node-graceful-exit

Add/Run additional process before the node intentionally/unintentionally close the app.

Setup

This library was setup with ES2015.

Installation

npm install --save node-graceful-exit

Usage

const server = require('http').createServer(app);
const gracefulExit = require('node-graceful-exit')({log: true});

gracefulExit.init();

gracefulExit.include(function(exit) {
    exit.wait = true;
    console.log('closing server in', process.pid);
    server.close(function() {
        // successfully close
        exit.done();
    });
    // run once
}, {once: false});

server.listen(3000, function() {
    console.log(`Node development server started on port 3000`);
});

gracefulExit.include will add all your additional process before exiting the application. The first parameter is requesting for a callback and the second parameter is asking for object.

gracefulExit.include(callback, object)

The callback parameter gave a first parameter which has a property of wait and done.

• wait - default false. It is useful to inform the process to wait for your asynchronous function before proceeding to terminate the app.
• done - this is useful when you are using the wait property. It is the one that signal that your asynchronous function is finish.

The second parameter object has a property.

• once - default: true. it informs that your process should be run only once. This is for instance that the terminated signal emit 2 events which will run your process by the number of events receive.

gracefulExit.addEvent - add additional close events to be listen.

// if the events being listen is not in the current configuration you can still that event
gracefulExit.addEvent({
    "code": "exit",
    "desc": "Application will now exit.",
    "comment": "on app close"
});

gracefulExit.removeEvent - remove events that is now being listen.

// remove event and adding event should be declare before initiazing the init
gracefulExit.removeEvent('code', 'exit')

References & Inspiration

• Cleanup Before Node Exit
• Graceful shutdown