I'm developing a sort of Flash Operator Pannel for Asterisk but, with Node.js and Socket.io instead of depending of Flash.
I've polished the node server and the front end BUT I don't know how could I send events from Asterisk to node server and do things that will be sended over the socket.
Given the fact that we have a heavily tuned Asterisk to suit our company needs, connecting to the AMI nor the Asterisk socket will solve my problem because we aren't working with real extensions.
So, despite the Asterisk part, I want to know how could I send info to node through bash or curls or whatever
I thought about using curls to the server but this could cause that someone who knows the commands (pretty unlikely) could alter the application flow with unreal data.
EDIT: Rethinking about it, I would just want to be able to receive requests through the socket/server ??? and then be able to perform actions that will be emited through socket.io.
Is that even possible?
The answer really depends upon what specific data you are trying to get from Asterisk to Node. You're trying to replace the Flash Operator Panel, yet you don't have real extensions. I'm guessing that you are using Asterisk as an SBC/proxy of sorts.
If you truly want an event-driven approach, I suggest modifying your dialplan to reach out to Node whenever needed, with whatever data you want. This would most easily be achieved by calling an AGI script with some number of arguments (written in whatever language) that then connects to Node via an HTTP POST, socket, or other.
If you want a more passive approach, you could have Node stream-read the asterisk log files for data, or, as already suggested, connect to the Asterisk Manager Interface (AMI) and stream from there. Contrary to what has been stated previously, I don't consider this to be a very daunting task.
You want to open a socket from Node to Asterisk's AMI (asterisk manager interface). I never used Node, but I would imagine the code would look roughly like this:
var astman = new net.socket().connect(5038);//connect to port 5039 on localhost
astman.on('data', function(data) {
//do something with received data
});
One of the most well maintained ami libraries are FreePBX's php-astmanager. While it's written in php, it should give you a pretty good idea of what your need to do.
You could certainly set up your node.js program to listen on a socket for messages from Asterisk. But you'd have to roll your own connection management scheme, authentication scheme, message durability (possibly), etc.
Alternatively -- and especially if there is the node server and asterisk server are not on the same machine -- you could use a message queue program like RabbitMQ. That takes care of a lot of the important details involved in interprocess communications. It's pretty easy, too. On the node side, check out https://github.com/postwait/node-amqp
I've never used Asterisk but running command line programs can be done with the child_process module.
http://nodejs.org/docs/latest/api/child_processes.html
Related
I'm working on enabling cluster support in a project I'm working on. This question comes directly from a statement in the Nodejs docs on the cluster module:
from: https://nodejs.org/api/cluster.html#cluster_cluster
Please note that, on Windows, it is not yet possible to set up a named pipe server in a worker.
What exactly does this mean?
What are the implications of this?
From the docs, and other research I've done, the actual practical consequences to this limitation are not clear to me.
A process can expose a named pipe as a way to communicate with other interested parties - ie. an nginx server could expose a named pipe where all incoming requests would be sent (just an idea - I am not sure if nginx can even do that).
From Node.js process (not a cluster worker, though), you could then start an http server (or even a plain TCP server, for that matter) which listens for messages sent to this named pipe:
http.createServer().listen('\\.\pipe\nginx')
Docs for the .listen() method's signature are here, specifically this part is of interest:
Start a server listening for connections on a given handle that has already been bound to a port, a UNIX domain socket, or a Windows named pipe
However, as per the warning, this functionality is not available from a cluster worker, for reasons beyond my understanding.
Here is a relevant commit in Node.js which hints at this limitation. You can find it by opening the Markdown document for cluster, look at git blame and go further into history a bit until you arrive at the commit which introduces this note.
Normal interprocess communication is not affected by this limitation, so a cluster works just the same on Win32 as it does on Unix systems.
Note: Upon further thought, that nginx example is a bit misleading since a named pipe, to my understanding, cannot be used for stateful bidirectional communication. It's just one-way, ie. source->listener. But I do hope I conveyed the general idea behind the limitation.
Is it possible to implement a two-way communication between client and server with Apache Thrift? Thus not only to be able to make RPC from client to server, but also the other way round? In my project I have the requirement that the server must also push some data to the client without being asked by the client before to do this.
There are two ways how to achieve this with Thrift.
If both ends are more or less peers and you connect them through sockets or pipes, you simply set up a server and a client on both ends and you're pretty much done. This does not work in all cases, however, especially with HTTP.
If you connect server and client through HTTP or a similar channel, there is a technique called "long polling". It basically requires the client to call the server as usual, but the call will only return when the server wants to send some data back to the client. After receiving the data, the client starts another call if he's still interested in more data.
As Denis pointed out, depending on your exact use case, you might want to consider using a MQ system. Note that it is still possible to use Thrift to de/serialize the messages into and from the queues. The contrib folder has some examples that show how to use Thrift with ZMQ, Rebus and some others.
You are better to use queues then, e.g. ZeroMQ.
I've got problem connecting Flash client to Node.js server.
Short story:
For a first time I'm building a Node.js server that should be used by both web client (WebSocket) as well as a Flash client (Socket). The web client, of course, works like a charm, but I can't get over the Flash one. I get SECURITY_ERROR. After a day of research I think it's because of the policy file not being loaded. Ideas (primus on top of engine.io) ?
Long story:
I'm using Primus as I thought I'll need it because I have both web sockets and flash sockets to handle. Not sure if this is accurate? :)
I'm using Engine.io as a 'transformer/transporter' - the main framework that the layer uses. I won't discuss the standard web client (using Chrome and primus-client), as it's easy to setup.
I'm using simple and standard Sockets in AS3:
_socket = new Socket();
_socket.addEventListener(Event.CONNECT, onSocketConnect);
//...
_socket.addEventListener(SecurityErrorEvent.SECURITY_ERROR, onSecurityError);
_socket.addEventListener(IOErrorEvent.IO_ERROR, onIOError);
_socket.connect('localhost', '1337);
When building it within Flash IDE, it goes to the onSocketConnect function, but if I try to write anything to the socked - I get disconnected. If I run this from the web browser, I get into the onSecurityError method.
I must say that I don't get any traces in the node console!
primus.on('connection', function connection(spark) {
console.log('new connection'); // never gets logged!
As I know, security error is thrown when there is error with the policy file, so I started searching for a solution for that.
I've read a lot of things online, and most common solution was simple usage of socket.io and so called FlashSocket.IO. I tried implementing it, but it's so old, that some of the code is a kind of missing and I finally got some errors from the hurlant library - I couldn't get it working.
I also saw some node package called policy, which runs separate server to server the policy file.
I tried adding a transport array with flashsocket in it - no change. I also can't understand why all of the samples are using transports - I've searched and both index.js and primus.js are using transport (why there are two separate files, Jesus?!)
I could try using only engine.io without primus, but I don't know if this would be of any help. All the posts and samples I've found are pretty old - please help me with any up to date solution or at least some explanation what needs to be done - seems like a whole new universe to me :)
Thanks in advance!
Edit:
Thanks to the The_asMan, I figured out it has something to do with the handshake. I've tried this simple example (despite the fact it's so old) - it worked perfectly for the Flash client! Of course I cannot connect web sockets to it, as the handshake is not proper - it has some kind of protocol for it.
So I guess I just have to understand how to get the <policy-file-request/> in node - I'll be able to return the policy file. But I don't know how to get it - I don't receive any kind of data nor connect handler...
You have a cross domain policy issue.
I answered it all here.
AS3 - Flash/AIR Socket Communication writeUTFBytes only works once
just an idea:
On some operating systems, flush() is called automatically between execution frames, but on other operating systems, such as Windows, the data is never sent unless you call flush() explicitly. To ensure your application behaves reliably across all operating systems, it is a good practice to call the flush() method after writing each message (or related group of data) to the socket.
I want to monitor in real time the data that users enter in comments table.
I have an Apache server running, and suppose that has a node server on port 1337.
How would I do that every time someone save new data, eg return me the total number of table rows in comment and show it in a view?
Maybe way is to make the $this->Comment->save($this->request->data); using a different port using Httpsockect?
Yes, it is possible.
You have multiple ways of solving this, let me give you my ideas
You can simply use long-polling and don't use Node.js at all. It's a suitable solution if there won't be too much traffic there, otherwise you will have a bad time.
You can use websockets and don't use Node.js at all. Here you have a basic guide about websockets and PHP. Although, I am almost sure you won't be able to create "rooms", that is, sending notifications for specific comments.
You can also use Ratchet. This is a more sophisticated library to handle websockets and it supports rooms.
Lastly, if you want to full dive in with Node.js and CakePHP, I would suggest start by watching this talk given on Cakefest 2012 which exactly describe your scenario.
After you have watched that, you might want to learn a little about Socket.io. This is a more complex solution, but it's what I have used when integrating CakePHP and Node.js to create real time applications.
The strategy here is to have the users join a room when they visit /article/view/123, let's say the room name is the articleID, then socket.io will be listening for events happening in this room.
You will have a Cakephp method that handles the save. Then, when user submits the form you don't call directly the Cake action, you have socket.io to dispatch an event, then in your event you pass the data to the server (Node.js) and nodejs will call your cakephp function that saves the data. When Nodejs receives confirmation from CakePHP then you broadcast an event (using socket.io), this event will let know all users connected to that room that a comment has been made.
You have basically the choice between Websockets and long polling.
Websockets (with Ratchet and Autobahn.js)
Long Polling Using Comet
Decide which technology you want to use and start implementing your use case. Consider that Websockets are more or less new. Depending on your requirements you might not be able to use Websockets because you might have to support crappy browsers. See this page.
I undesrand that Node.js is a server side (implementation?) of JavaScript. Server side means executes on the server (like say PHP or Python). Does that mean the code you write in JavaScript in Node is "invisible" (to the client)? I'm not quiet keen on server side stuff and this subject interests me. So say, you write something really super simple such as console.log("Hello World"); then that gets executed on the server and doesn't get shown to the client (like View Source, etc.)? Am I right?
I'm asking this here to seek an easier (small) explanation of the idea. Also, is this possibly something I'm looking for?
Yes, Node.js code runs completely on the server (just like python). In your link the goal is to encrypt the source code because a client has access to the servers filesystem. To communicate with the client you will need another component like the http module.