js/server.js

const fs = require("node:fs");
const http = require("node:http");
const https = require("node:https");
const path = require("node:path");
const express = require("express");
const helmet = require("helmet");
const socketio = require("socket.io");
const Log = require("logger");

const { ipAccessControl } = require("./ip_access_control");

const vendor = require("./vendor");

const { getHtml, getVersion, getEnvVars, cors } = require("#server_functions");

/**
 * Server
 * @param {object} configObj The MM config full and redacted
 * @class
 */
function Server (configObj) {
	const config = configObj.fullConf;
	const app = express();
	const port = process.env.MM_PORT || config.port;
	const serverSockets = new Set();
	let server = null;

	/**
	 * Opens the server for incoming connections
	 * @returns {Promise} A promise that is resolved when the server listens to connections
	 */
	this.open = function () {
		return new Promise((resolve) => {
			if (config.useHttps) {
				const options = {
					key: fs.readFileSync(config.httpsPrivateKey),
					cert: fs.readFileSync(config.httpsCertificate)
				};
				server = https.Server(options, app);
			} else {
				server = http.Server(app);
			}
			const io = socketio(server, {
				cors: {
					origin: /.*$/,
					credentials: true
				},
				allowEIO3: true,
				pingInterval: 120000, // server → client ping every 2 mins
				pingTimeout: 120000 // wait up to 2 mins for client pong
			});

			server.on("connection", (socket) => {
				serverSockets.add(socket);
				socket.on("close", () => {
					serverSockets.delete(socket);
				});
			});

			Log.log(`Starting server on port ${port} ... `);

			// Add explicit error handling BEFORE calling listen so we can give user-friendly feedback
			server.once("error", (err) => {
				if (err && err.code === "EADDRINUSE") {
					const bindAddr = config.address || "localhost";
					const portInUseMessage = [
						"",
						"────────────────────────────────────────────────────────────────",
						` PORT IN USE: ${bindAddr}:${port}`,
						"",
						" Another process (most likely another MagicMirror instance)",
						" is already using this port.",
						"",
						" Stop the other process (free the port) or use a different port.",
						"────────────────────────────────────────────────────────────────"
					].join("\n");
					Log.error(portInUseMessage);
					return;
				}

				Log.error("Failed to start server:", err);
			});

			server.listen(port, config.address || "localhost");

			if (config.ipWhitelist instanceof Array && config.ipWhitelist.length === 0) {
				Log.warn("You're using a full whitelist configuration to allow for all IPs");
			}

			app.use(ipAccessControl(config.ipWhitelist));
			app.use(helmet(config.httpHeaders));
			app.use("/js", express.static(__dirname));

			if (config.hideConfigSecrets) {
				app.get("/config/config.env", (req, res) => {
					res.status(404).send("<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n<meta charset=\"utf-8\">\n<title>Error</title>\n</head>\n<body>\n<pre>Cannot GET /config/config.env</pre>\n</body>\n</html>");
				});
			}

			let directories = ["/config", "/css", "/favicon.svg", "/defaultmodules", "/modules", "/node_modules/animate.css", "/node_modules/@fontsource", "/node_modules/@fortawesome", "/translations", "/tests/configs", "/tests/mocks"];
			for (const value of Object.values(vendor)) {
				const dirArr = value.split("/");
				if (dirArr[0] === "node_modules") directories.push(`/${dirArr[0]}/${dirArr[1]}`);
			}
			const uniqDirs = [...new Set(directories)];
			for (const directory of uniqDirs) {
				app.use(directory, express.static(path.resolve(global.root_path + directory)));
			}

			const startUp = new Date();
			const getStartup = (req, res) => res.send(startUp);

			const getConfig = (req, res) => {
				if (config.hideConfigSecrets) {
					res.send(configObj.redactedConf);
				} else {
					res.send(configObj.fullConf);
				}
			};
			app.get("/config", (req, res) => getConfig(req, res));

			app.get("/cors", async (req, res) => await cors(req, res));

			app.get("/version", (req, res) => getVersion(req, res));

			app.get("/startup", (req, res) => getStartup(req, res));

			app.get("/env", (req, res) => getEnvVars(req, res));

			app.get("/", (req, res) => getHtml(req, res));

			// Reload endpoint for watch mode - triggers browser reload
			app.get("/reload", (req, res) => {
				Log.info("Reload request received, notifying all clients");
				io.emit("RELOAD");
				res.status(200).send("OK");
			});

			server.on("listening", () => {
				resolve({
					app,
					io
				});
			});
		});
	};

	/**
	 * Closes the server and destroys all lingering connections to it.
	 * @returns {Promise} A promise that resolves when server has successfully shut down
	 */
	this.close = function () {
		return new Promise((resolve) => {
			for (const socket of serverSockets.values()) {
				socket.destroy();
			}
			server.close(resolve);
		});
	};
}

module.exports = Server;