zmq-json-pub

zmq-json-pub.js
================

A node.js module for publishing JSON messages via 0MQ (ZeroMQ)
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Install 0MQ

On a Mac:

$ brew install zmq

To verify the installation

$ man zmq

See __zeromq.org__

Install zmq-json-pub in your project

$ npm init
$ npm install zmq-json-pub --save

Usage

The complete project can be found in the __examples/demo__ folder.

This example shows how to create a simple app that publishes a heartbeat JSON message every 3 seconds. The example JSON is completely arbitrary. You can specify your own JSON format.

File: __examples/demo/config.js__

var config = {};
config.endpoint = "tcp://*:5431";
config.interval = 3000; // micro seconds
module.exports = config;

File: __examples/demo/index.js__

"use strict";

var ZmqJsonPub = require('zmq-json-pub'),
config = require('./config'),
pub = new ZmqJsonPub();

pub.publish(config.endpoint);

let data = {
type: "heartbeat",
status: "OK",
message: 'service is running',
timestamp: Date.now()
}

function heartbeat() {
data.timestamp = Date.now();
console.log("sending heartbeat at " + new Date(data.timestamp));
pub.send(data, function(err) {
if (err) {
console.log(err);
return;
}
});
setTimeout(heartbeat, config.interval);
}

console.log("Sending heartbeat every " + config.interval / 1000 + " seconds")

setTimeout(heartbeat, config.interval);

/*
Handle termination can close pub.
*/

// terminator === the termination handler.
function terminator(sig) {
if (typeof sig === "string") {
console.log('%s: Received %s - terminating Node server ...',
Date(Date.now()), sig);
console.log("Closing publisher before exit");
pub.close();
process.exit(1);
}
console.log('%s: Node server stopped.', Date(Date.now()) );
}

// Process on exit and signals.
process.on('exit', function() { terminator(); });

['SIGHUP', 'SIGINT', 'SIGQUIT', 'SIGILL', 'SIGTRAP', 'SIGABRT', 'SIGBUS',
'SIGFPE', 'SIGUSR1', 'SIGSEGV', 'SIGUSR2', 'SIGPIPE', 'SIGTERM'
].forEach(function(element, index, array) {
process.on(element, function() { terminator(element); });
});

To run:

$ node index.js

To stop press __Ctrl-C__.

Tests

Tests assume that __mocha__ has been installed globally. If not execute the following:

$ npm install -g mocha

Run the tests from the projects root folder in one of the following ways:

$ mocha --recursive --timeout 20000

Or

$ npm test

Or if you feel like kickin' it old skool:

make test

$3

To run the tests for each version (currently there is only one version (v0001)):

$ mocha --timeout 5000 --recursive test/v0001/*test.js

The tests generate log files in a logs/ folder under the projects root folder.

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Repo(s)

* bitbucket.org/mitchallen/zmq-json-pub.git

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Contributing

In lieu of a formal style guide, take care to maintain the existing coding style.
Add unit tests for any new or changed functionality. Lint and test your code.

*

Version History

#### Version 0.1.2 release notes

* Wrapped send call in setTimeout
* Added sendDelay property (in micro seconds)

#### Version 0.1.1 release notes

* Updated example to use published module

#### Version 0.1.0 release notes

* Initial release