:
         # get type from client data
         _type = data["type"]
 
+        # handle ping
+        if _type == "ping":
+            AsyncUtils.run_async(client.send_str(json.dumps({
+                "type": "pong",
+            })))
+
         # handle updating config
-        if _type == "config.set":
+        elif _type == "config.set":
 
             # get config from websocket
             config = data["config"]

src/frontend/js/WebSocketConnection.js

@@ -3,8 +3,18 @@ import mitt from 'mitt';
 class WebSocketConnection {
 
     constructor() {
+
         this.emitter = mitt();
         this.reconnect();
+
+        /**
+         * ping websocket server every 30 seconds
+         * this helps to prevent the underlying tcp connection from going stale when there's no traffic for a long time
+         */
+        setInterval(() => {
+            this.ping();
+        }, 30000);
+
     }
 
     // add event listener
@@ -47,6 +57,16 @@ class WebSocketConnection {
         }
     }
 
+    ping() {
+        try {
+            this.send(JSON.stringify({
+                "type": "ping",
+            }));
+        } catch(e) {
+            // ignore error
+        }
+    }
+
 }
 
 export default new WebSocketConnection();