swaf/src/components/WebSocketServerComponent.ts

import ApplicationComponent from "../ApplicationComponent";
import {Express, Request} from "express";
import WebSocket, {Server as WebSocketServer} from "ws";
import {log} from "../Logger";
import cookie from "cookie";
import cookieParser from "cookie-parser";
import config from "config";
import ExpressAppComponent from "./ExpressAppComponent";
import Application from "../Application";
import RedisComponent from "./RedisComponent";
import WebSocketListener from "../WebSocketListener";
import NunjucksComponent from "./NunjucksComponent";

export default class WebSocketServerComponent extends ApplicationComponent {
    private wss?: WebSocket.Server;

    public constructor(
        private readonly application: Application,
        private readonly expressAppComponent: ExpressAppComponent,
        private readonly storeComponent: RedisComponent,
        private readonly nunjucksComponent?: NunjucksComponent,
    ) {
        super();
    }

    public async start(_app: Express): Promise<void> {
        const listeners: { [p: string]: WebSocketListener<Application> } = this.application.getWebSocketListeners();
        this.wss = new WebSocketServer({
            server: this.expressAppComponent.getServer(),
        }, () => {
            log.info(`Websocket server started over webserver.`);
        }).on('error', (err) => {
            log.error(err, 'An error occurred in the websocket server.');
        }).on('connection', (socket, request) => {
            const listener = request.url ? listeners[request.url] : null;

            if (!listener) {
                socket.close(1002, `Path not found ${request.url}`);
                return;
            } else if (!request.headers.cookie) {
                listener.handle(socket, request, null).catch(err => {
                    log.error(err, 'Error in websocket listener.');
                });
                return;
            }

            log.debug(`Websocket on ${request.url}`);

            const cookies = cookie.parse(request.headers.cookie);
            const sid = cookieParser.signedCookie(cookies['connect.sid'], config.get('session.secret'));

            if (!sid) {
                socket.close(1002);
                return;
            }

            const store = this.storeComponent.getStore();
            store.get(sid, (err, session) => {
                if (err || !session) {
                    log.error(err, 'Error while initializing session in websocket.');
                    socket.close(1011);
                    return;
                }

                session.id = sid;

                store.createSession(<Request>request, session);
                listener.handle(socket, request, (<Request>request).session).catch(err => {
                    log.error(err, 'Error in websocket listener.');
                });
            });
        });

        const env = this.nunjucksComponent?.getEnvironment();
        if (env) {
            env.addGlobal('websocketUrl', config.get('public_websocket_url'));
        }
    }

    public async stop(): Promise<void> {
        const wss = this.wss;
        if (wss) {
            await this.close('WebSocket server', callback => wss.close(callback));
        }
    }
}