service-manager/lib/linux-service-controller.js

A service manager for linux(and windows SOON(TM)) scripts

#!/usr/bin/env node
//#
//# {name}
//#
//# chkconfig: 
//# description: {description} 
//#
//#

var spawn = require('child_process').spawn;
var exec = require('child_process').exec;
var sys = require('util');
var fs = require('fs');

SERVICE_NAME = "{name}";
SERVICE_DISPLAY = "{display}";
RUN_FILE = "{run}";
ARGS = [{args}];
PID_FILE = "/var/run/" + SERVICE_NAME + ".pid";
DOLOG = {log};

if(DOLOG) {
	try {
		var out = fs.openSync("/var/log/" + SERVICE_NAME + "_output.log", "a");
		var err = fs.openSync("/var/log/" + SERVICE_NAME + "_error.log", "a");
	} catch(e) {
		if (e.code == 'EACCES') {
			console.log(" * Error: must be root to use!");
		} else {
			throw e;
		}
	}
}
else {
	var out = fs.openSync("/dev/null", "a");
	var err = fs.openSync("/dev/null", "a");
}

function is_running(pid, callback) {
	exec("kill -0 " + pid, function(err, stdout, stderr) {
		callback(stderr == "");
	});
}
function is_root(callback) {
	exec("id -u", function(err, stdout, stderr) {
		callback(stdout.trim() == "0");
	});
}



function dostart() {
	sys.print(" * Starting " + SERVICE_DISPLAY + ": ");
	var proc = spawn(RUN_FILE, ARGS, {
		detached: true,
		stdio: [ 'ignore', out, err ]
	});
	console.log(SERVICE_NAME);
	fs.writeFileSync(PID_FILE, "" + proc.pid);
	proc.unref();
}
function start() {
	is_root(function(is) {
		if(!is) {
			console.log(" * Error: must be root to start!");
			return;
		}
		if(fs.existsSync(PID_FILE)) {
			is_running(fs.readFileSync(PID_FILE), function(run) {
				if(run == true) {
					console.log(" * " + SERVICE_NAME + " is already running!");
				} else {
					dostart();
				}
			});
		} else {
			dostart();
		}
	});
}
function stop() {
	is_root(function(is) {
		if(!is) {
			console.log(" * Error: must be root to stop!");
			return;
		}
		sys.print(" * Stopping " + SERVICE_DISPLAY + ": ");
		try {
			var pid = fs.readFileSync(PID_FILE);
			process.kill(pid);
			console.log(SERVICE_NAME);
		} catch(e) {
			if(e.code == 'ENOENT') {
				console.log("PID file not found!");
			} else {
				throw e;
			}
		}
	});
}
function restart() {
	stop();
	start();
}
function reload() {
}
function status() {
}


if(process.argv.length != 3) {
	console.log("Usage: " + SERVICE_NAME + " (start|stop|restart|reload|status)");
} else {
	switch(process.argv[2]) {
		case "start":
			start();
			break;
		case "stop":
			stop();
			break;
		case "restart":
			restart();
			break;
		case "reload":
			reload();
			break;
		case "status":
			status();
			break;
	}
}