asterisk users - Sep 2013 - How to get call progress events from WebSocket connected to Asterisk 12 ARI events API

Hello,

I am experimenting with Asterisk 12.0.0 alpha1.  I have a couple of SIP
phones working.  Good.  I can retrieve data using curl to interact with the
new Asterisk REST API (ARI).  Good.

Now I want to use the new ARI events API, which requires a WebSocket
connection.  I am using Node.js for the client, and have a stable
connection to ARI events on the Asterisk 12 server.

What I hope for is that my Node.js client will receive call related events
in JSON format messages as call activity occurs on the Asterisk server.
 But I don't know how to request this information via the API.

Do I need to specify something in the query string used for the initial
WebSocket connection?  Or do I need to send some kind of event subscription
messages within the WebSocket once connected?

Any guidance, sample client code, or web reference would be most welcome.

Thanks.

Jim

Node.js client connecting to ARI events:

  // app.js

  var WebSocket = require('ws');

  var ws = new WebSocket('ws://192.168.1.125:8088/ari/events?app=node-client
',
    { headers: {
        Authorization: 'Basic Y29tZXQ6MTIzNA=='
      },
      protocol: 'ari',
    });

  ws.on('open', function() {
    console.log('connected');
  });

  ws.on('message', function(message) {
    console.log('received: %s', message);
  });

  ws.on('error', function(err) {
    console.log(err);
  });

It runs and indicates a successful connection:

  $ node app.js
  connected

The Asterisk CLI logs the successful connection:

  == WebSocket connection from '192.168.1.125:34792' for protocol
'ari'
accepted using version '13'
  Creating Stasis app 'node-client'
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Jim Fathman wrote:
> Hello,
Bonjour!
> I am experimenting with Asterisk 12.0.0 alpha1.  I have a couple of SIP
> phones working.  Good.  I can retrieve data using curl to interact with
> the new Asterisk REST API (ARI).  Good.
>
> Now I want to use the new ARI events API, which requires a WebSocket
> connection.  I am using Node.js for the client, and have a stable
> connection to ARI events on the Asterisk 12 server.
>
> What I hope for is that my Node.js client will receive call related
> events in JSON format messages as call activity occurs on the Asterisk
> server.  But I don't know how to request this information via the API.
>
> Do I need to specify something in the query string used for the initial
> WebSocket connection?  Or do I need to send some kind of event
> subscription messages within the WebSocket once connected?
David Lee (ARI man supreme) is currently working on an issue [1] which 
covers support for subscribing for this information for delivery over 
the WebSocket connection in a branch [2]. I'd expect this to be 
integrated into 12 within a few weeks. I believe it should cover what 
you want to do.

[1] https://issues.asterisk.org/jira/browse/ASTERISK-22451
[2] 
http://svn.digium.com/svn/asterisk/team/dlee/ASTERISK-22451-ari-subscribe/

Cheers,

-- 
Joshua Colp
Digium, Inc. | Senior Software Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at:  www.digium.com  & www.asterisk.org