node-ipc

a nodejs module for local and remote Inter Process Communication for Linux, Mac and Windows.

npm install node-ipc

Package details websites :

• GitHub.io site. A prettier version of this site.
• NPM Module. The npm page for the node-ipc module.

Types of IPC Sockets

Windows users may want to use UDP servers for the fastest local IPC. Unix Servers are the fastest oprion on Linux and Mac, but not available for windows.

IPC Methods

These methods are available in the IPC Scope.

log

ipc.log(a,b,c,d,e...);

ipc.log will accept any number of arguments and if ipc.config.silent is not set, it will concat them all with a sincle space ' ' between them and then log them to the console. This is fast because it prevents any concation from happening if the ipc is set to silent. That way if you leave your logging in place it should not effect performance.

the log also supports colors implementation. All of the available styles are supported and the theme styles are as follows :

{
    good    : 'green',
    notice  : 'yellow',
    warn    : 'red',
    error   : 'redBG',
    debug   : 'magenta',
    variable: 'cyan',
    data    : 'blue'
}    

You can override any of these settings by requireing colors and setting the theme as follows :

var colors=require('colors');

colors.setTheme(
    {
        good    : 'zebra',
        notice  : 'redBG',
        ...
    }    
);

connectTo

ipc.connectTo(id,path,callback);

Used for connecting as a client to local Unix Sockets. This is the fastst way for processes on the same machine to communicate because it bypasses the network card which TCP and UDP must both use.

examples arguments can be ommitted solong as they are still in order.

ipc.connectTo('world');

or using just an id and a callback

ipc.connectTo(
    'world',
    function(){
        ipc.of.world.on(
            'hello',
            function(data){
                ipc.log(data.debug); 
                //if data was a string, it would have the color set to the debug style applied to it
            }
        )
    }
);

or explicitly setting the path

ipc.connectTo(
    'world',
    'myapp.world'
);

or explicitly setting the path with callback

ipc.connectTo(
    'world',
    'myapp.world',
    function(){
        ...
    }
);

connectToNet

ipc.connectToNet(id,host,port,callback)

Used to connect as a client to a TCP or TLS socket via the network card. This can be local or remote, if local, it is recommended that you use the Unix Socket Implementaion of connectTo instead as it is much faster since it avoids the network card alltogether.

examples arguments can be ommitted solong as they are still in order.
So while the default is : (id,host,port,callback), the following examples will still work because they are still in order (id,port,callback) or (id,host,callback) or (id,port) etc.

ipc.connectToNet('world');

or using just an id and a callback

ipc.connectToNet(
    'world',
    function(){
        ...
    }
);

or explicitly setting the host and path

ipc.connectToNet(
    'world',
    'myapp.com',serve(path,callback)
    3435
);

or only explicitly setting port and callback

ipc.connectToNet(
    'world',
    3435,
    function(){
        ...
    }
);

serve

ipc.serve(path,callback);

Used to create local Unix Socket Server to which Clients can bind. The server can emit events to specific Client Sockets, or broadcast events to all known Client Sockets.

examples arguments can be ommitted solong as they are still in order.

ipc.serve();

or specifying callback

ipc.serve(
    function(){...}
);

or specify path

ipc.serve(
    '/tmp/myapp.myservice'
);

or specifying everything

ipc.serve(
    '/tmp/myapp.myservice',
    function(){...}
);

serveNet

serveNet(host,port,UDPType,callback)

Used to create TCP, TLS or UDP Socket Server to which Clients can bind or other servers can send data to. The server can emit events to specific Client Sockets, or broadcast events to all known Client Sockets.

examples arguments can be ommitted solong as they are still in order.

default tcp server

ipc.serveNet();

default udp server

ipc.serveNet('udp4');

or specifying TCP server with callback

ipc.serveNet(
    function(){...}
);

or specifying UDP server with callback

ipc.serveNet(
    'udp4',
    function(){...}
);

or specify port

ipc.serveNet(
    3435
);

or specifying everything TCP

ipc.serveNet(
    'MyMostAwesomeApp.com',
    3435,
    function(){...}
);

or specifying everything UDP

ipc.serveNet(
    'MyMostAwesomeApp.com',
    3435,
    'udp4',
    function(){...}
);

IPC Stores and Default Variables

ipc.of

This is where socket connection refrences will be stored when connecting to them as a client via the ipc.connectTo or iupc.connectToNet.

example

ipc.connectTo(
    'world',
    function(){

        ipc.of.world.on(
            'message',
            function(data){...}
        );

    }
);

ipc.config

Set these variables in the ipc.config scope to overwrite or set default values.

{
    appspace        : 'app.',
    socketRoot      : '/tmp/',
    id              : os.hostname(),
    networkHost     : 'localhost',
    networkPort     : 8000,
    encoding        : 'utf8',
    silent          : false,
    maxConnections  : 100,
    retry           : 500
}

Basic Examples

Server for Unix Sockets & TCP Sockets

The server is the process keeping a socket for IPC open. Multiple sockets can connect to this server and talk to it. It can also broadcast to all clients or emit to a specific client. This is the most basic example which will work for both local Unix Sockets and local or remote network TCP Sockets.

var ipc=require('node-ipc');

ipc.config.id   = 'world';
ipc.config.retry= 1500;

ipc.serve(
    function(){
        ipc.server.on(
            'message',
            function(data,socket){
                ipc.log('got a message : '.debug, data);
                ipc.server.emit(
                    'message',
                    data+' world!'
                );
            }
        );
    }
);

ipc.server.start();

Client for Unix Sockets & TCP Sockets

The client connects to the servers socket for Inter Process Communication. The socket will recieve events emitted to it specifically as well as events which are broadcast out on the socket by the server. This is the most basic example which will work for both local Unix Sockets and local or remote network TCP Sockets.

var ipc=require('../../../node-ipc');

ipc.config.id   = 'hello';
ipc.config.retry= 1500;

ipc.connectTo(
    'world',
    function(){
        ipc.of.world.on(
            'connect',
            function(){
                ipc.log('## connected to world ##'.rainbow, ipc.config.delay);
                ipc.of.world.emit(
                    'message',
                    'hello'
                )
            }
        );
        ipc.of.world.on(
            'disconnect',
            function(){
                ipc.log('disconnected from world'.notice);
            }
        );
        ipc.of.world.on(
            'message',
            function(data){
                ipc.log('got a message from world : '.debug, data);
            }
        );
    }
);

Server & Client for UDP Sockets

UDP Sockets are different than Unix & TCP Sockets because they must be bound to a unique port on their machine to recieve messages. For example, A TCP or Unix Socket client could just connect to a seperate TCP or Unix Socket sever. That client could then exchange, both send and recive, data on the servers port or location. UDP Sockets can not do this. They must bind to a port to recieve or send data.

This means a UDP Client and Server are the same thing because inorder to recieve data, a UDP Socket must have its own port to recieve data on, and only one process can use this port at a time. It also means that inorder to emit or broadcast data the UDP server will need to know the host and port of the Socket it intends to broadcast the data to.

This is the most basic example which will work for both local Unix Sockets and local or remote network TCP Sockets.

UDP Server 1 - "World"

var ipc=require('../../../node-ipc');

ipc.config.id   = 'world';
ipc.config.retry= 1500;

ipc.serveNet(
    'udp4',
    function(){
        console.log(123);
        ipc.server.on(
            'message',
            function(data,socket){
                ipc.log('got a message from '.debug, data.from.variable ,' : '.debug, data.message.variable);
                ipc.server.emit(
                    socket,
                    'message',
                    {
                        from    : ipc.config.id,
                        message : data.message+' world!'
                    }
                );
            }
        );

        console.log(ipc.server);
    }
);

ipc.server.define.listen.message='This event type listens for message strings as value of data key.';

ipc.server.start();

UDP Server 2 - "Hello"

note we set the port here to 8001 because the world server is already using the default ipc.config.networkPort of 8000. So we can not bind to 8000 while world is using it.

ipc.config.id   = 'hello';
ipc.config.retry= 1500;

ipc.serveNet(
    8001,
    'udp4',
    function(){
        ipc.server.on(
            'message',
            function(data){
                ipc.log('got Data');
                ipc.log('got a message from '.debug, data.from.variable ,' : '.debug, data.message.variable);
            }
        );
        ipc.server.emit(
            {
                address : 'localhost',
                port    : ipc.config.networkPort
            },
            'message',
            {
                from    : ipc.config.id,
                message : 'Hello'
            }
        );
    }
);

ipc.server.define.listen.message='This event type listens for message strings as value of data key.';

ipc.server.start();