respawn

respawn

Spawn a process and restart it if it crashes.

npm install respawn

Usage

It is easy to use

var respawn = require('respawn');

var monitor = respawn(['node', 'server.js'], {
	env: {ENV_VAR:'test'}, // set env vars
	cwd: '.',              // set cwd
	maxRestarts:10,        // how many restarts are allowed within 60s
	                       // or -1 for infinite restarts
	sleep:1000,            // time to sleep between restarts,
	stdio: [...]           // forward stdio options
});

monitor.start(); // spawn and watch

Optionally you can specify the command to to spawn in the option map as command: [...]

API

• monitor.start() Starts the monitor

• monitor.stop(cb) Stops the monitor (kills the process if its running with SIGTERM)

• monitor.status Get the current monitor status. Available values are running, stopping, stopped and sleeping

Events

• monitor.on('start') The monitor has started

• monitor.on('stop') The monitor has fully stopped and the process is killed

• monitor.on('sleep') monitor is sleeping

• monitor.on('spawn', process) New child process has been spawned

• monitor.on('exit', code, signal) child process has exited

• monitor.on('stdout', data) child process stdout has emitted data

• monitor.on('stderr', data) child process stderr has emitted data

• monitor.on('warn', err) child process has emitted an error

Graceful restart

To do graceful restart simply have your app stop gracefully when receiving SIGTERM and do

// graceful restart (do not wait for old process to die)
monitor.stop();
monitor.start();

// hard restart (wait for old process to die)
monitor.stop(function() {
	monitor.start();
});

License

MIT