Use uniform Socket message size to avoid disconnects

Summary: During startup the socket connection would close a few times, among others because Scribe dumps 1.3 MB of data after startup, and the maximum payload of `socket.io` defaults to 1MB. This diff changes it to 100MB (the max size used by `ws` library). We know that we need at least > 10 MB, as that is what plugins like Network cap at.

Reviewed By: aigoncharov

Differential Revision: D33017653

fbshipit-source-id: 1233af6fbdc4b9eed42786ee418cfd6d43b2b433

desktop/flipper-server-core/src/comms/ServerWebSocket.tsx

@@ -35,6 +35,10 @@ export interface ConnectionCtx {
   request: IncomingMessage;
 }
 
+// based on https://github.com/websockets/ws/blob/master/lib/websocket-server.js#L40,
+// exposed to share with socket.io defaults
+export const WEBSOCKET_MAX_MESSAGE_SIZE = 100 * 1024 * 1024;
+
 /**
  * It serves as a base class for WebSocket based servers. It delegates the 'connection'
  * event to subclasses as a customisation point.
@@ -52,6 +56,7 @@ class ServerWebSocket extends ServerAdapter {
       const wsServer = new WSServer({
         server,
         verifyClient: this.verifyClient(),
+        maxPayload: WEBSOCKET_MAX_MESSAGE_SIZE,
       });
 
       // We do not need to listen to http server's `error` because it is propagated to WS

desktop/flipper-server-core/src/index.tsx

@@ -26,3 +26,5 @@ export function getGatekeepers(username: string): Record<string, boolean> {
   }
   return GKImplementation.allGKs();
 }
+
+export {WEBSOCKET_MAX_MESSAGE_SIZE} from './comms/ServerWebSocket';