cubic-node-ipc v9.2.1

cubic-node-ipc

Nodejs module for local and remote Inter Process Communication* with full support for Linux, Mac and Windows. It also supports all forms of socket communication from low level unix and windows sockets to UDP and secure TLS and TCP sockets.

IPC Config

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', //should resolve to 127.0.0.1 or ::1 see the table below related to this
        networkPort     : 8000,
        readableAll     : false,
        writableAll     : false,
        encoding        : 'utf8',
        rawBuffer       : false,
        delimiter       : '\f',
        sync            : false,
        silent          : false,
        logInColor      : true,
        logDepth        : 5,
        logger          : console.log,
        maxConnections  : 100,
        retry           : 500,
        maxRetries      : false,
        stopRetrying    : false,
        unlink          : true,
        interfaces      : {
            localAddress: false,
            localPort   : false,
            family      : false,
            hints       : false,
            lookup      : false
        }
    }

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 single space ' ' between them and then log them to the console. This is fast because it prevents any concatenation from happening if the ipc.config.silent is set true. That way if you leave your logging in place it should have almost no effect on performance.

The log also uses util.inspect You can control if it should log in color, the log depth, and the destination via ipc.config

    ipc.config.logInColor=true; //default
    ipc.config.logDepth=5; //default    
    ipc.config.logger=console.log.bind(console); // default

connectTo

ipc.connectTo(id,path,callback);

Used for connecting as a client to local Unix Sockets and Windows Sockets. This is the fastest 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 so long 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 and Windows Socket Implementaion of connectTo instead as it is much faster since it avoids the network card altogether.

For TLS and SSL Sockets see the node-ipc TLS and SSL docs. They have a few additional requirements, and things to know about and so have their own doc.

examples arguments can be ommitted so long 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(){
            ...
        }
    );

disconnect

ipc.disconnect(id)

Used to disconnect a client from a Unix, Windows, TCP or TLS socket. The socket and its refrence will be removed from memory and the ipc.of scope. This can be local or remote. UDP clients do not maintain connections and so there are no Clients and this method has no value to them.

examples

    ipc.disconnect('world');

serve

ipc.serve(path,callback);

Used to create local Unix Socket Server or Windows 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 omitted so long 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 Server Methods

IPC Events

Multiple IPC Instances

Sometimes you might need explicit and independent instances of node-ipc. Just for such scenarios we have exposed the core IPC class on the IPC singleton.

    const RawIPC=require('node-ipc').IPC;
    const ipc=new RawIPC;
    const someOtherExplicitIPC=new RawIPC;


    //OR

    const ipc=require('node-ipc');
    const someOtherExplicitIPC=new ipc.IPC;


    //setting explicit configs

    //keep one silent and the other verbose
    ipc.config.silent=true;
    someOtherExplicitIPC.config.silent=true;

    //make one a raw binary and the other json based ipc
    ipc.config.rawBuffer=false;

    someOtherExplicitIPC.config.rawBuffer=true;
    someOtherExplicitIPC.config.encoding='hex';

Server for Unix Sockets, Windows 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 local Unix and Windows Sockets as well as 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(
                        socket,
                        'message',  //this can be anything you want so long as
                                    //your client knows.
                        data+' world!'
                    );
                }
            );
			ipc.server.on(
				'socket.disconnected',
				function(socket, destroyedSocketID) {
					ipc.log('client ' + destroyedSocketID + ' has disconnected!');
				}
			);
        }
    );

    ipc.server.start();

Client for Unix Sockets & TCP Sockets

The client connects to the servers socket for Inter Process Communication. The socket will receive 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',  //any event or message type your server listens for
                        'hello'
                    )
                }
            );
            ipc.of.world.on(
                'disconnect',
                function(){
                    ipc.log('disconnected from world'.notice);
                }
            );
            ipc.of.world.on(
                'message',  //any event or message type your server listens for
                function(data){
                    ipc.log('got a message from world : '.debug, data);
                }
            );
        }
    );

Server & Client for UDP Sockets

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

This means a UDP Client and Server are the same thing because in order to receive data, a UDP Socket must have its own port to receive data on, and only one process can use this port at a time. It also means that in order 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 and remote UDP 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.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 : '127.0.0.1', //any hostname will work
                    port    : ipc.config.networkPort
                },
                'message',
                {
                    from    : ipc.config.id,
                    message : 'Hello'
                }
            );
        }
    );

    ipc.server.start();

Raw Buffer or Binary Sockets

Binary or Buffer sockets can be used with any of the above socket types, however the way data events are emit is slightly different. These may come in handy if working with embedded systems or C / C++ processes. You can even make sure to match C or C++ string typing.

When setting up a rawBuffer socket you must specify it as such :

    ipc.config.rawBuffer=true;

You can also specify its encoding type. The default is utf8

    ipc.config.encoding='utf8';

emit string buffer :

    //server
    ipc.server.emit(
        socket,
        'hello'
    );

    //client
    ipc.of.world.emit(
        'hello'
    )

emit byte array buffer :

    //hex encoding may work best for this.
    ipc.config.encoding='hex';

    //server
    ipc.server.emit(
        socket,
        [10,20,30]
    );

    //client
    ipc.server.emit(
        [10,20,30]
    );

emit binary or hex array buffer, this is best for real time data transfer, especially whan connecting to C or C++ processes, or embedded systems :

    ipc.config.encoding='hex';

    //server
    ipc.server.emit(
        socket,
        [0x05,0x6d,0x5c]
    );

    //client
    ipc.server.emit(
        [0x05,0x6d,0x5c]
    );

Writing explicit buffers, int types, doubles, floats etc. as well as big endian and little endian data to raw buffer nostly valuable when connecting to C or C++ processes, or embedded systems (see more detailed info on buffers as well as UInt, Int, double etc. here)https://nodejs.org/api/buffer.html:

    ipc.config.encoding='hex';

    //make a 6 byte buffer for example
    const myBuffer=Buffer.alloc(6).fill(0);

    //fill the first 2 bytes with a 16 bit (2 byte) short unsigned int

    //write a UInt16 (2 byte or short) as Big Endian
    myBuffer.writeUInt16BE(
        2, //value to write
        0 //offset in bytes
    );
    //OR
    myBuffer.writeUInt16LE(0x2,0);
    //OR
    myBuffer.writeUInt16LE(0x02,0);

    //fill the remaining 4 bytes with a 32 bit (4 byte) long unsigned int

    //write a UInt32 (4 byte or long) as Big Endian
    myBuffer.writeUInt32BE(
        16772812, //value to write
        2 //offset in bytes
    );
    //OR
    myBuffer.writeUInt32BE(0xffeecc,0)

    //server
    ipc.server.emit(
        socket,
        myBuffer
    );

    //client
    ipc.server.emit(
        myBuffer
    );

Server with the cluster Module

node-ipc can be used with Node.js' cluster module to provide the ability to have multiple readers for a single socket. Doing so simply requires you to set the unlink property in the config to false and take care of unlinking the socket path in the master process:

Server

    const fs = require('fs');
    const ipc=require('../../../node-ipc');
    const cpuCount = require('os').cpus().length;
    const cluster = require('cluster');
    const socketPath = '/tmp/ipc.sock';

    ipc.config.unlink = false;

    if (cluster.isMaster) {
       if (fs.existsSync(socketPath)) {
           fs.unlinkSync(socketPath);
       }

       for (let i = 0; i < cpuCount; i++) {
           cluster.fork();
       }
    }else{
       ipc.serve(
         socketPath,
         function() {
           ipc.server.on(
             'currentDate',
             function(data,socket) {
               console.log(`pid ${process.pid} got: `, data);
             }
           );
         }
      );

      ipc.server.start();
      console.log(`pid ${process.pid} listening on ${socketPath}`);
    }

Client

    const fs = require('fs');
    const ipc = require('../../node-ipc');

    const socketPath = '/tmp/ipc.sock';

    //loop forever so you can see the pid of the cluster sever change in the logs
    setInterval(
      function() {
        ipc.connectTo(
          'world',
          socketPath,
          connecting
         );
      },
      2000
    );

    function connecting(socket) {
      ipc.of.world.on(
        'connect',
        function() {
          ipc.of.world.emit(
            'currentDate',
            {
                 message: new Date().toISOString()
            }
          );
          ipc.disconnect('world');
        }
      );
    }