NodeBB/loader.js

"use strict";

var	nconf = require('nconf'),
	fs = require('fs'),
	pidFilePath = __dirname + '/pidfile',
	output = fs.openSync(__dirname + '/logs/output.log', 'a'),
	start = function() {
		var	nbb_start = function(callback) {
				if (timesStarted > 3) {
					console.log('\n[loader] Experienced three start attempts in 10 seconds, most likely an error on startup. Halting.');
					return nbb_stop();
				}

				timesStarted++;
				if (startTimer) {
					clearTimeout(startTimer);
				}
				startTimer = setTimeout(resetTimer, 1000*10);

				if (nbb) {
					nbbOld = nbb;
				}

				nbb = require('child_process').fork('./app', process.argv.slice(2), {
					env: process.env
				});

				nbb.on('message', function(message) {
					if (message && typeof message === 'object' && message.action) {
						switch (message.action) {
							case 'ready':
								if (!callback) return nbb.kill('SIGCONT');
								callback();
							break;
							case 'restart':
								nbb_restart();
							break;
						}
					}
				});

				nbb.on('exit', function(code, signal) {
					if (code) {
						nbb_start();
					} else {
						nbb_stop();
					}
				});
			},
			nbb_stop = function() {
				if (startTimer) {
					clearTimeout(startTimer);
				}

				nbb.kill();
				if (fs.existsSync(pidFilePath)) {
					var	pid = parseInt(fs.readFileSync(pidFilePath, { encoding: 'utf-8' }), 10);
					if (process.pid === pid) {
						fs.unlinkSync(pidFilePath);
					}
				}
			},
			nbb_restart = function() {
				nbb_start(function() {
					nbbOld.removeAllListeners('exit').on('exit', function() {
						nbb.kill('SIGCONT');
					});
					nbbOld.kill();
				});
			},
			resetTimer = function() {
				clearTimeout(startTimer);
				timesStarted = 0;
			},
			timesStarted = 0,
			startTimer;

		process.on('SIGINT', nbb_stop);
		process.on('SIGTERM', nbb_stop);
		process.on('SIGHUP', nbb_restart);

		nbb_start();
	},
	nbb, nbbOld;

nconf.argv();

// Start the daemon!
if (nconf.get('daemon') !== false) {
	// Check for a still-active NodeBB process
	if (fs.existsSync(pidFilePath)) {
		try {
			var	pid = fs.readFileSync(pidFilePath, { encoding: 'utf-8' });
			process.kill(pid, 0);
			process.exit();
		} catch (e) {
			fs.unlinkSync(pidFilePath);
		}
	}

	// Daemonize and record new pid
	require('daemon')({
		stdout: output
	});
	fs.writeFile(__dirname + '/pidfile', process.pid);

	start();
} else {
	start();
}