Added code to support self-updating windows service

package.json

@@ -1,6 +1,6 @@
 {
   "name": "meshcentral",
-  "version": "0.3.9-l",
+  "version": "0.3.9-m",
   "keywords": [
     "Remote Management",
     "Intel AMT",

winservice.js

@@ -1,5 +1,5 @@
 /**
-* @description MeshCentral main module
+* @description Windows Service Launcher
 * @author Ylian Saint-Hilaire
 * @copyright Intel Corporation 2018-2019
 * @license Apache-2.0
@@ -13,6 +13,64 @@
 /*jshint esversion: 6 */
 "use strict";
 
-// This module is only called when MeshCentral is running as a Windows service.
-// In this case, we don't want to start a child process, so we launch directly without arguments.
-require('./meshcentral.js').mainStart({ "launch": true });
+function start() {
+    if (require('os').platform() != 'win32') { console.log('ERROR: Win32 only'); process.exit(255); return; }
+
+    try {
+        const fs = require('fs');
+        const path = require('path');
+
+        // Search for meshcentral.js
+        var cwd = null;
+        var runarg = null;
+        if (fs.existsSync(path.join(__dirname, 'meshcentral.js'))) {
+            runarg = path.join(__dirname, 'meshcentral.js');
+            cwd = __dirname;
+        } else if (fs.existsSync(path.join(__dirname, '../node_modules/meshcentral/meshcentral.js'))) {
+            runarg = path.join(__dirname, '../node_modules/meshcentral/meshcentral.js');
+            cwd = path.join(__dirname, '..');
+        } else if (fs.existsSync(path.join(__dirname, '../meshcentral/meshcentral.js'))) {
+            runarg = path.join(__dirname, '../meshcentral/meshcentral.js');
+            cwd = path.join(__dirname, '../meshcentral');
+        }
+        if (runarg == null) { console.log('ERROR: Unable to find MeshCentral.js'); process.exit(255); return; }
+
+        // Setup libraries
+        const args = require(path.join(cwd, 'node_modules/minimist'))(process.argv.slice(2));
+        const nodewindows = require(path.join(cwd, 'node_modules/node-windows'));
+        const service = nodewindows.Service;
+        const eventlogger = nodewindows.EventLogger;
+        const servicelog = new eventlogger('MeshCentral');
+
+        // Check if we need to install, start, stop, remove ourself as a background service
+        if (((args.install == true) || (args.uninstall == true) || (args.start == true) || (args.stop == true) || (args.restart == true))) {
+            var env = [], xenv = ['user', 'port', 'aliasport', 'mpsport', 'mpsaliasport', 'redirport', 'exactport', 'debug'];
+            for (var i in xenv) { if (args[xenv[i]] != null) { env.push({ name: 'mesh' + xenv[i], value: args[xenv[i]] }); } } // Set some args as service environement variables.
+            var svc = new service({ name: 'MeshCentral', description: 'MeshCentral Remote Management Server', script: path.join(__dirname, 'winservice.js'), env: env, wait: 2, grow: 0.5 });
+            svc.on('install', function () { console.log('MeshCentral service installed.'); svc.start(); });
+            svc.on('uninstall', function () { console.log('MeshCentral service uninstalled.'); process.exit(); });
+            svc.on('start', function () { console.log('MeshCentral service started.'); process.exit(); });
+            svc.on('stop', function () { console.log('MeshCentral service stopped.'); if (args.stop) { process.exit(); } if (args.restart) { console.log('Holding 5 seconds...'); setTimeout(function () { svc.start(); }, 5000); } });
+            svc.on('alreadyinstalled', function () { console.log('MeshCentral service already installed.'); process.exit(); });
+            svc.on('invalidinstallation', function () { console.log('Invalid MeshCentral service installation.'); process.exit(); });
+
+            if (args.install == true) { try { svc.install(); } catch (e) { logException(e); } }
+            if (args.stop == true || args.restart == true) { try { svc.stop(); } catch (e) { logException(e); } }
+            if (args.start == true || args.restart == true) { try { svc.start(); } catch (e) { logException(e); } }
+            if (args.uninstall == true) { try { svc.uninstall(); } catch (e) { logException(e); } }
+            return;
+        }
+
+        // This module is only called when MeshCentral is running as a Windows service.
+        // In this case, we don't want to start a child process, so we launch directly without arguments.
+        require(cwd).mainStart({ "launch": true });
+    } catch (ex) { console.log(ex); }
+
+    // Logging funtions
+    function logException(e) { e += ''; logErrorEvent(e); }
+    function logInfoEvent(msg) { if (servicelog != null) { servicelog.info(msg); } console.log(msg); }
+    function logWarnEvent(msg) { if (servicelog != null) { servicelog.warn(msg); } console.log(msg); }
+    function logErrorEvent(msg) { if (servicelog != null) { servicelog.error(msg); } console.error(msg); }
+}
+
+start();