factorio-clusterio/packages/master/src/Master.js

"use strict";
const compression = require("compression");
const events = require("events");
const express = require("express");
const expressFileupload = require("express-fileupload");
const fs = require("fs-extra");
const http = require("http");
const https = require("https");
const path = require("path");


const libConfig = require("@clusterio/lib/config");
const libErrors = require("@clusterio/lib/errors");
const libPlugin = require("@clusterio/lib/plugin");
const libPluginLoader = require("@clusterio/lib/plugin_loader");
const libPrometheus = require("@clusterio/lib/prometheus");
const { logger } = require("@clusterio/lib/logging");

const HttpCloser = require("./HttpCloser");
const metrics = require("./metrics");
const routes = require("./routes");
const UserManager = require("./UserManager");
const WsServer = require("./WsServer");


const hitCounter = new libPrometheus.Counter(
	"clusterio_master_http_hits_total",
	"How many HTTP requests in total have been received"
);

/**
 * Manages all master related operations
 * @alias module:master/src/Master
 */
class Master {
	constructor(clusterLogger, pluginInfos, configPath, config) {
		this.clusterLogger = clusterLogger;
		/**
		 * Mapping of plugin name to info objects for known plugins
		 * @type {Map<string, Object>}
		 */
		this.pluginInfos = pluginInfos;
		this.configPath = configPath;
		/**
		 * Master config.
		 * @type {module:lib/config.MasterConfig}
		 */
		this.config = config;

		this.app = express();
		this.app.locals.master = this;

		/**
		 * Mapping of slave id to slave info
		 * @type {Map<number, Object>}
		 */
		this.slaves = null;

		/**
		 * Mapping of instance id to instance info
		 * @type {Map<number, Object>}
		 */
		this.instances = null;

		/**
		 * User and roles manager for the cluster
		 * @type {module:master/src/UserManager}
		 */
		this.userManager = null;
		this.httpServer = null;
		this.httpServerCloser = null;
		this.httpsServer = null;
		this.httpsServerCloser = null;

		/**
		 * Mapping of plugin name to loaded plugin
		 * @type {Map<string, module:lib/plugin.BaseMasterPlugin>}
		 */
		this.plugins = new Map();

		/**
		 * WebSocket server
		 * @type {module:master/src/WsServer}
		 */
		this.wsServer = new WsServer(this);

		this.debugEvents = new events.EventEmitter();
		this._events = new events.EventEmitter();
		// Possible states are new, starting, running, stopping, stopped
		this._state = "new";
		this._shouldStop = false;

		this.devMiddleware = null;
	}

	async start(args) {
		if (!this._state === "new") {
			throw new Error(`Cannot start in state ${this._state}`);
		}

		this._state = "starting";
		try {
			await this._startInternal(args);

		} catch (err) {
			await this._stopInternal();
			this._state = "stopped";
			this._events.emit("stop");
			throw err;
		}

		if (this._shouldStop) {
			this.stop();
		}
	}

	async _startInternal(args) {
		// Start webpack development server if enabled
		if (args.dev || args.devPlugin) {
			logger.warn("Webpack development mode enabled");
			/* eslint-disable global-require */
			const webpack = require("webpack");
			const webpackDevMiddleware = require("webpack-dev-middleware");
			const webpackConfigs = [];
			if (args.dev) {
				webpackConfigs.push(require("../webpack.config")({}));
			}
			if (args.devPlugin) {
				for (let name of args.devPlugin) {
					let info = this.pluginInfos.find(i => i.name === name);
					if (!info) {
						throw new libErrors.StartupError(`No plugin named ${name}`);
					}
					let config = require(path.posix.join(info.requirePath, "webpack.config"))({});
					config.output.publicPath = `/plugins/${name}/`;
					webpackConfigs.push(config);
				}
			}
			/* eslint-enable global-require */

			const compiler = webpack(webpackConfigs);
			this.devMiddleware = webpackDevMiddleware(compiler, {});
			app.use(this.devMiddleware);
		}

		let databaseDirectory = this.config.get("master.database_directory");
		await fs.ensureDir(databaseDirectory);

		this.slaves = await Master.loadSlaves(path.join(databaseDirectory, "slaves.json"));
		this.instances = await Master.loadInstances(path.join(databaseDirectory, "instances.json"));
		this.userManager = new UserManager(this.config);
		await this.userManager.load(path.join(databaseDirectory, "users.json"));

		for (let instance of this.instances.values()) {
			this.addInstancePluginHooks(instance);
		}

		// Make sure we're actually going to listen on a port
		let httpPort = this.config.get("master.http_port");
		let httpsPort = this.config.get("master.https_port");
		let bindAddress = this.config.get("master.bind_address") || "";
		if (!httpPort && !httpsPort) {
			logger.fatal("Error: at least one of http_port and https_port must be configured");
			process.exitCode = 1;
			return;
		}

		let tls_cert = this.config.get("master.tls_certificate");
		let tls_key = this.config.get("master.tls_private_key");

		if (httpsPort && (!tls_cert || !tls_key)) {
			throw new libErrors.StartupError(
				"tls_certificate and tls_private_key must be configure in order to use https_port"
			);
		}

		Master.addAppRoutes(this.app, this.pluginInfos);

		// Load plugins
		await this.loadPlugins();

		this.wsServer = new WsServer(this);

		// Only start listening for connections after all plugins have loaded
		if (httpPort) {
			this.httpServer = http.createServer(this.app);
			this.httpServerCloser = new HttpCloser(this.httpServer);
			await this.listen(this.httpServer, httpPort, bindAddress);
			logger.info(`Listening for HTTP on port ${this.httpServer.address().port}`);
		}

		if (httpsPort) {
			let certificate, privateKey;
			try {
				certificate = await fs.readFile(tls_cert);
				privateKey = await fs.readFile(tls_key);

			} catch (err) {
				throw new libErrors.StartupError(
					`Error loading ssl certificate: ${err.message}`
				);
			}

			this.httpsServer = https.createServer({
				key: privateKey,
				cert: certificate,
			}, this.app);
			this.httpsServerCloser = new HttpCloser(this.httpsServer);
			await this.listen(this.httpsServer, httpsPort, bindAddress);
			logger.info(`Listening for HTTPS on port ${this.httpsServer.address().port}`);
		}

		logger.info("Started master");
		this._state = "running";
	}

	/**
	 * Stops the master server.
	 *
	 * Save data and bring down the active connections.  This is the reverse
	 * of start and is valid at any point in time.
	 */
	async stop() {
		if (this._state === "starting") {
			this._shouldStop = true;
			await events.once(this._events, "stop");
			return;

		} else if (this._state === "running") {
			await this._stopInternal();
		}

		this._state = "stopped";
		this._events.emit("stop");
	}

	async _stopInternal() {
		// This function should never throw.
		this._state = "stopping";
		logger.info("Stopping master");

		logger.info("Saving config");
		await fs.outputFile(this.configPath, JSON.stringify(this.config.serialize(), null, 4));

		if (this.devMiddleware) {
			await new Promise((resolve, reject) => { devMiddleware.close(resolve); });
		}

		let databaseDirectory = this.config.get("master.database_directory");
		if (this.slaves) {
			await Master.saveSlaves(path.join(databaseDirectory, "slaves.json"), this.slaves);
		}

		if (this.instances) {
			await Master.saveInstances(path.join(databaseDirectory, "instances.json"), this.instances);
		}

		if (this.userManager) {
			await this.userManager.save(path.join(databaseDirectory, "users.json"));
		}

		await libPlugin.invokeHook(this.plugins, "onShutdown");

		if (this.wsServer) {
			await this.wsServer.stop();
		}

		let stopTasks = [];
		logger.info("Stopping HTTP(S) server");
		if (this.httpServer && this.httpServer.listening) { stopTasks.push(this.httpServerCloser.close()); }
		if (this.httpsServer && this.httpsServer.listening) { stopTasks.push(this.httpsServerCloser.close()); }
		await Promise.all(stopTasks);

		logger.info("Goodbye");
	}

	static async loadSlaves(filePath) {
		let serialized;
		try {
			serialized = JSON.parse(await fs.readFile(filePath));

		} catch (err) {
			if (err.code !== "ENOENT") {
				throw err;
			}

			return new Map();
		}

		// TODO: Remove after release.
		if (serialized.length && !(serialized[0] instanceof Array)) {
			return new Map(); // Discard old format.
		}

		return new Map(serialized);
	}

	static async saveSlaves(filePath, slaves) {
		await fs.outputFile(filePath, JSON.stringify([...slaves.entries()], null, 4));
	}

	static async loadInstances(filePath) {
		logger.info(`Loading ${filePath}`);

		let instances = new Map();
		try {
			let serialized = JSON.parse(await fs.readFile(filePath));
			for (let serializedConfig of serialized) {
				let instanceConfig = new libConfig.InstanceConfig("master");
				await instanceConfig.load(serializedConfig);
				let status = instanceConfig.get("instance.assigned_slave") === null ? "unassigned" : "unknown";
				let instance = { config: instanceConfig, status };
				instances.set(instanceConfig.get("instance.id"), instance);
			}

		} catch (err) {
			if (err.code !== "ENOENT") {
				throw err;
			}
		}

		return instances;
	}

	static async saveInstances(filePath, instances) {
		let serialized = [];
		for (let instance of instances.values()) {
			serialized.push(instance.config.serialize());
		}

		await fs.outputFile(filePath, JSON.stringify(serialized, null, 4));
	}

	static addAppRoutes(app, pluginInfos) {
		app.use((req, res, next) => {
			hitCounter.inc();
			next();
		});
		app.use(expressFileupload());
		app.use(compression());

		// Set folder to serve static content from (the website)
		app.use(express.static(path.join(__dirname, "..", "dist", "web")));
		app.use(express.static("static")); // Used for data export files

		// Add API routes
		routes.addRouteHandlers(app);

		// Add routes for the web interface
		for (let route of routes.webRoutes) {
			app.get(route, Master.serveWeb(route));
		}
		for (let pluginInfo of pluginInfos) {
			for (let route of pluginInfo.routes || []) {
				app.get(route, Master.serveWeb(route));
			}

			let pluginPackagePath = require.resolve(path.posix.join(pluginInfo.requirePath, "package.json"));
			let webPath = path.join(path.dirname(pluginPackagePath), "dist", "web");
			app.use(`/plugins/${pluginInfo.name}`, express.static(webPath));
		}
	}

	addInstancePluginHooks(instance) {
		instance.config.on("fieldChanged", (group, field, prev) => {
			libPlugin.invokeHook(this.plugins, "onInstanceConfigFieldChanged", instance, group, field, prev);
		});
	}

	async loadPlugins() {
		for (let pluginInfo of this.pluginInfos) {
			if (!this.config.group(pluginInfo.name).get("load_plugin")) {
				continue;
			}

			let MasterPluginClass = libPlugin.BaseMasterPlugin;
			try {
				if (pluginInfo.masterEntrypoint) {
					MasterPluginClass = await libPluginLoader.loadMasterPluginClass(pluginInfo);
				}

				let masterPlugin = new MasterPluginClass(pluginInfo, this, metrics, logger);
				await masterPlugin.init();
				this.plugins.set(pluginInfo.name, masterPlugin);

			} catch (err) {
				throw new libErrors.PluginError(pluginInfo.name, err);
			}

			logger.info(`Loaded plugin ${pluginInfo.name}`);
		}
	}

	/**
	 * Calls listen on server capturing any errors that occurs
	 * binding to the port.  Also adds handler for WebSocket
	 * upgrade event.
	 *
	 * @param {module:net.Server} server - Server to start the listening on.
	 * @param {*} args - Arguments to the .listen() call on the server.
	 * @returns {Promise} promise that resolves the server is listening.
	 */
	listen(server, ...args) {
		return new Promise((resolve, reject) => {
			server.on("upgrade", (req, socket, head) => {
				logger.verbose("handling WebSocket upgrade");
				this.wsServer.handleUpgrade(req, socket, head);
			});

			function wrapError(err) {
				reject(new libErrors.StartupError(
					`Server listening failed: ${err.message}`
				));
			}

			server.once("error", wrapError);
			server.listen(...args, () => {
				server.off("error", wrapError);
				resolve();
			});
		});
	}


	/**
	 * Returns the URL needed to connect to the master server.
	 *
	 * @returns {string} master URL.
	 */
	getMasterUrl() {
		return Master.calculateMasterUrl(this.config);
	}

	static calculateMasterUrl(config) {
		let url = config.get("master.external_address");
		if (!url) {
			if (config.get("master.https_port")) {
				url = `https://localhost:${config.get("master.https_port")}/`;
			} else {
				url = `http://localhost:${config.get("master.http_port")}/`;
			}
		}
		return url;
	}

	/**
	 * Servers the web interface with the root path set apropriately
	 *
	 * @param {string} route - route the interface is served under.
	 * @returns {function} Experess.js route handler.
	 */
	static serveWeb(route) {
		// The depth is is the number of slashes in the route minus one, but due
		// to lenient matching on trailing slashes in the route we need to
		// compensate if the request path contains a slash but not the route,
		// and vice versa.
		let routeDepth = (route.match(/\//g) || []).length - 1 - (route.slice(-1) === "/");
		return function(req, res, next) {
			let depth = routeDepth + (req.path.slice(-1) === "/");
			let webRoot = "../".repeat(depth) || "./";
			fs.readFile(path.join(__dirname, "..", "web", "index.html"), "utf8").then((content) => {
				res.type("text/html");
				res.send(content.replace(/__WEB_ROOT__/g, webRoot));
			}).catch(err => {
				next(err);
			});
		};
	}
}

module.exports = Master;